JP7228967B2 - joint - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint that joins rotating shafts so that the angle can be changed.

The torque of the rotating shaft of the electric motor of the electric railway vehicle is transmitted to the axle via the joint and the gearing. The joint transmits the torque of the rotating shaft of the electric motor to the driven shaft of the gear train. The gear train has a plurality of gears to reduce the number of revolutions of the driven shaft and transmit torque to the axle. An example of this type of joint is disclosed in US Pat.

The joint disclosed in Patent Literature 1 has an intermediate shaft fitted to both the rotating shaft and the axle to transmit torque. Torque of the rotating shaft is transmitted to the axle via the intermediate shaft. In this joint, an elastically deformable cushioning member is provided on the axially outer side of the intermediate shaft. By providing the cushioning member, when the intermediate shaft vibrates, the intermediate shaft and the cushioning member come into contact with each other, restricting the movement of the intermediate shaft in the axial direction. Further, when the relative position of the axle with respect to the rotating shaft is displaced, the intermediate shaft transmits the torque of the rotating shaft to the axle in an inclined state. In other words, the joint absorbs changes in the relative position of the axle with respect to the rotating shaft and transmits the torque of the rotating shaft to the axle.

JP 2014-034337 A

In the joint disclosed in Patent Document 1, the cushioning member is an elastically deformable member made of polymer material such as resin, rubber, or urethane. On the other hand, the rotating shaft, the axle, and the intermediate shaft fitted to both the rotating shaft and the axle to transmit torque are generally made of metal members. Compared to metal members, the above-described cushioning member is more likely to deteriorate due to aging and wear. Therefore, the maintenance cycle of the cushioning member is shorter than that of the intermediate shaft. Therefore, it is necessary to disassemble the joint, replace the shock absorbing member, and assemble the joint again in accordance with the maintenance cycle of the shock absorbing member, and the maintainability is low. The above problem is caused not only by the cushioning member provided on the axially outer side of the intermediate shaft, but also by parts formed of members that are more likely to deteriorate than metal members and provided at arbitrary positions of the joint.

SUMMARY OF THE INVENTION An object of the present invention is to provide a joint with improved maintainability.

In order to achieve the above object, a joint according to the present invention is a joint for transmitting torque of a rotating shaft of an electric motor to a driven shaft facing the rotating shaft across a gap in the direction of the central axis of the rotating shaft. The joint includes a first inner cylinder, first outer teeth, a second inner cylinder, second outer teeth, an outer cylinder, first inner teeth, second inner teeth, and a plate-like center plate. The first inner cylinder is a metal member having a tubular shape, and is fitted to the rotating shaft to rotate integrally with the rotating shaft. The first external tooth is annularly provided on the outer peripheral surface of the first inner cylinder. The second inner cylinder is a metal member having a tubular shape, and is fitted to the driven shaft to rotate together with the driven shaft. The second external tooth is annularly provided on the outer peripheral surface of the second inner cylinder. The outer cylinder has a tubular shape covering at least part of the outer peripheral surface of the first inner cylinder and at least part of the outer peripheral surface of the second inner cylinder. The first internal teeth are annularly provided on the inner peripheral surface of the outer cylinder and mesh with the first external teeth. The second internal teeth are annularly provided on the inner peripheral surface of the outer cylinder and mesh with the second external teeth. The center plate is arranged on the inner peripheral surface of the outer cylinder and positioned in the gap between the rotating shaft and the driven shaft. The end of the first inner cylinder facing the center plate has a first curved surface portion that is a curved surface protruding toward the center plate. The end of the second inner cylinder facing the center plate has a second curved surface portion that is a curved surface protruding toward the center plate. The center axis of the driven shaft and the center axis of the rotating shaft are aligned, and the end of the first inner cylinder facing the center plate and the end of the second inner cylinder facing the center plate are separated from the center plate. When the center axis of the driven shaft and the center axis of the rotating shaft are shifted from the state in which the driven shaft is located, the end facing the center plate of the first inner cylinder contacts the center plate at the first curved surface portion, or The end of the second inner cylinder facing the center plate contacts the center plate at the second curved surface portion.

