JP2017198292A - Gear speed reducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply configure a gear speed reducer to prevent a reverse rotation of a face gear when a reverse force to reverse a driving direction is acted in one which includes the face gear engaged with a pinion.SOLUTION: A gear speed reducer is configured so that a pinion 1 is capable of performing a shift operation in a direction along a driving axis X by a force acted between a pinion tooth part 11 and a face tooth part 16 when a reverse force is acted on a face gear 2. The gear speed reducer includes a brake mechanism 3 for causing a brake force to act on the pinion 1 by a contact of a brake surface 22s with a rotary member 21 that integrally rotates with the pinion tooth part 11 when the shift operation is carried out.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a gear reduction device including a pinion and a face gear.

  A reduction gear that transmits the rotational force of the pinion to the face gear and extracts it from the output shaft can reverse the pinion when a large load is applied to the output shaft in the reverse rotation direction. To do.

  To deal with such problems, Patent Document 1 includes a worm driven by a motor and a wheel gear meshing with the worm. When a reverse force acts on the wheel gear, the worm is shifted in the thrust direction. A technique with a mechanism for preventing reverse rotation by friction is shown. The technique of this Patent Document 1 is different in gear reduction structure from that provided with a pinion and a face gear, but enables prevention of reverse rotation of the wheel gear.

  Patent Document 2 includes a worm driven by a motor and a wheel gear meshing with the worm. When an external force acts on the wheel gear, the worm is shifted in a thrust direction, and the bearing device functions as a one-way clutch. A technique for preventing the rotation of the wheel gear is shown. The technique of Patent Document 2 also has a gear reduction structure different from that provided with a pinion and a face gear, but can prevent the reverse rotation of the wheel gear.

JP 2000-152969 A Japanese Patent Laid-Open No. 7-71491

  In Patent Document 1, as a specific configuration of a mechanism for preventing reverse rotation, a braking force is obtained by a frictional force caused by contact between a bearing that supports a worm and a wave washer when a thrust load is applied. However, in this configuration, since the friction surface is an annular region, it is difficult to obtain a large braking force with a small friction area.

  Further, in Patent Document 2, since the bearing device is configured to reach a contact state and prevent rotation when shifted by a predetermined amount in the thrust direction of the worm, high accuracy is required, and the number of parts is increased. There is room for improvement in terms of invitation.

  For this reason, it is required to simply configure a gear reduction device that prevents the face gear from rotating in the reverse direction when the reverse force acting in the direction opposite to the driving direction is applied to a device having a face gear meshing with the pinion. It is done.

A feature of the present invention is a pinion in which a helical pinion tooth portion centered on the drive shaft core is formed with respect to a pinion shaft rotating around the drive shaft core,
A face gear having a face tooth portion formed on one side surface of the outer periphery of a disk-like portion that is rotatably arranged around an operating shaft core in a posture orthogonal to the drive shaft core in a positional relationship that is different from the drive shaft core. ,
The pinion is allowed to shift in the direction along the drive shaft core by a shift force acting between the pinion tooth portion and the face tooth portion when a reverse force acts on the face gear,
And a braking mechanism that applies a braking force to the pinion when the braking unit comes into contact with at least one of the rotating member that rotates integrally with the pinion and the pinion tooth portion by performing the shift operation. It is in.

In this configuration, the pinion has a helical pinion tooth portion, and the pinion tooth portion meshes with the face tooth portion of the face gear. It is possible to shift the pinion in the direction along the drive shaft core by the force acting on. In addition, when the braking mechanism is arranged so that the braking part of the braking mechanism comes into contact with at least one of the rotating member that rotates integrally with the pinion and the pinion tooth part by the shift operation, a reverse force acts on the face gear. In addition, a braking force is applied to the pinion from the braking unit to prevent the reverse rotation of the pinion, and at the same time, the reverse rotation of the wheel gear can be prevented. In particular, in this configuration, the number of parts can be reduced as compared with that using a ratchet mechanism.
Therefore, a gear reduction device that has a face gear that meshes with the pinion and that effectively prevents reverse rotation of the face gear when the reverse rotation force is applied is simply configured.

