JPH10271751A - Geared motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a geared motor in which vibration resistance of a rotary displacement sensor can be enhanced. SOLUTION: A reduction gear 17 for driving a sensor has a gear housing 17B being fixed to a gear case 11. A rotary displacement sensor 16 is supported at the end part of the gear housing 17B through a member 18 for supporting the sensor on the bottom thereof. Head part of the rotary displacement sensor 16 is held on the bottom side of a sensor cover 22 through a sensor damper 27 disposed on inner surface at the bottom of the sensor cover 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor with a reduction gear provided with a rotational displacement sensor for detecting a rotational displacement of an output shaft or a shaft of a gear located at a stage preceding the output shaft.

[0002]

2. Description of the Related Art FIG. 4 shows the structure of a conventional electric motor with a speed reducer of this type. In the figure, 11 is the first
Is a gear case divided into a case half 11A and a second case half 11B, and the first and second case halves 11A and 11B are provided with through bolts with their respective openings abutting each other. They are mutually fastened by 11C.

In a gear case 11, gears 12a to 12a
The load reduction mechanism 12 for driving a load, which is a gear reduction mechanism provided with h. The output shaft 13 of the reduction mechanism 12
One end 13a supported by the first case half 11A and the second case half 11B via bearings 21 and 21 ', respectively, and connected to the load of the output shaft 13 is connected to the second case half 11B. It is led out through a hole 11B2 provided in the bottom wall 11B1. The load drive speed reducer 1 includes a gear case 11, a gear reduction mechanism 12, and an output shaft 13.
4 are configured.

The electric motor 15 is mounted on the first case half 11A, and constitutes an input portion of the speed reduction mechanism 12.
a is directly carved on the tip of the rotating shaft 15 a of the electric motor 15 inserted into the gear case 11. The other end of the output shaft 13 is led out through a through hole provided in the bottom wall 11A1 of the first case half 11A, and the other end of the output shaft 13 led out is connected to the first case half 11A. Is inserted into the sensor drive reduction gear 17 mounted on the outer surface of the sensor.

[0005] The sensor drive reduction gear 17 includes a gear 17a directly carved on the outer periphery of the other end of the output shaft 13 and a rotation shaft 17A.
Gear 1 attached to the gear and meshed with the gear 17a
7b is accommodated in a cylindrical housing 17B, and the rotating shaft 17A is supported by the housing 17B via a bearing.

[0006] Housing 17B of the reduction gear for driving the sensor
Is disposed in a state where the end plate 17B1 on one end side in the axial direction is fitted to the inner peripheral portion of an annular protrusion 11A2 provided on the outer surface of the bottom wall 11A1 of the first case half 11A, The end plate 17B1 is screwed to the bottom wall 11A1 of the first case half.

A gear 17a carved at the other end of the output shaft 13
Is connected to the housing 17 through a hole provided in the end plate 17B1.
B is engaged with the gear 17b of the rotating shaft 17A inserted into B. The tip 17A1 of the rotary shaft 17A of the sensor drive reduction gear penetrates the end plate on the other end side of the housing 17B and is led out.

In this example, the inner periphery of the annular projection 11A2 provided on the outer surface of the bottom wall 11A1 of the first case half 11A is fitted to the end of the housing 17B of the sensor drive reduction gear 17. It constitutes a positioning part for positioning. Also, the tip 17A1 of the rotating shaft 17A is the sensor drive reduction gear 1
7 constitute an output unit.

An inner peripheral portion of an opening end of a cylindrical sensor supporting member 18 is fitted to an outer peripheral portion of the annular projection 11A2, and is fitted by fitting the sensor supporting member 18 to an outer peripheral portion of the projection 11A2. , The sensor support member 18 is the sensor drive reduction gear 1
7 is positioned concentrically. The sensor support member 18 is fastened to the first case half 11A by a through bolt 19 provided so as to penetrate the peripheral wall of the support member in the axial direction. In this example, an outer peripheral portion of the annular projection 11A2 constitutes a spigot portion for positioning the sensor support member 18.

