Motor with reducer

Abstract

An electric motor (10) with a speed reducer includes: an electric motor (12); a first gear (20) that rotates by transmitting rotational force from the aforementioned rotating shaft; an eccentric shaft (22) that engages with the first gear and has a support portion (22B) that is radially offset relative to the rotational shaft of the first gear; a transmission gear (24) that includes a limiting protrusion (24E) supported on the support portion and protruding toward the first gear and revolves around the rotational shaft of the first gear by causing the first gear to rotate together with the eccentric shaft; an output portion (30) that rotates by the revolution of the transmission gear; a rotation limiting member (52, 60) that limits the rotation of the transmission gear by abutting and sliding against the limiting protrusion; and an interference avoidance portion (60A, 66, 68) provided between the rotation limiting member and the transmission gear and preventing interference between the corner portion of the rotation limiting member located on the side of the limiting protrusion and the protruding base end side of the limiting protrusion.

Description

[0001] Citation of relevant applications

[0002] This application is based on Japanese Patent Application No. 2021-077980, filed on April 30, 2021, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to an electric motor with a speed reducer. Background Technology

[0004] Patent Document 1 discloses an electric motor with a speed reducer, including a speed reducer that reduces the rotation of the electric motor. The speed reducer described in this document includes: a worm fixed to the rotating shaft of the electric motor; a worm wheel meshing with the worm; a gear that revolves while its own rotation is restricted by rotating the worm wheel; and an output shaft that rotates by the rotational force transmitted from the revolving gear. Furthermore, a member is provided between the worm wheel and the revolving gear to restrict the rotation of the revolving gear.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Chinese Patent Application Publication No. 104638830 Summary of the Invention

[0008] Furthermore, in the reducer of the electric motor with a speed reducer described in Patent Document 1 above, the rotation of the rotating gear is limited by engaging a protrusion provided on the revolving gear with a member that limits the rotation of the revolving gear. In this structure, from the viewpoint of ensuring durability and suppressing the generation of abnormal noise, it is desirable to ensure that the contact state between the protrusion provided on the revolving gear and the member that limits the rotation of the revolving gear is stable.

[0009] The purpose of this disclosure is to provide an electric motor with a speed reducer that can stabilize the contact state between the protrusion of the revolving gear and the component that limits the rotation of the revolving gear.

[0010] The electric motor with a speed reducer according to a first aspect of this disclosure includes: an electric motor having a rotating shaft; a first gear rotating by a rotational force transmitted from the rotating shaft; an eccentric shaft coupled to the first gear and having a support portion radially offset relative to the rotating shaft of the first gear; a transmission gear including a limiting protrusion supported on the support portion and protruding toward the first gear, revolving around the rotating shaft of the first gear by rotating the first gear together with the eccentric shaft; an output portion rotating by the revolution of the transmission gear; a rotation limiting member limiting the rotation of the transmission gear by abutting and sliding against the limiting protrusion; and an interference avoidance portion disposed between the rotation limiting member and the transmission gear, and preventing interference between the corner portion of the rotation limiting member located on the side of the limiting protrusion and the protruding base end side of the limiting protrusion.

[0011] This configuration ensures stable contact between the protrusion on the revolving gear and the component that restricts the rotation of the revolving gear. Attached Figure Description

[0012] The above-mentioned objects, other objects, features, and advantages of this disclosure will become clearer with reference to the accompanying drawings and the following detailed description. The drawings are described below.

[0013] Figure 1 It is an exploded 3D view of an electric motor with a speed reducer.

[0014] Figure 2 This is an exploded perspective view of an electric motor with a speed reducer, showing the... Figure 1 The diagram is viewed from the opposite side.

[0015] Figure 3 It is an exploded perspective view showing the eccentric shaft, fixed gear, transmission gear and output gear body that make up part of the reducer.

[0016] Figure 4 It is a cross-sectional view showing the cross-section obtained by cutting the eccentric shaft, fixed gear, transmission gear and output gear body that constitute part of the reducer along the rotation axis of the output gear body.

[0017] Figure 5 It is a schematic front view showing the fixed gear, sliding plate, and transmission gear.

[0018] Figure 6 This is a three-dimensional view of the sliding plate representing the comparative example.

[0019] Figure 7It is an enlarged cross-sectional view showing the contact area between the limiting protrusion and the sliding plate.

[0020] Figure 8 This is an enlarged cross-sectional view showing the contact area between the limiting protrusion and the sliding plate, illustrating the state of the limiting protrusion after deformation.

