JP7020442B2 - Reducer and motor with reducer - Google Patents

Description

The present invention relates to a speed reducer and a motor with a speed reducer.

The following Patent Document 1 discloses a motor with a speed reducer including a speed reducer that reduces the rotation of the motor. The speed reducer described in this document includes a worm fixed to the rotating shaft of a motor, a worm wheel that meshes with the worm, a cycloid gear that revolves and rotates when the worm wheel rotates, and a cycloid gear that revolves. And an output gear that rotates by transmitting the rotational force accompanying the rotation. Further, in the speed reducer described in this document, the convex portion provided on the output gear side and the hole formed in the cycloid gear are engaged with each other, so that the rotational force associated with the revolution and rotation of the cycloid gear is engaged. Is transmitted to the output gear side.

Chinese Patent Application Publication No. 101499695

By the way, in a configuration in which the rotational force of the revolving and rotating gears is transmitted through the convex portion and the hole in which the convex portion is engaged, it is desirable that the stress generated in the convex portion can be reduced.

In consideration of the above facts, an object of the present invention is to obtain a speed reducer and a motor with a speed reducer capable of reducing the stress generated in the convex portion for transmitting the rotational force of the revolving and rotating gears.

The speed reducer that solves the above-mentioned problems is a support that is coupled to the first gear that rotates by transmitting the rotational force and the first gear, and is offset in the rotational radial direction with respect to the rotation axis of the first gear. An eccentric shaft having a portion, an outer gear arranged radially outside the eccentric shaft, and being supported by the support portion and meshing with the outer gear, the first gear rotates together with the eccentric shaft. A transmission gear that revolves around the rotation axis of the first gear and rotates on its own, a second gear provided adjacent to the transmission gear along the rotation axis direction of the first gear, and the transmission. A hole provided in either one of the transmission gear and the second gear and opened on the other side of the transmission gear and the second gear, and in the other of the transmission gear and the second gear. Provided, the transmission gear projects toward either one side of the transmission gear or the second gear, and by engaging with the hole portion, the rotational force due to the revolution and rotation of the transmission gear is transmitted to the second gear. The outer diameter of one of the transmission gear and the second gear is set to be smaller than the outer diameter of the other side of the transmission gear and the second gear. , Is equipped.

Further, the speed reducer that solves the above problems is coupled to the first gear that rotates by transmitting the rotational force and the first gear, and is offset in the rotational radial direction with respect to the rotation axis of the first gear. An eccentric shaft having a support portion, an outer gear arranged radially outside the eccentric shaft, and being supported by the support portion and meshing with the outer gear, the first gear rotates together with the eccentric shaft. A transmission gear that revolves around the rotation axis of the first gear and rotates on its own, and a second gear that is provided adjacent to the transmission gear along the rotation axis direction of the first gear. A convex portion provided on either one of the transmission gear and the second gear and protruding toward either one of the transmission gear and the second gear, and the transmission gear and the second gear. The second gear is provided on either one, and the other side of the transmission gear and the second gear is opened, and the convex portion is engaged, so that the rotational force due to the revolution and rotation of the transmission gear is applied to the second gear. With a hole portion that is transmitted to and has an inner diameter of the other side portion of the transmission gear and the second gear smaller than the inner diameter of the one side portion of the transmission gear and the second gear. , Is equipped.

A motor with a speed reducer that solves the above-mentioned problems is coupled with a motor having a rotating shaft, a first gear that rotates by transmitting the rotational force of the rotating shaft, and the first gear, and the first gear of the first gear. An eccentric shaft having a support portion offset in the rotational radial direction with respect to the rotary shaft, an outer gear arranged radially outside the eccentric shaft, and being supported by the support portion and meshing with the outer gear. The transmission gear that revolves around the rotation axis of the first gear and rotates by rotating the first gear together with the eccentric shaft, and the transmission gear and the first gear along the rotation axis direction. A second gear provided adjacent to each other, a hole provided in one of the transmission gear and the second gear, and the other side of the transmission gear and the second gear being opened, and the said portion. The transmission gear is provided on the other of the transmission gear and the second gear, protrudes toward either one of the transmission gear and the second gear, and is engaged with the hole portion of the transmission gear. The rotational force due to revolution and rotation is transmitted to the second gear, and the outer diameter of one of the transmission gear and the second gear is the other side of the transmission gear and the second gear. It has a convex portion set smaller than the outer diameter of the portion.

Further, the motor with a speed reducer that solves the above problems is coupled to the first gear that rotates by transmitting the rotational force and the first gear, and is coupled to the first gear in the rotational radial direction with respect to the rotation axis of the first gear. An eccentric shaft having an offset support portion, an outer gear arranged radially outside the eccentric shaft, and being supported by the support portion and meshing with the outer gear, the first gear is the eccentric shaft. A transmission gear that revolves around the rotation axis of the first gear and rotates by rotating together with the transmission gear, and a second gear provided adjacent to the transmission gear along the rotation axis direction of the first gear. A convex portion provided on either one of the transmission gear and the second gear and protruding toward either one of the transmission gear and the second gear, and the transmission gear and the second gear. The transmission gear and the second gear are provided on either one of the gears, and the other side of the transmission gear and the second gear is opened, and the convex portion is engaged, so that the rotational force due to the revolution and rotation of the transmission gear is the first. A hole that is transmitted to two gears and whose inner diameter of the other side of the transmission gear and the second gear is set smaller than the inner diameter of one of the transmission gear and the second gear. It has a department.

