2. A lifting machine for an elevator as claimed in claim 1, wherein said resin buffering member has a plurality of insertion holes positioned in an outer peripheral side of said rotation detector so as to respectively insert a plurality of fixing screws - 19 -thereto, and is attached to the end portion of said fixed shaft by said plurality of fixing screws.

3. A lifting machine for an elevator as claimed in claim 2, wherein said resin buffering member has an inside cylinder portion storing said rotation detector, an outside cylinder portion arranged in an outer peripheral side of said inside cylinder portion, and a plurality of coupling portions coupling said inside cylinder portion and said outside cylinder portion to each other and respectively forming said plurality of insertion holes.

4. A lifting machine for an elevator as claimed in claim 2, wherein said rotation detector is connected to a rotating plate attached to a side surface of said sheave via said detecting shaft, and said rotating plate has a plurality of through holes respectively formed in correspondence to positions of said plurality of fixing screws.

5. A lifting machine for an elevator as claimed in claim 1, wherein said fixed shaft has a plurality of through holes for inserting a signal line of said rotation detector so as to get out to an outer portion.

Background of the Invention
(1) Field of the Invention
The present invention relates to a traction type elevator, and more particularly to a lifting machine for an elevator hoisting and lowering a rope connected to a cage and a counter weight.
(2) Description of Related Art
A traction type elevator is generally provided with a cage, a counter weight connected to the cage via a rope, a lifting machine hoisting and lowering the rope, and a control panel controlling so as to drive the lifting machine. The lifting machine has a rotation detector, for example, detecting a rotating amount of a sheave around which the rope is wound, and the control panel is structured such as to control a rotation of the sheave on the basis of a detected signal from the rotation detector.
In this case, in the elevator without any machine room, devices such as the lifting machine and the like are arranged within an elevator shaft, a downsizing of the devices, and a device layout within the elevator shaft are important. Further, since an inspecting work of the rope and the devices is carried out within the elevator shaft, a simplicity and easiness of a visual check work and a replacing work of

failed part is demanded.
Accordingly, for example, as a lifting machine of a thin type (in other words, in which an outside dimension of the lifting machine in an axial direction of a sheave is smaller than an outside dimension of the lifting machine in a diametrical direction of the sheave), there is proposed a structure provided with a housing having a concave portion which is open to one side, a support shaft protruded from a center of a bottom surface of the housing in an open side direction, a rotating body having a concave portion arranged in a fitted state in the concave portion of the housing and arranged in such a manner that an open side direction becomes the same as the housing, a boss formed in such a manner as to protrude from a center of a bottom surface of the concave portion in an open side direction and axially attached to the support shaft, and a sheave provided in a leading end of the boss, an electric motor including a stator coil provided in an inner peripheral surface of a side wall of the housing and an armature provided in an outer peripheral surface of a side wall of the concave portion of the rotating body, a brake engaging or disengaging a braking piece with or from an inner peripheral surface (a braking surface) of the wide wall of the concave portion of the rotating body, and a rotation detector (an encoder) stored in a concave portion of a leading end surface of the support shaft

and detecting an amount of rotation of the sheave via a detecting shaft connected to a rotating plate attached to a side surface of the sheave (for example, refer to patent document 1 (JP-A-2006-36438). In this lifting machine, the sheave, the brake, the rotation detector and the like are arranged in one side (in other words, in the open side of the housing and the rotating body), and it is possible to easily carry out a visual checking work (in detail, for example, a state check of a rope groove of the sheave, a check of an abrasion state of the braking piece, a check of a gap between the braking surface and the braking piece, and the like) and a replacing work of a failed part, by installing the lifting machine in such a manner that the sheave, the braking machine, the rotation detector and the like are directed to a center side of the elevator shaft (in other words, an opposite side to the elevator shaft wall).
In the lifting machine, the rotation detector is directly attached to the concave portion of the leading end surface of the support shaft, and does not sufficiently take into consideration an influence given to the rotation detector by a vibration of the rotating body at a time of driving. In other words, for example, a bending stress is generated in the detecting shaft of the rotation detector on the basis of the vibration of the rotating body, and there is a possibility that the detecting shaft is broken.