According to the present invention, a cylindrical first inner cylinder fitted to the rotating shaft of the electric motor and a cylindrical second inner cylinder fitted to the driven shaft are provided. The end of the first inner cylinder facing the center plate has a first curved surface protruding toward the center plate, and the end of the second inner cylinder facing the center plate has a second curved surface protruding toward the center plate. have a part. By providing the first curved surface portion and the second curved surface portion, the end portion of the first inner cylinder and the end portion of the second inner cylinder have no corners, and an elastic member for suppressing contact of the center plate with the corners. are not required to be provided at the ends of the first inner cylinder and the second inner cylinder facing the center plate, it is possible to provide a joint with improved maintainability.

FIG. 1 is a top view of a bogie of an electric railway vehicle according to Embodiment 1 of the present invention; 1 is a perspective view of a joint according to Embodiment 1 Sectional view of a joint according to Embodiment 1 Sectional view of a joint according to Embodiment 1 Sectional view of a joint according to Embodiment 2 of the present invention Cross-sectional view of a joint according to Embodiment 2

Hereinafter, joints according to embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals are given to the same or equivalent parts.

(Embodiment 1)
A bogie 1 shown in FIG. 1 is attached to the underfloor of an electric railway vehicle to support the vehicle body. The bogie 1 includes a bogie frame 2, wheels 3, axles 4 connecting the wheels 3, axle boxes 5 rotatably supporting the axles 4, an electric motor 6, and an example of a driven system driven by the electric motor 6. and a joint 8 that transmits the torque of the electric motor 6 to the gear device 7 . A gear device 7 is fitted to the axle 4 , and the torque of the electric motor 6 is transmitted to the axle 4 via the coupling 8 and the gear device 7 . In FIG. 1, the Z-axis is vertical, the X-axis is parallel to the central axis AX1 of the rotating shaft 61 of the electric motor 6, and the Y-axis is orthogonal to the X-axis and the Z-axis. The electric railway vehicle on which the bogie 1 is mounted runs in the positive or negative direction of the Y-axis.

Each part of the truck 1 having the above configuration will be described. The bogie frame 2 includes a pair of side beams 2a extending in the Y-axis direction and a horizontal beam 2b connecting the side beams 2a. An electric motor 6 is fixed to the lateral beam 2b. Also, the bogie frame 2 supports the vehicle body and on-vehicle equipment such as a power conversion device and an auxiliary power supply device. The wheels 3 rotate together with the axles 4 as the axles 4 connecting the wheels 3 are rotated by the gear device 7 . Axle 4 is rotated by gearing 7 and rotatably supported by axle box 5 . The axle box 5 is attached to the side sill 2a via an axle spring (not shown). The electric motor 6 is driven by being supplied with electric power from a power conversion device (not shown). When the electric motor 6 is driven, the rotating shaft 61 rotates. The gear device 7 reduces the rotational speed of the driven shaft 71 and transmits the torque of the driven shaft 71 to the axle 4 . In addition, the gear device 7 is attached to the horizontal beam 2b via the hanging device 9. As shown in FIG. The joint 8 is fitted to the rotating shaft 61 of the electric motor 6 and the driven shaft 71 of the gear device 7 to transmit the torque of the rotating shaft 61 to the driven shaft 71 .

When the electric railway vehicle is running, the electric motor 6 is supplied with power from a power conversion device (not shown) and rotates the rotating shaft 61 . The torque of the rotating shaft 61 is transmitted to the driven shaft 71 of the gear device 7 by the joint 8 . A speed reducer having a plurality of gears with different numbers of teeth is used as the gear device 7 . The gear device 7 has a small gear that fits on the driven shaft 71 and a large gear that meshes with the small gear and fits on the axle. The gear device 7 reduces the rotational speed of the driven shaft 71 and transmits the torque of the driven shaft 71 to the axle 4 . Then, the axle 4 and the wheels 3 connected by the axle 4 rotate.