An endless rotary displacement sensor 16 having no restriction on the rotation angle range of the input shaft is fixed to an end wall of the sensor support member 18 on the side opposite to the sensor drive reduction gear 17 by bonding or the like. The rotational displacement sensor 16 is connected to the input shaft 1
6A and a signal generator 16B for outputting a detection signal corresponding to the rotation angle of the input shaft 16A. The signal generator 16B converts the rotational displacement of the input shaft 16A into an electric signal. Conversion means is accommodated. This conversion means is composed of, for example, a potentiometer (variable resistor), and can detect a 360-degree rotation angle of the input shaft 16A.

The input shaft 16A of the rotational displacement sensor 16 is rotatably supported by a boss 16C fixed to the housing of the signal generating section 16B, and the boss 16C is attached to the bottom wall of a bottomed cylindrical sensor support member 18. It is fitted into the provided through hole 18a. By this fitting, the input shaft 16A of the rotational displacement sensor and the rotational shaft 17A of the sensor drive reduction gear 17 are coaxially positioned.

The input shaft 16A of the rotational displacement sensor 16 and the tip 17A1 of the rotary shaft 17A of the sensor drive reduction gear 17
Is inserted into a hole provided in the coupling 20 and screwed into a screw hole provided in the coupling 20.
a and 20b are input shafts 16A of the rotational displacement sensor, respectively.
And the rotary shaft 17A of the sensor drive reduction gear. The coupling 20 is fixed to the input shaft 16A and the rotating shaft 17A by tightening these screws, and the input shaft 16A and the rotating shaft 17A are connected via the coupling 20. In order to enable the screws 20a and 20b to be tightened, a window 18b for inserting a driver is provided through the peripheral wall of the sensor support member 18.

The sensor support member 18 and the rotational displacement sensor 16
And a bottomed cylindrical cover 22 that covers The cover 22 has an opening end that is the first case half 11A.
Are fitted and positioned in an annular spigot provided on the outer surface of the bottom wall 11A1. The open end of the protective cover 22 is also connected via a packing 23 to the first case half 1.
An appropriate number of protruding portions 22a that are in contact with the outer surface of the bottom wall portion of 1A and protrude radially outward from the outer peripheral portion of the open end of the cover 22 are provided with the first case half portion 11A by screws 24. Has been concluded.

A sensor driving reducer 17 having an input connected to the other end of the output shaft 13 and a sensor driving reducer 1
7 (the tip 17A1 of the rotating shaft 17A) is connected to the input shaft 16
A, a rotational displacement sensor 16 to which A is coupled, a support member 18 that supports the rotational displacement sensor 16, a coupling 20,
The protective cover 22 forms a rotational displacement detector 25.

When mounting the rotational displacement detector 25, first, the sensor drive reduction gear 17 is mounted on the first case half 11A, and the output shaft 1 is connected to the gear 17b of the reduction gear.
The gear 17a provided at the other end of the third gear 3 meshes. Next, the coupling 2 is attached to the tip of the rotation shaft 17A of the reduction gear 17.
With the “0” temporarily fixed, the sensor support member 18 supporting the rotational displacement sensor 16 is attached, and the tip of the rotational shaft 16A of the rotational displacement sensor 16 is inserted into the hole of the coupling 20. Next, the screws 20a and 20b of the coupling 20 are tightened through the window 18b of the support member 18 to fix the coupling 20 to the rotating shaft 16A and the rotating shaft 17A of the reduction gear 17. Thereafter, the protective cover 22 is attached, and the assembly of the rotational displacement detector 25 is completed. Since all of these assembling operations can be performed from the axial direction of the output shaft 13, the gear case 11 is arranged on a work table with the bottom wall 11A1 of the first case half 11A of the gear case 11 facing upward. By sequentially incorporating the components of the rotational displacement detector 25 in this state, the rotational displacement detector 25 can be easily assembled.

Although not shown, the output lead wire of the rotational displacement sensor 16 is a grommet (rubber bushing) attached to a hole provided through the protective cover 22.
To the outside through

The output shaft 13 of such an electric motor with a speed reducer
Is connected to a load (not shown) directly or via an appropriate power transmission mechanism such as a lever or a link. When the electric motor 15 rotates, the output shaft 13 rotates to drive the load, and also drives the rotational displacement sensor 16 via the sensor drive reduction gear 17. Therefore, the rotation displacement sensor 16 outputs a detection signal corresponding to the rotation angle of the input shaft. The magnitude of the rotation angle that can be detected by the rotational displacement sensor 16 is determined by the reduction ratio of the sensor drive reduction gear 17. For example, if the reduction ratio of the sensor drive reduction gear 17 is 10: 1, the input shaft 16A of the rotational displacement sensor 16 makes one rotation while the output shaft 13 makes ten rotations.
A rotation angle (3600 degrees) over 10 rotations can be detected.

