JP2001021008A - Worm reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent push-back caused when a worm reduction gear is pushed back from a worm wheel side by external force in the case where the worm reduction gear is operated or stopped by arranging a means for push-pressing a worm to a worm wheel. SOLUTION: In a worm reduction gear 10, a motor 14, a worm 16, and a worm wheel 18 are housed in a housing 12. An oval sliding groove 28 is disposed in the housing 12 so that a pair of ball bearings 24 are slid in the X-direction perpendicular to the axial direction of a work shaft. Each spring 32 is arranged between a recessed part 30 disposed on a lower side of the sliding groove 28 and the ball bearing 24. The spring 32 is formed as an extending spring in order to push-press the ball bearing upward. Namely, the ball bearings 24 are energized upward by a pair of spring 32, and thereby, the whole of the worm 16 is push-pressed to the worm wheel 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a worm reducer used for a massage machine, an actuator, and other mechanical devices.

[0002]

2. Description of the Related Art In a worm speed reducer, a worm is mounted on a rotating shaft of a motor, and the worm and the worm wheel are screwed together. Due to the difference in the number, the rotation speed of the motor is reduced.

In this worm speed reducer, when the motor is operated or stopped, the worm wheel is pushed back by an external force from the worm wheel side. Therefore, an electromagnetic brake or a friction brake is used to prevent the pushing back.

However, when an electromagnetic brake is used, the cost is increased, and when a friction brake is used, there is a problem that additional parts such as a disk for a brake are required, which also increases the cost. Was.

In view of the above problems, the present invention provides a worm speed reducer which can prevent the worm speed reducer from being pushed back by an external force from the worm wheel when the worm speed reducer is operated or stopped. It is.

[0006]

A worm speed reducer according to a first aspect of the present invention is a worm speed reducer in which a worm wheel is screwed onto a worm rotated by a motor to reduce the speed. The worm is pressed against the worm wheel. Means for performing the operation.

According to a second aspect of the present invention, there is provided a worm speed reducer in which a worm wheel is screwed onto a worm rotated by a motor to reduce the speed, wherein a sliding groove is provided in a housing of the worm speed reducer to rotate the worm. A bearing to be supported is slidably disposed inside the sliding groove, and the bearing is urged inside the sliding groove by an elastic body such as a spring so as to press the worm against the worm wheel. .

According to a third aspect of the present invention, there is provided a worm speed reducer in which a worm wheel is screwed onto a worm rotated by a motor to reduce the speed, wherein a bearing for rotatably supporting the worm is covered with a block member. A sliding groove is provided in the housing, and the block member is slidably disposed inside the sliding groove, and the elastic member such as a spring presses the worm against the worm wheel inside the sliding groove. The block member is biased.

According to a fourth aspect of the present invention, there is provided a worm speed reducer in which a worm wheel is screwed onto a worm rotated by a motor to reduce the speed, and an elastic body such as a spring is provided so as to press the worm against the worm wheel. This urges the rotating shaft of the worm.

According to a fifth aspect of the present invention, there is provided a worm speed reducer for reducing speed by screwing a worm wheel onto a worm rotated by a motor, wherein a space is provided between a housing of the worm speed reducer and the worm. The space is axially divided into a first space, a second space, and a passage connecting the first space and the second space. A brake member is housed inside the space, and the brake member connects the passage with the brake member. When passing, the worm is pressed to apply a brake.

According to a sixth aspect of the present invention, there is provided a worm speed reducer in which a worm wheel is screwed onto a worm rotated by a motor to reduce the speed, wherein the motor housing accommodating the motor, the worm and the worm wheel are accommodated. An elastic body for urging the wheel housing against the motor housing so that the wheel housing is rotatably mounted on the motor housing and the worm is pressed against the worm wheel. It is provided.

[0012]

According to the worm speed reducer of the present invention, when the worm is pressed against the worm wheel, a force is generated that presses the worm against the tooth surface against the worm wheel even in a running or stopped state. A friction force against slippage is generated, and it becomes difficult for the worm wheel to be turned by external force.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a plurality of embodiments of the present invention will be described in order.

(First Embodiment) A first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a longitudinal sectional view of a worm speed reducer 10 according to the present invention, and FIG. 2 is a sectional view taken along line AA in FIG.

The worm speed reducer 10 has a housing 1
2, a motor 14, a worm 16, and a worm wheel 18 are housed therein.

The rotating shaft of the motor 14 and the worm shaft 20 of the worm 16 are connected by a connecting device 22.
The worm shaft 20 is provided with a pair of ball bearings 2.
4 and 24 are rotatably supported. And
A worm wheel 18 is rotatably screwed to the worm 16.

