JPH0525029U - Speed reducer for electrical components - Google Patents

Abstract

(57) [Abstract] [Purpose] In a reduction gear device in which a rubber damper is interposed between wheels and power is transmitted between the wheels by compression of the rubber damper, improvement of initial impact force absorption is achieved. Secure a clearance space when the rubber damper is compressed. [Structure] A chamfered portion 8f is formed at a corner portion of the rubber damper 8.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a speed reducer for electrical equipment mounted on vehicles such as automobiles, buses, and trucks.

[0002]

[Problems to be Solved by Prior Art and Invention]

 In general, some of the reduction gears of this type include a rubber damper to measure the impact absorption during the transmission process from the worm wheel meshing with the worm gear provided on the motor output shaft to the power take-off shaft. As such a thing, those disclosed in JP-A-60-73982 and JP-A-62-82457 are generally known. That is, as shown in FIG. 8, basically, in these devices, the power take-off shaft 11 is rotatably supported on the inner peripheral surface of the boss cylinder portion 10a formed in the casing 10 through the bearing 12, and A worm wheel 14 meshing with a worm gear 13 is rotatably supported on the outer peripheral surface of the boss cylinder portion 10a, and a plate 15 engaged with the worm wheel 14 and a power take-off shaft 11 are integrally provided. The rubber damper 17 is interposed between the plate 16 and the plate 16 so that the rubber damper 17 is elastically twisted so as to absorb the shock in the power transmission system from the worm wheel 14 to the power takeoff shaft 11.

However, in this type, since the rubber damper is twisted at both end sides in the axial direction, if the adhesion between both plates and the rubber damper is insufficient, there is a fear that the rubber damper may be separated from the plate. Instead, these plates themselves need to be made of strong metal plates, and the power take-off shaft is also supported by a casing through a dedicated bearing, which is a factor that impairs weight reduction. Therefore, the applicant provided a new speed reducer as Japanese Patent Application No. 3-55728 and improved these drawbacks. In this one, the reliability is further improved and the initial impact force is further improved. It is proposed to ensure absorption.

[0004]

[Means for Solving the Problems]

 The present invention was devised with the object of providing a speed reducer for electrical equipment that can eliminate these drawbacks in view of the above-mentioned circumstances, and a worm gear of a motor output shaft meshes in a decelerated state. In a speed reducer for electrical equipment that elastically transmits power from a worm wheel to a power take-off shaft via a rubber damper, the worm wheel has a wheel gear meshing with the worm gear engraved on the outer peripheral surface. And a boss cylindrical portion that is rotatably supported on the outer peripheral surface of the casing boss cylindrical portion of the reduction gear transmission. A second wheel integrally formed with a boss cylindrical portion that is rotatably supported on the surface and an outer peripheral portion that rotatably supports the inner peripheral surface of the first wheel outer cylindrical portion is provided. E Of the first boss and the second wheel, which are opposed to each other. On the wheel plate surface to be rotated, pressing pieces are provided so as to be in a disengaged state with a predetermined distance from each other in the wheel rotating direction, and a rubber damper is interposed in the gap between the adjacent pressing pieces. The power transmission from the wheel to the second wheel is configured to be elastically performed by compression of the rubber damper, and each rubber damper has a surface facing the pressing piece and a plate surface of the first and second wheels. It is characterized by forming chamfers at the corners of the facing surface.

According to the present invention, according to this structure, the impact can be absorbed by the compression of the rubber damper, and the initial impact force can be surely absorbed, and the escape space at the time of the compression of the rubber damper can be secured. It was done.

[0006]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. In the drawing, reference numeral 1 denotes a casing in which a speed reducer for reducing the power from an electric motor 2 is incorporated, and a boss cylinder portion 1a is formed on the casing 1 so as to project therefrom. In addition, the boss cylinder portion 3a of the first wheel 3 made of resin is rotatably supported. On the outer peripheral surface of the outer cylinder portion 3b formed on the first wheel 3, a wheel gear 3c meshing with a worm gear 4 provided integrally with the output shaft 2a of the electric motor 2 is formed.

On the other hand, 5 is a power take-off shaft, and the power take-off shaft 5 is integrally formed by the cold forging method up to the output gear 5 a at the tip. A chamfered portion 5b is formed on the base end of the chamfered portion. Further, 6 is a second wheel, the power take-out shaft 5 is rotatably inserted into the boss cylinder portion 6a of the second wheel 6, and is fitted into the chamfered portion 5b in a rotation-stop manner. The rectangular connecting plate 7 is fitted into the stop groove 6b formed in the second wheel 6 in a rotation stop state, and the C-shaped stop ring prevents the power take-off shaft 5 and the second wheel from being pulled out. 6 is integrally connected to the inner peripheral surface of the casing boss cylindrical portion 1a, but the outer peripheral surface of the second wheel boss cylindrical portion 6a is rotatably fitted into the inner peripheral surface of the casing boss cylindrical portion 1a. When the second wheel 6 is assembled in the casing 1, the outer peripheral portion 6c of the second wheel 6 slides on the inner peripheral surface of the first wheel outer cylindrical portion 3b to support the first wheel 3. It has become.