Further, for example, the vibration is propagated to the housing in accordance with the vibration of the rotating body, the detecting shaft displaces slightly in the rotating direction, and there is a possibility that a detecting precision of the rotation detector is lowered. Since a detected value of the rotation detector is used for improving a ride quality and a landing precision of the cage, it is necessary to suppress an error thereof as much as possible.
Brief Summary of the Invention
An object of the present invention is to provide a lifting machine for an elevator which can reduce an influence given to a rotation detector by a vibration of a rotating body.
In order to achieve the object mentioned above, in accordance with the present invention, there is provided a lifting machine for an elevator including a fixed frame, a fixed shaft supported in a cantilever manner to the fixed frame, a rotating body rotatably supported to the fixed shaft via a bearing, a sheave arranged in an opposite side to the fixed frame side in an axial direction of the rotating body, and integrally formed in the rotating body, an electric motor provided in an opposed portion to the fixed frame and the rotating body and rotating the rotating body, a brake engaging or disengaging a braking piece with or from a peripheral surface of the rotating body, and a rotation

detector detecting an amount of rotation of the sheave via a detecting shaft connected to the rotating body, wherein the lifting machine is provided with an approximately tubular resin buffering member attached to an end portion of the fixed shaft and storing the rotation detector so as to softly support.
In the lifting machine for the elevator in accordance with the present invention, it is preferable that the resin buffering member has a plurality of insertion holes positioned in an outer peripheral side of the rotation detector so as to respectively insert a plurality of fixing screws thereto, and is attached to the end portion of the fixed shaft by a plurality of fixing screws.
In the lifting machine for the elevator in accordance with the present invention, it is preferable that the resin buffering member has an inside cylinder portion storing the rotation detector, an outside cylinder portion arranged in an outer peripheral side of the inside cylinder portion, and a plurality of coupling portions coupling the inside cylinder portion and the outside cylinder portion to each other and respectively forming a plurality of insertion holes.
In the lifting machine for the elevator in accordance with the present invention, it is preferable that the rotation detector is connected to a rotating plate attached to a side surface of the sheave via the detecting shaft, and the rotating plate has a plurality

of through holes respectively formed in correspondence to positions of a plurality of fixing screws.
In the lifting machine for the elevator in accordance with the present invention, it is preferable that the fixed shaft has a plurality of through holes for inserting a signal line of the rotation detector so as to get out to an outer portion.
Effect of the Invention
In accordance with the present invention, it is possible to reduce an influence given to the rotation detector by the vibration of the rotating body.
Brief Description of the Several Views of the Drawing
Fig. 1 is a perspective view showing an outline structure of an elevator of a type without any machine room corresponding to an applied subject of the present invention;
Fig. 2 is a plan view showing the outline structure of the elevator of the type without any machine room corresponding to the applied subject of the present invention;
Fig. 3 is an axial cross sectional view showing a detailed structure of an embodiment of a lifting machine for an elevator in accordance with the present invention; and
Fig. 4 is a diametrical cross sectional view

-showing a detailed structure of a resin buffering member in the embodiment of the lifting machine for the elevator in accordance with the present invention.
Detailed Description of the Invention
A description will be given of an embodiment in accordance with the present invention with reference to the accompanying drawings.
Fig. 1 is a perspective view showing an outline structure of an elevator of a type without any machine room corresponding to an applied subject of the present invention, and Fig. 2 is a plan view of the elevator.
In these Figs. 1 and 2, the elevator is provided with a cage 2 arranged so as to be movable up and down along a pair of guide rails 1A and IB, a counter weight 5 arranged so as to be movable up and down along a pair of guide rails 3A and 3B (in which only 3A is illustrated in Fig. 2), and connected to the cage 2 via a rope 4, a thin type lifting machine 6 installed in a lower portion (a pit) of an elevator shaft, and hoisting and lowering the rope 4, and a control panel (not shown) installed in the lower portion of the elevator shaft and controlling so as to drive the lifting machine 6.
The rope 4 is fixed to rope stops 7A and 7B provided in an upper portion of the elevator shaft by both ends, and is wound around pulleys 8A and 8B