[0021] Figure 9 This is an enlarged cross-sectional view showing the contact area between the limiting protrusion and the sliding plate, illustrating the ratio of the limiting protrusion to... Figure 8 The state shown is the transformed state.

[0022] Figure 10 This is a three-dimensional diagram showing a sliding plate with an interference-avoiding protrusion.

[0023] Figure 11 This is an enlarged cross-sectional view showing the contact area between the limiting protrusion and the sliding plate with interference avoidance protrusion.

[0024] Figure 12 It is an exploded perspective view showing the gears, washers, and sliding plates used for transmission.

[0025] Figure 13 It is a cross-sectional view showing the cross-section obtained by cutting the transmission gear, washer and sliding plate axially.

[0026] Figure 14 It is a cross-sectional view showing the cross-section obtained by cutting the transmission gear, spherical member and sliding plate axially. Detailed Implementation

[0027] use Figures 1-4 The electric motor 10 with a speed reducer according to the present disclosure will be described.

[0028] Furthermore, the arrows Z, R, and C, appropriately indicated in the diagram, represent the axial, radial, and circumferential sides of the output gear (pinion 30C), respectively. Conversely, the opposite sides of arrows Z, R, and C represent the axial, radial, and circumferential sides of the output gear (pinion 30C), respectively. Additionally, when only axial, radial, and circumferential directions are indicated, unless otherwise specified, they represent the axial, radial, and circumferential directions of the pinion 30C.

[0029] like Figure 1 , Figure 2 as well as Figure 3As shown, the motor 10 with a speed reducer in this embodiment is an electric seat motor for moving the seat cushion of a vehicle seat in the vertical direction. The motor 10 with a speed reducer includes a DC motor, i.e., a motor 12. Furthermore, the motor 10 with a speed reducer includes a speed reducer 14, which reduces the rotation of the rotating shaft 12A of the motor 12 and transmits it to an output gear body 30, which serves as an output unit. In addition, the motor 10 with a speed reducer includes a housing 16 in which the motor 12 is mounted and the speed reducer 14 is disposed internally.

[0030] The reducer 14 includes: a worm gear 18 fixed to the rotating shaft 12A of the motor 12; a helical gear 20 meshing with the worm gear 18 as a first gear; and an eccentric shaft 22 integrally disposed with the helical gear 20.

[0031] Furthermore, the reducer 14 includes: a transmission gear 24 and a locking gear 26 supported on the eccentric shaft 22; and a fixed gear 28 meshing with the locking gear 26. Additionally, the reducer 14 includes a sliding plate 52 that serves as a rotation limiting member supported on the fixed gear 28. The rotation of the transmission gear 24 is limited by engaging with the sliding plate 52. Furthermore, the reducer 14 includes an output gear body 30 that meshes with the transmission gear 24 and has a pinion 30C. The axial direction of this output gear body 30 is in the same direction as the axial directions of the helical gear 20, the transmission gear 24, and the locking gear 26 (the direction of arrow Z and the direction opposite to arrow Z), and it is coaxially arranged with the helical gear 20.

[0032] Additionally, the motor 10 with a speed reducer includes a spring 32 for suppressing loosening in the axial direction, such as the eccentric shaft 22 and the helical gear 20. Furthermore, the motor 10 with a speed reducer includes a cover plate 34, which is fixed to the housing 16 to house the speed reducer 14 within the housing 16.

[0033] like Figure 1 and Figure 2 As shown, the housing 16 is formed using resin material. The housing 16 includes a motor mounting portion 16A, which fixes the rotation shaft 12A of the motor 12 in a direction orthogonal to the axial direction (arrow Z direction). Additionally, the housing 16 includes a reducer receiving recess 16C that houses the reducer 14. The reducer receiving recess 16C is formed as a recess that is open on one axial side (arrow Z direction side).

[0034] like Figure 1As shown, the reducer receiving recess 16C is configured to include: a bottom wall portion forming the bottom of the reducer receiving recess 16C; and a side wall portion 16E extending axially from the outer periphery of the bottom wall portion and having an inner periphery that is substantially cylindrical. A cylindrical bushing portion is erected at the center of the bottom wall portion of the reducer receiving recess 16C, and the bushing portion is inserted into the end of the rotation center shaft 40 on the other axial side with a gap. In addition, a spring 32 is arranged around the bushing portion of the bottom wall portion. Furthermore, a washer 36 is sandwiched between the bottom wall portion and the spring 32.

[0035] Three fixed gear engaging portions 16G are formed on the inner periphery of the side wall portion 16E of the reducer receiving recess 16C. These fixed gear engaging portions 16G are fitted with a portion of the fixed gear 28 (described later) to restrict the circumferential rotational displacement of the fixed gear 28. A cylindrical column portion 16I is provided in each of the three fixed gear engaging portions 16G.