  In the present invention, the rotating member is configured to have an outer peripheral surface centered on the drive shaft core, and the braking member has a concave shape that fits when the rotating member performs the shift operation, and the direction of the face gear A braking surface that opens may be provided.

  According to this, when the pinion tooth portion is shifted, the outer peripheral surface of the rotating member reaches a position where it can come into contact with the concave braking surface. Further, even during reverse rotation, a load acts between the face tooth portion of the face gear and the pinion tooth portion of the pinion, and a force acts in a direction in which the pinion tooth portion is separated from the face tooth portion by the action of this load. The rotating member can be brought into strong contact with the braking surface using the force acting in this manner, and the reverse rotation of the face gear can be satisfactorily prevented by the braking force from the braking surface.

  In the present invention, the rotating member projects and forms a plurality of contact friction bodies on the outer periphery of a cylindrical member centering on the drive shaft core, and the contact friction body is in a direction opposite to the rotational drive direction of the pinion. You may form in the attitude | position which protrudes toward.

  According to this, even if the protruding end of the contact friction body contacts the concave braking surface during the rotation of the pinion, the resistance acting on the rotation can be reduced, and the pinion is opposite to the driving rotation direction. When rotating in the direction, the protruding end of the contact friction body comes into contact with the concave braking surface so that a strong braking force can be applied. Thereby, it is possible to satisfactorily perform braking when the face gear is reversely rotated.

  In the present invention, the rotating member is configured to include an outer peripheral surface centered on the drive shaft core, and the braking portion that contacts the outer peripheral surface of the rotating member during the shift operation of the rotating member includes the shift member. It may be formed as a braking surface having a shape in which the contact area increases with the operation or a shape in which the contact area decreases with the shift operation.

  According to this, in the case where the braking surface is formed in such a shape that the contact area increases with the shift operation, the contact area between the rotating member and the braking surface increases as the rotating member shifts due to the action of the reverse rotation force. And pinion reversal can be reliably prevented. On the other hand, when the braking surface is formed in such a shape that the contact area decreases with the shift operation, the increasing tendency of the braking force can be reduced as the rotating member is shifted by the action of the reverse force. To prevent the reversal of the pinion smoothly.

  The present invention includes a contact member that contacts at least one of the rotating member and the pinion tooth portion and operates in a shift direction, and a return spring that biases the contact member in a direction opposite to the shift operation. You may prepare.

  According to this, when the pinion tooth portion is shifted, the contact member abuts against at least one of the rotating member that rotates integrally with the pinion tooth portion and the pinion tooth portion, and this contact member acts as a return spring. Operates in the shift direction against the urging force. Thus, it becomes possible to lightly apply a braking force to the pinion by the contact of the contact member. When the load in the reverse rotation direction decreases, the abutment member operates toward the side opposite to the shift operation by the biasing force of the return spring, so that the pinion tooth portion is moved to the position before the shift operation is performed. Enable operation to return to.

It is a longitudinal cross-sectional view of a gear reduction device. It is a cross-sectional view of a gear reduction device. It is a longitudinal cross-sectional view which shows the action | operation of a pinion when reverse force acts. It is a cross-sectional view which shows the action | operation of a pinion when reverse force acts. It is a perspective view which shows a rotation member and a braking member. It is a perspective view which shows the rotating member and braking member of another embodiment (a). It is a perspective view which shows the rotating member and braking member of another embodiment (b). It is a perspective view which shows the rotation member and braking member of another embodiment (c). It is sectional drawing of the rotation member of another embodiment (c). It is sectional drawing which shows the contact member and return spring of embodiment (d).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Basic configuration]
As shown in FIGS. 1 and 2, the pinion 1 that can rotate around the drive shaft core X and the operation shaft core Y orthogonal to the drive shaft core X in a positional relationship that is different from the drive shaft core X are rotatable. A gear reduction device 100 is configured including a simple face gear 2 and a braking mechanism 3. The gear reduction device 100 is accommodated in the housing 4.

