SPECIFICATION
TITLE OF THE INVENTION
BALL BEARING WITH A ROTATIONAL SPEED DETECTION ENCODER FOR A
MOTORCYCLE AND A ROTATIONAL SPEED DETECTION DEVICE FOR A MOTORCYCLE
USING THIS ENCODER
BACKGROUND OF THE INVENTION
[Field of the Invention]
[0001] The present invention relates to a ball bearing with a rotational speed detection encoder for
a motorcycle wheel that supports a wheel of motorcycles (two-wheeled motor vehicles) such as
standard motorcycles and scooters such that the wheel rotates freely with respect to a frame thereof,
and that is used for finding the rotational speed of the wheel.
[Description of the Related Art]
[0002] Anti-lock brake systems (ABS) are widely used as a device for stabilizing the traveling
state of an automobile. Use of such an ABS has mainly been centered on four-wheeled motor
vehicles, however, in recent years, such systems have begun to be used in two-wheeled motor
vehicles as well. As is well known, in order for ABS control it is necessary to find the rotational
speed of the wheel, so conventionally installing a rotational speed detection device in a
wheel-supporting ball bearing unit for allowing a wheel to be supported by the suspension such that
the wheel rotates freely is widely performed.
[0003] However, a wheel-supporting ball bearing for a two-wheeled motor vehicle is rather
compact when compared with a wheel-supporting ball bearing for a four-wheeled motor vehicle, and
whereas many wheel-supporting ball bearings for four-wheeled motor vehicles are inner-race
rotating type, many of the wheel-supporting ball bearings for two-wheeled motor vehicles are
outer-race rotating type, and for that reason the construction of a rotational speed detection device for
a four-wheeled motor vehicle cannot be applied as for use in a two-wheeled motor vehicle.
[0004] Ball bearings with an encoder for detecting the rotational speed of a motorcycle for
controlling the ABS for this motorcycle are known, such as disclosed in JP2006-105341(A),
JP2007-139075(A), JP2007-211840(A), JP2007-285514(A) and JP2009-229157(A). The
construction of a wheel-supporting unit of a motorcycle and construction of a ball bearing with
encoder disclosed in JP2007-285514(A) is explained with reference to FIG. 16 to FIG. 19.
[0005] FIG 16 is a first example of the construction of a wheel-supporting unit for a motorcycle,
and illustrates the construction of the part that supports the front wheel of a relatively small
motorcycle such as a scooter. In this construction, a pair of support plates 2 is fastened to the
bottom end sections of a pair of left and right forks 1 of the suspension such that they are parallel
with each other. Both end sections of a support shaft 3 are supported and fastened between both of
these support plates 2. A pair of single-row deep groove ball bearings are located at two location in
the middle section of this support shaft 3. More specifically, the inner rings of these ball bearings 4
fit around the outside of the support shaft 3, and the positions in the axial direction of both of these
inner rings are secured by inner ring spacers 5a, 5b, 5c. A cylindrical hub 6 is placed around the
support shaft 3 such that it is concentric with the support shaft 3. The outer rings of both of the ball
bearings 4 fit around the inner surface of the hub 6 in the portions near both ends. Furthermore, the
wheel 7 is supported and fastened around the outer surface of the hub 6.
[0006] FIG 17 is a second example of construction of a wheel-supporting unit of a motorcycle,
and illustrates the construction of the part that supports the rear wheel of a relatively small
motorcycle such that the wheel rotates freely. In this construction, both end sections of a support
shaft 3a arc supported and fastened between a pair of arms 31 of the suspension, Three single-row
deep groove ball bearings 4a to 4c are located at three locations in the middle section of this support
shaft 31, and a hub 6a that is integrated with the wheel 7a is such that it is concentric with the
support shaft 3 a and rotates freely.
[0007] When assembling the ABS in the motorcycle, of the component members of the ball
bearings of the wheel-supporting section of the motorcycle as described above, it is feasible to
assemble the encoder in a race that rotates together with the wheel 7, 7a, or in other words, in an
outer ring, which is a race on the rotating side. FIG 18 shows an example of a ball bearing with an
encoder for rotational speed detection of a wheel for a motorcycle, which is disclosed in
JP2007-285514(A). The ball bearing with an encoder having this conventional construction is a
combination of a single-row deep-groove ball bearing 8 and a circular ring shaped encoder 9.
[0008] The ball bearing 8 has: an outer ring 11 that has a deep groove outer ringway 10 that is
formed around its inner surface and that rotates during use, an inner ring 13 that has a deep groove
inner ringway 12 that is formed around its outer surface and that does not rotate during use, and a
plurality of balls 15 that are held by a retainer 14 and located between the outer ringway 10 and inner
ringway 12 such that they can roll freely. The openings on both ends of the space inside the bearing
between the inner surface of the outer ring 11 and the outer surface of the inner ring 3 where the balls
15 are located are covered by seal rings 18a, 18b that comprise ring-shaped metal cores 16a, 16b and
elastic seal lips 17a, 17b. The encoder 9 is attached and fastened to the outside surface of the metal
core 16a of one of the seal rings 18a (the right seal ring in FIG 18).
[0009] As illustrated in FIG 19, the support shaft 3 supports a rotation detection sensor 30a of the
rotational speed detection device that is combined with the ball bearing with encoder 8. More
specifically, the support shaft 3 supports this sensor 30a by way of a ring-shaped holder member 36.
The detecting part of this sensor 30a is supported by the portion that faces the detected surface
(outside surface in the axial direction) of the encoder 9 that is assembled in the ball bearing 8 with
encoder. The encoder 9 of this example is made of a permanent magnet such as a rubber magnet
that is magnetized in the axial direction, with the magnetization direction alternating and changing at
uniform intervals in the circumferential direction, Therefore, the detected part is arranged on the
outside surface in the axial direction of the encoder 9 so that the S pole and N pole alternate at
uniform intervals in the circumferential direction. This kind of encoder 9 is mounted on and
fastened to the outside surface in the axial direction of the metal core 16a of the seal ring 18a such
that it is concentric with the metal core 16a. The detecting part of the sensor 30a that is supported
by the holder member 36 faces the detected surface of the encoder 9 in the axial direction via a
suitable detection space.
[0010] As the motorcycle is moving and the wheel 7 rotates, the seal ring 18a to which the
encoder 9 is mounted rotates together with the outer ring 11 that is fastened on the inside of the hub 6.
As a result, the S poles and N poles that exist on the detected surface of the encoder 9 alternately
pass the portion directly in front of the detecting part of the rotation detection sensor 30a, and the
output signal from this sensor 30a changes. The rotational speed of the wheel is found from the
period or frequency of change of this output signal.
[0011] This kind of ball bearing with encoder is installed between the outer surface of the support
shaft 3 and the inner surface of the hub 6 instead of one of the pair of ball bearings (for example, the
right ball bearing) that is installed in the construction illustrated in FIG 16 described above, and by
having the detecting part of the sensor that is supported by the non-rotating portion face the outside
surface of the encoder 9, it is possible to detect the rotational speed of the wheel of a motorcycle.
[0012] In the case of the conventional construction illustrated in FIG 18, the effect of preventing
foreign matter from getting inside the internal space of the bearing is not always sufficient. In other
words, of the seal rings 18a, 18b that cover the openings on both ends of the internal space of the
bearing, the seal ring 18a to which the encoder 9 is mounted is often located on the outside end in the
axial direction of the support shaft 3 due to the relationship with the installation position of the
sensor. Therefore, the portion of the seal ring 18a to which the encoder 9 is mounted is easily
exposed to foreign matter such as muddy water while the motorcycle is moving. In the case of the
construction illustrated in FIG. 18, portion where the tip end edge of the seal lip 17a slides along the
surface of the inner ring 13 is exposed to the outside space, so it is easy for foreign matter to adhere
to this sliding portion, and thus it becomes easy for this foreign matter to pass through this sliding
section and get inside internal space of the bearing.