[0036] The cover plate 34 is formed using steel plate or similar materials. An exposure opening 34A is formed in the cover plate 34 to expose the pinion 30C to the outside of the reducer receiving recess 16C in the housing 16. Furthermore, an annular rib 34B, bent towards the axial direction, is formed around the periphery of the exposure opening 34A in the cover plate 34.

[0037] A helical tooth is formed on the outer periphery of the worm gear 18. By fixing the motor 12, which is in the state of fixing the worm gear 18 to the rotating shaft 12A, to the housing 16, the worm gear 18 is disposed on the bottom wall side of the reducer receiving recess 16C of the housing 16 and on the inner peripheral surface side of the side wall 16E.

[0038] like Figure 1 and Figure 2 As shown, the helical gear 20 is formed using resin material. Multiple external teeth are formed on the outer periphery of the helical gear 20 to mesh with the teeth of the worm gear 18. Furthermore, the eccentric shaft 22, described later, is fixed to the central axis of the helical gear 20 by insert molding. In addition, the helical gear 20 is rotatably supported on the housing 16 via the eccentric shaft 22 and the rotation center shaft 40.

[0039] like Figure 2 and Figure 3 As shown, the eccentric shaft 22 is formed using a metallic material, and it can rotate integrally with the helical gear 20 by embedding a portion of it into the helical gear 20. Specifically, the eccentric shaft 22 includes a circular plate portion 22A formed as a circular plate extending radially with the axial direction as its thickness direction. The outer periphery of the circular plate portion 22A is formed with an uneven shape along its circumferential direction. Furthermore, with the axial center of the circular plate portion 22A aligned with the rotation center of the helical gear 20, the circular plate portion 22A is fixed to the inner periphery of the helical gear 20.

[0040] In addition, such as Figure 1 and Figure 3 As shown, the eccentric shaft 22 includes a support portion 22B protruding axially from the center of the circular plate portion 22A. One axial side of the support portion 22B is a first support portion 22B1 that rotatably supports the transmission gear 24 (described later). The other axial side of the support portion 22B is a second support portion 22B2, which is configured to have a larger diameter than the first support portion 22B1 and rotatably supports the locking gear 26 (described later). The axial center of the first support portion 22B1 is offset radially outward relative to the axial center of the circular plate portion 22A, and the axial center of the second support portion 22B2 is also offset radially outward relative to the axial center of the circular plate portion 22A.

[0041] In addition, such as Figure 2 , Figure 3 and Figure 4 As shown, a rotating center shaft insertion hole 22C is formed in the eccentric shaft 22, which axially penetrates the circular plate portion 22A, the first support portion 22B1, and the second support portion 22B2. A rotating center shaft 40 is inserted into this rotating center shaft insertion hole 22C. Furthermore, the axial center of the rotating center shaft insertion hole 22C (the axial center of the rotating center shaft 40 inserted into the rotating center shaft insertion hole 22C) coincides with the axial center of the circular plate portion 22A.

[0042] like Figure 2 and Figure 4 As shown, the output gear body 30 is formed using a metallic material. The output gear body 30 includes a transmission gear engagement portion 30B that engages with the transmission gear 24. Figure 2 As shown, a receiving recess 30E is formed in the gear engagement portion 30B for transmission. The receiving recess 30E is open on the gear 24 side (the other side in the axial direction) and allows the gear body portion 24D of the gear 24 to be disposed inside. A plurality of internal teeth 30F that mesh with the external teeth 24A of the gear 24 are formed on the inner circumference of the radially outer side of the receiving recess 30E.

[0043] Furthermore, the output gear body 30 includes a pinion 30C, which is coaxially arranged with the transmission gear engagement portion 30B on one axial side relative to the transmission gear engagement portion 30B, and has a plurality of external teeth formed on its outer periphery. Additionally, the intermediate portion between the transmission gear engagement portion 30B and the pinion 30C in the output gear body 30 is a shaft support portion 30D supported by a rib 34B formed on the cover plate 34. Furthermore, a bearing bushing 42 made of resin or the like is engaged on the inner circumferential surface of the rib 34B. This prevents or suppresses metal-to-metal contact between the shaft support portion 30D of the output gear body 30 and the rib 34B of the cover plate 34. Finally, a rotating central shaft 40 formed in the shape of a metal rod is fixed to the central portion of the output gear body 30 by pressing or the like.