The speed reducer and the motor with a speed reducer according to the present invention have an excellent effect that the stress generated in the convex portion for transmitting the rotational force of the revolving and rotating gears can be reduced.

It is an exploded perspective view which shows the motor with a speed reducer disassembled. It is an exploded perspective view which shows the motor with a speed reducer disassembled, and shows the figure seen from the side opposite to FIG. It is sectional drawing which shows the cross section which cut the motor with a speed reducer along the rotation axis direction of an output gear body. It is a perspective view which shows the lock gear, the fixed gear and the transmission gear. It is a perspective view which looked at the output gear body from the transmission gear engaging part side. It is a front view which saw the output gear body from the transmission gear engaging part side. FIG. 6 is an enlarged cross-sectional view showing an enlarged portion of a transmission gear engaging portion of an output gear body cut along line 7-7 shown in FIG. 6 in which a recess is formed. It is a perspective view which looked at the transmission gear from the side where the convex part was formed. It is a perspective view which looked at the transmission gear from the side where the convex part was formed. FIG. 9 is an enlarged cross-sectional view showing an enlarged portion of a transmission gear cut along the line 10-10 shown in FIG. 9 in which a convex portion is formed. It is sectional drawing which shows the engaging part of the convex part and the concave part of this embodiment. It is sectional drawing which shows the engaging part of the convex part and the concave part of the comparative example. It is sectional drawing which shows the engaging part of a convex part and a concave part, and shows the state before the base end part of a convex part is compression deformed. It is sectional drawing which shows the engaging part of the convex part and the concave part, and shows the state which the base end part of the convex part was compression-deformed. It is a perspective view which shows the output gear body and the transmission gear of another form. It is a perspective view which shows the output gear body and the transmission gear of another form. It is sectional drawing which shows the engaging part of the convex part and the concave part of another form.

The motor 10 with a speed reducer will be described with reference to FIGS. 1 to 4. The arrow Z direction, the arrow R direction, and the arrow C direction, which are appropriately shown in the drawing, indicate one side in the rotation axis direction, the outside in the rotation radial direction, and one side in the rotation circumferential direction of the pinion gear 30C which is an output gear, respectively. Further, the side opposite to the arrow Z direction, the side opposite to the arrow R direction, and the side opposite to the arrow C direction are the other side in the rotation axis direction, the inside in the rotation radial direction, and the other side in the rotation circumferential direction of the pinion gear 30C which is an output gear. Shall be shown respectively. Further, when the axial direction, the radial direction, and the circumferential direction are simply indicated, unless otherwise specified, the rotation axis direction, the rotation radial direction, and the rotation circumferential direction of the pinion gear 30C are indicated.

As shown in FIGS. 1, 2 and 3, the motor 10 with a speed reducer of the present embodiment is a motor for a power seat for moving the seat cushion of the vehicle seat in the vertical direction of the seat. The motor 10 with a speed reducer includes a motor 12 which is a DC motor. Further, the motor 10 with a speed reducer includes a speed reducer 14 for reducing and transmitting the rotation of the rotation shaft 12A (see FIG. 3) of the motor 12 to the output gear body 30 as an output unit. Further, the motor 10 with a speed reducer includes a housing 16 in which the motor 12 is attached and the speed reducer 14 is provided inside the motor 12.

The speed reducer 14 includes a worm gear 18 fixed to the rotating shaft 12A of the motor 12, a helical gear 20 as a first gear that meshes with the worm gear 18, and an eccentric shaft 22 provided integrally with the helical gear 20.

Further, the speed reducer 14 includes a transmission gear 24 and a locking gear 26 supported by the eccentric shaft 22, and a fixed gear 28 as an outer gear that meshes with the transmission gear 24 and the locking gear 26. .. Further, the speed reducer 14 engages with the transmission gear 24 and has a pinion gear 30C, and the axial direction thereof is the same as the axial direction of the transmission gear 24 and the lock gear 26 (arrow Z direction and arrow Z direction). Is provided with an output gear body 30 as a second gear directed in the opposite direction).

Further, the motor 10 with a speed reducer includes a spring 32 for suppressing rattling in the axial direction of the eccentric shaft 22 and the helical gear 20 and the like. Further, the motor 10 with a speed reducer includes a cover plate 34 in which the speed reducer 14 is housed in the housing 16 by being fixed to the housing 16.

