Description:FIELD
[0001] Embodiments described herein relate generally to a rotating electric machine.
5
BACKGROUND
[0002] Conventionally, a rotating electric machine including a rotor, a stator, and a case
that houses the rotor and the stator has been known.
[0003] A pressure-resistant and explosion-proof rotating electric machine, which is one
10 type of rotating electric machine, has been designed to prevent sparks from reaching the
outside of its case when a gas explosion occurs inside the case of the rotating electric
machine.
[0004] The pressure-resistant and explosion-proof rotating electric machine as
described above is disclosed in, for example, a utility model publication JP S61-104750
15 U.
[0005] It is advantageous to this type of rotating electric machine, if an explosion
pressure can be reduced when an explosion occurs inside the case.
[0006] A problem to be solved by the present invention is to obtain a rotating electric
machine that is capable of reducing an explosion pressure when an explosion occurs
20 inside a case thereof.
SUMMARY
[0007] A rotating electric machine according to one aspect of the present disclosure
includes a case, a stator, a rotor, and bearings. The case is provided with a tubular
25 frame and brackets. The brackets are fitted into edges of the frame. The stator is
housed in the case. The rotor is provided with a rotor core and a shaft. The rotor core is
provided inside the stator. The shaft rotates integrally with the rotor core. The bearings
are supported by the brackets. The bearings support the shaft to allow the shaft to rotate
2
around a central axis of rotation. Each of the brackets includes an outer peripheral part,
an inner peripheral part, and a wall part. The outer peripheral part is coupled to a
corresponding one of the edges of the frame. The inner peripheral part supports a
corresponding one of the bearings. The wall part extends between the outer peripheral
part and the inner peripheral pa 5 rt. The wall part includes a projecting part with a curved
shape projecting toward an inside of the case.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a cross-sectional view that schematically illustrates a rotating electric
10 machine of an embodiment and illustrates half the rotating electric machine;
FIG. 2 is a cross-sectional view illustrating part of the rotating electrical
machine of the embodiment; and
FIG. 3 is a cross-sectional view illustrating part of a bracket in a rotating electric
machine of a modification of the embodiment.
15
DETAILED DESCRIPTION
[0009] A rotating electric machine 1 according to a present embodiment will be
described hereinafter with reference to the drawings. The configuration of the
embodiment described below and functions and results (effects) provided by the
20 configuration are mere examples, and are not limited to the following description. Note
that in the present specification, ordinal numbers are used only to distinguish
components and members, and do not indicate order or priority.
[0010] In addition, the drawings are schematic, and the dimensional relationship
between each element, the ratio between each element, and the like may be different
25 from those in reality. In addition, the drawings may include parts having different
dimensional relationships and ratios. Moreover, in the present specification, ordinal
numbers are used only to distinguish components, members, parts, positions, directions,
and the like, and do not indicate order or priority.
3
[0011] FIG. 1 is a cross-sectional view that schematically illustrates the rotating electric
machine 1 of the present embodiment and illustrates half the rotating electric machine 1.
In one example, the rotating electric machine 1 of the present embodiment is a pressureresistant
explosion-proof rotating electric machine. More specifically, the rotating
5 electric machine 1 may be a motor or a generator.
[0012] As illustrated in FIG. 1, the rotating electric machine 1 includes a stator 11, a
rotor 12, a case 14, two bearings 15, a terminal box 16, a plurality of cables 17, an outer
fan 18, an outer fan cover 19, and a terminal member 24. In the rotating electric
machine 1, the rotor 12 rotates around a central axis Ax of rotation. The central axis Ax
10 of rotation is the center of rotation of the rotor 12 (shaft 121) in the rotating electric
machine 1. In one example, the central axis Ax of rotation is represented by a virtual
straight line passing through the center of the rotor 12 (shaft 121).
[0013] In the following description, an axial direction, a radial direction, and a
circumferential direction of the central axis Ax of rotation are defined for convenience.
15 The axial direction is a direction along the central axis Ax of rotation The radial
direction is a direction orthogonal to the central axis Ax of rotation. The
circumferential direction is a direction around the central axis Ax of rotation. In the
following description, the axial direction, the radial direction, and the circumferential
direction are the axial direction, the radial direction, and the circumferential direction of
20 the central axis Ax of rotation, respectively, unless specifically mentioned.
[0014] The stator 11 includes a stator core 111 and a stator winding 112. The stator
core 111 is fixed to the case 14. The stator core 111 is formed in a substantially tubular
shape that surrounds the central axis Ax of rotation. The stator winding 112 penetrates
through a plurality of slots (not illustrated) formed in the stator core 111 and extends in
25 the axial direction. The stator winding 112 is fixed to the stator core 111.
[0015] The rotor 12 includes the shaft 121, a rotor core 122, and a conductor 123. The
shaft 121 is supported by the case 14 via the two bearings 15 so that the shaft 121 can
rotate around the central axis Ax of rotation surrounded by the stator 11. In other
4
words, the two bearings 15 support the shaft 121 such that the shaft 121 is rotatable with
respect to the case 14.