  For example, in a vehicle such as an automobile, the gear reduction device 100 is used as a drive source for setting a seat back posture of a driver's seat, operating a power slide door, or opening / closing a sunroof. In order to enable such driving, the pinion 1 is transmitted the rotational driving force of the electric motor 5.

  The pinion 1 is provided with a helical (helical) pinion tooth portion 11 centered on the drive shaft core X with respect to the pinion shaft 10 arranged coaxially with the drive shaft core X. The pinion 1 is formed of a metal material or a resin material. In addition, the number of teeth of the pinion tooth part 11 may be one or plural.

  The pinion shaft 10 is supported in a cantilevered manner with respect to the housing 4 by a first bearing 12 formed of a ball bearing so as to be rotatable in a direction along the drive shaft core X. That is, the pinion shaft 10 is supported so as to be shiftable in the direction along the drive shaft core X with respect to the inner periphery of the inner race of the first bearing 12. A bush may be used as the first bearing 12.

  Although a specific structure is not shown, for example, the pinion shaft 10 is connected to the output shaft of the electric motor 5 by a transmission portion such as a spline structure so as to be able to shift and transmit torque. Further, the position where the pinion 1 is in the position shown in FIGS. 1 and 2 in the direction along the drive shaft core X is referred to as a reference position. At this reference position, the contact formed at a position adjacent to the pinion tooth portion 11. The position is determined by the portion 11 a coming into contact with the first bearing 12.

  Further, the direction of the pinion 1 along the drive shaft core X is maintained in the transmission portion described above so that the contact portion 11a is in contact with the first bearing 12 without a reverse force acting on the output shaft 17. It has a spring or the like that biases it. In addition, you may comprise a transmission part, without providing a spring etc.

  In particular, for example, a shaft body that rotates about the drive shaft core X by the rotational driving force of the electric motor 5 is provided, and the pinion tooth portion 11 is supported so as to be capable of shifting operation and transmitting torque to the shaft body. It is also conceivable to constitute the pinion 1. Although the pinion 1 does not include the pinion shaft 10 described above, the pinion 1 can be shifted in the direction along the drive shaft X.

  The face gear 2 is formed with a plurality of face teeth 16 on one side of the outer periphery of a disk-shaped part 15 that is disk-shaped around the operating axis Y, and the operating axis is in the center of the disk-shaped part 15. A Y-coaxial sleeve 15a is formed to protrude.

  An output shaft 17 is inserted through the sleeve 15a so as to be able to transmit torque, and the output shaft 17 is supported by the housing 4 by two second bearings 18 formed of ball bearings. A bush may be used as the second bearing 18.

  The face gear 2 is formed of a metal material or a resin material. When the face gear 2 is formed of a metal material, it may be manufactured by cutting, forging, or pressing.

  The housing 4 creates an internal space by overlapping and connecting the upper case 4a and the lower case 4b. The configuration of the braking mechanism 3 will be described later.

  The gear reduction device 100 rotates the pinion 1 in the driving direction R by the electric motor 5, whereby the face gear 2 rotates in the output direction S, and the output shaft 17 uses the rotational force in the output direction S as deceleration power. Is configured to output from.

  Further, in the gear reduction device 100 having this configuration, when the pinion 1 is driven, a force acts in a direction in which the pinion tooth portion 11 of the pinion 1 and the face tooth portion 16 of the face gear 2 are separated from each other. In particular, the braking mechanism 3 prevents reverse rotation of the output shaft 17 when a reverse rotation force (reverse input) reverse to the drive direction R acts on the output shaft 17 while the electric motor 5 is stopped. To do.

[Brake mechanism]
As shown in FIGS. 1 to 5, the braking mechanism 3 includes a braking member 22 having a rotating member 21 that rotates integrally with the pinion 1, and a braking surface 22 s (an example of a braking unit) that can contact the outer peripheral surface of the rotating member 21. And.

  The braking mechanism 3 is configured such that at least one of the outer peripheral surface of the rotating member 21 and the braking surface 22s is a rough surface, and a strong braking force is obtained by contacting each of them. The braking mechanism 3 may be configured such that the outer peripheral surface of the pinion tooth portion 11 is brought into contact with the braking surface 22s.