As shown in FIGS. 1 and 3, the housing 16 is formed using a resin material. The housing 16 is connected to a motor fixing portion 16A fixed in a state where the rotating shaft 12A of the motor 12 is oriented in a direction orthogonal to the axial direction (arrow Z direction), and an external connector for supplying power to the motor 12. The connector portion 16B (see FIG. 2) is provided. Further, the housing 16 includes a speed reducer accommodating recess 16C in which the speed reducer 14 is accommodated. The speed reducer accommodating recess 16C is formed in a concave shape with one side in the axial direction (side in the direction of arrow Z) open.

As shown in FIG. 3, the speed reducer accommodating recess 16C extends from the outer peripheral portion of the bottom wall portion 16D forming the bottom of the speed reducer accommodating recess 16C and the outer peripheral portion of the bottom wall portion 16D to one side in the axial direction and has an inner peripheral surface. Is configured to include a side wall portion 16E formed in a substantially cylindrical surface shape. At the center of the bottom wall portion 16D of the speed reducer accommodating recess 16C, a cylindrical boss portion 16F into which the end on the other side in the axial direction of the rotation center shaft 40, which will be described later, is inserted with a clearance is erected. There is. Further, a spring 32 is arranged around the boss portion 16F in the bottom wall portion 16D. A metal washer 36 is interposed between the bottom wall portion 16D and the spring 32.

As shown in FIG. 1, a part of the fixed gear 28, which will be described later, is fitted to the inner peripheral portion of the side wall portion 16E of the speed reducer accommodating recess 16C, so that the fixed gear 28 rotates in the circumferential direction. Three fixed gear engaging portions 16G that regulate displacement are formed. The three fixed gear engaging portions 16G are composed of a square groove-shaped groove portion 16H extending in the axial direction and a columnar column portion 16I erected in the axial direction.

Further, three screw engaging portions 16J are provided on the outer peripheral portion of the housing 16 on the open end side of the speed reducer accommodating recess 16C. The cover plate 34 is fixed to the housing 16 by screwing the bolt 38 into the three screw engaging portions 16J.

The cover plate 34 is formed by using a steel plate material or the like. The cover plate 34 is formed with an exposed opening 34A for exposing the pinion gear 30C to the outside of the speed reducer accommodating recess 16C of the housing 16. Further, on the peripheral edge of the exposed opening 34A in the cover plate 34, an annular rib 34B bent toward the other side in the axial direction is formed. Further, the cover plate 34 is formed with a bolt insertion hole 34C into which the bolt 38 is inserted. Further, a weld nut 34D to which a bolt for attaching a motor 10 with a speed reducer to an attached portion such as a seat cushion frame is screwed is joined to the cover plate 34.

As shown in FIG. 3, a spiral tooth portion is formed on the outer peripheral portion of the worm gear 18. When the motor 12 in which the worm gear 18 is fixed to the rotary shaft 12A is fixed to the housing 16, the worm gear 18 is on the bottom wall portion 16D side of the speed reducer accommodating recess 16C of the housing 16 and the inner circumference of the side wall portion 16E. It is arranged on the surface side.

As shown in FIGS. 1, 2 and 3, the helical gear 20 is formed by using a resin material. A plurality of external teeth that mesh with the teeth of the worm gear 18 are formed on the outer peripheral portion of the helical gear 20. Further, an eccentric shaft 22, which will be described later, is fixed to the shaft center portion of the helical gear 20 by insert molding. The helical gear 20 is rotatably supported by the housing 16 via the eccentric shaft 22 and the rotation center shaft 40.

As shown in FIGS. 1 and 3, the eccentric shaft 22 is formed of a metal material, and a part of the eccentric shaft 22 is inserted into the helical gear 20 so that the eccentric shaft 22 can rotate integrally with the helical gear 20. Specifically, the eccentric shaft 22 includes a disk portion 22A formed in a disk shape extending in the radial direction with the axial direction as the thickness direction. The disk portion 22A is fixed to the inner peripheral portion of the helical gear 20 in a state where the axis center of the disk portion 22A and the rotation center of the helical gear 20 coincide with each other. Further, the eccentric shaft 22 includes a support portion 22B that protrudes from the central portion of the disc portion 22A toward one side in the axial direction. One side of the support portion 22B in the axial direction is a first support portion 22B1 as a support portion in which the transmission gear 24 described later is rotatably supported. Further, the other side of the support portion 22B in the axial direction is set to have a diameter larger than that of the first support portion 22B1 and is a second support portion 22B2 in which the lock gear 26 described later is rotatably supported. The axial centers of the first support portion 22B1 and the second support portion 22B2 are offset in one direction radially outward with respect to the axial center of the disk portion 22A. The direction in which the first support portion 22B1 and the second support portion 22B2 are offset with respect to the axis center of the disk portion 22A is referred to as "offset direction D".

Further, the eccentric shaft 22 is formed with a rotation center shaft insertion hole 22C that penetrates the disk portion 22A, the first support portion 22B1 and the second support portion 22B2 in the axial direction and through which the rotation center shaft 40 is inserted. .. The axis center of the rotation center shaft insertion hole 22C (the axis center of the rotation center shaft 40 inserted through the rotation center shaft insertion hole 22C) coincides with the axis center of the disk portion 22A.