[0016] The shaft 121 penetrates the case 14 and extends in the axial direction along the
central axis Ax of rotation. A part between both edges 121a in the axial direction of the
shaft 121 is housed in the case 5 14. The both edges 121a in the axial direction of the
shaft 121 project outward from the case 14.
[0017] One of the edges 121a of the shaft 121 is coupled to, for example, various
external devices. Those external devices are driven by the rotation of the shaft 121.
[0018] The rotor core 122 is formed in a substantially tubular shape that extends in the
10 axial direction. The rotor core 122 is disposed substantially concentrically with the
stator 11. The rotor core 122 is disposed inside the stator 11 via clearance. The rotor
core 122 is attached to the part between the both edges 121a in the axial direction of the
shaft 121. Thus, the rotor core 122 rotates integrally with the shaft 121.
[0019] The conductor 123 includes conductor bars 123a and a pair of short-circuit rings
15 (not illustrated). The conductor bars 123a penetrate the rotor core 122 in the axial
direction. The short-circuit rings are coupled to both edges in the axial direction of the
conductor bars 123a.
[0020] The stator 11 and the rotor core 122 are not limited to the above-described
configuration as long as rotational force can be generated by electromagnetic force. In
20 one example, the rotor core 122 may include magnets.
[0021] In one example, the case 14 is formed of metal in a box shape. Note that the
case 14 may be formed of another material. A housing chamber 30 is provided inside
the case 14. The housing chamber 30 is a space having a substantially columnar shape
extending in the axial direction. Note that the housing chamber 30 is not limited to a
25 columnar shape, and may have another shape. The stator 11, part of the shaft 121, and
the rotor core 122 are housed in the housing chamber 30. Thus, the case 14 houses the
stator 11, part of the shaft 121, and the rotor core 122. The case 14 supports the two
bearings 15.
5
[0022] The outer fan 18 is coupled to the shaft 121 on the outside of the case 14. Thus,
the outer fan 18 can rotate around the central axis Ax of rotation integrally with the
shaft 121 (rotor 12). In one example, the outer fan 18 is a centrifugal fan that rotates to
flow gas at least in the outward direction of the radial direction. By way of example,
the outer fan 18 can flow 5 gas in the outward direction of the radial direction and in the
axial direction toward the case 14 side by rotating. Note that the outer fan 18 is not
limited to the above-described type.
[0023] The outer fan cover 19 is disposed outside the case 14 and covers the outer fan
18. In one example, the outer fan cover 19 is made of metal. The outer fan cover 19 is
10 fixed to an edge in the axial direction of the case 14. An end wall in the axial direction
of the outer fan cover 19 is provided with a plurality of intake holes.
[0024] The outer fan 18 can take outside air into the inside of the outer fan cover 19
through the intake holes of the outer fan cover 19 by rotating. As a result, an airflow
toward the outer fan 18 is generated. The airflow of outside air generated by the
15 rotating outer fan 18 is, for example, discharged to the outside of the case 14 through a
passage provided between the outer fan cover 19 and the outer surface of the case 14,
and flows in the axial direction along an outer peripheral surface 21a of a frame 21
constituting the outer surface of the case 14. Thus, an airflow along the outer surface of
the case 14 is generated. The airflow of outside air exchanges heat with the case 14. As
20 a result, the airflow of outside air cools gas in the stator 11 and the housing chamber 30
of the case 14 via the case 14. In this way, a housed member such as the rotor 12 in the
case 14 is cooled.
[0025] The terminal member 24 is fixed to the case 14. In one example, the terminal
member 24 is formed in a plate shape. The terminal member 24 is a member that can be
25 electrically connected to the stator winding 112. The terminal member 24 includes a
cover 241 and a plurality of terminals 242.
6
[0026] The cover 241 is formed in a plate shape and is coupled to the frame 21 by bolts.
The terminals 242 are conductors penetrating the cover 241. In the present
embodiment, the terminals 242 are electrically connected to the terminal box 16.
[0027] The terminal box 16 is fixed to the case 14. By way of example, the terminal
box 16 is fixed to t 5 he case 14 via the terminal member 24. The terminal box 16 is
provided outside the case 14. The terminal box 16 includes a terminal box case and a
housed component. The terminal box case is fixed to the case 14.
[0028] The housed component is housed inside the terminal box case. In one example,
the housed component is a terminal block that includes a base and terminals. The
10 terminals of the housed component are electrically connected to a connection target via
the terminals 242 and the cables 17. In addition, the terminals of the housed component
are electrically connected to an external device via a member for external connection.
Thus, the terminal box 16 is electrically connected to the connection target in the case
14 via the terminal member 24. The connection target includes the stator winding 112.
15 Note that the connection target may be various sensors or the like provided in the case
14 in addition to the stator winding 112. The sensors may be a temperature sensor, a
current sensor, and the like.
[0029] The cables 17 electrically connect the stator winding 112, a sensor disposed in
the housing chamber 30, and the like to the terminals 242. Thus, the terminal box 16 is
20 electrically connected to the stator winding 112, the sensor disposed in the housing
chamber 30, and the like via the terminals 242 and the cables 17.