[0018]

However, in such a conventional motor with a speed reducer, the rotational displacement sensor 16 is not provided.
Of the gear case 1 with the through bolt 19 through the support member 18
1, the vibration of the actual machine to which the electric motor with the speed reducer is attached is directly transmitted without attenuating from the gear case 11 to the rotational displacement sensor 16. In general, the rotational displacement sensor 16 is vulnerable to vibration. For example, the rotational displacement sensor 16 including a wire-wound type potentiometer has a risk of disconnection due to vibration.

An object of the present invention is to provide a motor with a speed reducer that can improve the vibration resistance of a rotational displacement sensor.

Another object of the present invention is to provide an electric motor with a speed reducer that can easily mount a sensor damper for preventing vibration of a rotational displacement sensor into a sensor cover.

Another object of the present invention is to provide an electric motor with a speed reducer which can easily attach a sensor damper to a rotational displacement sensor.

[0022]

According to the present invention, there is provided an electric motor with a speed reducer, in which a load drive reduction mechanism is housed in a gear case, and an output shaft of the reduction mechanism is connected to the load. A speed reducer for use, an electric motor mounted on a gear case and having a rotating shaft coupled to an input portion of the speed reduction mechanism, and an input portion connected to an output shaft of the load drive speed reducer or a shaft of a gear positioned at a stage preceding the output shaft. And a rotational displacement detector attached to the gear case.The rotational displacement detector has an input portion coupled to an output shaft of the load drive reduction gear or a gear shaft located at a stage preceding the output shaft. A speed reducer for driving the sensor, and a rotational displacement sensor having an input shaft connected to an output portion of the speed reducer for driving the sensor and supported on the bottom of a bottomed cylindrical sensor support member. Drive reducer and sensor support And the rotational displacement sensor is housed in bottomed cylindrical sensor in the cover, the sensor cover is a structure that is attached to the gear case.

In the present invention, the sensor drive speed reducer is supported by the gear case by attaching the speed reducer housing to the gear case. The rotational displacement sensor is supported at the end of the reduction gear housing via a sensor support member that supports the rotational displacement sensor at the bottom. The top of the rotational displacement sensor is
It is held on the bottom side of the sensor cover via a sensor damper arranged on the inner surface of the bottom inside the sensor cover.

As described above, when the reduction gear housing is mounted on the gear case, the sensor support member is mounted on the end of the reduction gear housing, and the rotational displacement sensor is mounted on the end of the sensor support member. The support to the rotational displacement sensor has a flexible structure, and the vibration from the gear case to the rotational displacement sensor can be attenuated. Further, even if the rotational displacement sensor vibrates due to vibration transmitted through the reduction gear housing and the sensor support member, the vibration can be attenuated by the sensor damper. Therefore, the vibration resistance of the rotational displacement sensor can be improved.

In this case, the sensor damper is preferably fitted and supported on the inner surface of the bottom in the sensor cover. With this configuration, it is possible to easily mount the sensor damper for preventing vibration of the rotational displacement sensor into the sensor cover.

It is preferable that the sensor damper has a concave portion into which the top of the rotational displacement sensor is fitted. This makes it possible to easily attach the sensor damper to the rotational displacement sensor.

As the sensor damper, a non-sponge-like rubber molded product or a sponge-like rubber molded product is preferable. Such a sensor damper has an outer surface shape slightly larger than the inner surface shape on the bottom side of the sensor cover, and can be easily mounted inside the sensor cover by pushing it into the sensor cover. In the case of a sponge-like rubber-based molded product, the sponge-like rubber-based molded product is easily depressed by pressing against the top of the rotational displacement sensor, so that the sponge-like rubber-based molded product can be easily formed without a concave portion. The top of the rotational displacement sensor can be held.

[0028]

1 and 2 (A) and 2 (B) show an example of an embodiment of a motor with a reduction gear according to the present invention. FIG. 1 shows a main part of the present invention. FIG. 2A is a longitudinal sectional view of a rotational displacement detector, FIG. 2A is a side view of a sensor damper used in this example, and FIG. 2B is a bottom view of the sensor damper used in this example.