As shown in FIGS. 2 and 3, the output gear body 30 is formed by using a metal material. The output gear body 30 includes a transmission gear engaging portion 30B in which a plurality of recesses 30A are formed as holes for engaging with the transmission gear 24. In the present embodiment, the other side in the axial direction is open, and six recesses 30A arranged at equal intervals in the circumferential direction are formed in the transmission gear engaging portion 30B. Further, the output gear body 30 is arranged coaxially with the transmission gear engaging portion 30B on one side in the axial direction with respect to the transmission gear engaging portion 30B, and a plurality of external teeth are formed on the outer peripheral portion. It is equipped with a pinion gear 30C. Further, the intermediate portion between the transmission gear engaging portion 30B and the pinion gear 30C in the output gear body 30 is a shafted support portion 30D pivotally supported by the rib 34B formed on the cover plate 34. A bearing bush 42 formed of a resin material or the like is engaged with the inner peripheral surface of the rib 34B. As a result, the metal-to-metal contact between the shaft-mounted support portion 30D of the output gear body 30 and the rib 34B of the cover plate 34 is prevented or suppressed. Further, a rotation center shaft 40 formed in a rod shape using a metal material is fixed to the shaft center portion of the output gear body 30 by press fitting or the like.

As shown in FIGS. 1 and 4, the fixed gear 28 is formed by pressing a metal material or the like. The fixed gear 28 includes a fixed gear main body 28A formed in an annular shape in the axial direction. Further, the fixed gear 28 includes three engaging protrusions 28B protruding outward in the radial direction from the fixed gear main body 28A. The engaging protrusion 28B is formed with a pillar insertion hole 28C into which the pillar 16I of the housing 16 is inserted. Then, in a state where the engaging protrusion 28B is engaged with the fixed gear engaging portion 16G of the housing 16 (the engaging protrusion 28B is arranged in the groove 16H and the pillar 16I is inserted into the pillar insertion hole 28C). The fixed gear 28 is fixed to the housing 16 by engaging the push nut 44 with the pillar portion 16I (in the inserted state).

Further, a plurality of internal teeth 28D in which the transmission gear 24 and the lock gear 26, which will be described later, are engaged with each other are formed on the inner peripheral portion of the fixed gear main body portion 28A.

As shown in FIG. 2, the fixed gear 28 includes a second regulating portion 28E that protrudes from the fixed gear main body portion 28A toward the other side in the axial direction. The second regulating portion 28E projects from a part of the fixed gear main body portion 28A in the circumferential direction to the other side in the axial direction.

As shown in FIGS. 2, 3 and 4, the transmission gear 24 is formed in a disk shape by pressing a metal material or the like. External teeth 24A that mesh with the internal teeth 28D of the fixed gear 28 are formed on the outer peripheral portion of the transmission gear 24 over the entire circumference. Further, in the central portion of the transmission gear 24, a support hole 24B supported by the first support portion 22B1 of the eccentric shaft 22 via the bush 46 is formed. Further, the transmission gear 24 includes six convex portions 24C that project toward one side in the axial direction and are arranged at equal intervals in the circumferential direction. The outer diameter of the convex portion 24C is set to an inner diameter smaller than the inner diameter of the concave portion 30A of the output gear body 30. As a result, the convex portion 24C is engaged with the concave portion 30A of the output gear body 30 with a clearance.

Like the transmission gear 24, the lock gear 26 is formed in a disk shape by pressing a metal material or the like. External teeth 26B that mesh with the internal teeth 28D of the fixed gear 28 are formed on the outer peripheral portion of the locking gear 26 over the entire circumference. In the present embodiment, the number of teeth of the external teeth 26A of the locking gear 26 is set to be larger than the number of teeth of the external teeth 24A of the transmission gear 24. Further, in the central portion of the locking gear 26, a support hole 26B supported by the second support portion 22B2 of the eccentric shaft 22 via the bush 48 is formed. Further, the locking gear 26 includes a first regulating portion 26C that projects outward in the radial direction and is formed in a fan shape when viewed from the axial direction. The first regulating portion 26C is provided in a part of the locking gear 26 in the circumferential direction. Further, in a state where the outer teeth 26A of the locking gear 26 mesh with the inner teeth 28D of the fixed gear 28, the first regulating portion 26C is along the other side surface of the fixed gear main body portion 28A of the fixed gear 28 in the axial direction. Have been placed.

Further, as shown in FIG. 3, the external teeth 24A of the transmission gear 24 mesh with the internal teeth 28D of the fixed gear 28, and the external teeth 26A of the locking gear 26 and the internal teeth 28D of the fixed gear 28. In the meshed state, the surface of the transmission gear 24 on the other side in the axial direction and the surface of the lock gear 26 on the other side in the axial direction are in contact with each other. That is, the transmission gear 24 and the lock gear 26 are arranged so as to be overlapped in the axial direction.

(Action and effect of this embodiment)
Next, the operation and effect of this embodiment will be described.