[0030] The case 14 includes the frame 21, two brackets 22, and two oil slingers 23.
[0031] The frame 21 and the two brackets 22 surround the housing chamber 30. The
frame 21 and the two brackets 22 constitute the housing chamber 30.
25 [0032] The frame 21 is formed in a substantially tubular shape around the central axis
Ax of rotation. More specifically, a through hole 50 penetrating the frame 21 in the
axial direction is formed in the frame 21. The through hole 50 includes the housing
chamber 30. The frame 21 surrounds the stator 11, the rotor core 122, and the housing
7
chamber 30. The frame 21 is disposed substantially concentrically with the stator 11
and the rotor core 122, and is fixed to the stator 11. Note that the frame 21 is not
limited to a tubular shape, and may have another shape.
[0033] FIG. 2 is a cross-sectional view illustrating part of the rotating electric machine
1 of the present embodiment. Note tha 5 t, in FIG. 2, some members illustrated in FIG. 1
are omitted. As illustrated in FIGS. 1 and 2, the frame 21 includes the outer peripheral
surface 21a and an inner peripheral surface 21b. The outer peripheral surface 21a is a
curved surface with a substantially tubular shape extending in the axial direction. The
outer peripheral surface 21a faces the outside of the frame 21.
10 [0034] The inner peripheral surface 21b is a curved surface having a substantially
tubular shape extending in the axial direction. The inner peripheral surface 21b forms
(defines or sections) the through hole 50. The inner peripheral surface 21b faces inward
in the radial direction. In other words, the inner peripheral surface 21b faces the inside
of the through hole 50. The inner peripheral surface 21b surrounds the through hole 50.
15 [0035] The outer peripheral surface 21a and the inner peripheral surface 21b extend
between both edges 21c in the axial direction of the frame 21.
[0036] The edges 21c include a joint surface 21d. The joint surface 21d is connected to
an end of the inner peripheral surface 21b in an outward direction Dxo of the axial
direction. The outward direction Dxo of the axial direction is a direction toward the
20 outside of the case 14 in the axial direction and is included in the axial direction. The
direction opposite to the outward direction Dxo of the axial direction is an inward
direction Dxi of the axial direction. The inward direction Dxi of the axial direction is a
direction toward the inside of the case 14 in the axial direction and is included in the
axial direction. In one example, the joint surface 21d is a flat surface having a
25 substantially annular shape extending outward in the radial direction from the end of the
inner peripheral surface 21b. The joint surface 21d faces in the outward direction Dxo
of the axial direction. The outward direction Dxo of the axial direction is orthogonal to
the direction in which the inner peripheral surface 21b faces. Note that the joint surface
8
21d may face in another direction intersecting the direction in which the inner
peripheral surface 21b faces.
[0037] As illustrated in FIG. 1, the outer peripheral surface 21a of the frame 21 is
provided with two terminal seats 211, a hanging part 212, a rib 213, and a plurality of
5 fins 214.
[0038] The terminal seats 211 project outward in the radial direction from the outer
peripheral surface 21a of the frame 21. The two terminal seats 211 are spaced apart
from each other in the axial direction. The terminal seats 211 are also referred to as
projections. The terminal seats 211 each include a distal end surface 211c. The
10 terminal box 16 is fixed to the distal end surface 211c.
[0039] As illustrated in FIG. 2, the terminal seat 211 is provided with a through hole 31.
The through hole 31 is a hole penetrating the terminal seat 211 in the radial direction.
The through hole 31 penetrates the frame 21 and the terminal seat 211 in the radial
direction to cause the housing chamber 30 to communicate with the outside of the case
15 14.
[0040] The through hole 31 includes a first hole 31a and a second hole 31b. The first
hole 31a is provided in the terminal seat 211. The second hole 31b is provided in the
frame 21 and is connected to the first hole 31a. The second hole 31b is provided inside
in the radial direction with respect to the first hole 31a. The diameter of the first hole
20 31a is larger than the diameter of the second hole 31b. In other words, the diameter of
the second hole 31b is smaller than the diameter of the first hole 31a. Thus, a step
serving as a protruding part 21e described later is formed in the through hole 31. As
illustrated in FIG. 1, the terminal member 24 is placed in the through hole 31.
Specifically, the terminal member 24 is placed in the first hole 31a of the through hole
25 31.
[0041] As illustrated in FIG. 1, the hanging part 212 projects outward in the radial
direction from the outer peripheral surface 21a of the frame 21. The hanging part 212 is
provided between the two terminal seats 211. The hanging part 212 is hooked by a
9
hook of a lifting device or the like. The lifting device can lift the rotating electric
machine 1 by hooking the hanging part 212.
[0042] The rib 213 projects outward in the radial direction from the outer peripheral
surface 21a of the frame 21. The rib 213 extends between the hanging part 212 and
5 each of the terminal seats 211.