[0008] Further, three pressing pieces 3d and 6d are provided on each of the plate surface portions of the first wheel 3 and the second wheel 6 which are opposed to each other at predetermined intervals in the wheel rotation direction. A rubber damper 8 in the form of a block is interposed in the gap between the adjacent pressing pieces 3d and 6d. When the first wheel 3 is rotated by the driving of the electric motor 2, the pressing piece 3d on the first wheel 3 side presses the rubber damper 8 toward the pressing piece 6d on the second wheel 6 side. As a result, elastic power transmission is performed from the first wheel 3 to the second wheel 6, and each of these rubber dampers 8 has a connecting ring 8a formed of the same rubber material. It is configured as a one-piece body that is connected in series. Further, each rubber damper 8 has corners of surfaces 8b and 8c facing the pressing pieces 3d and 6d, and surfaces 8d and 8e facing the plate surface portions of the first and second wheels 3 and 6, respectively. A chamfered portion 8f is formed on each portion.

In the embodiment of the present invention configured as described above, the dynamic force from the motor output shaft 2 a is transmitted to the power take-off shaft 5 via the first wheel 3, the rubber damper 8 and the second wheel 6. It should be noted that the rubber damper 8 provided in this transmission process is interposed in the gap between the pressing pieces 3d and 6d which are arranged in a gap in the rotational direction of the wheels 3 and 6, and the rubber damper 8 rotates the wheel. By compressing in the same direction, elastic power is transmitted from the first wheel 3 to the second wheel 6 to absorb the shock, and as a result, the elastic power is generated by twisting the conventional rubber damper. There is no need to consider such as firmly adhering the rubber damper to the plate as in the case of transmission, and the rubber damper 8 only needs to be arranged between the pressing pieces 3d and 6d. For this reason, not only is the quality stable and the reliability is greatly improved, but also the metal plate for bonding the rubber damper is not required, which contributes to weight reduction.

Moreover, in the first wheel 3 in which the wheel gear 3c is formed, the boss cylinder portion 3a is supported by the casing boss cylinder portion 1a, and the outer cylinder portion 3b is further provided integrally with the power take-off shaft 5. Since it is supported by the outer peripheral portion 6c of the two wheels 6, it is possible to reliably prevent the first wheel 3 from being deformed by the load due to the meshing of the worm gear, and it is possible to prevent transmission problems such as tooth jumps. Can be avoided. On the other hand, in the second wheel 6, the boss cylinder portion 6a is supported by the casing 1, and the outer peripheral portion 6c is supported by the first wheel 3 supported by the casing 1. Since it is not necessary to support the power take-off shaft 5 through the bearing in the casing 1 as in the conventional case, the bearing can be omitted, and the number of parts can be reduced and the weight can be reduced. Become.

In addition, each rubber damper 8 is provided at each corner portion of the surfaces 8b and 8c facing the pressing pieces 3d and 6d and the surfaces 8d and 8e facing the plate surface portions of the first and second wheels 3 and 6, respectively. Since the chamfered portions 8f are respectively formed and the cross-sectional areas of both ends of the rubber damper 8 in the wheel rotation direction are smaller than the central portion, both ends of the rubber damper 8 are first deformed to absorb the initial impact force when absorbing the impact. Will be absorbed. As a result, as in the experimental example shown in FIG. 7, the rising time of the restraint torque can be delayed as compared with the case without the chamfered portion, and the impact force relaxation can be improved. Furthermore, the chamfered portion 8f can secure an escape space for the rubber damper 8 compressed, and the corner portion is located between the wheel plate surface portion and the pressing pieces 3d and 6d like the one without the chamfered portion. It is possible to avoid the fear of biting into the rotation of the first and second wheels 3 and 6, and also to assemble the rubber damper 8 in the wheel rotation direction without play, which results in Workability can be significantly improved.