As shown in FIG. 3, according to the motor 10 with a speed reducer of the present embodiment, the rotation of the rotating shaft 12A of the motor 12 is decelerated by the speed reducer 14 and transmitted to the output gear body 30. That is, when the rotating shaft 12A of the motor 12 rotates, the worm gear 18 rotates. Further, when the worm gear 18 rotates, the helical gear 20 that meshes with the worm gear 18 rotates together with the eccentric shaft 22.

Further, when the eccentric shaft 22 rotates, the transmission gear 24 supported by the first support portion 22B1 of the eccentric shaft 22 revolves and rotates around the rotation center shaft 40 while meshing with the fixed gear 28. Further, when the transmission gear 24 revolves and rotates, among the rotational forces associated with the revolution and rotation, the rotational force associated with the rotation is applied from the convex portion 24C of the transmission gear 24 to the output gear via the concave portion 30A of the output gear body 30. It is transmitted to the body 30. More specifically, by pushing the inner peripheral surface while the outer peripheral surface of the convex portion 24C of the transmission gear 24 is in sliding contact with the inner peripheral surface of the concave portion 30A of the output gear body 30, the transmission gear 24 revolves and rotates. Of the rotational forces, the rotational force associated with the rotation is transmitted to the output gear body 30. As a result, the output gear body 30 rotates, and the power seat of the vehicle can be operated via the gear that meshes with the pinion gear 30C of the output gear body 30. Here, the rotational force is transmitted from the transmission gear 24 to the output gear body 30 via the convex portion 24C and the concave portion 30A, so that the transmission gear 24 is transmitted to the output gear body 30. Compared with the case where the rotational force is transmitted by the gear, the configuration of the transmission gear 24 and the output gear body 30 can be simplified. In addition, the concave portion 30A may be formed in the transmission gear 24, and the convex portion 24C may be formed in the output gear body 30.

Further, when the eccentric shaft 22 rotates, the locking gear 26 supported by the second support portion 22B2 of the eccentric shaft 22 revolves and rotates around the rotation center shaft 40 while meshing with the fixed gear 28. Then, as shown in FIGS. 2 and 3, when the first regulating portion 26C of the locking gear 26 comes into contact with the second regulating portion 28E of the fixed gear 28, the revolution and rotation of the locking gear 26 are restrained. .. As a result, the rotation of the eccentric shaft 22 and the helical gear 20 is stopped, and the rotation of the output gear body 30 is stopped (rotation is restricted). As a result, it is prevented or suppressed that an excessive force is applied from the motor 10 with a speed reducer to the vehicle seat, and deterioration of sitting comfort due to deformation of the members constituting the vehicle seat is prevented or suppressed. Can be done.

(Optimal configuration for ensuring the strength of the convex portion 24C of the transmission gear 24)
Next, an optimum configuration for ensuring the strength of the convex portion 24C of the transmission gear 24 will be described. In the following description, the description of the portion overlapping with the description of the speed reducer 14 described above will be omitted.

By the way, when an external force is input to the vehicle seat due to a vehicle collision or the like, a large rotational force for rotating the pinion gear 30C of the output gear body 30 may be input to the pinion gear 30C. In this case, it is conceivable that the inner peripheral surface of the concave portion 30A of the output gear body 30 presses the convex portion 24C of the transmission gear 24, and the stress generated in the convex portion 24C increases.

Therefore, in order to reduce the stress generated in the convex portion 24C, as shown in FIGS. 5 to 7 and 8 to 10, the shapes of the plurality of convex portions 24C are elongated in the rotational circumferential direction of the transmission gear 24. In addition to being formed in a shape, the shapes of the plurality of recesses 30A of the output gear body 30 to which the plurality of protrusions 24C are engaged with each other are formed in a long shape along the rotation circumferential direction of the output gear body 30. In addition to this, the tip portions 24C1 of the plurality of convex portions 24C are formed into a tapered shape (a shape having a smaller outer diameter than the base end portion 24C2).

Specifically, as shown in FIGS. 5 to 7, the recess 30A formed in the transmission gear engaging portion 30B of the output gear body 30 is a pitch circle centered on the rotation center O1 of the output gear body 30. It is formed in a long hole shape along the circumferential direction of L1. Further, in the examples shown in FIGS. 5 to 7, the three recesses 30A are arranged at equal intervals along the circumferential direction of the pitch circle L1.

Further, the inner peripheral surfaces 30S1 at both ends of the output gear body 30 in the concave portion 30A in the rotational circumferential direction are formed in a cylindrical surface shape having the same radius of curvature as the inner peripheral surface of the concave portion 30A shown in FIG. .. Further, the inner peripheral surface 30S2 on the outer side in the rotational radial direction of the output gear body 30 in the recess 30A has a cylindrical surface shape connecting the outermost outer peripheral portions of the inner peripheral surfaces 30S1 at both ends of the output gear body 30 in the concave portion 30A in the rotational circumferential direction. It is formed. Further, the inner peripheral surface 30S3 on the inner side in the rotational radial direction of the output gear body 30 in the recess 30A has a cylindrical surface shape connecting the innermost peripheral portions of the inner peripheral surfaces 30S1 at both ends of the output gear body 30 in the concave portion 30A in the rotational circumferential direction. Is formed in. The width dimension W1 between the inner peripheral surface 30S2 on the outer side of the output gear body 30 in the recess 30A and the inner peripheral surface 30S3 on the inner side in the radial direction of the output gear 30 in the recess 30A is shown in FIG. The width is set to be the same as the inner diameter of the recess 30A. That is, the recesses 30A of the output gear body 30 shown in FIGS. 5 to 7 are the two recesses 30A of the output gear body 30 shown in FIG. 2 (two recesses adjacent to each other in the rotational circumferential direction of the output gear body 30). 30A) is connected in the rotation circumferential direction of the output gear body 30.