[0043] The plurality of fins 214 projects outward in the radial direction from the outer
peripheral surface 21a of the frame 21. An airflow generated by the outer fan 18 flows
along the outer surfaces of the fins 214.
[0044] As illustrated in FIG. 2, the frame 21 includes a protruding part 21e. The
10 protruding part 21e projects from an inner edge 211b in the radial direction of an inner
peripheral surface 211a of the terminal seat 211. The protruding part 21e is formed in
an annular shape surrounding the second hole 31b. In other words, the protruding part
21e forms the second hole 31b. The protruding part 21e supports the terminal member
24 inside in the radial direction with respect to the terminal member 24 (FIG. 1).
15 Specifically, the protruding part 21e includes a support surface 21f that supports the
terminal member 24. The support surface 21f is an outer surface in the radial direction
of the protruding part 21e. The support surface 21f is an example of a first surface. The
protruding part 21e is also referred to as a support part.
[0045] The thickness t1 of the protruding part 21e in a projecting direction D1 of the
20 terminal seat 211 is less than or equal to the thickness t2 of an outer part 21g of the
frame 21, which lies outside (or on the periphery of) the terminal seat 211. In other
words, the thickness t1 of the protruding part 21e in the projecting direction D1 of the
terminal seat 211 is less than or equal to the thickness t2 of the frame 21 on the outside
of the terminal seat 211.
25 [0046] In addition, a position P1 in the radial direction of the support surface 21f of the
protruding part 21e is closer, in the radial direction, to a position P2 of the outer
peripheral surface 21a of the outer part 21g than a position P3 of the inner peripheral
surface 21b of the outer part 21g. Alternatively, the position P1 of the support face 21f
10
corresponds, in the radial direction, to the position P2 of the outer peripheral surface 21a
in the radial direction. In the example illustrated FIG. 2, the position P1 of the support
surface 21f is closer, in the radial direction, to the position P2 of the outer peripheral
surface 21a than position P3 of the inner peripheral surface 21b.
[0047] The protruding part 5 21e is provided with a surface 21h. The surface 21h is a flat
surface having a substantially annular shape extending inward in the radial direction
from the end of the inner peripheral surface 21b. The surface 21h faces in the outward
direction Dxo of the axial direction.
[0048] As illustrated in FIG. 1, the two brackets 22 are coupled (fixed) to the frame 21
10 in a state of being fitted into both edges 21c of the frame 21 in the axial direction. The
brackets 22 thereby close both edges 21c of the frame 21. In one example, the brackets
22 are fixed to the frame 21 by bolts. Outer surfaces 22a of the brackets 22 are
provided with fins 215.
[0049] As illustrated in FIG. 2, the bracket 22 includes an outer peripheral part 221, an
15 inner peripheral part 222, and a wall part 223. The outer peripheral part 221 is an outer
part in the radial direction of the bracket 22, and is fitted into (coupled to) the edge 21c
of the frame 21. The inner peripheral part 222 is an inner part in the radial direction of
the bracket 22 and supports the bearings 15. The wall part 223 is a part extending
between the outer peripheral part 221 and the inner peripheral part 222. Note that the
20 illustration of the rib 213, the fins 214 and 215, and the like is omitted in FIG. 2. The
outer peripheral part 221 is also referred to as a fitting part or a coupling part, and the
inner peripheral part 222 is also referred to as a support part.
[0050] The outer peripheral part 221 is coupled (fixed) to the edge 21c of the frame 21.
The outer peripheral part 221 includes a base part 221a and a projecting part 221b.
25 [0051] The base part 221a includes a joint surface 221c. The joint surface 221c faces in
the inward direction Dxi of the axial direction. The joint surface 221c faces the joint
surface 21d of the frame 21 in the axial direction and covers the joint surface 21d.
11
[0052] The projecting part 221b projects in the inward direction Dxi of the axial
direction from an inner edge in the radial direction of the joint surface 21d of the base
part 221a. Thus, the projecting part 221b projects into the housing chamber 30 from the
inner edge in the radial direction of the joint surface 21d of the base part 221a. The
projecting part 221b is 5 formed in a tubular shape around the central axis Ax of rotation.
The projecting part 221b is fitted into the edge 21c of the frame 21. A distal end surface
221i of the projecting part 221b faces the surface 21h in the axial direction.
[0053] The projecting part 221b includes an outer peripheral surface 221d. The outer
peripheral surface 221d is a curved surface having a substantially tubular shape
10 extending in the axial direction. The diameter of the outer peripheral surface 221d is
equal to or slightly shorter than the diameter of the inner peripheral surface 21b at the
edge 21c of the frame 21. In the axial direction, the length of the outer peripheral
surface 221d is substantially equal to the length of the inner peripheral surface 21b.
[0054] The outer peripheral surface 221d faces outward in the radial direction. In other
15 words, the outer peripheral surface 221d faces the inner peripheral surface 21b of the
frame 21. Note that the outer peripheral surface 221d may be in contact with the inner
peripheral surface 21b or may be slightly separated from the inner peripheral surface
21b. The outer peripheral surface 221d and the inner peripheral surface 21b are
disposed substantially concentrically and are disposed substantially parallel.