The pair of ball bearings 24, 24 are housed inside the housing 12. The ball bearings 24 are arranged in the X direction orthogonal to the axial direction of the worm shaft 26 (hereinafter, simply referred to as the axial direction) in FIG. An oblong sliding groove 28 is provided inside the housing 12 so as to be slidable, as shown in FIG. A recess 30 is provided below the sliding groove 28, and a spring 32 is provided between the recess 30 and the ball bearing 24. This spring 32 is an extension spring in both FIG. 1 and FIG. 2 to press the ball bearing 24 upward. That is, the pair of springs 3
The entire worm 16 is pressed against the worm wheel 18 by urging the ball bearings 24, 24 upward by the 2, 32.

In the worm speed reducer 10, the worm 16 is rotated at a regular position by a reaction force between the worm 16 and the worm wheel 18 during a normal operation in which the motor 14 is rotating. That is, the ball bearings 24, 24 are located at the lower ends of the sliding grooves 28, 28 against the urging force of the springs 32, 32.

On the other hand, when the worm gear 10 is operated or stopped, the worm 16 is pressed against the worm wheel 18 by the force of the springs 32. Therefore, friction against the relative slip between the worm 16 and the worm wheel 18 is generated, and the worm 16 is hard to rotate due to external force. Therefore, the rotation of the worm 16 can be braked without using a conventional electromagnetic brake or friction brake, and a force for holding the stop position is generated.

(Second Embodiment) Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.

FIG. 3 shows a worm speed reducer 1 according to a second embodiment.
0 is a longitudinal sectional view, and FIG. 4 is a sectional view taken along line BB in FIG.

The difference between the present embodiment and the first embodiment is that a rectangular block member 34 is covered on the outer periphery of the ball bearing 24. And this block member 3
4 is slidable in the slide groove 28 in the X direction.

By placing the block member 34 on the ball bearing 24 in this manner, the ball bearing 24
When the slider slides in the sliding groove, the rattling can be prevented, and further, abrasion can be prevented, and the worm 16 can press the worm wheel 18 more reliably.

(Third Embodiment) A third embodiment of the present invention will be described with reference to FIG.

FIG. 5 shows a worm speed reducer 1 according to a third embodiment.
0 is a longitudinal sectional view.

In the first embodiment, the ball bearing 24 is pressed by the spring 32. In the present embodiment, the ball bearing 24 is slidable in the sliding groove 28.
As a means for pressing the worm shaft 2 as shown in FIG.
0 is biased by a spring 36 so as to be pulled upward.

The spring 36 is a compression spring and always pulls the worm shaft 20 upward.
Is pressed by the worm wheel 18.

(Fourth Embodiment) A worm speed reducer 10 according to a fourth embodiment of the present invention will be described with reference to FIGS.
explain.

FIG. 6A is a longitudinal sectional view of the worm speed reducer 10 according to the fourth embodiment, and FIG. 7 is a sectional view taken along line CC in FIG.

The feature of the present embodiment is different from the worm speed reducer 10 of the first to third embodiments in that the ball bearing 24
Is fixed at a predetermined position. Instead, a space 38 is provided between the housing 12 and the worm 16 facing the worm wheel 18. This space 38
Consists of a first space 40 and a second space 46, and a passage connecting the first space 40 and the second space 46.

As shown in FIG. 6B, an elastic brake member 4 made of a rectangular parallelepiped rubber or the like is provided inside the space 38.
6 are stored.

Hereinafter, a structure in which the worm 16 presses the worm wheel 18 in the worm speed reducer 10 will be described.

First, in a normal operation in which the motor 14 is rotating, the brake member 46 is stopped from the first space 40 through the passage 42 to the second space 44. In this case, since the passage 42 is narrower than the first space 40 and the second space 44, the brake member 46 presses the worm 16 when passing through the passage 42, and is an elastic body. Because of that, it passes in concave. However, since the motor 14 is rotating, the worm 16 rotates against the force, and the worm 16 does not stop.

On the other hand, when the motor 14 stops, the worm 16 tends to reverse due to the external force, so that the brake member 46 tends to move from the second space 44 to the first space 40 through the passage 42. When passing through the narrow passage 42, the brake member 46 presses the worm 16.

Unlike when the motor 14 is rotating,
Since the motor 14 is stopped, the worm 16 has no rotating force against the pressing force of the brake member 46, and the worm 16 stops when the brake member 46 is caught in the passage 42.

When the motor 14 is rotated again with the brake member 46 blocked in the passage 42, the worm 16 rotates against the pressing force of the brake member 46, and normal operation can be performed.

FIG. 8 shows a modification of the fourth embodiment. The difference is that in the fourth embodiment, the brake member 46 is different from that of FIG.
Although it was a rectangular parallelepiped as shown in (b), the point in FIG. 8 (a) is that it is cylindrical as shown in FIG. 8 (b).