[0013] In regards to this, JP2009-168130(A), JP2009-271028(A) and JP2008-107187(A) disclose
construction in which of a combined seal ring that comprises a slinger and seal ring, the encoder is
mounted and fastened to the outside surface of the rotating circular ring section of the slinger.
JP2008-107187(A) discloses this kind of construction that can be applied to ABS control of a
two-wheeled motor vehicle. With construction in which the encoder is installed using the slinger of
a combined seal ring, it is possible to prevent the sliding section between the tip end edge of the seal
lip and the opposing surface from being exposed to the outside space, and thus it is possible to
improve the effect of preventing foreign matter from getting inside the internal space of the bearing.
However, JP2009-168130(A), JP2009-271028(A) and JP2008-107187(A) do not disclose detailed
construction for rotatably supporting a motorcycle wheel and for making it possible to detect the
rotational speed of this wheel.
[0014] Moreover, an optical type or capacitance type encoder can be used as the encoder 9,
however, normally a magnetic encoder is used. Nitrile rubber that contains strontium ferrite as a
magnetic powder is used as typical clastic magnetic material that is used for a magnetic encoder, and
the material is mixed with a roll mill such that the magnetic powder is mechanically oriented. This
ferrite type magnetic powder is easily oriented by mechanical sharing between rolls, with the
thickness dimension being relatively small and the ability to be formed into a plate high. The
strontium ferrite magnetic powder for this mechanical orientation contains a large amount of barium
in order to improve the ability to form a plate, and while the residual magnetic flux density (Br) is
lower than that of the strontium ferrite magnetic powder for magnetic field orientation, the coercive
force (bHc) and the intrinsic coercive force (iHc) are higher than that of the strontium ferrite
magnetic powder for magnetic field orientation.
[0015] However, the wheel-supporting ball bearing for a motorcycle is very compact, so the size
of a magnetic encoder that can be used is limited. Therefore, when compared with the magnetic
encoder for a four-wheeled motor vehicle, the magnetic encoder comprising a rubber magnet that
contains ferrite according to the conventional mechanical orientation method has less magnetic
density per pole, so in order to detect rotational speed with good precision, it is necessary to make
the gap (air gap) between the sensor and magnetic encoder small, or reduce the number of poles
around the circumferential direction of the magnetic encoder; however, making the gap small is
limited from the aspect of preventing contact between the sensor and magnetic encoder, and reducing
the number of poles has a problem in that the requirement for high resolution of the rotational speed
detection device cannot be sufficiently met
[0016] Furthermore, in the case of a rotational speed detection device for the wheel of a
motorcycle, differing from the case of a rotational speed detection device for a four-wheeled motor
vehicle, the encoder 9 is not directly fastened to the hub, but is rather supported by way of a race on
the rotating side such as the outer ring 11. Consequently, when there is sliding of the area of fit
between the hub 6 and the race on the rotating side such as the outer ring 11, or in other words, when
creeping occurs, the rotational speed of the hub 6 does not coincide with the rotational speed of the
encoder 9, and reliability of detecting the rotational speed of the wheel is lost. Therefore, as is
disclosed in JP10-82428(A), JP2001-27255(A), JP2005-33999(A), JP09-314695(A),
JP2003-287043(A) and JP2007-315585(A), in order to prevent creep between the race of a rolling
bearing and the opposing member, a method has been known by which a construction for preventing
rotation is provided between the race and the opposing member. However, using the construction
disclosed in these patent literatures for preventing this kind of creep in order to improve the
reliability of rotational speed detection of a wheel of a motorcycle was not considered in the past,
[Related Literature]
[Patent Literature]
[0017] Patent Literature 1: JP2006-105341(A)
Patent Literature 2: JP2007-139075(A)
Patent Literature 3: JP2007-211840(A)
Patent Literature 4: JP2007-285514(A)
Patent Literature 5: JP2009-229157(A)
Patent Literature 6: JP2009-168130(A)
Patent Literature 7: JP2009-271028(A)
Patent Literature 8: JP2008-107187(A)
Patent Literature 9: JP10-82428(A)
Patent Literature 10: JP2001-27255(A)
Patent Literature 11: JP2005-33999(A)
Patent Literature 12: JP09-314695(A)
Patent Literature 13: JP2003-287043(A)
Patent Literature 14: JP2007-315585(A)
SUMMARY OF THE INVENTION
[Problems to be Solved by the Invention]
[0018] In consideration of the situation described above, the object of the present invention is to
provide a compact ball bearing with a rotational speed detection encoder that, together with being
able to support the wheels of a motorcycle (two-wheeled vehicle) and detect the rotational speed of
the wheels, is able to prevent grease inside the internal space of the ball bearing from leaking out,
and conversely, is able to prevent foreign matter in the surrounding outside space from getting inside
this internal space.
[0019] Moreover, when the encoder is a magnetic encoder, another object of the present invention
is to provide a ball bearing with rotational speed detection encoder that, while being compact, detects
the rotational speed of the wheels of a motorcycle with high precision without reducing the number
of poles in the circumferential direction of the magnetic encoder.
[0020] Furthermore, another object of the present invention is to provide construction that makes
it possible to prevent the rotating side ring on which the encoder is mounted from rotating (creeping)
relative to the opposing member that fits with and supports this rotating side ring, and to improve the
reliability of the rotational speed detection of the wheels of a motorcycle.
[Means of Solving the Problems]
[0021] The ball bearing with a rotational speed detection encoder for a motorcycle of the present
invention, as in a conventionally know ball bearing with a rotational speed detection encoder for a
motorcycle, including the construction disclosed in JP2006-105341(A), JP2007- 139075(A),
JP2007-211840(A) and JP2007-285514(A), is a single-row deep groove ball bearing comprising an
outer ring, an inner ring and a plurality of balls.
[0022] The outer ring has a single-row deep groove outer-raceway formed around the middle
section in the axial direction of the inner circumferential surface thereof The inner ring has a
single-row deep groove inner-raceway formed around the middle section in the axial direction of the
outer circumferential surface. The plurality of bails are located between the outer-raceway and the
inner-raceway and held by a retainer so as to be able to roll freely. In this ball bearing, one of the
outer ring and the inner ring corresponds to a rotating side ring that is fitted and fastened to a rotating
side member that rotates together with a wheel of a motorcycle, and the other of the outer ring and
the inner ring corresponds to a stationary side ring that is fitted and fastened to a stationary side
member that does not rotate.
[0023] The encoder is a ring shaped member, and the properties of the outside surface in the axial
direction, which is a detected surface, alternate and change at uniform intervals in the circumferential
direction. The encoder is fastened to one of the inner and outer circumferential surfaces of the
rotating side ring that corresponds to a circumferential surface on the rotating side that faces the
stationary side ring,
[0024] The ball bearing with rotational speed detection encoder of the present invention comprises
a combined seal ring, having a slinger and seal ring, that covers the space between the inner
circumferential surface on one end section of the outer ring and the outer circumferential surface of
one end section of the inner ring. The encoder is fastened to the circumferential surface on the
rotating side by supporting and fastening the encoder to the slinger.
[0025] Preferably, the slinger is formed by bending a metal plate into an ring shape, having a
cylindrical section on the rotating side that is fitted and fastened to the circumferential surface of the
rotating side, and a circular ring section on the rotating side that is bent at a right angle from the edge
of the outer end in the axial direction of the cylindrical section on the rotating side toward the
stationary side ring.
