JP2597790Y2 - Motor with reduction mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a motor with a speed reduction mechanism used as a wiper motor, for example, in which two worm wheels are arranged opposite to each other on both sides of a motor shaft provided with two worms. The present invention relates to a motor with a speed reduction mechanism configured to cancel a thrust load applied to a motor shaft.

[0002]

2. Description of the Related Art Conventionally, a motor having a speed reduction mechanism as described above has, for example, a structure in which a gear case is connected to an open end of a motor yoke, and the speed reduction mechanism is housed inside the gear case closed by a gear cover made of an iron plate. There is something to do. This reduction mechanism includes two worms formed at the tip end of a motor shaft protruding into a gear case and facing each other, and two reduction worms arranged on opposite sides of the motor shaft to mesh with the worms. Wheels and
The speed reduction worm wheel is composed of two reduction gear pinions provided integrally with each other and an output gear meshing with the reduction gear wheel. The two reduction gear worm wheels integrally having the reduction gear pinions are supported by being sandwiched between a gear case and a gear cover. Thus, the movement of these deceleration worm wheels in the thrust direction when the motor is operated is restricted.

[0003]

In the motor with a speed reduction mechanism described above, the gear case is closed by a gear cover made of iron plate, so that the movement of the speed reduction worm wheel in the thrust direction during the operation of the motor is satisfied. However, when an electric circuit is set on the gear cover, it is necessary to install another synthetic resin component, which has been expensive.

Therefore, recently, a synthetic resin gear cover has been used instead of an iron plate gear cover. In this case, for example, a large load is required for this motor with a speed reduction mechanism. If it is used as a wiper motor, it can not be said that there is no risk of causing problems such as cracks due to the moving force of the deceleration worm wheel in the thrust direction, and eventually it is necessary to add another structure to prevent the movement of the deceleration worm wheel, There is a problem that the cost is increased, and it has been a conventional problem to solve this problem.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and it is possible to restrict the movement of the deceleration worm wheel in the thrust direction during operation without damaging the gear cover. In addition, it is an object of the present invention to provide a motor with a speed reduction mechanism that also realizes cost reduction.

[0006]

According to the present invention, there is provided a motor shaft having two worms whose teeth run in opposite directions, and two reduction gears which are disposed on both sides of the motor shaft and mesh with the worm. A worm wheel, two worm portions of the motor shaft and two reduction worm wheels are accommodated in a gear case, and the gear case is closed by a synthetic resin gear cover fixed to the gear case via a plurality of screws. In the motor with a speed reduction mechanism, the two speed reduction worm wheels are sandwiched by the gear case and the gear cover,
The gear cover is characterized in that a rib is provided on a line passing substantially on the axis of the reduction worm wheel and connecting the screws, and the configuration of such a motor with a reduction mechanism is described above. This is a means for solving the conventional problem.

[0007]

In the motor with the speed reduction mechanism according to the invention, when a load in the thrust direction is applied to the two speed reduction worm wheels during operation, the load is received by the gear case and the gear cover. At this time, the gear cover is provided with a rib passing substantially on the axis of the deceleration worm wheel, and since the rib is provided by connecting screws for fixing the gear cover to the gear case, the rib is provided in the thrust direction. The portion where the largest stress is applied by the load is reinforced, and therefore the gear cover regulates the movement of the reduction worm wheel in the thrust direction without any trouble.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIGS. 1 to 4 show an embodiment of a motor with a speed reduction mechanism according to the present invention. In this embodiment, the motor with a speed reduction mechanism according to the present invention is a wiper motor.

As shown in FIG. 2, a wiper motor (motor with a speed reduction mechanism) 1 has an armature 3 and a commutator 4 fitted on a motor shaft 2 and an opening end 6a of a motor yoke 6 accommodating a magnet 5 and the like. A gear case 7 having a built-in reduction mechanism is connected thereto, and the distal end side of the motor shaft 2 penetrates the holder base 8 and protrudes into the gear case 7.

The deceleration mechanism includes two worms 2a and 2b formed integrally with the tip of the motor shaft 2 and having oppositely directed tooth traces, and worms 2a disposed opposite to both sides of the motor shaft 2. , 2b, respectively, and an output gear 11 which meshes with two reduction pinions 9a, 10a provided coaxially and integrally with the reduction worm wheels 9, 10, respectively. It is.

In this case, the gear case 7 is opened at the upper side in FIG. 3, and the two reduction worm wheels 9 and 10 each have a pin hole 9b (only one is shown) provided at the bottom of the gear case 7. 12 (only one is shown), and the output gear 11 is fixed to an end of the output shaft 13 which is prevented from slipping through the bottom of the gear case 7.

As shown in FIG. 4, a clearance groove 7a is provided on the bottom of the gear case 7 below the worms 2a and 2b of the motor shaft 2.
By tilting the motor shaft 2 about a bearing 2c that supports the distal end of the worm, the worms 2a and 2b can be moved so that they can be removed from between the speed reduction worm wheels 9 and 10.

The open end of the gear case 7 is closed by a gear cover 14. This gear cover 1
Numeral 4 is formed of a synthetic resin, and a projection 14a (only one of which is shown) substantially in contact with the tip of each of the deceleration pinions 9a, 10a of the deceleration worm wheels 9, 10 is integrally provided on the inner surface thereof. When the open end of the gear case 7 is closed by the gear cover 14, the deceleration worm wheels 9, 10 are sandwiched between the projection 14a and the bottom of the gear case 7 to restrict the movement in the respective axial directions. .