  The rotating member 21 is formed integrally and protrudes at an outer position of the pinion tooth portion 11, and includes an outer peripheral surface with the drive shaft core X as the center. The braking member 22 protrudes from the inner surface of the upper case 4 a of the housing 4 and is formed with a concave braking surface 22 s that can be in close contact with the outer peripheral surface of the rotating member 21. The rotating member 21 may be a member in which a cylindrical member is connected to the outer end position of the pinion tooth portion 11. In addition, the pinion 1 may be formed with a pinion tooth portion 11 at the center of the pinion shaft 10, and one of the pinion shafts 10 may be used as the rotating member 21.

  The braking surface 22s has a shape obtained by dividing a cylindrical inner surface having a radius equal to the radius of the rotating member 21, and is formed in a posture that opens toward the disk-shaped portion 15 (a posture that opens downward in FIG. 1). Yes. In particular, the axis of the braking surface 22s is parallel to the drive axis X, but is spaced apart from the disk-shaped portion 15 by an offset distance with respect to the drive axis X.

  The braking surface 22s need not be formed with a radius equal to the radius of the rotating member 21, and may be formed with a radius larger than the radius of the rotating member 21, for example, the cross-sectional shape is trapezoidal, It may be formed in a V-shaped groove.

  The above-described offset distance is the distance between the outer peripheral surface of the rotating member 21 and the braking surface 22s of the braking member 22 when the rotating member 21 is shifted in the direction along the drive axis X (operation to the right in FIG. 1). It is a value that forms a slight gap between them.

  In this gear reduction device 100, the pinion 1 includes a helical pinion tooth portion 11, and the pinion tooth portion 11 meshes with the face tooth portion 16 of the face gear 2. Therefore, as shown in FIG. 4, when a reverse force acts on the output shaft 17 and rotation in the reverse direction T starts, the pinion 1 is reversely driven by the force acting on the pinion tooth portion 11 from the face tooth portion 16. Slightly rotates in direction U. As the pinion 1 rotates in the reverse drive direction U in this way, the shift force F1 acting in the direction along the drive shaft core X acts on the pinion tooth portion 11, and the shift operation is performed so that the pinion 1 protrudes. .

  In the gear reduction device 100, as described above, when the pinion 1 is driven, a force acts in a direction in which the pinion tooth portion 11 of the pinion 1 and the face tooth portion 16 of the face gear 2 are separated from each other. For this reason, even when the face gear 2 rotates in the reverse rotation direction T, the force that separates the pinion tooth portion 11 and the face tooth portion 16 acts on the rotating member 21 as the displacement force F2.

  For this reason, when a reverse rotation force acts on the output shaft 17 in a situation where the electric motor 5 is stopped, the pinion tooth portion 11 is projected by the shift force F1, as shown in FIGS. By performing the shift operation, the outer peripheral surface of the rotating member 21 reaches a position where it can come into contact with the braking surface 22 s of the braking member 22. Further, along with this shift operation, the displacement force F2 acts to elastically deform the pinion 1 so as to bend.

  As a result, the outer peripheral surface of the rotating member 21 comes into a state of being in strong contact with the braking surface 22s of the braking member 22, and the rotation of the pinion 1 in the reverse rotation direction T is blocked. Is prevented, and the gear reduction device 100 is locked.

  In particular, the braking portion can be formed with a plurality of engaging recesses in the braking member 22 in the same manner as the internal gear instead of the braking surface 22s. In this way, the engagement recess is formed by forming a plurality of engagement protrusions on the outer periphery of the rotating member 21 in the same manner as the external gear, so that the engagement protrusions are formed in the engagement recess during the shift operation of the pinion 1. The pinion 1 can be reliably prevented from rotating by engaging.

  Moreover, as a structure which makes braking force act by engagement as the braking mechanism 3, not only what forms an engagement recessed part and an engagement protrusion in gear shape, but the recessed part or the convex part is formed in the braking part, It is possible to adopt a simple configuration such as forming a convex portion or a concave portion on the outer periphery of the rotating member 21.