[0026] Moreover, the seal ring comprises a metal core and seal lips. The metal core is formed by
bending a metal plate into a ring shape, having a cylindrical section on the stationary side that is
fitted and fastened to one of the inner and outer circumferential surfaces of the stationary side ring
that corresponds to a circumferential surface on the stationary side that faces the circumferential
surface on the rotating side, and a circular ring section on the rotating side that is bent at a right angle
from the edge of the inside end in the axial direction of the cylindrical section on the stationary side
toward the rotating side ring. The seal lips are made of an elastic material, having a base end
section that is connected and fastened all around the metal core, and edges on the tip ends that come
in sliding contact all the way around part of the slinger.
[0027] In this case, the encoder is mounted on and fastened all the way around the outside surface
in the axial direction of the circular ring section on the rotating side.
[0028] More preferably, the space between the inner circumferential surface on the other end of
the outer ring and the outer circumferential surface on the other end of the inner ring is covered by a
second seal ring that comprises a second metal core and second seal lips that are fastened to the base
end section of the second metal core.
[0029] On the other hand, the encoder is a plastic magnet having magnetic powder mixed in
synthetic resin, and together with the plastic magnet being magnetized in the axial direction, the
magnetization direction alternates and changes at uniform intervals in the circumferential direction,
with alternating S poles and N placed at uniform intervals on the outside surface in the axial
direction, which is the detected surface of the encoder.
[0030] In this case, the plastic magnet of the encoder comprises magnetic powder and a binder
that is obtained by adding an impact resistance improving agent to a polyamide resin.
[0031] The rotational speed detection apparatus for a wheel of a motorcycle of the present
invention comprises: a center axis member that is concentric with the wheel; an outer diameter side
member that is provided around the center axis member and is concentric with the center axis
member; a ball bearing with rotational speed detection encoder that is provided between the outer
circumference of the center axis member and the inner circumferential surface of the outer diameter
side member; and a rotation detection sensor that is supported by and fastened to part of one of the
center axis member and the outer diameter side member that corresponds to the stationary side
member that does not rotate, so that the rotation detection sensor faces the outside surface in the
axial direction of the encoder of the ball bearing with rotational speed detection encoder, the rotation
detection sensor outputting a signal that changes according to the rotation of the encoder.
Preferably, the ball bearing with rotational speed detection encoder of the present invention is used
as this ball bearing with rotational speed detection encoder.
[0032] The outer ring of the ball bearing with rotational speed detection encoder is fitted and
fastened inside the outer diameter side member, and the inner ring of the ball bearing is fitted and
fastened around the center axis member. One of the outer ring and the inner ring corresponds to the
rotating side ring that is fitted to one of the center axis member and the outer diameter side member
that corresponds to the rotating side member that rotates together with the wheel. The other race
corresponds to the stationary side ring that is fitted to the stationary side member that does not rotate.
[0033] In the ball bearing with rotational speed detection encoder of the present invention, a
rotation restraining member is provided on one of the inner and outer circumferential surfaces of the
rotating side ring that corresponds to the circumferential surface of the engaging side that engages
with one of the center axis member and outer diameter side member that corresponds to the rotating
side member, and due to the engagement between the rotation restraining member and the
circumferential surface of the rotating side member, the rotation of the rotating side ring with respect
to the rotating side member is prevented.
[0034] In the aspect in which the rotation restraining member is provided, a fastening concave
groove is formed all the way around the circumferential surface on the engaging side of the rotating
side ring; as the rotation restraining member, an O-ring may be used that has the diameter of the
cross-sectional shape in the free state being greater than the depth of the fastening groove and is
mounted in the fastening concave groove; and in the state where the rotating side ring is engaged
with the rotating side member, the rotation of the rotating side ring with respect to the rotating side
member is prevented by elastically pressing the O-ring between the bottom surface of the fastening
groove and the circumferential surface of the rotating side member.
[0035] Alternatively, an eccentric groove is formed around the circumferential surface on the
engaging side such that the center of the bottom surface of the eccentric groove is eccentric with
respect to the center of the circumferential surface of the engaging side and the depth gradually
changes in the circumferential direction, and a retaining ring having an broken annular ring shape
with a convex section located in the middle section in the circumferential direction that protrudes in
the radial direction can be used as the rotation retaining member, and this retaining ring is mounted
in the eccentric groove. In this case, as the convex section of the retaining ring has frictional
engagement with the circumferential surface of the rotating side member, the end section in the
circumferential direction of the retaining ring is wedged between the bottom surface of the eccentric
groove and the circumferential surface of the rotating side member, preventing the rotating side ring
from rotating with respect to the rotating side member.
[0036] Furthermore, a fastening groove is formed in the axial direction on circumferential surface
of the rotating side member, and a fastening pin that protrudes in the radial direction from the
circumferential surface on the engaging side can be used as the rotation retaining member. In this
case, the engaging pin engages with a fastening groove that is formed in the axial direction in the
circumferential surface of the rotating side member, preventing the rotating side ring from rotating
with respect to the rotating side member.
[0037] Moreover, a fastening groove can be formed around the circumferential surface on the
engaging side, and a friction ring made of synthetic resin can be mounted in the fastening groove as
the rotation restraining member. In this construction as well, the rotating side ring can be prevented
from rotating with respect to the rotating side member.
[Effect of the Invention]
[003S] The ball bearing with rotational speed detection encoder of the present invention,
constructed as described above, supports the wheel of a motorcycle so that the wheel can rotate
freely, and makes it possible to detect the rotational speed of that wheel, as well as sufficiently
improves the effect of preventing foreign matter from getting into the internal space of the bearing.
[0039] Moreover, by covering the space between the inner circumferential surface on the other
end section of the outer ring and the outer circumferential surface on the other end section of the
inner ring with a typical seal ring, it is possible to effectively prevent grease that is in the internal
space inside the bearing from flowing out from the internal space inside the bearing.
[0040] Furthermore, by using an encoder having alternating S-poles and N-poIes arranged at
uniform intervals around the outside surface in the axial direction, which is the detected surface, it is
possible to improve the detection capability (reliability related to the detection of the changing
characteristics of the detected surface), and thus it is possible to maintain reliability of detection of
the rotational speed of the wheel.
[0041] In the case of using a magnetic encoder as the encoder, by using a plastic magnet made
using magnetic powder and plastic, it is possible to improve the magnetic characteristics over the
case of using a rubber magnet. As a result, it is possible to form many poles in the circumferential
direction of the magnetic encoder, and it becomes possible to detect the rotational speed of the wheel
with high precision.
[0042] By providing a rotation retaining member on the circumferential surface on the engaging
side of the rotating side ring that engages with the rotating side member, it is possible to prevent the
rotating side ring to which the encoder is mounted from relative rotation (creep) with respect to the
rotating side member, which is the opposing member that fits with and supports this rotating side
ring, and thus it is possible to improve the reliability of the detection of the rotational speed of a
wheel of a motorcycle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] FIG. 1 is a cross-sectional view of the major parts of a first embodiment of the present
invention.
FIG 2 is a cross-sectional view of the major parts of a second embodiment of the present
invention.
FIG 3 is a cross-sectional view of the major parts of athird embodiment of the present
invention, and is for explaining a ball bearing with magnetic rotational speed detection encoder for
detecting the rotational speed of the wheels of a motorcycle.
FIG 4 is a perspective view illustrating an example of the magnetic pattern of the magnetic
encoder that is provided in the ball bearing with magnetic encoder illustrated in FIG 3.
FIG 5 is a cross-sectional view of the major parts of a fourth embodiment of the present
invention.