As shown in FIGS. 8 to 10, the convex portion 24C of the transmission gear 24 is formed in a long shape along the circumferential direction of the pitch circle L2 centered on the rotation center O2 of the transmission gear 24. .. The diameter of the pitch circle L2 is the same as the diameter of the pitch circle L1 (see FIG. 6) described above. Further, in the examples shown in FIGS. 8 to 10, the three convex portions 24C are arranged at equal intervals along the circumferential direction of the pitch circle L2.

The outer peripheral surface 24S1 at both ends of the transmission gear 24 in the rotational circumferential direction at the base end portion 24C2 of the convex portion 24C (the base end portion in the protruding direction of the convex portion 24C) is the outer peripheral surface of the convex portion 24C shown in FIG. It is formed in a cylindrical surface shape having the same radius of curvature as. Further, the outer peripheral surface 24S2 of the transmission gear 24 on the base end portion 24C2 of the convex portion 24C on the outer peripheral surface in the rotational radial direction is the outermost outer peripheral portion of the outer peripheral surface 24S1 at both ends of the transmission gear 24 in the convex portion 24C in the rotational circumferential direction. It is formed in the shape of a cylindrical surface that connects them. Further, the outer peripheral surface 24S3 on the inner side of the transmission gear 24 in the base end portion 24C2 of the convex portion 24C in the rotational radial direction is the innermost peripheral portion of the outer peripheral surface 24S1 at both ends of the transmission gear 24 in the convex portion 24C in the rotational circumferential direction. It is formed in the shape of a cylindrical surface that connects the two. Then, between the outer peripheral surface 24S2 of the transmission gear 24 on the proximal end portion 24C2 of the convex portion 24C and the outer peripheral surface 24S3 on the inner peripheral surface of the transmission gear 24 in the proximal end portion 24C2 of the convex portion 24C. The width dimension W2 of is set to the same width dimension as the outer diameter of the convex portion 24C shown in FIG. That is, the base end portion 24C2 of the convex portion 24C of the transmission gear 24 shown in FIGS. 8 to 10 is for transmission shown in FIG. 4, except that the dimensions of the convex portion 24C in the protruding direction are different. The shape is such that two convex portions 24C of the gear 24 (two convex portions 24C adjacent to each other in the rotational circumferential direction of the transmission gear 24) are connected in the rotational circumferential direction of the transmission gear 24.

The tip portion 24C1 of the convex portion 24C (the tip portion in the protruding direction of the convex portion 24C) is formed so as to gradually narrow from the base end portion 24C2 side of the convex portion 24C toward the tip end side. As a result, the outer peripheral surfaces 24S1, 24S2, and 24S3 of the tip portion 24C1 of the convex portion 24C are tapered surfaces.

Further, as shown in FIG. 10, a U-shaped groove 24D having a curved inner peripheral surface thereof is formed around the convex portion 24C on the base end side 24E of the convex portion 24C in the transmission gear 24 in the protruding direction. It is formed along. As a result, the stress concentration coefficient of the base end side 24E in the protruding direction of the convex portion 24C is smaller than that in the case where the groove 24D is not formed.

In the configuration described above, in which the elongated convex portion 24C1 has a tapered convex portion 24C and the elongated concave portion 30A, the helical gear 20 rotates together with the eccentric shaft 22 due to the rotation of the rotating shaft 12A of the motor 12. , The transmission gear 24 revolves and rotates. Further, when the transmission gear 24 revolves and rotates, the rotational force associated with the rotation among the rotational forces associated with the revolution and rotation is applied from the convex portion 24C of the transmission gear 24 to the output gear via the concave portion 30A of the output gear body 30. It is transmitted to the body 30.

More specifically, as shown in FIG. 11, when the transmission gear 24 revolves and rotates, the end portion of the transmission gear 24 on one side in the rotational circumferential direction at the base end portion 24C2 of the convex portion 24C of the transmission gear 24. The outer peripheral surface 24S1 pushes the inner peripheral surface 30S1 while being in sliding contact with the inner peripheral surface 30S1 at one end of the output gear body 30 in the concave portion 30A of the output gear body 30 in the rotation circumferential direction. As a result, of the revolutionary force associated with the revolution and rotation of the transmission gear 24, the rotational force associated with the rotation is transmitted to the output gear body 30, and the output gear body 30 rotates.