20 [0055] The inner peripheral part 222 includes a base part 222a and a projecting part
222b. The base part 222a surrounds the bearings 15 so as to support the bearings 15.
[0056] The projecting part 222b projects from the base part 222a in the inward direction
Dxi of the axial direction. Thus, the projecting part 222b projects into the housing
chamber 30 from the base part 222a. The projecting part 222b is formed in a tubular
25 shape around the central axis Ax of rotation. The projecting part 222b surrounds the oil
slingers 23 so as to support the oil slingers 23.
[0057] The wall part 223 includes a projecting part 223a. The projecting part 223a
projects toward the inside of the case 14, namely, toward the housing chamber 30. The
12
projecting part 223a is formed in a curved shape. The projecting part 223a is curved
such that its width in the radial direction becomes narrower toward a top part 223d of
the projecting part 223a. The projecting part 223a may be part of a wavy shape. In the
example illustrated in FIG. 2, a cross-sectional shape in the axial direction of the
projecting part 223a is a substantially U-shape 5 whose edges reach the outer peripheral
part 221 and the inner peripheral part 222 of the bracket 22. The projecting part 223a
has an annular shape around the central axis Ax of rotation, namely, around the shaft
121.
[0058] The projecting part 223a includes a projecting surface 223b and a recessed
10 surface 223c. The projecting surface 223b is a surface facing the inside of the case 14,
namely, the housing chamber 30. The projecting surface 223b projects toward the
inside of the case 14, namely, toward the housing chamber 30. The projecting surface
223b is formed in a curved shape. The projecting surface 223b is a curved surface
smoothly curved such that the width in the radial direction becomes narrower toward
15 the top part 223d of the projecting part 223a. The recessed surface 223c is provided on
the opposite side to the projecting surface 223b and is aligned with the projecting
surface 223b in the axial direction. The recessed surface 223c is a surface facing the
outside of the case 14. The recessed surface 223c is recessed in a recessed shape toward
the inside of the case 14 (housing chamber 30), and is formed in a curved shape. The
20 recessed surface 223c is a curved surface smoothly curved such that the width in the
radial direction becomes narrower toward the top part 223d of the projecting part 223a.
The recessed surface 223c is substantially along the projecting surface 223b.
[0059] In addition, the projecting part 223a is separated from the stator 11 and the rotor
12. The top part 223d of the projecting part 223a is aligned with the stator winding 112
25 of the stator 11 in the axial direction to leave a space between them.
[0060] Moreover, as illustrated in FIG. 1, the brackets 22 are each provided with an
opening part 32. Specifically, the opening part 32 is provided in the inner peripheral
part 222 of the bracket 22. The opening part 32 is open in the axial direction in the
13
bracket 22. The opening part 32 causes the outside of the case 14 to communicate with
the housing chamber 30. Note that the opening part 32 may not independently cause the
outside of the case 14 to communicate with the housing chamber 30. In one example,
the opening part 32 may be provided in the middle of a passage that independently
causes the outside of the 5 case 14 to communicate with the housing chamber 30. The
shaft 121 is disposed to penetrate through the opening part 32. In other words, the shaft
121 penetrates the brackets 22 in the axial direction.
[0061] The oil slingers 23 are formed in an annular shape intersecting the axial
direction. The oil slingers 23 are provided further inside the case 14 than the brackets
10 22. Each of the oil slingers 23 is coupled to the corresponding bracket 22 by one or
more bolts. The shaft 121 penetrates the inside of the oil slingers 23. The oil slingers
23 restrict the movement of oil in the case 14 to the outside of the case 14.
[0062] Bearing chambers 34 are provided between the brackets 22 and the oil slingers
23 coupled to the brackets 22.
15 [0063] The bearing chambers 34 house the bearings 15. In one example, the bearings
15 are attached to the brackets 22 in the bearing chambers 34. The bearings 15 support
the shaft 121 so that the shaft 121 can rotate around the central axis Ax of rotation.
[0064] The frame 21, the brackets 22, the oil slingers 23, the terminal member 24, and
the terminal seats 211 are coupled to each other by spigot joining. Spigot joining is also
20 called inlay (“i-n-ro” in Japanese language). In spigot joining, a projection or a plug
provided in one member is fitted into a recess or a hole provided in the other member.
Note that the frame 21, the brackets 22, the oil slingers 23, the terminal member 24, and
the terminal seats 211 may be coupled to each other by another method.
[0065] The rotating electric machine 1, which is an explosion-proof motor having the
25 above-described configuration, can prevent sparks from reaching the outside of the case
14 even if a gas explosion occurs in the housing chamber 30. The following description
explains a case where an explosion occurs in the housing chamber 30. Note that the
14
rotating electric machine 1 has various configurations that can suppress the occurrence
of an explosion in the housing chamber 30.