FIG 6 is a cross-sectional view of the major parts of a fifth embodiment of the present
invention.
FIG 7 is a cross-sectional view of the major parts of a sixth embodiment of the present
invention.
FIG 8 is a cross-sectional view of the major parts of a seventh embodiment of the present
invention.
FIG 9 is a cross-sectional view of the major parts of an eighth embodiment of the present
invention.
FIG 10 is a schematic diagram illustrating the relationship between an eccentric groove
that is formed around the outer circumferential surface of the outer ring, and a retaining ring that fits
inside this eccentric groove.
FIG 11 is a cross-sectional view of the major parts of a ninth embodiment of the present
invention.
FIG 12 is an end view of a ball bearing with a fastening pin supported on the outer
circumference of the outer ring.
FIG 13 is a cross-sectional view of the major parts of a tenth embodiment of the present
invention.
FIG 14 is a cross-sectional view of the major parts of an eleventh embodiment of the
present invention.
FIG 15 is a cross-sectional view of the major parts of a twelfth embodiment of the present
invention.
FIG 16 is a cross-sectional view illustrating a first example of the construction of a
rotation supporting unit for the wheel of a motorcycle.
FIG. 17 is a cross-sectional view illustrating a second example of the construction of a
rotation supporting unit for the wheel of a motorcycle.
FIG 18 is a partial cross-sectional view illustrating an example of a conventionally known
ball bearing with encoder.
FIG 19 is a cross-sectional view of an example of a conventionally known ball bearing
with encoder, and illustrates the state of constructing a rotational speed detection apparatus that is
combined with a rotational speed sensor.
BEST MODES FOR CARRYING OUT THE INVENTION
[Embodiment 1]
[0044] FIG 1 illustrates a first embodiment of the present invention. This example, as in the first
embodiment of conventional construction illustrated in FIG 16, relates to the construction of an
outer ring rotating type ball bearing that supports the wheel 7 such that it rotates freely around a
non-rotating support shaft 3. In the ball bearing with rotational speed detection encoder for a
motorcycle of this embodiment, an opening on one end (right end in FIG 1) of the internal space 19
inside a single-row deep groove ball bearing 8a is covered by a combined seal ring 20, and a plastic
magnet ring-shaped encoder 9a is mounted and fastened all the way around the slinger 21 of this
combined seal ring 20. In the present invention, the one end of the ends of the internal space 19 of
the bearing is the side that faces the outer space, and the other end is the side that does not face the
outer space, or more specifically, is the side that faces the space on the inner diameter side of the hub
6 (see FIG. 16).
[0045] The ball bearing 8a has an outer ring Ha, which is the rotating side ring, an inner ring 13a,
which is the stationary side ring, and a plurality of balls 15. The outer ring 11a has a single-row
deep groove outer-raceway 10a that is formed around the middle section in the axial direction of the
inner circumferential surface thereof. Moreover, the inner ring 13a has a single-row deep groove
inner-raceway 12a that is formed around the middle section in the axial direction of the outer
circumferential surface thereof. Furthermore, the balls 15 are located between the outer-raceway
10a and the inner-raceway 12a, and held by a retainer 14 such that they can roll freely. Together
with fitting and fastening the inner ring 13a around the support shaft 3 with an interference fit, the
outer ring 1 la is fastened on the inside of the hub 6 (see FIG 16), which is located in the center of the
wheel 7, with an interference fit, so that the wheel 7 is supported around the support shaft such that it
can rotate freely.
[0046] A pair of ball bearings that are separated in the axial direction are provided between the
outer circumferential surface of the support shaft 3 and the inner circumferential surface of the hub 6,
and a contact angle for back-to-back arrangement is applied to these ball bearings. One of these
ball bearings (the bearing on the right side in FIG. 16, for example) is a ball bearing with rotational
speed detection encoder that comprises the encoder 9a of the present invention, and the other ball
bearing (the bearing on the left side in FIG 16, for example) is a typical ball bearing (no encoder is
installed). However, also in this typical ball bearing, the seal ring on the outside in the axial
direction (the seal ring on the left side in FIG 16, for example) of the seal rings that cover the
openings on both ends of the internal space inside the bearing is preferably constructed of a
combined seal ring that has excellent sealing characteristics such as resistance to dirty water.
[0047] Of the openings on both ends of the internal space 19 inside the bearing of the ball bearing
Sa with rotational speed detection decoder as described above, the opening on the one end that faces
the external space during operation is covered by a combined seal ring 20, and the other end (left end
in FIG 1) is covered by a typical seal ring 18b as in the case of the conventional construction.
[0048] The combined seal ring 20 comprises a slinger 21 and a seal ring 22. The slinger 21 is
formed into a circular ring shape around the entire circumference with an L-shaped cross section by
bending a magnetic metal plate such as mild steel plate, martensite or ferrite stainless steel plate or
the like. In this embodiment, this slinger 21 is fastened inside the inner circumferential surface of
the end section of the outer ring 11a, which is the rotating circumferential surface. In order for this,
this slinger 21 comprises an outer-diameter side cylindrical section 23, which is a rotating cylindrical
section, and an outside circular ring section 24, which is bent inward in the radial direction at a right
angle from the edge of the outside end in the axial direction of this outer-diameter side cylindrical
section 23, and is a rotating circular ring section. The outside end is the end section of this
cylindrical section that is on the external space side in the axial direction of the ball bearing 8a.
[0049] Moreover, the seal ring 22 comprises a metal core 25 and seal lips 26. The metal core 25
is formed into a circular ring shape around the entire circumference with an L-shaped cross section
by bending a metal plate, and comprises an inner-diameter side cylindrical section 27r which is a
stationary cylindrical section, that is fitted and fastened around the outer circumferential surface of
the end section of the inner ring I3a, which is a stationary circumferential surface, with an
interference fit, and an inside circular ring section 28, which is bent at aright angle outward in the
radial direction from the edge on the inside end in the axial direction Of this inner-diameter side
cylindrical section 27, and is a stationary circular ring section. The seal lips 26 are made of an
elastic material such as an elastomer that contains rubber, and the base end section thereof is
connected and fastened around the entire circumference to the metal core 25, and the edges of the tip
ends thereof come in sliding contact around the entire circumference with part of the slinger 21. In
the example in the figures, the edges of the tip ends at three locations of the seal lips 26 come in
sliding contact with inner circumferential surface of the outer-diameter side cylindrical section 23
and the inside surface of the outside circular ring section 24.
[0050] The encoder 9a is mounted on and fastened to the outside surface of the outside circular
ring section 24 of the slinger 21 of the combined seal ring 20 described above. It is possible to
adopt various encoders as the encoder 9a depending on the type of sensors with which the encoder 9a
is combined; for example, a magnetic encoder, an optical encoder, a capacitance encoder and the like
can be used, Topically a magnetic encoder is used, and in this embodiment as well, a magnetic
encoder is used. In a magnetic encoder for detecting the rotational speed of a wheel of a
four-wheeled vehicle, as was described above, a rubber magnet that contains ferrite that uses
strontium ferrite magnetic powder particularly for mechanical alignment is used. In the present
invention, it is also possible to use this kind of ferrite containing rubber magnet, however, as will be
described in detail in the third embodiment, preferably a plastic magnet in which the magnetic
powder above is mixed in synthetic resin is used.
[0051] The magnetic encoder is magnetized in the axial direction, however, by alternating the
magnetization direction at-uniform intervals in the circumferential direction, the characteristics of the
outside surface in the axial direction, which is the surface to be detected, is similarly changed in the
circumferential direction. More specifically, S poles and N poles on the outside surface in the axial
direction, which is surface of the encoder 9a to be detected, are alternated at uniform intervals.