As described above, the electric motor 6 is fixed to the lateral beam 2b, while the axle box 5 is attached to the side beam 2a via the shaft spring, and the gear device 7 is attached to the side beam 2a via the suspension device 9. It is attached. Therefore, transmission of vibration of the axle box 5 rotatably supporting the axle 4 and vibration of the gear device 7 fitted to the axle 4 to the bogie frame 2 during running of the electric railway vehicle is suppressed. In other words, the vibrations of the axle box 5 and the gear unit 7 are greater than the vibrations of the electric motor 6 when the electric railway vehicle is running. Therefore, the relative position of the driven shaft 71 with respect to the rotating shaft 61 changes when the electric railway vehicle is running.

Therefore, the joint 8 absorbs the change in the relative position of the driven shaft 71 with respect to the rotating shaft 61 and transmits the torque of the rotating shaft 61 to the rotating shaft 61 and the driven shaft 71 . Specifically, the joint 8 transmits the torque of the rotating shaft 61 to the driven shaft 71 facing the rotating shaft 61 across a gap in the direction of the central axis AX1 of the rotating shaft 61 . A configuration of the joint 8 will be described with reference to FIGS. 2 and 3. FIG. 3 is a cross-sectional view taken along the line AA in FIG. 1. FIG. Note that FIG. 2 shows the joint 8 when the central axis AX1 of the rotating shaft 61 and the central axis of the driven shaft 71 are aligned. Therefore, the central axis of the driven shaft 71 is not shown.

The joint 8 includes a first inner cylinder 11 having a cylindrical shape that fits on the rotating shaft 61 , a second inner cylinder 13 that has a cylindrical shape that fits on the driven shaft 71 , and the first inner cylinder 11 . and an outer cylinder 15 having a tubular shape covering at least part of the second inner cylinder 13 . The joint 8 further includes a plate-shaped central plate 18 provided on the inner peripheral surface of the outer cylinder 15 . The center plate 18 is positioned in the gap between the rotating shaft 61 and the driven shaft 71 . The first inner cylinder 11, the second inner cylinder 13, the outer cylinder 15, and the center plate 18 are formed of metal members such as carbon steel and stainless steel. Although the details will be described later, the end portion of the first inner cylinder 11 facing the center plate 18 and the end portion of the second inner cylinder 13 facing the center plate 18 have curved surfaces. The end of the second inner cylinder 13 has no corners, and the first inner cylinder 11 or the second inner cylinder 13 is prevented from coming into contact with the center plate 18 and being damaged due to vibration during running of the railway vehicle. In addition, it is not necessary to provide an elastic member for suppressing contact of the center plate 18 with the corners of the first inner cylinder 11 or the corners of the second inner cylinder 13, and the maintainability of the joint 8 is improved.

The first inner cylinder 11 and the second inner cylinder 13 have a cylindrical shape with both ends open. The end of the first inner cylinder 11 facing the center plate 18 has a first curved surface portion 11a. Therefore, the end of the first inner cylinder 11 facing the center plate 18 has no corners. The shape of the first curved surface portion 11 a is an arbitrary curved surface projecting toward the center plate 18 . As an example, the first curved surface portion 11 a has an arc shape in a cross section passing through the central axis of the first inner cylinder 11 . In Embodiment 1, the first curved surface portion 11 a is part of the surface of an annular ring centered on the central axis of the first inner cylinder 11 . The end of the second inner cylinder 13 facing the center plate 18 has a second curved surface portion 13a. Therefore, the end of the second inner cylinder 13 facing the center plate 18 has no corners. The shape of the second curved surface portion 13 a is an arbitrary curved surface projecting toward the center plate 18 . As an example, the second curved surface portion 13 a has an arc shape in a cross section passing through the central axis of the second inner cylinder 13 . In Embodiment 1, the second curved surface portion 13a is part of the surface of an annular ring centered on the central axis of the second inner cylinder 13 .