Here, when the configuration of the convex portion 24C and the concave portion 30A is applied, the sectional moment of inertia of the convex portion 24C can be increased as compared with the convex portion 24C shown in FIG. As a result, the stress generated in the convex portion 24C can be reduced.

In addition to this, the stress concentration coefficient of the proximal end side 24E in the protruding direction of the convex portion 24C is smaller due to the groove 24D, so that the stress of the proximal end side 24E in the protruding direction of the convex portion 24C can be reduced. ..

Further, in the configuration in which the tip portion 24C1 of the convex portion 24C has a tapered shape, the input point of the load F on the contact surface between the outer peripheral surface 24S1 of the base end portion 24C2 of the convex portion 24C and the inner peripheral surface 30S1 of the concave portion 30A. The position of P (the position where the evenly distributed load is replaced with the concentrated load) is moved to the base end side 24E of the convex portion 24C as compared with the configuration in which the tip portion 24C1 of the convex portion 24C does not have a tapered shape (see FIG. 12). It can be shifted. As a result, the bending stress of the base end side 24E of the convex portion 24C can be effectively reduced.

Here, FIG. 13 shows an engaging portion between the convex portion 24C and the concave portion 30A in a state before the convex portion 24C is deformed. As shown in this figure, the length from the bottom of the groove 24D to the boundary 24C3 (the boundary between the tapered portion and the non-tapered portion) between the tip portion 24C1 and the base end portion 24C2 of the convex portion 24C. Is L1, and the depth of the groove 24D is h.

Further, FIG. 14 shows an engaging portion between the convex portion 24C and the concave portion 30A in a state where the load F is input from the concave portion 30A to the convex portion 24C and the convex portion 24C is deformed. As shown in this figure, the contact length between the outer peripheral surface of the convex portion 24C and the inner peripheral surface of the concave portion 30A (contact length of the convex portion 24C in the protruding direction) is L2, and half of the contact length is L2 / 2. .. Then, assuming that the length from the bottom of the groove 24D in this state to the position corresponding to half of the contact length L2 between the outer peripheral surface of the convex portion 24C and the inner peripheral surface of the concave portion 30A is Lmax, the following equation (1) is used. Is true.
Lmax = (L2 / 2) + h ... Equation (1)

Then, when the maximum assumed load is input from the concave portion 30A to the convex portion 24C and the convex portion 24C is deformed, L1 becomes a value smaller than Lmax calculated by the above equation (1). By setting the boundary 24C3 (FIG. 13), the effect of reducing the bending stress of the base end side 24E of the convex portion 24C described above can be obtained more reliably.

In the above description, the shapes of the plurality of convex portions 24C are formed in a long shape in the rotational circumferential direction of the transmission gear 24, and the plurality of output gear bodies 30 in which the plurality of convex portions 24C are engaged with each other are formed. An example in which the shape of the recess 30A is formed in a long shape along the rotation circumferential direction of the output gear body 30 has been described, but the present invention is not limited thereto. For example, by forming the tip portion 24C1 of the convex portion 24C of the transmission gear 24 shown in FIG. 4 into a tapered shape as shown in FIG. 15, the bending stress of the base end side 24E of the convex portion 24C is effective. Can be reduced.

Further, as shown in FIG. 16, a convex portion 24C may be provided on the output gear body 30 side, and a hole portion 30A with which the convex portion 24C is engaged may be provided. Since the hole 30A corresponds to the recess 30A described above, the hole 30A has the same reference numeral as the recess 30A.

Further, as shown in FIG. 17, the configuration of the convex portion 24C may be the same as that of the convex portion 24C shown in FIG. 4, and the configuration of the hole portion 30A may be set as follows. That is, the inner peripheral surface of the portion of the hole 30A facing the base end portion 24C2 in the protruding direction of the convex portion 24C is formed in a straight shape (along the protruding direction of the convex portion 24C), and the convex portion 24C is formed in the hole portion 30A. The inner peripheral surface of the portion facing the tip portion 24C1 in the projecting direction may be formed in a tapered shape (so that the diameter gradually increases toward the projecting direction side of the convex portion 24C).

Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and can be modified in various ways other than the above within a range not deviating from the gist thereof. Of course.

10 Motor with reducer 12 Motor 12A Rotating shaft 14 Reducer 20 Helical gear (1st gear)
22 Eccentric shaft 22B1 First support part (support part)
24 Transmission gear 24C Convex 30 Output gear body (second gear)
30A recess (hole)

Claims (10)