[0044] like Figure 1 and Figure 2 As shown, the fixed gear 28 is formed by stamping or other processes on a metal material. The fixed gear 28 includes a fixed gear body portion 28A that is ring-shaped when viewed axially. Furthermore, the fixed gear 28 includes three engaging protrusions 28B that protrude radially outward from the fixed gear body portion 28A. Moreover, when the engaging protrusions 28B are engaged with the fixed gear engaging portion 16G of the housing 16, a thrust nut (not shown) engages with the column portion 16I. Thus, the fixed gear 28 is fixed to the housing 16.

[0045] In addition, a plurality of internal teeth 28D are formed on the inner periphery of the fixed gear body 28A, which mesh with the locking gear 26 described later.

[0046] Furthermore, the fixed gear 28 includes a second limiting portion 28E, which protrudes from the fixed gear body portion 28A toward the other side in the axial direction. The second limiting portion 28E protrudes from a circumferential portion of the fixed gear body portion 28A toward the other side in the axial direction.

[0047] Furthermore, a sliding plate engaging hole 28F is formed on the axial side of the portion of the fixed gear body 28A of the fixed gear 28 where the internal teeth 28D are formed. The edge of the sliding plate engaging hole 28F is rectangular when viewed axially. A sliding plate 52 is disposed inside the sliding plate engaging hole 28F. Additionally, a second sliding surface 28G is formed on the edge of the sliding plate engaging hole 28F, which is radially opposed to a pair of first sliding surfaces 52C of the sliding plate 52 (described later). Furthermore, by arranging the first sliding surfaces 52C and the second sliding surfaces 28G opposite and close to each other, the rotation of the sliding plate 52 relative to the fixed gear 28 is restricted. Furthermore, by allowing the first sliding surfaces 52C to slide on the second sliding surfaces 28G, the sliding plate 52 and the transmission gear 24 are allowed to shift radially in one direction R1. Therefore, when the eccentric shaft 22 rotates, the transmission gear 24, which is supported by the first support portion 22B1 of the eccentric shaft 22, revolves around the axis center of the rotation center shaft 40 while the rotation of the transmission gear 24 is restricted.

[0048] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the transmission gear 24 is formed into a generally circular plate shape by stamping or other processes on a metal material. The transmission gear 24 includes a transmission gear body portion 24D with a plurality of external teeth 24A formed on its outer periphery. A support hole 24B is formed at the center of the transmission gear body portion 24D, supporting a first support portion 22B1 on the eccentric shaft 22. Furthermore, the transmission gear 24 includes two limiting protrusions 24E protruding from a surface on the other side of the axial direction of the transmission gear body portion 24D. These two limiting protrusions 24E are arranged at equal intervals (180-degree intervals) along the circumferential direction. Moreover, the rotation (self-rotation) of the transmission gear 24 about the first support portion 22B1 of the eccentric shaft 22 is limited by engaging the two limiting protrusions 24E with the sliding plate 52 described later.

[0049] like Figure 1 and Figure 3As shown, the sliding plate 52 is formed using a sheet metal, and is rectangular when viewed axially. The sliding plate 52 is disposed within the sliding plate engagement hole 28F formed in the fixed gear 28, between the two limiting protrusions 24E of the transmission gear 24. Furthermore, on the outer periphery of the sliding plate 52, the surfaces radially opposite to the two limiting protrusions 24E are respectively called engagement surfaces 52B. Moreover, with the sliding plate 52 disposed between the two limiting protrusions 24E of the transmission gear 24, the displacement of the transmission gear 24 relative to the sliding plate 52 in the direction opposite to the engagement surfaces 52B and the limiting protrusions 24E (radial direction R1) is restricted, and the rotation (self-rotation) of the transmission gear 24 relative to the sliding plate 52 is also restricted. Furthermore, by allowing the limiting protrusion 24E to slide on the engaging surface 52B, the transmission gear 24 in the direction in which the engaging surface 52B and the limiting protrusion 24E slide (the other radial direction R2, which is orthogonal to one radial direction R1) is allowed to shift relative to the sliding plate 52. Additionally, in the outer periphery of the sliding plate 52, a pair of first sliding surfaces 52C are respectively arranged opposite and close to the second sliding surface 28G of the sliding plate engaging hole 28F. Furthermore, an elongated through hole 52A (with the other radial direction R2 being an elongated hole along its longer side) is formed in the axial center of the sliding plate 52 for the first support portion 22B1 of the eccentric shaft 22 to pass through. In this embodiment, the interval between the pair of engaging surfaces 52B of the sliding plate 52 is set to a size smaller than the interval between the pair of first sliding surfaces 52C. Thus, when viewed axially, the sliding plate 52 is a rectangle with the pair of engaging surfaces 52B as longer sides and the pair of first sliding surfaces 52C as shorter sides.