provided in a lower portion of the cage 2, a deflecting pulley 9A provided in the upper portion of the elevator shaft, a sheave 10 of the lifting machine 6, a deflecting pulley 9B provided in the upper portion of the elevator shaft, and a pulley 11 provided in an upper portion of the counter weight 5 in this order. In other words, there is employed a two-to-one roping way that the lifting machine 6 takes up the rope 4 having a length which is twice a moving amount of the cage 2.
In this case, the lifting machine 6 is arranged between a rear surface of the cage 2 (in other words, an opposite surface to a door 12) and an elevator shaft wall 13, and the sheave 10 of the lifting machine 6 is arranged in a center side of the elevator shaft (in other words, an opposite side to the elevator shaft wall 13).
Fig. 3 is an axial cross sectional view showing a detailed structure of the lifting machine 6 in accordance with the present embodiment.
In this Fig. 3, the lifting machine 6 is provided with a bowl shaped housing 14 (a fixed frame) arranged in the elevator shaft wall 13 side (a right side in Fig. 3), a fixed shaft 15 supported in a cantilever manner to the housing 14, and extending to a center side of the elevator shaft (a left side in Fig. 3), and a rotor 17 (a rotating body) provided in the fixed shaft 15 so as to be rotatable via a bearing 16.

The housing 14 has a disc-shaped bottom portion 18 arranged so as to be a vertical direction, a cylindrical outside wall portion 19 perpendicularly provided in an outer edge of the bottom portion 18, and a cylindrical inside wall portion 20 positioned in an inner peripheral side of the outside wall portion 19 and perpendicularly provided in the bottom portion 18. In this case, the walls 19 and 20 are formed in such a manner that they protrude to a center side of the elevator shaft from the bottom portion 18 and a center axis becomes concentric with the fixed shaft 15.
The rotor 17 has an annular bottom portion 21 arranged in parallel to the bottom portion 18 of the housing 14, a cylindrical wall portion 22 perpendicularly provided in an outer edge of the bottom portion 21, a boss 23 formed in a center of the bottom portion 21 and holding the bearing 16, and the sheave 10 formed in a center side of the elevator shaft of the boss 23. In this case, the wall portion 22 of the rotor 17 is formed in such a manner as to protrude to the elevator shaft wall 13 side from the bottom portion 21, and the center axis becomes concentric with the fixed shaft 15. Further, the boss 23 of the rotor 17 and the sheave 10 are formed in such a manner that the center axis becomes concentric with the fixed shaft 15. Further, a hollow portion is formed in the sheave 10 of the rotor 17, and the hollow portion of the sheave 10 is communicated with a hollow portion of the boss 23

in other words, a holding portion of the bearing 16).
A stator (a coil winding) 24 is provided in an outer peripheral surface of the inside wall portion 20 of the housing 14, a rotor (a permanent magnet) 25 is provided in an inner peripheral surface of the wall portion 22 of the rotor 17 (in other words, an outer rotor type that the rotor 25 is arranged in an outer side of the stator 24), and the rotor 25 and the stator 24 construct an electric motor 26 rotating the rotor 17. In this case, the electric motor may be structured as an inner rotor type that the rotor 25 is arranged in an inner side of the stator 24.
In a hollow portion of the sheave 10, there are arranged a rotation detector 27 (an encoder) detecting an amount of rotation of the sheave 10, and an approximately cylindrical resin buffering member 29 fixed to an end surface of the fixed shaft 15 by a plurality of screws 28 and storing the rotation detector 27 so as to softly support. In the fixed shaft 15, there is formed a through hole 15a for inserting a signal line 27a of the rotation detector 27 therethrough so as to take out to an outer portion (in detail, to the elevator shaft wall 13 side from the housing 14).
It is possible to easily carry out a visual checking work and replacing work of the rotation detector in the space that is open to one side.
A rotating plate 30, for example, having an

approximately circular shape is detachably provided in a side surface of the sheave 10, and a detecting shaft 27b of the rotation detector 27 is coupled to the rotating plate 30. The rotating plate 3 0 has an annular step portion 3 0a fitted to a side surface opening of the sheave 10 for improving a precision of its attached position. Accordingly, it is possible to secure a concentricity between the detecting shaft 27b of the rotation detector 27 and the center axis of the sheave 10. Further, in the rotating plate 30, there are formed a plurality of through holes 3 0b capable of inserting a leading end portion of a fixing tool such as a screw driver or the like in correspondence to positions of a plurality of fixing screws 28.
A description will be given of a detailed structure of the resin buffering member 29 corresponding to a substantial part of the present6 invention with reference to Fig. 4. Fig. 4 is a diametrical cross sectional view showing a detailed structure of the resin buffering member 29.
In Fig. 4 and Fig. 3 mentioned above, the resin buffering member 29 is constructed by an inside cylinder portion 31 storing the rotation detector 27, an outside cylinder portion 32 arranged in an outer peripheral side of the inside cylinder portion 31, and elements, for example, three coupling portions (spokes) 33 coupling the inside cylinder portion 31 and the outside cylinder portion 32 to each other. The inside