The joint 8 further comprises a first external tooth 12 annularly provided on the outer peripheral surface of the first inner cylinder 11 , a second external tooth 14 annularly provided on the outer peripheral surface of the second inner cylinder 13 , and an outer cylinder 15 . A first internal tooth 16 that is annularly provided on the inner peripheral surface of the outer cylinder 15 and meshes with the first external tooth 12 , and a second internal tooth 17 that is annularly provided on the inner peripheral surface of the outer cylinder 15 and meshes with the second external tooth 14 . Prepare. The top portion 16a of the first internal tooth 16 is flat, while the top portion 12a of the first external tooth 12 is a curved surface protruding toward the first internal tooth 16. As shown in FIG. In addition, while the top portion 17a of the second internal tooth 17 is flat, the top portion 14a of the second external tooth 14 has a curved surface protruding toward the second internal tooth 17 .

The operation of each part of the joint 8 when the joint 8 having the above configuration transmits the torque of the rotating shaft 61 to the driven shaft 71 will be described. The first inner cylinder 11 fitted to the rotating shaft 61 rotates together with the rotating shaft 61 . By meshing the first external teeth 12 and the first internal teeth 16, the torque of the rotating shaft 61 is transmitted to the outer cylinder 15 via the first inner cylinder 11, and the outer cylinder 15 rotates. By meshing the second external teeth 14 and the second internal teeth 17, the torque of the outer cylinder 15 is transmitted to the second inner cylinder 13, and the second inner cylinder 13 rotates. The second inner cylinder 13 is fitted to the driven shaft 71 , and the driven shaft 71 rotates integrally with the second inner cylinder 13 . That is, the torque of the outer cylinder 15 is transmitted to the driven shaft 71 through the second inner cylinder 13 .

As described above, the relative position of the driven shaft 71 of the gear device 7 with respect to the rotating shaft 61 of the electric motor 6 changes during running of the electric railway vehicle. In other words, the central axis AX1 of the rotating shaft 61 and the central axis of the driven shaft 71 may not match. As shown in FIG. 4, the central axis AX1 of the rotating shaft 61 and the central axis AX2 of the driven shaft 71 do not match, so that the outer cylinder 15 and the central plate 18 are tilted from the positions shown in FIG. Since the outer cylinder 15 and the center plate 18 are tilted, the first curved surface portion 11a of the first inner cylinder 11 comes into sliding contact with the center plate 18 . As described above, the end portion of the first inner cylinder 11 facing the center plate 18 has no corners, and the first curved surface portion 11a contacts the center plate 18 smoothly. contact, the damage to the first inner cylinder 11 and the center plate 18 is suppressed. Since the end of the first inner cylinder 11 facing the center plate 18 has no corners, a cushioning member for suppressing contact of the center plate 18 with the corners is provided facing the center plate 18 of the first inner cylinder 11 . It does not need to be provided at the end.

The curvature of the first curved surface portion 11a is determined so that the first curved surface portion 11a contacts the center plate 18 inside the edge 11b. The edge 11 b indicates the portion where the first curved surface portion 11 a contacts the outer peripheral surface 11 c of the first inner cylinder 11 . By setting the curvature of the first curved surface portion 11a as described above, it is possible to prevent the edge 11b of the first curved surface portion 11a from contacting the center plate 18 and damaging the first inner cylinder 11 and the center plate 18. be.

Although the outer cylinder 15 and the center plate 18 are tilted counterclockwise with respect to the Y-axis in FIG. 4, the outer cylinder 15 and the center plate 18 are tilted in any direction. As an example, the outer cylinder 15 and center plate 18 may be tilted clockwise with respect to the Y-axis. In this case, the second curved surface portion 13a of the second inner cylinder 13 contacts the center plate 18 in a sliding manner. As described above, the end portion of the second inner cylinder 13 facing the center plate 18 has no corners, and the second curved surface portion 13a contacts the center plate 18 smoothly. contact, the second inner cylinder 13 and the center plate 18 are prevented from being damaged. Since the end of the second inner cylinder 13 facing the center plate 18 has no corners, a cushioning member for suppressing contact of the center plate 18 with the corners is provided facing the center plate 18 of the second inner cylinder 13 . It does not need to be provided at the end.