On the other hand, ribs 14b, 14b and a terminal block receiver 14c are integrally provided on the upper surface of the gear cover 14, as shown in FIG. These ribs 14b, 14b allow the gear cover 14 to
1 between the two screws 15 on the upper side in FIG. 1 and between the two screws 15 on the right side in FIG. 1, respectively, and pass almost above the protrusions 14a for holding the reduction worm wheels 9 and 10, respectively. In other words, by passing over approximately the axis P, Q of each of the reduction worm wheels 9, 10, respectively.
The gear cover 14 made of synthetic resin is prevented from being deformed or cracked by the thrust load of the reduction worm wheels 9 and 10 transmitted via the protrusions 14a when the motor is operated.

The terminal block receiver 14c is a high rotation terminal 1 connected to the brush 16 on the holder base 8.
7, a low rotation terminal 18, a ground terminal 19 and an auto stop terminal 20 connected to an auto stop switch 22 provided on the inner surface of the gear cover 14, and a power supply terminal 2.
1 is fitted into the terminal block 29, and the terminal block 29 is covered with a connector cover 30. In this case, the terminals 17 to 21 are connected to the gear cover 1.
4 and is connected to the brush 16 side and the auto stop switch 22 side inside the gear cover 14. In particular, hook-shaped connection terminals 18a (the connection terminals of the high rotation terminal 17 and the power supply terminal 21 are omitted) connected to the high rotation terminal 17, the low rotation terminal 18 and the power supply terminal 21 by caulking are holders. The connection to the brush connection terminal 28 on the base 8 side is made at the same time when the gear cover 14 is assembled. The auto stop switch 22 is connected to the auto stop terminal 20 and has an auto stop plate 23 integrally formed with a rotary shaft 23 a by drawing, and a contactor 25 rotatably fitted to the rotary shaft 23 a of the auto stop plate 23 by a push nut 24. And a power supply connection plate 27, which is connected to the ground terminal 19 and the contact 25a of the contactor 25 is in contact with and separates from the power supply connection plate 27. When the wiper switch (not shown) is turned off, the contact 25a of the contactor 25 is The wiper motor 1 is stopped in a predetermined state by rotating the contactor 25 so that the wiper motor 1 contacts the power supply connection plate 27.

In the wiper motor 1, when a load in the thrust direction is generated on the two reduction worm wheels 9, 10 during operation, the reduction worm wheels 9, 10 are connected to the bottom of the gear case 7 and the projection 14 a of the gear cover 14. This load will be received by being pinched.

At this time, the two screws 15 on the right side of FIG. 1 and between the two screws 15 on the upper side of FIG.
And the ribs 14b, 14b passing substantially on the axes P, Q of the deceleration worm wheels 9, 10, respectively, are provided. Will be reinforced.

Therefore, the gear cover 14 regulates the movement of the reduction worm wheels 9, 10 in the thrust direction without causing deformation or cracking.

If the motor shaft 2 on which the armature 3 and the commutator 4 are fitted needs to be replaced, the gear case 7
A relief groove 7a located below the worm 2a, 2b portion of the motor shaft 2 is provided at the bottom of the motor shaft 2, so that the worm 2a, 2b portion is pressed toward the side opposite to the output gear 11, When the motor shaft 2 is tilted about the bearing 2c, the worms 2a and 2b move to the clearance groove 7a, so that the motor shaft 2 can be replaced.

Further, in the wiper motor 1, since the rotation shaft 23a is formed integrally with the auto stop plate 23, the number of parts and the cost can be reduced.

In this embodiment, the case where the motor with the speed reduction mechanism according to the present invention is a wiper motor has been described, but the present invention is not limited to this.

Further, the detailed configuration of the motor with a speed reduction mechanism according to the present invention is not limited to the configuration of the above-described embodiment.

[0024]

As described above, in the motor with a speed reduction mechanism according to the present invention, the above-described configuration allows the motor to receive the thrust load generated on the speed reduction worm wheel during operation without harming the gear cover. Since there is no need to use other components to receive the thrust load, a very excellent effect that cost reduction can be realized is brought about.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view of a wiper motor showing an embodiment of a motor with a speed reduction mechanism according to the present invention.

FIG. 2 is an explanatory plan view of a partially crushed state of the wiper motor shown in FIG. 1 with a gear cover removed.

FIG. 3 is an explanatory sectional view of a gear case portion of the wiper motor shown in FIG. 1;

FIG. 4 is an explanatory side view of a partially crushed wiper motor shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wiper motor (motor with reduction mechanism) 2 Motor shaft 2a, 2b Worm 7 Gear case 9, 10 Reduction worm wheel 14 Gear cover 14b, 14b Rib 15 Screw P, Q Shaft center of reduction worm wheel

Claims (1)

(57) [Scope of request for utility model registration] A motor shaft having two worms whose tooth traces face in opposite directions; and two reduction worm wheels disposed on opposite sides of the motor shaft and meshing with the worms, respectively. A motor with a speed reduction mechanism in which the two worm portions and two reduction worm wheels are housed in a gear case and the gear case is closed by a synthetic resin gear cover fixed to the gear case via a plurality of screws. A gear case and a gear cover sandwiching the two reduction worm wheels, and the gear cover is provided with a rib on a line passing substantially on the axis of the reduction worm wheel and connecting the screws. Motor with mechanism.