cylinder portion 31 is formed, for example, as a closed-end cylindrical shape in such a manner as to come into contact with a bottom surface and a side surface of the rotation detector 27. Further, in a bottom portion of the inside cylinder portion 31, there is formed a through hole (not shown) for inserting the signal line 27a of the rotation detector 27 so as to lead out to the through hole 15a of the fixed shaft 15. Further, in an inner peripheral surface of the inside cylinder portion 31, there is formed a convex portion 31a fitting to an axial groove 27c formed in a side surface of the rotation detector 27, as a rotation stop mechanism. The coupling portion 33 is formed in such a manner that an axial dimension thereof comes to an equal level to the inside cylinder portion 31 and the outside cylinder portion 32, and an insertion hole 33a inserting the fixing screw 28 thereto is formed. In other words, the through of the resin buffering member 29 is formed in such a manner as to be positioned in an outer peripheral side of the rotation detector 27. In this case, the resin buffering member 29 can be inexpensively manufactured in accordance with an integral mold forming, and it is desirably to form by a resin which is excellent in an oil resistance such as an NBR, an urethane or the like.
In the present embodiment structured as mentioned above, since the rotation detector 27 is softly supported by the resin buffering member 29, it

is possible to absorb the vibration of the rotor 17 at a time of driving. Further, the resin buffering member 29 generally has a high damping, for example, in comparison with a metal leaf spring elastically supporting the rotation detector 27, and it is possible to increase a vibration proofing performance in a diametrical direction and an axial direction. Further, for example, in the case of fixing the metal leaf spring to the end surface of the fixed shaft 15, it is necessary to adjust a fixed position of the leaf spring to an optimum state for deriving the vibration proofing performance of the leaf spring to the maximum. As an adjusting work of the fixed position of the leaf spring, for example, there can be considered a method of inserting a leading end portion of a fixing tool such as a screw driver or the like from a through hole of the rotating disc 30. However, in the structure in which the rotation detector 27 is arranged in the hollow portion of the sheave 10 such as the present embodiment, since a storing space of the rotation detector 27 is comparatively narrow, and a head position of the fixing screw fixing the leaf spring becomes near the end surface of the fixed shaft 15 and becomes remote from the rotating disc 30, it becomes hard to carry out the adjusting work of the fixed position of the leaf spring. On the contrary, in the resin buffering member 29 in the present embodiment, since the vibration proofing performance is not lowered
in accordance with the fixed position, it is possible to securely obtain a desired vibration proofing performance. Accordingly, it is possible to prevent the detecting shaft 27b from being broken due to a generation of a bending stress in the detecting shaft 27b of the rotation detector 27. Further, it is possible to suppress a reduction of the detecting precision of the rotation detector 27.
Further, the resin buffering member 29 has a plurality of through holes 33a positioned in an outer peripheral side of the rotation detector 27 and respectively inserting a plurality of fixing screws 28 thereto. Accordingly, it is possible to move the head position of the fixing screw 28 close to the rotating disc 3 0 side, and it is possible to improve a workability, for example, in the case of carrying out a checking work for checking a fastened state of the fixing screw 28. Further, for example, even in the case that the fastening of the fixing screw 28 is slacken for some reason or other, it is possible to easily carry out the fastening work of the fixing screw 28 because the fixing screw 28 is held by the resin buffering member 29.
Further, since the rotating plate 30 connected to the detecting shaft 27b of the rotation detector 27 has the annular step portion 30a fitted to the side surface opening of the sheave 10, it is possible to improve a precision of the attached