  In the gear reduction device 100, the outer peripheral surface of the rotating member 21 contacts the braking surface 22 s of the braking member 22 even when an excessive reverse force acts on the output shaft 17 in a situation where the electric motor 5 is operating. In the same manner as described above, the gear reduction device 100 reaches the locked state.

[Another embodiment]
In addition to the above-described embodiments, the present invention may be configured as follows (the components having the same functions as those of the embodiments are given the same numbers and symbols as those of the embodiments).

(A) As shown in FIG. 6, the shape of the braking surface 22 s is set so that the braking surface 22 s of the braking member 22 increases toward the downstream side in the shift operation direction of the pinion 1. That is, the groove depth of the braking surface 22s on the upstream side in the shift operation direction is set shallower, and the side wall portion of the braking member 22 is formed on the inclined surface so that the groove depth becomes deeper toward the downstream side in the shift operation direction.

  As a result, when the reverse rotation force acts on the output shaft 17 and the rotating member 21 is shifted, the area of the braking surface 22s that contacts the outer peripheral surface of the rotating member 21 increases with the shifting operation. The braking force is increased in a relationship directly proportional to the amount to realize reliable braking in the reverse direction.

(B) As shown in FIG. 7, the shape of the braking surface 22s is set so that the braking surface 22s of the braking member 22 decreases toward the downstream side in the shift operation direction. That is, the groove depth of the braking surface 22s on the upstream side in the shift operation direction is set deeper, and the side wall portion of the braking member 22 is formed on the inclined surface so that the groove depth becomes shallower on the downstream side in the shift direction.

  As a result, when a reverse force acts on the output shaft 17 and the rotating member 21 shifts, the area of the braking surface 22s that contacts the outer peripheral surface of the rotating member 21 is large at the initial stage of contact. With the shift operation, the increasing tendency of the contact area is reduced, so that the occurrence of impact is suppressed and the reverse rotation is smoothly prevented.

(C) As shown in FIGS. 8 and 9, the rotating member 21 includes a columnar member 21 a centered on the drive shaft X and a plurality of contact friction bodies 21 b formed to protrude from the outer periphery of the columnar member 21 a. And consist of In this configuration, the contact friction body 21b is formed in a posture protruding in the direction opposite to the driving direction R of the pinion 1.

  As a result, when the pinion 1 rotates in the driving direction R, even if a part of the contact friction body 21b comes into contact with the braking surface 22s, it is possible to reduce the resistance acting on the rotation. Further, when the pinion tooth portion 11 reverses, the protruding end of the contact friction body 21b comes into contact with the braking surface 22s in a state of biting, and a strong braking force is applied to the reverse rotation of the face gear 2. The strong braking force is applied and the reverse rotation can be reliably prevented.

  In this structure, it is not restricted to what forms the contact friction body 21b by cutting of the outer periphery of the cylindrical member 21a, It forms in the form which attaches the contact friction body 21b formed with resin to the outer periphery of the cylindrical member 21a. Things can be used. Further, the reverse rotation can be more effectively prevented by forming the braking surface 22s as a rough surface.

(D) As shown in FIG. 10, the braking mechanism 3 includes a rotating member 21 and a braking member 22, and abutment that is urged by a return spring 25 to return the rotating member 21 to the position before the shift. A member 26 is provided.

  As a result, when the reverse force acts on the face gear 2 and the rotating member 21 shifts together with the pinion tooth portion 11, the outer peripheral surface of the rotating member 21 contacts the braking surface 22 s of the braking member 22, and the rotating member The protruding end of 21 abuts against the abutting member 26 and operates in a direction to push the abutting member 26 against the urging force of the return spring 25.

  Thus, when the contact member 26 contacts the rotating member 21, a braking force can be applied to the rotation of the rotating member 21. Then, when the reverse rotation force is reduced thereafter, the contact member 26 is projected by the urging force of the return spring 25, so that the rotation member 21 can be reliably returned.