The first gear that rotates by transmitting the rotational force,
An eccentric shaft coupled to the first gear and having a support portion offset in the radial direction with respect to the rotation shaft of the first gear.
The outer gear arranged radially outside the eccentric shaft,
A transmission gear that is supported by the support portion and meshes with the outer gear, and the first gear rotates together with the eccentric shaft to revolve around the rotation shaft of the first gear and rotate on its axis.
The transmission gear, the second gear provided adjacent to each other along the rotation axis direction of the first gear, and the second gear.
A hole provided in either one of the transmission gear and the second gear and the other side of the transmission gear and the second gear is opened.
The transmission gear is provided on either one of the transmission gear and the second gear, projects toward either one of the transmission gear and the second gear, and is engaged with the hole portion. The rotational force due to the revolution and rotation of the engine is transmitted to the second gear, and the outer diameter of one of the transmission gear and the second gear is the other side of the transmission gear and the second gear. The convex part set smaller than the outer diameter of the part of
A reducer equipped with. The outer diameter of either one of the transmission gear and the second gear in the convex portion is set to a constant outer diameter.
The speed reducer according to claim 1, wherein the outer diameter of the other side portion of the transmission gear and the second gear in the convex portion becomes smaller toward the other side. When an external force is input from the second gear to the transmission gear side, one of the transmission gear and the second gear in the convex portion is deformed, and the transmission in the convex portion. The speed reducer according to claim 2, wherein the portion on the other side of the gear and the second gear comes into contact with the inner peripheral surface of the hole. A claim in which a groove having a curved inner peripheral surface thereof is formed along the circumference of the convex portion on the proximal end side of the convex portion in any one of the transmission gear and the second gear in the protruding direction. The speed reducer according to any one of items 1 to 3. The first gear that rotates by transmitting the rotational force,
An eccentric shaft coupled to the first gear and having a support portion offset in the radial direction with respect to the rotation shaft of the first gear.
The outer gear arranged radially outside the eccentric shaft,
A transmission gear that is supported by the support portion and meshes with the outer gear, and the first gear rotates together with the eccentric shaft to revolve around the rotation shaft of the first gear and rotate on its axis.
The transmission gear, the second gear provided adjacent to each other along the rotation axis direction of the first gear, and the second gear.
A convex portion provided on either one of the transmission gear and the second gear and protruding toward either one of the transmission gear and the second gear.
The transmission gear is provided on either one of the transmission gear and the second gear, and the other side of the transmission gear and the second gear is opened, and the convex portion is engaged to revolve the transmission gear. And the rotational force due to rotation is transmitted to the second gear, and the inner diameter of the other side portion of the transmission gear and the second gear is the one side portion of the transmission gear and the second gear. Holes set smaller than the inner diameter and
A reducer equipped with. A motor with a rotation axis and
The first gear that rotates by transmitting the rotational force of the rotating shaft,
An eccentric shaft coupled to the first gear and having a support portion offset in the radial direction with respect to the rotation shaft of the first gear.
The outer gear arranged radially outside the eccentric shaft,
A transmission gear that is supported by the support portion and meshes with the outer gear, and the first gear rotates together with the eccentric shaft to revolve around the rotation shaft of the first gear and rotate on its axis.
The transmission gear, the second gear provided adjacent to each other along the rotation axis direction of the first gear, and the second gear.
A hole provided in either one of the transmission gear and the second gear and the other side of the transmission gear and the second gear is opened.
The transmission gear is provided on either one of the transmission gear and the second gear, projects toward either one of the transmission gear and the second gear, and is engaged with the hole portion. The rotational force due to the revolution and rotation of the engine is transmitted to the second gear, and the outer diameter of one of the transmission gear and the second gear is the other side of the transmission gear and the second gear. The convex part set smaller than the outer diameter of the part of
Motor with reducer. The outer diameter of either one of the transmission gear and the second gear in the convex portion is set to a constant outer diameter.
The motor with a speed reducer according to claim 6, wherein the outer diameter of the other side portion of the transmission gear and the second gear in the convex portion becomes smaller toward the other side. When an external force is input from the second gear to the transmission gear side, one of the transmission gear and the second gear in the convex portion is deformed, and the transmission in the convex portion. The motor with a speed reducer according to claim 7, wherein the portion on the other side of the gear and the second gear comes into contact with the inner peripheral surface of the hole. A claim in which a groove having a curved inner peripheral surface thereof is formed along the circumference of the convex portion on the proximal end side of the convex portion in any one of the transmission gear and the second gear in the protruding direction. Item 6. The motor with a speed reducer according to any one of items 6 to 8. The first gear that rotates by transmitting the rotational force,
An eccentric shaft coupled to the first gear and having a support portion offset in the radial direction with respect to the rotation shaft of the first gear.
The outer gear arranged radially outside the eccentric shaft,
A transmission gear that is supported by the support portion and meshes with the outer gear, and the first gear rotates together with the eccentric shaft to revolve around the rotation shaft of the first gear and rotate on its axis.
The transmission gear, the second gear provided adjacent to each other along the rotation axis direction of the first gear, and the second gear.
A convex portion provided on either one of the transmission gear and the second gear and protruding toward either one of the transmission gear and the second gear.
The transmission gear is provided on either one of the transmission gear and the second gear, and the other side of the transmission gear and the second gear is opened, and the convex portion is engaged to revolve the transmission gear. And the rotational force due to rotation is transmitted to the second gear, and the inner diameter of the other side portion of the transmission gear and the second gear is the one side portion of the transmission gear and the second gear. Holes set smaller than the inner diameter and
Motor with reducer.

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