[0050] like Figure 1 and Figure 2 As shown, similar to the transmission gear 24, the locking gear 26 is formed into a circular plate shape by stamping or other processes on a metal material. On the outer periphery of the locking gear 26, external teeth 26A that mesh with the internal teeth 28D of the fixed gear 28 are formed along the entire outer periphery. Furthermore, a support hole 26B for supporting a second support portion 22B2 on the eccentric shaft 22 is formed at the center of the locking gear 26. In addition, the locking gear 26 includes a first limiting portion 26C that protrudes radially outward and is fan-shaped when viewed axially. The first limiting portion 26C is provided on a portion of the circumference of the locking gear 26. Furthermore, when the external teeth 26A of the locking gear 26 are meshing with the internal teeth 28D of the fixed gear 28, the first limiting portion 26C is disposed on the surface on the other side of the axial direction of the fixed gear body portion 28A of the fixed gear 28.

[0051] (The function and effects of this implementation method)

[0052] Next, the function and effects of this embodiment will be explained.

[0053] like Figure 1 and Figure 2 As shown, in the motor 10 with a speed reducer according to this embodiment, when the rotating shaft 12A of the motor 12 rotates, the worm gear 18 rotates. In addition, when the worm gear 18 rotates, the helical gear 20 meshing with the worm gear 18 rotates together with the eccentric shaft 22.

[0054] Furthermore, when the eccentric shaft 22 rotates, the transmission gear 24, supported on the first support portion 22B1 of the eccentric shaft 22, revolves around the rotation center axis 40. More specifically, as... Figure 5 As shown, when the eccentric shaft 22 rotates, the limiting protrusion 24E of the transmission gear 24 slides on the engaging surface 52B of the sliding plate 52, and simultaneously moves radially (arrow R2 and the direction opposite to R2). Furthermore, the first sliding surface 52C of the sliding plate 52 slides on the second sliding surface 28G of the fixed gear 28, while both the sliding plate 52 and the transmission gear 24 move radially (arrow R1 and the direction opposite to R1). Thus, with the rotation of the transmission gear 24 supported on the first support portion 22B1 of the eccentric shaft 22 restricted, the transmission gear 24 revolves around the axis of rotation 40.

[0055] like Figure 1 and Figure 2 As shown, when the transmission gear 24 revolves, the rotational force accompanying this revolution is transmitted from the external teeth 24A of the transmission gear 24 to the internal teeth 30F of the output gear body 30. As a result, the output gear body 30 can be rotated, and the electric seat of the vehicle can be operated via the gear meshing with the pinion 30C of the output gear body 30.

[0056] Furthermore, when the eccentric shaft 22 rotates, the locking gear 26, supported on the second support portion 22B2 of the eccentric shaft 22, revolves and rotates around the rotation center axis 40 while meshing with the fixed gear 28. Moreover, when the first limiting portion 26C of the locking gear 26 abuts against the second limiting portion 28E of the fixed gear 28, the revolution and rotation of the locking gear 26 are restricted. This stops the rotation of the eccentric shaft 22 and the helical gear 20, and also stops (restricts) the rotation of the output gear body 30. As a result, it is possible to prevent or suppress excessive force input from the motor 10 with the reducer to the vehicle seat.

[0057] Furthermore, the reducer 14, which constitutes part of the electric motor 10 with a reducer described above, is a reducer that uses a so-called planetary gear mechanism. Therefore, it is sufficient to appropriately select the gear that limits rotation, taking into account the reduction ratio required by the reducer 14. That is, it is sufficient to appropriately select whether to adopt a planetary, sun-type, or star-shaped structure, such as a 2K-H type planetary gear mechanism or a 3K type planetary gear mechanism, taking into account the reduction ratio required by the reducer 14.

[0058] (A structure that stabilizes the contact state between the sliding plate 60 and the limiting protrusion 24E of the transmission gear 24)

[0059] Next, the structure for stabilizing the contact state between the sliding plate 60 and the limiting protrusion 24E of the transmission gear 24 will be described in detail. First, the structure of the sliding plate 62 of the comparative example and the deformation of the limiting protrusion 24E caused by the motor with a speed reducer that includes the sliding plate 62 will be described. Next, the structure of the sliding plate 60 of this disclosure, which sometimes suppresses the deformation of the limiting protrusion 24E caused by the motor with a speed reducer that includes the sliding plate 62 of the comparative example, will be described.