The curvature of the second curved surface portion 13a is determined so that the second curved surface portion 13a contacts the center plate 18 inside the edge 13b. Edge 13b indicates a portion where second curved surface portion 13a contacts outer peripheral surface 13c of second inner cylinder 13 . By setting the curvature of the second curved surface portion 13a as described above, it is possible to prevent the edge 13b of the second curved surface portion 13a from contacting the center plate 18 and damaging the second inner cylinder 13 and the center plate 18. be.

Even if the central axis AX1 and the central axis AX2 do not match, the first external teeth 12 mesh with the first internal teeth 16 in an inclined state because the apexes 12a of the first external teeth 12 have curved surfaces. Similarly, even when the central axis AX1 and the central axis AX2 do not match, the curved surface of the top portion 14a of the second external tooth 14 causes the second external tooth 14 to mesh with the second internal tooth 17 in an inclined state. Therefore, the joint 8 can transmit the torque of the rotating shaft 61 to the driven shaft 71 .

As described above, in the joint 8 according to Embodiment 1, the end portion of the first inner cylinder 11 facing the center plate 18 has the first curved surface portion 11a, and the center plate 18 of the second inner cylinder 13 The facing end has a second curved surface portion 13a. Contact of the first curved surface portion 11a or the second curved surface portion 13a with the center plate 18 suppresses damage due to contact between the first inner cylinder 11 or the second inner cylinder 13 and the center plate 18 . In addition, since the end portion of the first inner cylinder 11 facing the center plate 18 and the end portion of the second inner cylinder 13 facing the center plate 18 have no corners, the center plate 18 is prevented from being damaged due to contact with the corners. There is no need to provide an elastic member in the Compared to the joint with the elastic member, the joint 8 without the elastic member does not require the work of disassembling the joint 8 and exchanging the elastic member according to the elastic member whose maintenance cycle is shorter than that of the metal member. High maintainability.

(Embodiment 2)
In Embodiment 1, the first inner cylinder 11 and the second inner cylinder 13 of the joint 8 have a tubular shape with both ends open. The shapes of the first inner cylinder 11 and the second inner cylinder 13 are not limited to tubular shapes with both ends open. As an example, in Embodiment 2, a joint 8 including a first inner cylinder and a second inner cylinder having a cylindrical shape with one end closed will be described with reference to FIG. 5 . 5 shows the joint 8 when the central axis AX1 of the rotating shaft 61 and the central axis of the driven shaft 71 are aligned. Therefore, the central axis of the driven shaft 71 is not shown in FIG. The joint 8 according to Embodiment 2 includes a first inner cylinder 21 having a cylindrical shape that fits on the rotating shaft 61 instead of the first inner cylinder 11 . In place of the second inner cylinder 13 , the joint 8 also includes a second inner cylinder 22 having a cylindrical shape that fits over the driven shaft 71 . The first inner cylinder 21, the second inner cylinder 22, the outer cylinder 15, and the center plate 18 are formed of metal members such as carbon steel and stainless steel.