In this electric motor with a speed reducer, the speed reducer 17 for driving the sensor is supported by the gear case 11 by attaching the speed reducer housing 17B to the gear case 11 in the same manner as the conventional example shown in FIG. The rotational displacement sensor 16 includes a sensor support member 18 for supporting the rotational displacement sensor 16 at the bottom.
And is supported at the end of the reduction gear housing 17B by screws 26. The top of the rotational displacement sensor 16 is held on the bottom side of the sensor cover 22 via a sensor damper 27 arranged on the inner surface of the bottom inside the sensor cover 22. The sensor damper 27 is formed of a non-sponge-like rubber-based molded product such as chloroprene rubber having a hardness Hs of 30 to 40 degrees, and a concave portion 27 a in which the top of the rotational displacement sensor 16 is fitted is provided in advance on the bottom surface. . Such a sensor damper 27 has an outer surface shape slightly larger than the inner surface shape on the bottom side of the sensor cover 22 and is attached to the inner surface on the bottom side of the sensor cover 22 by being pushed into the sensor cover 22. ing. Further, the sensor damper 27 holds the top of the rotational displacement sensor 16 by fitting a concave portion 27a on the bottom surface thereof to the top of the rotational displacement sensor 16.

As described above, the reduction gear housing 17B is mounted on the gear case 11, the sensor support member 17 is mounted on the end of the reduction gear housing 17B, and the rotational displacement sensor 16 is mounted on the end of the sensor support member 17. Then, the support from the gear case 11 to the rotational displacement sensor 16 has a flexible structure, and the vibration from the gear case 11 to the rotational displacement sensor 16 can be attenuated. Further, even if the rotational displacement sensor 16 vibrates, the vibration can be attenuated by the sensor damper 27. Further, even if the vibration on the gear case 11 side is transmitted to the sensor cover 22, the vibration can be attenuated by the sensor damper 27, so that the vibration on the gear case 11 side does not directly transmit a large vibration to the rotational displacement sensor 16. Therefore, the vibration resistance of the rotational displacement sensor 16 can be improved.

In this case, the outer shape of the sensor damper 27 is slightly larger than the inner shape of the bottom of the sensor cover 22, and the sensor damper 27 is fitted and supported by being pushed into the inner bottom of the sensor cover 22. Mounting of the sensor damper 27 for shaking into the sensor cover 22 can be easily performed. Further, when the sensor damper 27 includes the concave portion 27a into which the top of the rotational displacement sensor 16 is fitted, the attachment of the sensor damper 27 to the rotational displacement sensor 16 can be easily performed.

FIGS. 3A and 3B show another example of the sensor damper 27 used in the present invention. FIG. 3A is a side view of the sensor damper used in the present example, and FIG. It is a bottom view of the sensor damper used in the example.

The hardness of the sensor damper 27 is Hs25.
It is formed in a square shape with a sponge-like rubber-based molded product such as a rubber sponge. In the case of the sensor damper 27 made of such a sponge-like rubber-based molded product, the concave portion 27
a is not provided.

The sensor damper 27 is also formed to have an outer surface slightly larger than the inner surface at the bottom of the sensor cover 22. Installed. The sensor damper 27 holds the top of the rotational displacement sensor 16 by pressing the bottom of the sensor damper 27 against the top of the rotational displacement sensor 16 so that the sensor damper 27 itself is depressed.

According to the sensor damper 27 made of such a sponge-like rubber-based molded product, when the sensor damper 27 is pressed against the top of the rotational displacement sensor 16, the sensor damper 27 is depressed, so that the sensor damper 27 can be easily formed without providing the concave portion 27 a in advance. The sensor damper 27 can hold the top of the rotational displacement sensor 16.