[0060] like Figure 6 As shown, the basic structure of the sliding plate 62 in the comparative example is substantially the same as that of the sliding plate 52 described above. Therefore, in the sliding plate 62 of the comparative example, the parts corresponding to the parts corresponding to the parts of the sliding plate 52 described above are marked with the same symbols as the parts corresponding to the sliding plate 52 described above, and their descriptions are omitted.

[0061] like Figure 6 and Figure 7 As shown, a C-shaped chamfer is applied to the corner portion 64 on the gear body 24D side (axial side) of the transmission gear 24 in the sliding plate 62 of the comparative example. The portion in the sliding plate 62 with the C-shaped chamfer is referred to as the chamfered portion 62A. The size of the chamfered portion 62A is set such that, when the limiting protrusion 24E is in contact with the engaging surface 52B of the sliding plate 62, the corner portion 64 does not interfere with the R portion 24F on the protruding base side (axial side) of the limiting protrusion 24E.

[0062] In the sliding plate 62 of this comparative example, when the contact pressure between the limiting protrusion 24E and the engaging surface 52B of the sliding plate 62 increases, such as Figure 8 As shown, the sliding plate 62 is inclined into the limiting protrusion 24E along the chamfered portion 62A, and it is assumed that the limiting protrusion 24E side will deform. Furthermore, the deformed portion in the limiting protrusion 24E is referred to as the deformed portion 24G. In this state, if the motor with a speed reducer constructed including the sliding plate 62 of the comparative example continues to be used, then as... Figure 9As shown, the sliding plate 62 will further sink along the inclination of the chamfered portion 62A, thereby causing further deformation of the limiting protrusion 24E side (deformation development of the deformed portion 24G). In this way, the contact state between the sliding plate 62 and the limiting protrusion 24E of the transmission gear 24 changes, and the contact state between the two becomes unstable.

[0063] Therefore, in order to suppress this phenomenon, such as Figure 10 and Figure 11 As shown, the sliding plate 60 employing the structure of this disclosure includes four interference-avoidance protrusions 60A that protrude towards the transmission gear body 24D side (axial side) of the transmission gear 24, serving as interference-avoidance portions. When the sliding plate 60 is forged, these four interference-avoidance protrusions 60A are integrally formed with the sliding plate 60. Furthermore, when viewed from the axial side, the four interference-avoidance protrusions 60A are formed at the four corners of the sliding plate 60. Additionally, four recesses 60B are formed on the other axial side of the sliding plate 60 at locations corresponding to the four interference-avoidance protrusions 60A. The portions of the sliding plate 60 corresponding to the aforementioned sliding plate 52 are marked with the same symbols as the portions corresponding to the aforementioned sliding plate 52, and their descriptions are omitted.

[0064] Furthermore, the front end face 60C of the interference-avoiding protrusion 60A in the protruding direction is formed into a planar shape that abuts against the face on the other side of the axial direction of the transmission gear body 24D. Additionally, the dimension H of the interference-avoiding protrusion 60A in the protruding direction (axial direction) is set to the following size: when the front end face 60C of the four interference-avoiding protrusions 60A in the protruding direction abuts against the face on the other side of the axial direction of the transmission gear body 24D of the transmission gear 24, and when the limiting protrusion 24E is in contact with the engaging surface 52B of the sliding plate 60, the corner portion 64 of the transmission gear body 24D side of the transmission gear 24 of the sliding plate 60 does not interfere with the R portion 24F on the base end side of the protruding direction of the limiting protrusion 24E.

[0065] Here, the range within which a pair of limiting protrusions 24E slide on a pair of engaging surfaces 52B of the sliding plate 60 is defined as the sliding range 60D. Furthermore, in the sliding plate 60 of this disclosure, when viewed from the radially outer side opposite to the engaging surfaces 52B, the four interference-avoiding protrusions 60A are positioned offset relative to the sliding range 60D. Specifically, when viewed from the engaging surface 52B side, the two interference-avoiding protrusions 60A on that side are offset relative to the sliding range 60D in the direction of arrow R1 and in the direction opposite to arrow R1, respectively. Additionally, when viewed from the engaging surface 52B side, the two interference-avoiding protrusions 60A on that side are offset relative to the sliding range 60D in the direction of arrow R1 and in the direction opposite to arrow R1, respectively. Furthermore, in the sliding plate 60 of this disclosure, the corner portion 64 of the transmission gear body portion 24D side (axial side) of the transmission gear 24 in the sliding plate 60 does not have the chamfer portion 62A as in the sliding plate 62 of the comparative example.