[0052] Moreover, by also covering the space between the inner circumferential surface on the
other end of the outer ring, and the outer circumferential surface of the other end of the inner ring
with a normal seal ring, it is possible to effectively prevent the grease that is inside the internal space
of the bearing from flowing out from the internal space of the bearing.
[0053] The seal ring 18b that covers the opening on the other end of the internal space 19 of the
ball bearing 8 with rotational speed detection encoder faces the space on the inner diameter side of
the hub 6 (see FIG 16) and does not face the outside space, so the installation thereof is arbitrary.
However, by covering the space between the inner surface on the other end of the outer ring 11a and
the outer surface of the other end of the inner ring 13a with this seal ring 18b, it is possible to
effectively preventing the grease that is inside the internal space 19 of the bearing from leaking out
from there. This seal ring 18b comprises a second ring shaped metal core that is fastened to the end
section of the inner circumferential surface of the outer ring 11a, which is a rotating surface, and seal
lips, the base end of which is fastened to the second metal core, and the tip ends of which come in
sliding contact around the entire surface of the outer circumferential surface of the inner ring 13a,
which is a stationary surface.
[0054] The ball bearing 8a with rotational speed detection encoder for the wheel of a motorcycle
of the embodiment above, as was described above, supports the wheel 7 such that the wheel can
rotate freely around a non-rotating support shaft 3. Moreover, a sensor holder 29 fits around the
portion in the middle of the support shaft 3 that is adjacent to the bail bearing 8a, and the detection
unit of a sensor 30 that is held in this sensor holder 29 faces in the axial direction the outside surface
in the axial direction of the encoder 9a through a detection space of about 0.5 to 2 mm. m this state,
as the encoder 9a rotates together with the wheel 7, the output signal from the sensor 30 changes at a
frequency that is proportional to the rotational speed of the wheel 7. Therefore, by transmitting this
output signal to a controller (not illustrated in the figure), the rotational speed of the wheel 7 can be
found.
[0055]
[Embodiment 2]
FIG 2 illustrates a second embodiment of the present invention. In this embodiment, the
case of applying the present invention to the construction of a rotating inner ring type ball bearing in
which a rotating shaft 33 is supported on the inner diameter side of a bearing housing 32 is described.
In order to achieve the construction of a rotating inner ring type of bearing using a ball bearing 8a
having the same construction, in this embodiment, the slinger 21a of the combined seal ring 20a is
fitted and fastened around the outer circumferential surface of the inner ring 13a with an interference
fit. Moreover, the metal core 25a of the seal ring 22a is fitted and fastened around the inner
circumferential surface of the end section of the outer ring 11a. Therefore, in the construction of
this embodiment, an outer-diameter side cylindrical section 23 a is provided for the metal core 25a,
and an inner-diameter side cylindrical section 27a is provided for the slinger 21a. As far as the
construction of the combined seal ring 20a is concerned, except for the point that the installation
location of each part has changed as the bearing is changed from a rotating outer ring type bearing to
a rotating inner ring type bearing, the construction is the same as that in the first embodiment
described above, so any redundant explanation will be omitted.
[0056] The encoder 9b is mounted on and fastened to the entire outside surface of the outside
circular ring section 24 of the slinger 21a. The sensor 30 is supported by a support flange 34 that is
formed on the bearing housing 32.
[0057]
[Embodiment 3]
FIG 3 illustrates a third embodiment of the present invention. Basically, the construction
of this embodiment is the same as the conventional construction illustrated in FIG 18, so the
following explanation will concentrate on the construction and structure of the encoder 9ct which is
the feature of tins third embodiment, and an explanation of the other basic construction will be
omitted. However, it is also possible to apply the encoder 9c of this embodiment to the
construction described in the first and second embodiments.
[0058] The seal ring 18b is formed into a ring shape by covering a metal core 16b as a
reinforcement member with an elastic member 35. A seal fastening groove 36 is formed in the
inner circumferential surface on the end section in the axial direction of the outer ring 11, and by
utilizing the elasticity of the elastic member to fit the outer circumferential section of the seal ring
18b around this seal fastening groove 36, the seal ring 18b is fastened to the outer ring II.
Moreover, a seal groove 38 is formed in the outer circumferential surface on both end sections in the
axial direction of the inner ring 13, and the seal lips 17b that are formed around the inner
circumferential section of the seal ring 18b come in sliding contact with this seal groove 38.
[0059] On the other hand, the seal ring 18a with magnetic encoder comprises an outer-diameter
circumferential edge section 39 that fitted in a stepped section 37 that is formed around the inner
circumferential surface of the other end section in the axial direction of the outer ring 11, a metal
core 16a having a ring shaped plate section 40, seal lips 17a that come in sliding contact with the seal
groove 38 that is formed around the outer circumferential surface of the end section in the axial
direction of the inner ring 13, and a magnetic encoder 9c that is mounted on and fastened to the
outside surface of the ring shaped plate section 40.
[0060] Preferably, a magnetic material such as a ferrite stainless steel (SUS430 or the like), or
martensite stainless steel (SUS410 or the like) whose magnetic properties of the magnetic material
do not decrease, and from the aspect of operating conditions, can withstand corrosion at a certain
level or greater, is used as the material of the metal core 16a.
[0061] The feature of this embodiment is that a plastic magnet in which magnetic power is mixed
with synthetic resin is used as the magnetic encoder 9c. As illustrated in FIG: 4, this magnetic
encoder 9c is a ring shape member wherein the N poles and S poles are arranged such that they are
continuously alternated in the circumferential direction, and this magnetic encoder 9c is attached to
the surface of the ring shaped plate section 40 of the metal core 16a that faces outward in the axial
direction.
[0062] The sensor (not illustrated in the figure) detects the rotation of the outer ring 11 by
detecting the magnetic pulse of the fluctuation in magnetic flux density that occurs on the detected
surface of the magnetic encoder 9c that rotates together with the outer ring 11. This detected
rotational speed information can be suitably used for braking control by calculating the deviation of
the detected rotational speed information from rotational speed information that is predetermined by
an ABS apparatus, for example. As long as the sensor is attached to a stationary side member
(non-rotating side member), it can be used to form a unit together with the ball bearing 8 with this
magnetic encoder.
[0063] Mounting and fastening the magnetic encoder 9c to the metal core 16a is performed by
first using the metal core 16a, to which adhesive is burned and applied beforehand, as a core and
inserting a magnetic material. When doing this, preferably a disk gate type injection molding
machine is used. By putting the molten magnetic material that has been spread into a disk shape, in
the die for the portion that will be the thick section of the inner diameter, the ramentum shaped
magnetic powder that is contained inside is oriented parallel to the surface. Moreover, during
formation, when magnetic field is applied to the die in the thickness direction (magnetic field
formation), anisotropy becomes close to perfect. On the other hand, even when magnetic field
formation is performed, in the case of side gate, when the viscosity of the molten magnetic material
that is gradually becoming solidified is in the process of increasing, it is difficult to make the
orientation in weld sections completely anisotropic, and thus, together with the magnetic field
characteristics dropping, there is a possibility of cracking occurring in the weld sections with
decreased mechanical strength when used over a long period of time, so is not preferred.
[0064] After the magnetic material has been filled into the die in this way, while being cooled in
the die, demagnetization is performed using a magnetic field that is in the opposite direction as the
magnetization direction. Next, after removing the gate section and allowing the adhesive to
completely harden, an oil condenser type demagnetization machine is used to further perform
demagnetization to a magnetic flux density of 2mT or less, or more preferably to a magnetic flux
density of lmT or less.