In the above example, an endless sensor whose rotation angle range of the input shaft is not limited (the input shaft can freely rotate) is used as the rotational displacement sensor 16. May be limited, it is also possible to use a multi-rotation type rotational displacement sensor capable of detecting a rotation angle over a number of rotations of the input shaft. In this case, the detectable rotation angle range is determined by both the reduction ratio of the reduction gear incorporated in the multi-rotation type rotational displacement sensor and the reduction ratio of the sensor drive reduction gear 17. For example, when a five-rotation type multi-rotation displacement sensor is used as the rotation displacement sensor 16, the reduction ratio of the sensor drive reduction gear 17 is set to 1.4.
Then, a rotation angle (360 × 7 degrees) over seven rotations can be detected. Therefore, even when only two types of multi-rotational rotational displacement sensors, a 5-rotational rotational displacement sensor and a 10-rotational rotational displacement sensor, are available, it is possible to detect the rotational angle over an intermediate rotational speed. It is possible to increase the degree of freedom in setting the rotation angle detection range.

In the above example, the motor 15 is mounted on the first case half 11A of the case 11, but the motor 15 may be mounted on the case 11 on the side of the second case half 11B.

[0038]

In the motor with a speed reducer according to the present invention, the speed reducer housing is mounted on the gear case, the sensor support member is mounted on the end of the speed reducer housing, and the rotational displacement sensor is mounted on the end of the sensor support member. Because of the stacked structure, the support from the gear case to the rotational displacement sensor has a flexible structure, and the vibration from the gear case to the rotational displacement sensor can be attenuated.
Further, since the top of the rotational displacement sensor is held on the bottom side of the sensor cover via a sensor damper disposed on the inner surface of the bottom inside the sensor cover, the rotational displacement is caused by vibration transmitted through the reduction gear housing and the sensor support member. Even if the sensor vibrates, the vibration can be attenuated by the sensor damper. Therefore, the vibration resistance of the rotational displacement sensor can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a rotational displacement detector which is a main part of an example of an embodiment of an electric motor with a speed reducer according to the present invention.

FIG. 2A is a side view of a sensor damper used in this example, and FIG. 2B is a bottom view of the sensor damper used in this example.

3A and 3B show another example of a sensor damper used in the present invention, wherein FIG. 3A is a side view of the sensor damper, and FIG.
Is a bottom view of the sensor damper.

FIG. 4 is a longitudinal sectional view of a conventional electric motor with a speed reducer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Gear case 11A 1st case half 11A1 1st case half bottom wall 11B 2nd case half 11C Through bolt 12 Reduction mechanism 12a-12h Gear 13 Output shaft 14 Load drive reduction gear 15 Motor 15a Rotation Shaft 16 Rotational displacement sensor 17 Sensor drive reduction gear 17A Rotation shaft 17B Housing 17a Gear 17b Spur gear 18 Sensor support member 19 Through bolt 22 Sensor cover 27 Sensor damper 27a Recess

Claims (5)

[Claims] 1. A load drive reduction mechanism in which a load drive reduction mechanism is housed in a gear case and an output shaft of the load reduction mechanism is connected to a load. An electric motor coupled to an input of the mechanism, and a rotational displacement detector attached to the gear case with an input coupled to an output shaft of the load driving reducer or a shaft of a gear positioned upstream of the output shaft. A rotational displacement detector, wherein the rotational displacement detector has a sensor driving reduction gear having an input portion coupled to an output shaft of the load driving reduction gear or a shaft of a gear located at a stage preceding the output shaft; and A rotational displacement sensor having an input shaft coupled to an output portion of the reduction gear for rotation and supported on the bottom of a bottomed cylindrical sensor support member. Sensor and bottomed cylindrical A motor with a speed reducer housed in a sensor cover and the sensor cover attached to the gear case, wherein the sensor drive speed reducer is supported by the gear case by attaching the speed reducer housing to the gear case; The rotational displacement sensor is supported at an end of the reduction gear housing via the sensor support member that supports the rotational displacement sensor at the bottom, and a top of the rotational displacement sensor has a sensor damper disposed on a bottom inner surface in the sensor cover. An electric motor with a speed reducer, which is held on the bottom side of the sensor cover via the sensor cover. 2. The electric motor with a reduction gear according to claim 1, wherein the sensor damper is fitted and supported on an inner surface of a bottom portion in the sensor cover. 3. The electric motor with a reduction gear according to claim 1, wherein the sensor damper has a concave portion into which a top of the rotational displacement sensor is fitted. 4. The electric motor with a speed reducer according to claim 1, wherein said sensor damper is a non-sponge-like rubber-based molded product. 5. The electric motor with a reduction gear according to claim 1, wherein the sensor damper is a sponge-like rubber-based molded product.