The first inner cylinder 21 and the second inner cylinder 22 have a cylindrical shape with one end closed. One closed end of the first inner cylinder 21 faces the center plate 18 . One closed end of the second inner cylinder 22 faces the center plate 18 . One closed end of the first inner cylinder 21 has a first curved surface portion 21a. Therefore, the end of the first inner cylinder 21 facing the center plate 18 has no corners. The shape of the first curved surface portion 21 a is an arbitrary curved surface projecting toward the center plate 18 . As an example, the first curved surface portion 21 a has an arc shape in a cross section passing through the central axis of the first inner cylinder 21 . In Embodiment 2, the first curved surface portion 21 a is a portion of the curved surface whose center of curvature is positioned on the central axis of the first inner cylinder 21 . For example, the first curved surface portion 21 a is a portion of a spherical surface whose center is located on the central axis of the first inner cylinder 21 . One closed end of the second inner cylinder 22 has a second curved surface portion 22a. Therefore, the end of the second inner cylinder 22 facing the center plate 18 has no corners. The shape of the second curved surface portion 22 a is an arbitrary curved surface projecting toward the center plate 18 . As an example, the second curved surface portion 22 a has an arc shape in a cross section passing through the central axis of the second inner cylinder 22 . In Embodiment 2, the second curved surface portion 22a is a portion of a curved surface whose center of curvature is located on the central axis of the second inner cylinder 22. As shown in FIG. For example, the second curved surface portion 22 a is a portion of a spherical surface whose center is located on the central axis of the second inner cylinder 22 .

The joint 8 includes first external teeth 12, second external teeth 14, first internal teeth 16, and second internal teeth 17, as in the first embodiment. The operation of each part of the joint 8 when the joint 8 having the above configuration transmits the torque of the rotating shaft 61 to the driven shaft 71 will be described. The first inner cylinder 21 fitted to the rotating shaft 61 rotates together with the rotating shaft 61 . By meshing the first external teeth 12 and the first internal teeth 16, the torque of the rotating shaft 61 is transmitted to the outer cylinder 15 via the first inner cylinder 21, and the outer cylinder 15 rotates. By meshing the second external teeth 14 and the second internal teeth 17, the torque of the outer cylinder 15 is transmitted to the second inner cylinder 22, and the second inner cylinder 22 rotates. The second inner cylinder 22 is fitted to the driven shaft 71 , and the driven shaft 71 rotates integrally with the second inner cylinder 22 . That is, the torque of the outer cylinder 15 is transmitted to the driven shaft 71 through the second inner cylinder 22 . The torque of the rotary shaft 61 is transmitted to the driven shaft 71 via the joint 8 in the order described above.

As in the first embodiment, the central axis AX1 of rotating shaft 61 and the central axis of driven shaft 71 may not coincide. As shown in FIG. 6, the central axis AX1 of the rotating shaft 61 and the central axis AX2 of the driven shaft do not match, so that the outer cylinder 15 and the central plate 18 are tilted from the positions shown in FIG. The inclination of the outer cylinder 15 and the center plate 18 causes the first curved surface portion 21a of the first inner cylinder 21 to come into sliding contact with the center plate 18 . As described above, the end portion of the first inner cylinder 21 facing the center plate 18 has no corners, and the first curved surface portion 21a contacts the center plate 18 smoothly. contact, the first inner cylinder 21 and the center plate 18 are prevented from being damaged. Since the end portion of the first inner cylinder 21 facing the center plate 18 has no corners, a buffer member for suppressing contact of the center plate 18 with the corners is provided facing the center plate 18 of the first inner cylinder 21 . It does not need to be provided at the end.

The curvature of the first curved surface portion 21a is determined so that the first curved surface portion 21a contacts the center plate 18 inside the edge 21b. Edge 21b indicates a portion where first curved surface portion 21a contacts outer peripheral surface 21c of first inner cylinder 21 . By setting the curvature of the first curved surface portion 21a as described above, it is possible to prevent the edge 21b of the first curved surface portion 21a from contacting the center plate 18 and damaging the first inner cylinder 21 and the center plate 18. be.

Although the outer cylinder 15 and the center plate 18 are tilted counterclockwise with respect to the Y-axis in FIG. 6, the outer cylinder 15 and the center plate 18 are tilted in any direction. As an example, the outer cylinder 15 and center plate 18 may be tilted clockwise with respect to the Y-axis. In this case, the second curved surface portion 22a of the second inner cylinder 22 contacts the center plate 18 in a sliding manner. As described above, the end portion of the second inner cylinder 22 facing the center plate 18 has no corners, and the second curved surface portion 22a contacts the center plate 18 smoothly. contact, the second inner cylinder 22 and the center plate 18 are prevented from being damaged. Since the end of the second inner cylinder 22 facing the center plate 18 has no corners, a cushioning member for suppressing contact of the center plate 18 with the corners is provided facing the center plate 18 of the second inner cylinder 22 . It does not need to be provided at the end.