Fifth Embodiment A worm speed reducer 10 according to a fifth embodiment will be described with reference to FIG.

The housing 12 of the worm speed reducer 10 of the present embodiment has a motor housing 48 for housing the motor 14.
And a wheel housing 50 that houses the worm 16 and the worm wheel 18.

The wheel housing 50 and the motor housing 48 are mounted so as to be rotatable about a fulcrum 52. The fulcrum 52 is provided at a position orthogonal to the axial direction, and is provided on an extension of the action line Y.

That is, as shown in FIG.
The worm 16 exerts a force on the worm wheel 18 in a direction orthogonal to the Z line along the tooth surface of No. 6. For this reason,
By providing the fulcrum 52 connecting the motor housing 48 and the wheel housing 50 on the action line Y which is a direction orthogonal to the tooth surface of the worm 16, the wheel housing 50 rotates about the fulcrum 52 by the force from the worm 16. Nothing.

A compression spring 54 may be provided above the motor housing 48 and the wheel housing 50, or an extension spring 56 may be provided below the motor housing 48 and the wheel housing 50. Are applied to the motor housing 48 clockwise. Thus, the worm 16 is configured to press the worm wheel 18.

Also in the worm speed reducer 10 of the fifth embodiment, a force pressing against the wavefront of the worm 16 is generated when the motor 14 is operating or stopped, and the worm 16
Becomes difficult to rotate.

[0045]

As described above, according to the worm speed reducer of the present invention, the worm constantly presses the worm wheel, and a pressing force is generated against the tooth surface of the worm even in the running or stopped state. A frictional force against the relative slip is generated, and the worm does not easily turn due to external force. In addition, the number of components for achieving this effect can be reduced, and the cost does not increase.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a worm speed reducer showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a longitudinal sectional view of a worm speed reducer according to a second embodiment.

FIG. 4 is a sectional view taken along line BB in FIG. 3;

FIG. 5 is a longitudinal sectional view of a worm speed reducer according to a third embodiment.

FIG. 6A is a longitudinal sectional view of a worm speed reducer according to a fourth embodiment. (B) is a perspective view of a brake member.

FIG. 7 is a sectional view taken along line CC in FIG.

FIG. 8A is a longitudinal sectional view of a worm speed reducer according to a modified example of the fourth embodiment. (B) is a perspective view of a brake member.

FIG. 9 is a longitudinal sectional view of a worm speed reducer according to a fifth embodiment.

[Explanation of symbols]

 Reference Signs List 10 worm reducer 12 housing 14 motor 16 worm 18 worm wheel 20 worm shaft 24 ball bearing 28 sliding groove 32 spring

Claims (6)

[Claims] 1. A worm speed reducer for decelerating a worm rotated by a motor by screwing a worm wheel onto the worm, further comprising means for pressing the worm against the worm wheel. 2. A worm speed reducer for reducing speed by screwing a worm wheel onto a worm rotated by a motor, wherein a sliding groove is provided in a housing of the worm speed reducer, and a bearing for rotatably supporting the worm is provided on the sliding. A worm reducer, which is slidably disposed inside the groove and urges the bearing inside the sliding groove by an elastic body such as a spring so as to press the worm against the worm wheel. 3. A worm speed reducer for reducing speed by screwing a worm wheel onto a worm rotated by a motor, wherein a bearing for rotatably supporting the worm is covered with a block member, and a sliding groove is formed in a housing of the worm speed reducer. The block member is slidably disposed inside the sliding groove, and the block member is urged inside the sliding groove by an elastic body such as a spring so as to press the worm against the worm wheel. A worm speed reducer, characterized in that: 4. A worm speed reducer for decelerating a worm rotated by a motor by screwing a worm wheel onto the worm, wherein the worm is rotated by an elastic body such as a spring so as to press the worm against the worm wheel. A worm reducer characterized by being biased. 5. A worm speed reducer for reducing speed by screwing a worm wheel onto a worm rotated by a motor, wherein a space is provided between a housing of the worm speed reducer and the worm, and the space extends in an axial direction. A first space, a second space, and a passage connecting the first space and the second space, wherein a brake member is housed in the space, and the worm is used when the brake member passes through the passage. A worm reducer characterized by applying a brake when pressed. 6. A worm speed reducer for reducing speed by screwing a worm wheel onto a worm rotated by a motor, comprising: a motor housing housing the motor; a wheel housing housing the worm and the worm wheel; The wheel housing is rotatably mounted on the motor housing, and an elastic body is provided for urging the wheel housing against the motor housing so as to press the worm against the worm wheel. Worm reducer.