[0066] When the sliding plate 60 of this disclosure described above is applied to the aforementioned motor 10 with a speed reducer, the four interference-avoidance protrusions 60A of the sliding plate 60 abut against the surface on the other side of the axial direction of the transmission gear body 24D of the transmission gear 24. In this state, when the motor 10 with the speed reducer is operating, the corner portion 64 on the transmission gear body 24D side of the transmission gear 24 in the sliding plate 60 does not interfere with the R portion 24F on the protruding direction base end side of the limiting protrusion 24E. Furthermore, the corner portion 64 of the sliding plate 60 of this disclosure does not have a chamfered portion 62A like that of the sliding plate 62 of the comparative example. Therefore, in the motor 10 with a speed reducer using the sliding plate 60 of this disclosure, during the operation of the motor 10 with the speed reducer, deformation of the limiting protrusion 24E caused by the corner portion 64 of the sliding plate 60 sinking into the limiting protrusion 24E will not occur or is unlikely to occur. As a result, the contact state between the sliding plate 60 and the limiting protrusion 24E of the transmission gear 24 can be stabilized.

[0067] Furthermore, in the sliding plate 60 of this disclosure, four interference-avoidance protrusions 60A are integrally formed with the sliding plate 60. This reduces the likelihood of an increase in the number of components in the motor 10 with the speed reducer. Additionally, the sliding plate 60 of this disclosure eliminates the need for machining processes required to form the chamfered portions 62A, as in the sliding plate 62 of the comparative example.

[0068] Furthermore, in the sliding plate 60 of this disclosure, when viewed from one axial side, four interference-avoidance protrusions 60A are formed at the four corners of the sliding plate 60. This prevents the sliding plate 60 from changing from a state where the four interference-avoidance protrusions 60A are in contact with the surface on the other side of the axial direction of the transmission gear body 24D of the transmission gear 24 to a state where it is tilted relative to the transmission gear 24.

[0069] Furthermore, in the sliding plate 60 of this disclosure, when viewed from the radially outer side opposite to the engaging surface 52B, the four interference-avoiding protrusions 60A are positioned offset relative to the sliding range 60D. Therefore, regardless of the positional relationship between the limiting protrusion 24E of the transmission gear 24 and the sliding plate 60, interference between the corner portion 64 of the sliding plate 60 and the R portion 24F of the limiting protrusion 24E can be avoided.

[0070] (The electric motor with a speed reducer in the second embodiment)

[0071] Next, use Figure 12 and Figure 13 The second embodiment of the electric motor with a speed reducer will be described.

[0072] like Figure 12 and Figure 13 As shown, the second embodiment of the motor with a speed reducer includes a transmission gear 24 and a sliding plate 52 with the same structure as the motor 10 with a speed reducer described above. Furthermore, the second embodiment of the motor with a speed reducer includes a washer 66 disposed between the transmission gear 24 and the sliding plate 52 as an interference avoidance part. The outer diameter of the washer 66 is set to be smaller than the distance between the pair of engaging surfaces 52B of the sliding plate 52. Additionally, the inner diameter of the washer 66 is set to be larger than the inner diameter of the support hole 24B of the transmission gear 24 and approximately the same as the inner diameter of the insertion hole 52A of the sliding plate 52 in the short-side direction. Furthermore, the thickness of the washer 66 is set such that, when the washer 66 is clamped between the transmission gear 24 and the sliding plate 52 and the limiting protrusion 24E is in contact with the engaging surface 52B of the sliding plate 60, the corner portion 64 of the transmission gear body 24D side of the transmission gear 24 in the sliding plate 52 does not interfere with the R portion 24F of the base end side of the protruding direction of the limiting protrusion 24E.

[0073] In the motor with a speed reducer described above in the second embodiment, similar to the motor with a speed reducer including the sliding plate 60 described above, the contact state between the sliding plate 52 and the limiting protrusion 24E of the transmission gear 24 can be stabilized.

[0074] (The electric motor with a speed reducer in the third embodiment)

[0075] Next, use Figure 14 The electric motor with a speed reducer in the third embodiment will be described.

[0076] like Figure 14 As shown, the electric motor with a speed reducer in the third embodiment includes a transmission gear 24 and a sliding plate 52 with the same structure as the electric motor 10 with a speed reducer described above. Furthermore, the electric motor with a speed reducer in the third embodiment includes a plurality of spherical members 68 disposed between the transmission gear 24 and the sliding plate 52 as interference avoidance parts. In this embodiment, four spherical members 68 are provided. Additionally, when the sliding plate 52 is viewed axially, four fitting holes 70 are formed at the four corners of the sliding plate 52, each for a portion of one of the four spherical members 68 to be inserted into.