The curvature of the second curved surface portion 22a is determined so that the second curved surface portion 22a contacts the center plate 18 inside the edge 22b. Edge 22b indicates a portion where second curved surface portion 22a contacts outer peripheral surface 22c of second inner cylinder 22 . By setting the curvature of the second curved surface portion 22a as described above, the edge 22b of the second curved surface portion 22a is prevented from coming into contact with the center plate 18 and damaging the second inner cylinder 22 and the center plate 18. be.

As in Embodiment 1, even when the central axis AX1 and the central axis AX2 do not match, the top portion 12a of the first external tooth 12 has a curved surface, so that the first external tooth 12 is tilted and the first internal tooth 16 meshes. Similarly, even when the central axis AX1 and the central axis AX2 do not match, the curved surface of the top portion 14a of the second external tooth 14 causes the second external tooth 14 to mesh with the second internal tooth 17 in an inclined state. Therefore, the joint 8 can transmit the torque of the rotating shaft 61 to the driven shaft 71 .

As described above, in the joint 8 according to Embodiment 2, the closed end of the first inner cylinder 21 has the first curved surface portion 21a, and the closed end of the second inner cylinder 22 has the first curved surface portion 21a. It has two curved surfaces 22a. Contact of the first curved surface portion 21a or the second curved surface portion 22a with the center plate 18 suppresses damage due to contact between the first inner cylinder 21 or the second inner cylinder 22 and the center plate 18 . In addition, since the end portion of the first inner cylinder 21 facing the center plate 18 and the end portion of the second inner cylinder 22 facing the center plate 18 have no corners, the center plate 18 is prevented from being damaged due to contact with the corners. There is no need to provide an elastic member in the Compared to the joint with the elastic member, the joint 8 without the elastic member does not require the work of disassembling the joint 8 and exchanging the elastic member according to the elastic member whose maintenance cycle is shorter than that of the metal member. High maintainability.

The shape of each part of the joint 8 described above is an example. The shapes of the first curved surface portions 11a and 21a and the second curved surface portions 13a and 22a are not limited to the above examples, and may be arbitrary curved surfaces. As an example, the first curved surface portions 11a and 21a and the second curved surface portions 13a and 22a may be curved surfaces having recesses. Moreover, the shape of the end portion of the first inner cylinder 11 facing the center plate 18 is an arbitrary shape having at least the first curved surface portion 11a. As an example, the end portion of the first inner cylinder 11 facing the center plate 18 may have the first curved surface portion 11a and a flat surface continuous with the inner edge of the first curved surface portion 11a. The same applies to the first inner cylinder 21 and the second inner cylinders 13 and 22 . The joint 8 may include the first inner cylinder 11 fitted to the rotating shaft 61 and the second inner cylinder 22 fitted to the driven shaft 71 , or the first inner cylinder 21 fitted to the rotating shaft 61 . and a second inner cylinder 13 fitted to the driven shaft 71 . The outer cylinder 15 and the center plate 18 may be integrally formed.

The joint 8 is not limited to electric railcars, and can be installed in any device that needs to transmit torque to shafts whose relative positions change. Further, the gear device 7 is an arbitrary device that transmits the torque of the driven shaft 71 to an arbitrary shaft, and is a transmission as an example.