[0066] As illustrated in FIG. 2, gaps G1, G2, and G3 may be provided between the
frame 21 and each of the brackets 22. The gap G1 is provided between the joint surface
21d and the joint surface 5 221c. The gap G2 is provided between the inner peripheral
surface 21b and the outer peripheral surface 221d. The gap G3 is provided between the
surface 21h provided on the protruding part 21e and the distal end surface 221i of the
projecting part 221b. The surfaces forming the gaps G1, G2, and G3 are also referred to
as explosion-proof surfaces. Note that an explosion-proof surface is provided in
10 addition to the above explosion-proof surfaces.
[0067] The gap G1 extends in the radial direction and communicates with the outside of
the case 14. The gap G3 extends in the radial direction and communicates with the
housing chamber 30. The gap G2 extends in the axial direction and causes the gap G1
and the gap G3 to communicate with each other. Therefore, the housing chamber 30
15 communicates with the outside of the case 14 through the gaps G1, G2, and G3.
[0068] When an explosion occurs in the housing chamber 30, a spark may enter the gap
G3. However, the spark collides with the inner peripheral surface 21b at a place where
the gap G3 and the gap G2 are connected, which leads to a pressure loss. The spark
with the reduced pressure travels in the axial direction through the gap G2, which is
20 longer than the gap G3. Therefore, the rotating electric machine 1 can eliminate the
spark in the gap G2.
[0069] As described above, the rotating electric machine 1 of the embodiment includes
the case 14, the stator 11, the rotor 12, and the bearings 15. The case 14 includes the
tubular frame 21 and the brackets 22 fitted to the edges 21c of the frame 21. The stator
25 11 is housed in the case 14. The rotor 12 includes the rotor core 122 provided inside the
stator 11 and the shaft 121 that rotates integrally with the rotor core 122. The bearings
15 are supported by the brackets 22 and support the shaft 121 to allow the shaft 121 to
rotate around the central axis Ax of rotation. Each of the brackets 22 includes the outer
15
peripheral part 221 coupled to a corresponding one of the edges 21c of the frame 21, the
inner peripheral part 222 that supports a corresponding one of the bearings 15, and the
wall part 223 that extends between the outer peripheral part 221 and the inner peripheral
part 222. The wall part 223 includes the curved projecting part 223a that projects
5 toward the inside of the case 14.
[0070] According to the configuration above, the wall part 223 includes the curved
projecting part 223a projecting toward the inside of the case 14. Therefore, in
comparison with a configuration in which the projecting part 223a is not provided, the
above-described configuration is capable of reducing the volume inside the case 14 and
10 thereby reducing the amount of gas in the case 14. The volume of the inside of the case
14 is proportional to the explosion pressure generated in the case 14 when a gas
explosion occurs in the case 14. Therefore, even if a gas explosion occurs inside the
case 14, the explosion pressure in the case 14 can be reduced.
[0071] Since the above-described configuration can reduce the explosion pressure in the
15 case 14, the thicknesses (wall thicknesses) of the frame 21 and the brackets 22 of the
case 14 can be reduced. It is therefore possible to reduce the cost of materials of the
case 14, and also reduce the cost of the rotating electric machine 1.
[0072] Moreover, the above-described configuration includes the projecting part 223a.
Therefore, the surface area of the case 14 can be increased as compared to a
20 configuration in which the projecting part 223a is not provided. The heat dissipation of
the case 14 can be improved, and the cooling performance of the stator 11 and the rotor
12 can be improved.
[0073] The projecting part 223a has an annular shape around the shaft 121.
[0074] Such a configuration can further reduce the volume of the inside of the case 14,
25 and thereby further reduce the amount of gas in the case 14. Therefore, even if a gas
explosion occurs inside the case 14, the explosion pressure in the case 14 can be
reduced.
16
[0075] The rotating electric machine 1 includes the terminal box 16 and the terminal
member 24. The terminal member 24 electrically connects a connection target (for
example, the stator winding 112) in the case 14 and the terminal box 16. The case 14
includes the terminal seats 211 and the protruding parts 21e. Each of the terminal seats
211 includes the distal end surf 5 ace 211c to which the terminal box 16 is attached. In the
terminal seat 211, the terminal member 24 is housed. The terminal seat 211 have a
tubular shape projecting from the outer peripheral surface 21a of the frame 21 in the
radial direction of the shaft 121. The protruding part 21e projects from the inner edge
211b in the radial direction of the terminal seat 211. The protruding part 21e including
10 a support face 21f that supports the terminal member 24 at the inside in the radial
direction with respect to the terminal member 24. The thickness t1 of the protruding
part 21e in the projecting direction D1 of the terminal seat 211 is less than or equal to
the thickness t2 of the frame 21 outside the terminal seat 211. The position P1 in the
radial direction of the support surface 21f (first surface) outside in the radial direction in
15 the protruding part 21e is closer, in the radial direction to, the position P2 of the outer
peripheral surface 21a of the frame 21 outside the terminal seat 211 than the position P3
of the inner peripheral surface 21b of the frame 21 outside the terminal seat 211. The
position P1 may corresponds, in the radial direction to, the position P2.