position thereof. Accordingly, it is possible to suppress an eccentricity between the detecting shaft 27b of the rotation detector 27 and the center axis of the sheave 10. From this standpoint, it is possible to prevent the detecting shaft 27b from being broken due to the generation of the bending stress in the detecting shaft 27b of the rotation detector 27, and it is possible to suppress the reduction of the detecting precision of the rotation detector 27.
In this case, for example, there is assumed the case of attaching the resin buffering member 29 storing the rotation detector 27 to the end surface of the fixed shaft 15, attaching the rotating disc 3 0 to the side surface of the sheave 10, and thereafter coupling the detecting shaft 27b of the rotation detector 27 and the rotating disc 30. In the case mentioned above, since the resin buffering member 29 is attached from the side surface opening of the sheave 10 to which the rotating disc 30 is not attached, it is possible to easily carry out the fixing work of the resin buffering member 29. However, the eccentricity is generated only slightly between the detecting shaft 27b of the rotation detector 27 and the center axis of the rotating disc 3 0 (in other words, the center axis of the sheave 10), and there is a possibility that it becomes hard to couple the detecting shaft 27b of the rotation detector 27 and the rotating disc 30 while securing the concentricity. Accordingly, in the

present embodiment, the resin buffering member 29 is formed as a double cylinder structure (in other words, a structure in which an air gap is formed between the inside cylinder portion 31 and the outside cylinder portion 32). Therefore, even if the main body of the rotation detector 27 somewhat displaces in a diametrical direction in the case of coupling the rotating disc 3 0 and the detecting shaft 27b of the rotation detector 27 while securing the concentricity, it is possible to absorb the displacement by the air gap portion of the resin buffering member 29. Accordingly, an unreasonable force is not applied to the detecting shaft 27b of the rotation detector 27. In this case, in the embodiment mentioned above, the resin buffering member 29 is explained by exemplifying the case that the resin buffering member 29 is formed as the double cylinder structure including the inside cylinder portion 31, the outside cylinder portion 32 and three coupling portions 33, however, is not limited to this. In other words, for example, if there is assumed the case of coupling the detecting shaft 27b of the rotation detector 27 stored in the resin buffering member 29 and the rotating disc 30, and thereafter attaching the resin buffering member 29 to the end surface of the fixed shaft 15, it is not necessary to form the air gap in the resin buffering member 29. Specifically, for example, it is possible to employ a structure in which the number of the

coupling portions 33 is increased, or a structure in which the resin is filled in the air gap between the inside cylinder portion 31 and the outside cylinder portion 32 (in other words, a structure constructed by one closed-end cylinder portion). In the case mentioned above, it is possible to increase a deformation strength and a vibration proofing performance of the resin buffering member 29.

CLAIMS:
1.A lifting machine for an elevator comprising:a fixed frame;a fixed shaft supported in a cantilever manner to said fixed frame;
a rotating body rotatably supported to said fixed shaft via a bearing;
a sheave arranged in an opposite side to said fixed frame side in an axial direction of said rotating body, and integrally formed in said rotating body;
an electric motor provided in an opposed portion to said fixed frame and said rotating body and rotating said rotating body;
a brake engaging or disengaging a braking piece with or from a peripheral surface of said rotating body; and
a rotation detector detecting an amount of rotation of said sheave via a detecting shaft connected to said rotating body,
wherein the lifting machine is provided with an approximately tubular resin buffering member attached to an end portion of said fixed shaft and storing said rotation detector so as to softly support.
2. A lifting machine for an elevator as claimed
in claim 1, wherein said resin buffering member has a
plurality of insertion holes positioned in an outer
peripheral side of said rotation detector so as to
respectively insert a plurality of fixing screws

- 19 -thereto, and is attached to the end portion of said fixed shaft by said plurality of fixing screws.
3. A lifting machine for an elevator as claimed in claim 2, wherein said resin buffering member has an inside cylinder portion storing said rotation detector, an outside cylinder portion arranged in an outer peripheral side of said inside cylinder portion, and a plurality of coupling portions coupling said inside cylinder portion and said outside cylinder portion to each other and respectively forming said plurality of insertion holes.
4. A lifting machine for an elevator as claimed in claim 2, wherein said rotation detector is connected to a rotating plate attached to a side surface of said sheave via said detecting shaft, and said rotating plate has a plurality of through holes respectively formed in correspondence to positions of said plurality of fixing screws.
5. A lifting machine for an elevator as claimed in claim 1, wherein said fixed shaft has a plurality of through holes for inserting a signal line of said rotation detector so as to get out to an outer portion.