[0065] Next, gate cutting is performed, and in order to completely harden the adhesive, heating is
performed at a fixed temperature and fixed amount of time in a constant temperature oven. In some
cases, it is possible to perform heating over a short period of time at a high temperature, such as by
using high frequency heating.
[0066] After that, the material is overlaid onto a magnetized yoke such that there is multi-pole
magnetization in the circumferential direction (see FIG 4), and the magentic encoder is obtained.
[0067] Talcing into consideration magnetic properties and weather resistance, ferrite magnetic
powder such as strontium ferrite, barium ferrite and the like, or rare-earth magnetic powder such
samarium-iron-nitride, samarium-cobalt, neodymium-iron-boron and the like can be suitably used as
the magnetic powder of the magnetic material, and these magnetic powders can be used alone, or a
plurality of kinds can be used in combination. When strong magnetic properties (exceeding a
BHmax of 2.0 MGOe) are required, rare-earth magnetic powder is used, and when weaker magnetic
properties will suffice (BHmax of 1.6 to 2.0 MGOe), also taking into consideration cost, preferably a
ferrite magnetic powder is used as the major component. The amount of magnetic powder that is
contained in the magnetic material differs according to the type of magnetic powder used, however,
as long as the amount is within the range of 70 to 92 mass%, there is no problem for practical use.
[0068] A binder is made by adding an impact resistance improving agent to a polyamide resin. A
polyamide resin is a resin having excellent resistance to fatigue and to heat, and is effective in
improving the resistance to thermal shock of a magnetic section, The impact resistance improving
agent is an elastic material having the function of lessening vibration and shock, and in the present
invention, a resin or rubber material such as illustrated below can be suitably used.
[0069] A modified polyamide resin can be used as the impact resistance improving agent. This
modified polyamide resin is a block copolymer having a hard segment comprising a polyamide resin,
and a soft segment comprising at least one of a polyester component and a polyether component,
where a modified polyamide resin having polyamide 6, polyamide 11 ,polyamide 12 and the like as
hard segment are known as commercial products.
[0070] Powder made from styrene-butadiene rubber, acrylic rubber, acrylonitrile butadiene rubber,
carboxyl modified acrylonitrile butadiene rubber, silicon rubber, chloroprene rubber, hydrogenated
nitrile rubber, carboxyl modified hydrogenated nitrile rubber, carboxyl modified styrene-butadiene
rubber is preferred as the rubber material, where these can be used alone, or a plurality of kinds can
be used in combination.
[0071] Ethylene propylene non-conjugated diene rubber (EPDM), maleic anhydride modified
ethylene propylene non-conjugated diene rubber (EPDM), ethylene/acrylate copolymer, ionomer and
the like can be used as the impact resistance improving agents.
[0072] The amount that these impact resistance improving agents are added is preferably 5 to 50
mass % of the total amount of polyamide resin, and more preferably 10 to 40 mass %. When the
amount added is less thanS mass %, the amount is too small and there is little effect for improving
the impact resistance, so is not preferred. When the amount added exceeds 50 mass %, the relative
amount of polyamide resin become small, and the ultimate tensile strength decreases, so the
practicability decreases.
[0073] A phenolic resin adhesive, epoxy resin adhesive and the like that can be diluted with
solvent and whose hardening reaction advances in nearly two stages is preferred as the adhesive
which is to be burned and applied to the metal core 16a. These adhesives have the advantage of
having excellent heat resistance, chemical resistance, and ease of handling.
[0074] Above, an example is shown where the attachment and fixation of the magnetic encoder 9c
to the metal core 16a is performed by shaping the magnetic material using the metal core 16a as a
core by insert molding and then by performing the multi-pole magnetization, however, it is also
possible to form the metal core 16a and the magnetic encoder 9c as separate members, and then join
the metal core 16a and the magnetic encoder 9c with adhesive and perform multi-pole magnetization.
[0075] By using this kind of plastic magnet comprising magnetic powder and plastic, it is possible
to fill the magnet with a larger amount of magnetic powder than in a rubber magnet, so it is possible
to improve the magnetic properties. As a result, it becomes possible to form a large number of
poles in the circumferential direction of the magnetic encoder.
[0076]
[Embodiment 4]
FIG. 5 illustrates a fourth embodiment of the present invention. A fastening concave
groove 42 is formed all the way around the outer circumferential surface of the outer ring lib, which
is a rotating side ring. An O-ring 43 is mounted in this fastening groove 42. This O-ring 43 is
such that the cross-sectional diameter in the free state illustrated in FIG 5 is larger than the depth of
the fastening concave groove 42. Therefore, with the outer ring 1 lb in the state before being fitted
inside the hub 6, the end section on the outer diameter side of the O-ring 43 protrudes further
outward in the radial direction than the outer circumferential surface of the outer ring lib.
Therefore, when the outer ring lib is fitted inside the hub 6 with an interference fit, the O-ring 43 is
elastically pressed between the bottom surface of the fastening groove 42 and the inner
circumferential surface of the hub 6. In this state, a large friction force acts between this bottom
surface and inner circumferential surface and both the inner and outer circumferential surfaces of the
O-ring 43. Consequently, even when the interference of the interference fit between the hub 6 and
the outer ring 1 lb decreases or disappears, the outer ring 1 lb on which the encoder 9 is mounted
does not rotate (creep) relative to the hub 6 that rotates together with the wheel. As a result, the
TOtational speed of the wheel and the encoder 9 perfectly coincide, and the reliability of detecting the
rotational speed of the wheels of a motorcycle can be improved.
[0077] Furthermore, in this embodiment, a fastening concave groove 42a is also formed in the
inner circumferential surface of the inner ring 13b, and an O-ring 43a is also mounted inside that
fastening groove 42a. When the inner ring 13b is fitted around and fastened to the support shaft 3
with an interference fit, this O-ring 43a is elastically pressed between the outer circumferential
surface of the support shaft 3 and the bottom surface of the fastening groove 42a.
[0078] In the construction of this embodiment, the O-ring 43 prevents the outer ring 1 lb (and the
encoder 9 mat is fastened to and supported by the outer ring lib) from rotating relative to the hub 6,
and also both of the O-rings 43, 43a maintain a seal between the inner circumferential surface of the
hub 6 and the outer circumferential surface of the outer ring lib, and the inner circumferential
surface of the inner ring 13b and the outer circumferential surface of the support shaft 3.
[0079] The construction and function of the other parts is nearly the same as in the conventional
construction illustrated and described in FIGS. 16 to 19, so any redundant explanation is omitted.
[0080]
[Embodiment 5]
FIG, 6 illustrates a fifth embodiment of the present invention. In this embodiment, two
fastening concave grooves 42 are formed around the outer circumferential surface of the outer ring
lie, two fastening concave grooves 42a are formed around the inner circumferential surface of the
inner ring 13c, and O-rings 43, 43a are respectively mounted in these fastening concave grooves 42,
42a. With the construction of this embodiment, when compared with the fourth embodiment
described above, the effect of preventing creep by the outer ring lie with respect to the hub 6 is
improved, and the seal between the inner circumferential surface of the hub 6 and the outer
circumferential surface of the outer ring lie, and the seal between the inner circumferential surface
of the inner ring 13c and the outer circumferential surface of the support shaft 3 can be maintained
more sufficiently.
[0081]
[Embodiment 6]
FIG 7 illustrates a sixth embodiment of the present invention. In this embodiment,
fastening concave grooves 42, 42a are respectively formed around the outer circumferential surface
of the outer ring lid and the inner circumferential surface of the inner ring 13d in the construction of
the first embodiment, and O-rings 43, 43a are respectively mounted in these fastening concave
grooves 42, 42a.