[0076] The above-described configuration can secure the strength and rigidity of the
20 protruding part 21e and can reduce the height h1 (FIG. 2), which is the amount of
projection of the terminal seat 211 from the outer peripheral surface 21a of the frame
21, as compared to a configuration in which the support surface 21f of the protruding
part 21e is further outside in the radial direction than the position of the outer peripheral
surface 21a of the frame 21, namely, a configuration in which the protruding part 21e is
25 provided in the terminal seat 211. It is therefore possible to reduce the volume of the
inside of the terminal seat 211, and also reduce the amount of gas in the case 14. Thus,
even if a gas explosion occurs in the case 14, the explosion pressure in the case 14 can
be reduced.
17
[0077] Moreover, the projecting part 223a is aligned with the stator 11 in the axial
direction.
[0078] The above-described configuration can release heat from the stator 11 to the
outside of the case 14 via the projecting part 223a. Therefore, the cooling performance
5 of the stator 11 can be improved.
[0079] A modification of the embodiment will be described next. FIG. 3 is a crosssectional
view illustrating part of the bracket 22 in the rotating electric machine 1 of the
modification of the present embodiment.
[0080] As illustrated in FIG. 3, the wall part 223 of the bracket 22 in the rotating
10 electric machine 1 of the modification includes the projecting part 223a and a projecting
part 223e. The projecting part 223e is curved in a projecting shape toward the outside
of the case 14 (FIG. 1). The projecting part 223e is located outside in the radial
direction with respect to the projecting part 223a and is connected to the projecting part
223a. The projecting part 223e has an annular shape around the central axis Ax of
15 rotation, namely, around the shaft 121. The amount of projection in the axial direction
of the projecting part 223e is less than the amount of projection in the axial direction of
the projecting part 223a. In other words, the amount of projection in the axial direction
of the projecting part 223a is larger than the amount of projection in the axial direction
of the projecting part 223e. The projecting part 223a and the projecting part 223e form
20 a wavy shape. Thus, each of the projecting part 223a and the projecting part 223e is
part of the wavy shape. The wavy shape may include one cycle or may include two or
more cycles. Note that the projecting part 223e may be provided in the radial direction
with respect to the projecting part 223a and be connected to the projecting part 223a.
[0081] According to such a configuration, the projecting part 223a is provided, even if
25 the projecting part 223e is provided. It is therefore possible to reduce the volume of the
inside of the case 14 and also reduce the amount of gas in the case 14, as compared to a
configuration in which the projecting part 223a is not provided. Thus, even if a gas
explosion occurs in the case 14, the explosion pressure in the case 14 can be reduced.
18
[0082] In addition, the above-described configuration can increase the surface area of
the case 14, as compared to a configuration in which the projecting parts 223a and 223e
are not provided. Thus, the heat dissipation of the case 14 can be improved, and thereby
the cooling performance of the stator 11 and the rotor 12 can be improved.
[0083] 5 While the embodiment of the present invention has been described, the
embodiment has been presented by way of example only, and is not intended to limit the
scope of the invention. The above-described embodiment can be embodied in a variety
of other forms, and various omissions, substitutions, combinations, and changes may be
made without departing from the spirit of the invention. In addition, specifications
10 (structure, type, direction, form, size, length, width, thickness, height, number,
arrangement, position, material, and the like) of each configuration, shape, and the like
can be appropriately changed and implemented.
19
I/We Claim:
1. A rotating electric machine (1) comprising:
a case (14) with a tubular frame (21) and brackets (22), the brackets (22) being
fitted into edges (21c) of the frame (21);
a 5 stator (11) housed in the case (14);
a rotor (12) with a rotor core (122) and a shaft (121), the rotor core (122) being
provided inside the stator (11), the shaft (121) rotating integrally with the rotor core
(122); and
bearings (15) supported by the brackets (22), the bearings (15) supporting the
10 shaft (121) to allow the shaft (121) to rotate around a central axis of rotation (Ax),
wherein
each of the brackets (22) includes
an outer peripheral part (221) coupled to a corresponding one of the
edges (21c) of the frame (21),
15 an inner peripheral part (222) supporting a corresponding one of the
bearings (15), and
a wall part (223) extending between the outer peripheral part (221) and
the inner peripheral part (222), and
the wall part (223) includes a projecting part (223a) with a curved shape
20 projecting toward an inside of the case (14).
2. The rotating electric machine (1) as claimed in claim 1, wherein the projecting
part (223a) is provided annularly around the shaft (121).