  As a modification of this other embodiment, when the pinion tooth portion 11 is shifted, the contact member 26 may be in contact with the end portion of the pinion tooth portion 11. In order to realize this, for example, a configuration in which the rotating member 21 is formed in a ring shape and the contact member 26 is inserted through the internal space of the rotating member 21 when the pinion 1 is shifted is conceivable.

(E) The outer surface shape of the rotating member 21 is formed into a taper shape with a taper on the downstream side in the protruding direction. Correspondingly, the braking surface 22 s of the braking member 22 is also formed in a shape along the outer surface shape of the rotating member 21. With this configuration, when the rotating member 21 is shifted, the rotating member 21 can be smoothly introduced into the braking surface 22s, and the braking force can be reliably applied.

(F) The outer surface shape of the rotating member 21 is formed into a reverse taper shape in which the downstream side in the protruding direction slightly widens. Correspondingly, the braking surface 22 s of the braking member 22 is also formed in a shape along the outer surface shape of the rotating member 21. With this configuration, when the rotating member 21 is shifted and then brought into contact with the braking surface 22s by the displacement force F2, the operation of the rotating member 21 in the return direction along the drive axis X is limited. Thus, it is possible to maintain a good braking state.

(G) The braking mechanism 3 is configured such that the protruding end surface of the rotating member 21 that rotates integrally with the pinion tooth portion 11 contacts the braking surface 22 s (braking portion) of the braking member 22. The configuration of the braking mechanism 3 functions in the same manner as the disc brake.

  As a modified example of such a configuration, a plurality of engaging recesses may be formed instead of the braking surface 22 s serving as a braking portion, and an engaging protrusion may be formed on the end surface on the protruding side of the rotating member 21. Even in this modification, it is possible to reliably prevent the rotation of the rotating member 21 during the shift operation.

  The present invention can be used in a gear reduction device including a pinion and a face gear.

DESCRIPTION OF SYMBOLS 1 Pinion 2 Face gear 3 Braking mechanism 10 Pinion shaft 11 Pinion tooth part 13 Holding spring (biasing member)
16 Face tooth portion 21 Rotating member 21a Columnar member 21b Contact friction body 22s Braking surface (braking portion)
25 Return spring 26 Contact member 100 Gear reduction device X Drive shaft core Y Actuation shaft core

Claims (5)

A pinion formed with a helical pinion tooth portion centered on the drive shaft core with respect to a pinion shaft rotating about the drive shaft core;
A face gear having a face tooth portion formed on one side surface of the outer periphery of a disk-like portion that is rotatably arranged around an operating shaft core in a posture orthogonal to the drive shaft core in a positional relationship that is different from the drive shaft core. ,
The pinion is allowed to shift in the direction along the drive shaft core by a shift force acting between the pinion tooth portion and the face tooth portion when a reverse force acts on the face gear,
A gear provided with a braking mechanism that applies a braking force to the pinion when the braking unit comes into contact with at least one of the rotating member that rotates integrally with the pinion and the pinion tooth portion by performing the shift operation. Reducer.   The rotating member is configured to include an outer peripheral surface centered on the drive shaft core, and the braking member is a concave shape that is fitted when the rotating member performs the shift operation, and is released in the direction of the face gear. The gear reduction device according to claim 1, comprising a surface.   The rotating member protrudes and forms a plurality of contact friction bodies on the outer periphery of a cylindrical member centering on the drive shaft core, and the contact friction body protrudes in a direction opposite to the rotation driving direction of the pinion. The gear reduction device according to claim 2, wherein the gear reduction device is formed in a posture.   The rotating member is configured to include an outer peripheral surface centered on the drive shaft core, and the braking portion that contacts the outer peripheral surface of the rotating member during the shift operation of the rotating member is brought into contact with the shift operation. The gear reduction device according to claim 1, wherein the gear reduction device is formed as a braking surface having a shape in which an area increases or a shape in which a contact area decreases with the shift operation.   A contact member that contacts at least one of the rotating member and the pinion tooth portion and operates in a shift direction, and a return spring that biases the contact member in a direction opposite to the shift operation. Item 5. The gear reduction device according to any one of Items 1 to 4.

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