[0082]
[Embodiment 7]
FIG. 8 illustrates a seventh embodiment of the present invention. In this embodiment,
fastening concave grooves 42,42a are respectively formed around the outer circumferential surface
of the outer ring 11 e and the inner circumferential surface of the inner ring 13e in the construction of
the second embodiment, and O-rings 43, 43a are respectively mounted in these fastening concave
grooves 42, 42a,
[0083]
[Embodiment 8]
FIGS. 9 and 10 illustrate an eighth embodiment of the present invention. An eccentric
groove 44 is formed around the outer circumferential surface of the outer ring 11 f, which is a rotating
side ring, and this eccentric groove 44 is such that the center of the bottom surface 45 is eccentric
with respect to the center of the outer circumferential surface of the outer ring llf, and such that the
depth gradually changes in the circumferential direction. A retaining ring 46 is mounted in the
eccentric groove 44. This retaining ring 46 is obtained by bending a wire material such as stainless
spring steel having a rectangular cross section, and has a C shape that is a little larger than a
semicircle (the center angle is a little greater than 180 degrees). The thickness t of the wire material
in the radial direction is greater than the depth d of shallowest portion of the eccentric groove 44, and
is less than the depth D of the deepest portion (d < t < D). Moreover, the center section in the
circumferential direction of this retaining ring 46 is bent with a curvature that is larger than other
portions, and an elastic convex section 47 that protrudes outward in the radial direction is formed in
that portion. The height H from the inner circumferential surface of the retaining ring 46 to the
peak in the free state of this elastic convex section 47 that is illustrated by dot-dash line in FIG 10 is
greater than the depth D of the deepest portion of the eccentric groove 44 (K > D).
[0084] When fitting and fastening the outer ring 11 f inside the hub 6 (see FIG 16), first the
retaining ring 46 is mounted in the eccentric groove 44, and the elastic convex section 47 is
positioned at the deepest portion of the eccentric groove 44. Then as illustrated by the solid line in
FIG 10, while pressing the elastic convex section 47 inward in the radial direction such that the peak
of this elastic convex section 47 does not protrude outward in the radial direction from the outer
circumferential surface of the outer ring llf, the outer ring llf is fitted inside the hub 6 with an
interference fit. In the fitted state, the peak of this elastic convex section 47 comes in elastic
contact with the inner circumferential surface of the hub 6. In this state, this elastic convex section
47 presses both of the inner circumferential surface of the hub 6 and the bottom surface 45 of the
eccentric groove 44, and a large friction force due to this pressing force prevents the outer ring llf
from rotating with respect to the hub 6. Furthermore, when there is a tendency for this outer ring
llf to rotate with respect to the hub 6 against this pressing force, the end section in the
circumferential direction of the retaining ring 46 displaces to the shallowest portion of the eccentric
groove 44 and wedges in between the bottom surface 45 of the eccentric groove 44 and the inner
circumferential shape of the hub 6. As a result, an extremely large friction force acts at the area of
contact between the bottom surface 45 and the inner circumferential surface of the hub 6 and both
the inner and outer circumferential surfaces of the end section in the circumferential direction of the
retaining ring 46, and absolutely prevents the outer ring 11f from rotating with respect to the hub 6.
[0085] In the example in the figure, the thickness in the radial direction of the retaining ring 46 is
constant around the circumferential direction. However, it is also possible to use an eccentric ring
such as disclosed in JP10-82428(A) wherein the center axis of the outer circumferential surface and
the center axis of the inner circumferential surface are eccentric, and the thickness in the radial
direction is the greatest in the center section in the circumferential direction, and becomes small
going toward both end sections in the circumferential direction. The amount of eccentricity of this
kind of eccentric ring can be made to nearly coincide with the amount of eccentricity of the outer
circumferential surface of the outer ring 11f and the bottom surface 45 of the eccentric groove 44, or
to be a little less. By using this eccentric ring, the wedge action when there is a tendency for the
outer ring 11f to rotate with respect to the hub 6 is large, and the effect of preventing relative rotation
(creep) between the outer ring 11f and the hub 6 becomes even larger.
[0086]
[Embodiment 9]
FIGS. 11 to 12 illustrate a ninth embodiment of the present invention. In this
embodiment, a fastening pin 48 is supported on the outer circumferential surface of the outer ring
11g such that the pin protrudes outward in the radial direction from this outer circumferential surface.
In order for this, a spring pin is pressure fitted into a concave hole that is formed in part of the
circumferential surface of the outer ring 11g. On the other hand, a fastening groove (not illustrated
in the figure) is formed in the axial direction on the inner circumferential surface of the hub 6 (see
FIG. 16) into which the outer ring 1 lg is to be fitted, such that the fastening groove is open toward
the end surface in the axial direction of the hub 6. As the outer ring llg is fitted inside the hub 6
with an interference fit, the fastening pin 48 engages with the fastening groove. As a result, the
outer ring 11g is prevented from rotating with respect to the hub 6.
[0087]
[Embodiment 10]
FIG. 13 illustrates a tenth embodiment of the present invention. In this embodiment,
fastening grooves 49 are formed at two locations in the axial direction of the outer circumferential
surface of the outer ring llh, and friction rings 50 that are each made of synthetic resin are mounted
in both of these fastening grooves 49. Both of these friction rings SO have a rectangular
cross-sectional shape and are formed into a ring shape around the entire circumference, having a
break at one location in the circumferential direction so that the friction rings 50 can be mounted in
both of the fastening grooves 49. With both of these friction rings 50 mounted in both of the
fastening grooves 49, the outer circumferential surfaces of these friction rings 50 and the outer
circumferential surface of the outer ring 11h are located on a single cylindrical surface, or the
surfaces of the rings 50 protrude outward a little more than the outer circumferential surface of the
outer ring 11h.
[0088] The linear expansion coefficient of both of the friction rings 50, which are each made of
synthetic resin are greater than the linear expansion coefficient of the ferrous alloy or aluminum of
the hub 6 (see FIG 16) into which the outer ring 11h fits. Therefore, as the temperature rises, both
of the friction rings 50 thermally expand more than the outer ring 11h and the hub 6, and both the
inner and outer circumferential surfaces of both of the friction rings 50 are strongly pressed by the
bottom surfaces of both fastening grooves 49 and the inner circumferential surface of the hub 6. As
a result, a large friction force acts between these surfaces, and the outer ring 11h is prevented from
rotating relative to the hub 6.