25 3. The rotating electric machine (1) as claimed in claim 2, further comprising:
a terminal box (16); and
a terminal member (24) electrically connecting a connection target (112) in the
case (14) and the terminal box (16), wherein
20
the case (14) includes
a tubular terminal seat (211) in which the terminal member (24) is
housed, the terminal seat (211) having a distal end surface (211c) to which the terminal
box (16) is attached, the terminal seat (211) projecting from an outer peripheral surface
(21a) of the frame (21) in a radial direction 5 orthogonal to the central axis of rotation
(Ax), and
a protruding part (21e) protruding from an inner edge (211b) in the radial
direction of the terminal seat (211), the protruding part (21e) including a support face
(21f) supporting the terminal member (24) at an inside in the radial direction with
10 respect to the terminal member (24),
a thickness (t1) of the protruding part (21e) in a projecting direction of the
terminal seat (211) is less than or equal to a thickness (t2) of the frame (21) outside the
terminal seat (211), and
the support face (21f) of the protruding part (21e) is located at
15 a position (P1) that is closer, in the radial direction, to a position (P2) of
the outer peripheral surface (21a) of the frame (21) on the outside of the terminal seat
(211) than a position (P3) of an inner peripheral surface (21b) of the frame (21) on the
outside of the terminal seat (211), or
a position (P1) that corresponds, in the radial direction, to the position
20 (P2) of the outer peripheral surface (21a) of the frame (21).
4. The rotating electric machine (1) as claimed in claim 1, wherein the projecting
part (223a) is aligned with the stator (11) in an axial direction along the central axis of
rotation (Ax).
25
5. The rotating electric machine (1) as claimed in claim 1, wherein a crosssectional
shape of the projecting part (223a) in an axial direction along the central axis
21
of rotation (Ax) is a U-shape whose edges reach the outer peripheral (221) part and the
inner peripheral part (222) of the bracket (22).
22
ABSTRACT
ROTATING ELECTRIC MACHINE
A rotating electric machine (1) includes a case (14), a stator (11), a rotor (12),
and bearings (15). The case (14) 5 includes a tubular frame (21) and brackets (22). Each
of the brackets (22) includes an outer peripheral part (221), an inner peripheral part
(222), and a wall part (223). The outer peripheral part (221) is coupled to a
corresponding one of edges (21c) of the frame (21) of the case. The inner peripheral
part (222) supports a corresponding one of the bearings (15). The wall part (223)
10 extends between the outer peripheral part (221) and the inner peripheral part (222). The
wall part (223) includes a projecting part (223a) with a curved shape that projects
toward an inside of the case (14).
23 , Claims:I/We Claim:
1. A rotating electric machine (1) comprising:
a case (14) with a tubular frame (21) and brackets (22), the brackets (22) being
fitted into edges (21c) of the frame (21);
a 5 stator (11) housed in the case (14);
a rotor (12) with a rotor core (122) and a shaft (121), the rotor core (122) being
provided inside the stator (11), the shaft (121) rotating integrally with the rotor core
(122); and
bearings (15) supported by the brackets (22), the bearings (15) supporting the
10 shaft (121) to allow the shaft (121) to rotate around a central axis of rotation (Ax),
wherein
each of the brackets (22) includes
an outer peripheral part (221) coupled to a corresponding one of the
edges (21c) of the frame (21),
15 an inner peripheral part (222) supporting a corresponding one of the
bearings (15), and
a wall part (223) extending between the outer peripheral part (221) and
the inner peripheral part (222), and
the wall part (223) includes a projecting part (223a) with a curved shape
20 projecting toward an inside of the case (14).
2. The rotating electric machine (1) as claimed in claim 1, wherein the projecting
part (223a) is provided annularly around the shaft (121).
25 3. The rotating electric machine (1) as claimed in claim 2, further comprising:
a terminal box (16); and
a terminal member (24) electrically connecting a connection target (112) in the
case (14) and the terminal box (16), wherein
20
the case (14) includes
a tubular terminal seat (211) in which the terminal member (24) is
housed, the terminal seat (211) having a distal end surface (211c) to which the terminal
box (16) is attached, the terminal seat (211) projecting from an outer peripheral surface
(21a) of the frame (21) in a radial direction 5 orthogonal to the central axis of rotation
(Ax), and
a protruding part (21e) protruding from an inner edge (211b) in the radial
direction of the terminal seat (211), the protruding part (21e) including a support face
(21f) supporting the terminal member (24) at an inside in the radial direction with
10 respect to the terminal member (24),
a thickness (t1) of the protruding part (21e) in a projecting direction of the
terminal seat (211) is less than or equal to a thickness (t2) of the frame (21) outside the
terminal seat (211), and
the support face (21f) of the protruding part (21e) is located at
15 a position (P1) that is closer, in the radial direction, to a position (P2) of
the outer peripheral surface (21a) of the frame (21) on the outside of the terminal seat
(211) than a position (P3) of an inner peripheral surface (21b) of the frame (21) on the
outside of the terminal seat (211), or
a position (P1) that corresponds, in the radial direction, to the position
20 (P2) of the outer peripheral surface (21a) of the frame (21).
4. The rotating electric machine (1) as claimed in claim 1, wherein the projecting
part (223a) is aligned with the stator (11) in an axial direction along the central axis of
rotation (Ax).
25
5. The rotating electric machine (1) as claimed in claim 1, wherein a crosssectional
shape of the projecting part (223a) in an axial direction along the central axis
21
of rotation (Ax) is a U-shape whose edges reach the outer peripheral (221) part and the
inner peripheral part (222) of the bracket (22)