[0012]

[Operation effect]

 In short, since the present invention is configured as described above, the power from the motor output shaft is transmitted to the power output shaft via the first wheel, the rubber damper, and the second wheel. The rubber damper provided in this transmission process is elastically transmitted from the first wheel to the second wheel by being compressed by the pressing pieces arranged in a disparate shape in the rotational direction of each wheel. As a result, the rubber damper is firmly attached to the plate, as in the case of elastic power transmission by twisting a conventional rubber damper. It only needs to be placed between the adjacent pressing pieces, which not only stabilizes the quality and greatly improves the reliability, but also eliminates the need for a metal plate for bonding the rubber damper, which makes it lightweight. It will be able to contribute to.

Moreover, since the outer cylinder portion of the first wheel on which the wheel gear is formed is supported by the second wheel integrally provided on the power take-off shaft, the outer cylinder portion is supported by the load caused by the worm gear meshing. The deformation of one wheel can be reliably prevented, and transmission problems such as tooth jump can be avoided. On the other hand, in the second wheel, the boss cylinder is supported by the casing, and Since the outer peripheral part is supported by the first wheel supported by the casing, it is not necessary to support the power take-off shaft through the bearing as in the conventional case, and the bearing is omitted. Therefore, the number of parts can be reduced and the weight can be reduced accordingly.

In addition, each rubber damper has chamfered portions formed at the corners of the surface facing the pressing piece and the surface facing the plate surface portions of the first and second wheels, respectively. Since the cross-sectional area at both ends in the direction is smaller than that at the center, both ends of the rubber damper will be deformed first to absorb the initial impact force during impact absorption. As a result, the rising time of the restraint torque can be delayed as compared with the case without the chamfered portion, and the impact force relaxation can be improved. Furthermore, since the escape space for the rubber damper compressed by the chamfer can be secured in this chamfer, the corner part digs into the gap between the wheel plate chamfer and the pressing piece as in the case without the chamfer. It is possible to avoid the fear of hindering the rotation of the wheel, and it is possible to assemble the rubber damper without looseness in the wheel rotation direction, which greatly improves the workability of the assembly work.

[Brief description of drawings]

FIG. 1 is an overall front view of an actuator for electrical equipment, showing a cross section of a reduction gear unit.

2A is a sectional view taken along the line AA of FIG. 1, and FIG. 2B is a sectional view taken along the line BB of FIG.

3A is a front view of the first wheel, FIG. 3B is a horizontal sectional view of the same, and FIG. 3C is a rear view of the same.

4A is a front view of the second wheel, FIG. 4B is a front view of the same, and FIG. 4C is a side view of the same.

5A is a front view of the rubber damper, FIG. 5B is a front view of the same, and FIG. 5C is a perspective view of the same.

FIG. 6 is a front view showing a state where a rubber damper is attached to the wheel.

FIG. 7 is a graph showing an experimental example of restraint torque rise time.

FIG. 8 is a horizontal sectional view of a speed reducer showing a conventional example.

[Explanation of symbols]

 2a Motor output shaft 3 First wheel 3a Boss cylinder part 3b Outer cylinder part 3c Wheel gear 3d Pressing piece 4 Worm gear 5 Power extraction shaft 6 Second wheel 6a Boss cylinder part 6c Outer peripheral part 6d Pressing piece 8 Rubber damper 8f Chamfering part

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F16H 1/16 Z 9240-3J 55/14 8012-3J H02K 7/116 6821-5H

Claims (1)

[Scope of utility model registration request] 1. A speed reducer for electrical equipment, wherein a worm wheel meshing with a worm gear of a motor output shaft in a decelerating state elastically transmits power to a power take-off shaft through a rubber damper. Is a first wheel in which an outer cylinder part in which a wheel gear meshing with a worm gear is engraved on the outer peripheral surface and a boss cylinder part that is rotatably supported on the outer peripheral surface of the casing boss cylinder part of the reduction gear transmission are formed. Further, the power take-off shaft is formed with a boss cylinder rotatably supported on the inner peripheral surface of the casing boss cylinder and an outer peripheral portion rotatably supporting the inner peripheral surface of the first wheel outer cylinder. The second wheel is integrally provided, and the first wheel is configured to be supported at two locations, that is, the casing boss tubular portion and the second wheel outer peripheral portion that is integrally provided on the power take-off shaft. Furthermore On the wheel plate surfaces of the first and second wheels facing each other, pressing pieces are respectively provided so as to be in a disagreeable state with a predetermined distance from each other in the wheel rotation direction, and between the adjacent pressing pieces. A rubber damper is interposed in the gap so that the power transmission from the first wheel to the second wheel is elastically performed by compression of the rubber damper, and each rubber damper has a surface facing the pressing piece and a second surface. (1) A speed reducer for electrical equipment, characterized in that chamfers are formed at respective corners of the surface of the second wheel facing the plate surface.