[0089]
[Embodiment 11]
FIG. 14 illustrates an eleventh embodiment of the present invention. In this embodiment,
the construction of the eighth embodiment, wherein an eccentric groove 44 is formed around the
outer circumferential surface of the outer ring 11i and a retaining ring 46 is mounted in this eccentric
groove 44, is applied to the construction of the first embodiment
[0090]
[Embodiment 12]
FIG 15 illustrates a twelfth embodiment of the present invention. In this embodiment,
the construction of the eighth embodiment, wherein an eccentric groove 44 is formed around the
inner circumferential surface of the inner ring 13j and a retaining ring 46 is mounted in this eccentric
groove 44, is applied to the construction of the second embodiment
[Explanation of Reference Numbers]
[0091]
1 fork
2 Support plate
3,3a Support shaft
4,4a, 4b, 4c Ball bearing
5a, 5b, 5c Inner ring spacer
6,6a Hub
7,7a Wheel
8, 8a, 8b, 8c, 8d, 8e, 8f, 8g, 8h, 8i, 8j Ball bearing with encoder
9,9a, 9b, 9c Encoder
10, 10a Outer-raceway
11, 11a, 11b, 11e, 11d, 11e, 11f, 11g, 11g, 11i, 11j Outer ring
12,12a 'Inner-raceway
13,13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h, 13i, 13j Inner ring
14 Retainer
15 Ball
16a, 16b Metal core
17a, 17b Seal lips
18a, 18b Seal ring
19 Space inside the bearing
20, 20a Combined seal ring
21,21a Slinger
22, 22a Seal ring
23, 23a Outer-diameter side cylindrical section
24,24a Outside circular ring section
25, 25a Metal core
26, 26a Seal lips
27, 27a Inner-diameter side cylindrical section
28, 28a Inside circular ring section
29 Sensor holder
30,30a Sensor
31 Arm
32 Bearing housing
33 Rotating shaft
34 Support flange
35 Elastic member
36 Seal fastening groove
37 Stepped section
38 Seal groove
39 Outer-diameter circumferential edge section
40 Ring shaped plate section
41 Holder member
42 Fastening concave groove
43 O-ring
44 Eccentric groove
45 Bottom surface
46 Retaining ring
47 Elastic convex section
48 Fastening pin
49 Fastening groove
50 Friction ring
CLAIMS
What is claimed is:
1. A ball bearing with a rotational speed detection encoder for a motorcycle, comprising:
a single-row deep groove ball bearing comprising an outer ring having a single-row deep
groove outer-raceway formed around the middle section in the axial direction of the inner
circumferential surface thereof, an inner ring having a single-row deep groove inner-raceway formed
around the middle section in the axial direction of the outer circumferential surface and a plurality of
balls that are located between the outer-raceway and the inner-raceway and held by a retainer so as to
be able to roll freely, with one of the outer ring and the inner ring being fitted and fastened to a
member on the rotating side that rotates together with the wheel of a motorcycle, and the other being
fitted and fastened to a stationary side member that does not rotate;
an encoder fastened to one of the inner and outer circumferential surfaces of the rotating
side ring that corresponds to a circumferential surface on the rotating side that faces the stationary
side ring, the properties on the outside surface thereof which corresponds to a detected surface,
alternating at uniform intervals in the circumferential direction; and
a combined seal ring, having a slinger and a seal ring, that covers the space between the
inner circumferential surface on one end section of the outer ring and the outer circumferential
surface of one end section of the inner ring,
the encoder being fastened to the circumferential surface on the rotating side by supporting
and fastening the encoder to the slinger.
2. The ball bearing with rotational speed detection encoder for the wheel of a motorcycle
according to claim 1, wherein
the slinger is formed by bending a metal plate into an ring shape, having a cylindrical
section on the rotating side that is fitted and fastened to the circumferential surface of the rotating
side, and a circular ring section on the rotating side that is bent at a right angle from the edge of the
outer end in the axial direction of the cylindrical section on the rotating side toward the race on the
stationary side;
the seal ring comprises a metal core and seal lips;
the metal core is formed by bending a metal plate into a ring shape, having a cylindrical
section on the stationary side that is fitted and fastened to one of the inner and outer circumferential
surfaces of the stationary side ring that corresponds to a circumferential surface on the stationary side
that faces the circumferential surface on the rotating side, and a circular ring section on the rotating
side that is bent at a right angle from the edge of the inside end in the axial direction of the
cylindrical section on the stationary side toward the rotating side ring;
the seal lips are made of an elastic material, having a base end section that is connected
and fastened all around the metal core, and edges on the tip ends that come in sliding contact all the
way around part of the slinger; and
the encoder is mounted on and fastened all the way around the outside surface in the axial
direction of the circular ring section on the rotating side.
3. The ball bearing with rotational speed detection encoder for the wheel of a motorcycle
according to claim 1, wherein the space between the inner circumferential surface on the other end of
the outer ring and the outer circumferential surface on the other end of the inner ring is covered by a
second seal ring that comprises a second metal core and second seal lips that are fastened to the base
end section of the second metal core.
4. The ball bearing with rotational speed detection encoder for the wheel of a motorcycle
according to claim 1, wherein the encoder is a plastic magnet having magnetic powder mixed in
synthetic resin, and together with the plastic magnet being magnetized in the axial direction, the
magnetization direction alternates and changes at uniform intervals in the circumferential direction,
with alternating S poles and N placed at uniform intervals on the outside surface in the axial
direction, which is the detected surface of the encoder.
5. The bail bearing with rotational speed detection encoder for the wheel of a motorcycle
according to claim 4, wherein the encoder is a plastic magnet comprising magnetic powder and a
binder that is obtained by adding an impact resistance improving agent to a polyamide resin.
6. A rotational speed detection apparatus for a wheel of a motorcycle, comprising:
a center axis member that is concentric with the wheel;
an outer diameter side member that is provided around the center axis member and is
concentric with the center axis member;
a ball bearing with rotational speed detection encoder according to claim 1 that is provided
between the outer circumference of the center axis member and the inner circumferential surface of
the outer diameter side member;
a rotation detection sensor that is supported by and fastened to part of one of the center
axis member and the outer diameter side member that corresponds to the stationary side member that
does not rotate, so that the rotation detection sensor faces the outside surface in the axial direction of
the encoder of the ball bearing with rotational speed detection encoder, the rotation detection sensor
outputting a signal that changes according to the rotation of the encoder; and
a rotation restraining member provided on one of the inner and outer circumferential
surfaces of the rotating side ring that corresponds to the circumferential surface of the engaging side
that engages with one of the center axis member and outer diameter side member that corresponds to
the rotating side member, and due to the engagement between the rotation restraining member and
the circumferential surface of the rotating side member, the rotation of the rotating side ring with
respect to the rotating side member being prevented.
7. The rotational speed detection apparatus for a wheel of a motorcycle according to claim 6,
wherein
a fastening concave groove is formed all the way around the circumferential surface on the
engaging side of the rotating side ring;
an O-ring is used as the rotation restraining member that has the diameter of the
cross-sectional shape in the free state being greater than the depth of the fastening groove and is
mounted in the fastening concave groove; and
in the state where the rotating side ring is engaged with the rotating side member, the
rotation of the rotating side ring with respect to die rotating side member is prevented by elastically
pressing the O-ring between the bottom surface of the fastening groove and the circumferential
surface of the rotating side member.
8. The rotational speed detection apparatus for a wheel of a motorcycle according to claim 6,
wherein
an eccentric groove is formed around the circumferential surface on the engaging side such
that the center of the bottom surface of the concentric groove is eccentric with respect to the center
of the circumferential surface of the engaging side and the depth gradually changes in the
circumferential direction;
a retaining ring having an broken annular ring shape with a convex section located in the
middle section in the circumferential direction that protrudes in the radial direction is as the rotation
retaining member; the retaining ring being mounted in the eccentric groove; and
as the convex section of the retaining ring has frictional engagement with the
circumferential surface of the rotating side member, the end section in the circumferential direction
of the retaining ring is wedged between the bottom surface of the eccentric groove and the
circumferential surface of the rotating side member, preventing the rotating side ring from rotating
with respect to the rotating side member.
9. The rotational speed detection apparatus for a wheel of a motorcycle according to claim 6,
wherein
a fastening pin is supported by the circumferential surface on the engaging side such that
the pin protrudes in the radial direction from the circumferential surface on the engaging side; and
a fastening groove is formed in the axial direction in the circumferential surface of the
rotating side member;
the engaging pin engages with the fastening groove, preventing the rotating side ring from
rotating with respect to the rotating side member.
10. The rotational speed detection apparatus for a wheel of a motorcycle according to claim 6,
wherein
a fastening groove is formed around the circumferential surface on the engaging side; and
a friction ring made of synthetic resin is mounted in the fastening groove.