[0077] The protrusion of the spherical member 68 from the sliding plate 52 is set to the following size: when the spherical member 68 is in contact with the axial side of the transmission gear body 24D of the transmission gear 24 and when the limiting protrusion 24E is in contact with the engaging surface 52B of the sliding plate 60, the corner portion 64 of the transmission gear body 24D side of the transmission gear 24 in the sliding plate 52 does not interfere with the R portion 24F on the protrusion direction base end side of the limiting protrusion 24E.

[0078] In the motor with a speed reducer described above in the third embodiment, the contact state between the sliding plate 52 and the limiting protrusion 24E of the transmission gear 24 can be stabilized, similar to the motor with a speed reducer including the sliding plate 60 or the motor with a speed reducer in the second embodiment.

[0079] The above describes one embodiment of the present disclosure. However, the present disclosure is not limited to the above. In addition to the above, various modifications and implementations can be made without departing from the spirit of the present disclosure.

[0080] Furthermore, although this disclosure has been described with reference to embodiments, it should be understood that this disclosure is not limited to the above-described embodiments and structures. This disclosure also includes various modifications and equivalent variations. In addition, various combinations and methods, and further combinations and methods that include only one element or more or less, also fall within the scope and concept of this disclosure.

Claims

1. An electric motor with a speed reducer, comprising: An electric motor having a rotating shaft; The first gear rotates by the rotational force transmitted from the rotating shaft; An eccentric shaft, which engages with the first gear and has a support portion that is radially offset relative to the axis of rotation of the first gear; A transmission gear, the transmission gear including a limiting protrusion supported on the support portion and protruding toward the first gear side, revolves about the rotation axis of the first gear by rotating the first gear together with the eccentric shaft; An output section that rotates via the revolution of the transmission gear; A rotation limiting member, wherein the rotation limiting member limits the rotation of the transmission gear by means of the limiting protrusion abutting against and sliding; as well as An interference avoidance part is provided between the rotation limiting member and the transmission gear, and prevents interference between the corner portion of the rotation limiting member located on the side of the limiting protrusion and the base end side of the limiting protrusion in the protruding direction. The interference avoidance part is disposed between the rotation limiting member and the transmission gear, and is a different member from the rotation limiting member and the transmission gear, and is formed in the form of a ring or a ball.

2. An electric motor with a speed reducer, comprising: An electric motor having a rotating shaft; The first gear rotates by the rotational force transmitted from the rotating shaft; An eccentric shaft, which engages with the first gear and has a support portion that is radially offset relative to the axis of rotation of the first gear; A transmission gear, the transmission gear including a limiting protrusion supported on the support portion and protruding toward the first gear side, revolves about the rotation axis of the first gear by rotating the first gear together with the eccentric shaft; An output section that rotates via the revolution of the transmission gear; A rotation limiting member, wherein the rotation limiting member limits the rotation of the transmission gear by means of the limiting protrusion abutting against and sliding; as well as An interference avoidance part is provided between the rotation limiting member and the transmission gear, and prevents interference between the corner portion of the rotation limiting member located on the side of the limiting protrusion and the base end side of the limiting protrusion in the protruding direction. The interference avoidance part is an interference avoidance protrusion that protrudes toward the transmission gear and is integrally formed with the rotation limiting member.

3. The electric motor with a speed reducer as described in claim 1 or 2, characterized in that, The transmission gear includes a pair of the aforementioned limiting protrusions. The rotation-limiting member is disposed between a pair of the limiting protrusions.

4. The electric motor with a speed reducer as described in claim 2, characterized in that, The rotation-limiting component is formed in the shape of a rectangular block. When viewed from the rotational axis of the eccentric shaft, the interference-avoiding protrusions are formed at the four corners of the rotation-limiting member.

5. The electric motor with a speed reducer as described in claim 3 of claim 2, characterized in that, The rotation-limiting component is formed in the shape of a rectangular block. When viewed from the rotational axis of the eccentric shaft, the interference-avoiding protrusions are formed at the four corners of the rotation-limiting member.

6. The electric motor with a speed reducer as described in claim 4 or 5, characterized in that, The rotation limiting member includes engaging surfaces, which are respectively disposed opposite to the limiting protrusions in the rotational radial direction of the eccentric shaft. The range on the mating surface for the limiting protrusion to slide is defined as the sliding range. When viewed radially from the rotation of the eccentric shaft, the interference-avoiding protrusion is positioned offset relative to the sliding range.

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