1 bogie 2 bogie frame 2a side beam 2b cross beam 3 wheel 4 axle 5 axle box 6 electric motor 7 gear device 8 joint 9 suspension device 11, 21 first inner cylinder 11a first curved surface Part 11b, 13b, 21b, 22b Edge 11c, 13c, 21c, 22c Peripheral surface 12 First external tooth 12a, 14a, 16a, 17a Top 13, 22 Second inner cylinder 13a Second curved surface portion 14 second external tooth, 15 outer cylinder, 16 first internal tooth, 17 second internal tooth, 18 center plate, 21a first curved surface portion, 22a second curved surface portion, 61 rotating shaft, 71 driven shaft, AX1, AX2 central axis.

Claims (9)

A joint for transmitting torque of a rotating shaft of an electric motor to a driven shaft facing the rotating shaft across a gap in the direction of the central axis of the rotating shaft,
a first inner cylinder, which is a metal member having a cylindrical shape and is fitted to the rotating shaft and rotates integrally with the rotating shaft;
a first external tooth annularly provided on the outer peripheral surface of the first inner cylinder;
a second inner cylinder, which is a metal member having a tubular shape and is fitted to the driven shaft and rotates integrally with the driven shaft;
a second external tooth provided annularly on the outer peripheral surface of the second inner cylinder;
an outer cylinder having a tubular shape covering at least part of the outer peripheral surface of the first inner cylinder and at least part of the outer peripheral surface of the second inner cylinder;
a first internal tooth that is annularly provided on the inner peripheral surface of the outer cylinder and meshes with the first external tooth;
a second internal tooth that is annularly provided on the inner peripheral surface of the outer cylinder and meshes with the second external tooth;
a plate-shaped center plate disposed on the inner peripheral surface of the outer cylinder and positioned in the gap sandwiched between the rotating shaft and the driven shaft;
with
an end portion of the first inner cylinder facing the center plate has a first curved surface portion that is a curved surface protruding toward the center plate;
an end portion of the second inner cylinder facing the center plate has a second curved surface portion that is a curved surface protruding toward the center plate;
The center axis of the driven shaft and the center axis of the rotating shaft are aligned, and the end portion of the first inner cylinder facing the center plate and the end portion of the second inner cylinder facing the center plate When the state separated from the center plate changes to the state where the center axis of the driven shaft and the center axis of the rotating shaft are deviated, the end portion of the first inner cylinder facing the center plate moves toward the center plate. one curved surface portion contacts the center plate, or the end of the second inner cylinder facing the center plate contacts the center plate at the second curved surface portion;
fittings. When the center plate is tilted from the position of the center plate when the center axis of the driven shaft and the center axis of the rotating shaft are aligned, the end portion of the first inner cylinder facing the center plate becomes the first contacting the center plate inside the edge of one curved surface portion, or the end of the second inner cylinder facing the center plate contacts the center plate inside the edge of the second curved surface portion;
A joint according to claim 1 . the apex of the first external tooth has a curved surface protruding toward the first internal tooth;
the apex of the second external tooth has a curved surface protruding toward the second internal tooth,
A joint according to claim 1 or 2. The first inner cylinder has a tubular shape with both ends open, and the shape of the end of the first inner cylinder facing the center plate is centered on the central axis of the first inner cylinder. is part of the surface of the torus that
A joint according to any one of claims 1 to 3. The first inner cylinder has a cylindrical shape with one end closed, and the shape of the closed end is a part of a curved surface having a center of curvature located on the central axis of the first inner cylinder. ,
A joint according to any one of claims 1 to 3. The shape of the closed end of the first inner cylinder is a portion of a spherical surface centered on the central axis of the first inner cylinder,
A joint according to claim 5. The second inner cylinder has a tubular shape with both ends open, and the shape of the end of the second inner cylinder facing the center plate is such that the center is positioned on the central axis of the second inner cylinder. is part of the surface of the torus that
A joint according to any one of claims 1 to 6. The second inner cylinder has a tubular shape with one end closed, and the shape of the closed one end is a part of a curved surface whose center of curvature is located on the central axis of the second inner cylinder. ,
A joint according to any one of claims 1 to 6. The shape of the closed one end of the second inner cylinder is a part of a spherical surface centered on the central axis of the second inner cylinder,
A joint according to claim 8 .

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