JPH01316550A - Planetary gear type reduction gear - Google Patents

Abstract

PURPOSE:To prevent the seizure between a ring gear and a pad and prevent the change in a slip torque value caused by temperature change by forming at least one of the pad and an elastic member forming a friction type torque slip mechanism provided on the outer periphery side of a ring gear with a shape memory alloy. CONSTITUTION:If a rotary shaft 4 is fixed because of the failure of a motor, an output shaft 5 side tends to rotate by inertia causing a large load to act on a reduction mechanism 2. As this load gets above a torque slip value of a friction type torque slip mechanism 105, an A-line side ring gear 102 is rotated against the energizing force of the mechanism 105. When temperature rises to above a defined temperature, the shape of a pad 107 which is formed with a shape memory alloy is changed into an arc shape, thereby increasing the sliding contact area between the pad 107 and the ring gear 102. Thereby, the lowering of the frictional force between the pad 107 and ring gear 102 can be compensated, accordingly, preventing inadvertent rotation of the ring gear 102.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a planetary gear type reducer, and in particular, one provided with a torque slip mechanism that prevents damage to the device by slipping when an overload occurs. Regarding.

(Prior Art) A conventional example will be explained with reference to FIG. FIG. 7 is a sectional view showing the configuration of a conventional planetary gear type reducer, and the reference numeral 1 in the figure is
is a case in which a speed reduction mechanism 2 is used, and a motor 3 is installed above the case 1. The rotation output through the shaft 4 of the motor 3 is decelerated through the speed reduction mechanism 2 and output through the output shaft 5. Incidentally, the case 1 and the motor 3 side are connected by a fastening bolt 6, and a mounting flange 7 is formed at the lower end of the case 1. Ru.

Next, the configuration of the speed reduction mechanism 2 will be explained.

The speed reduction mechanism 2 is composed of a row A located on the motor 3 side, a row B located on the output shaft 5 side, and a ring gear 9 installed on the inner peripheral side of the case 1.

First, regarding the A row, A is fixed to the output shaft 4 of the motor 3.
A row-side sun gear 10 and an A-row side planet that meshes with the A-row sun gear 10 and meshes with the ring gear 9, and revolves around the A-row sun gear while rotating on its own axis due to the rotational force from the A-row sun gear 10. Gear 11 and this A
The A-row carrier 13 is connected to the row-side planet gear 11 via a bearing 12, allows the A-row planet gear 11 to rotate, and rotates as the A-row planet gear 11 revolves. On the other hand, regarding row B, the sun gear 14 on the row B side is fixed to the carrier 13 on the row A side, and the sun gear 14 on the row B side meshes with the sun gear 14 on the row B side and also meshes with the ring gear 9. A planet gear 15 on the B-row side that rotates on its own axis due to force and revolves around the sun gear 14 on the B-row side along the ring gear 9, and a planet gear on the B-row side that is connected to the B-row side planet gear 15 via a bearing 16. 15
and a B-row side carrier 17 that allows the rotation of the planet gear 15 and rotates as the B-row planet gear 15 revolves. The B row side carrier 17 is fixed to the output shaft 5.

Further, the A row side carrier 13 and the B row side carrier 17 are rotatably connected to each other via a bearing 18.

The rotation of the ring gear 9 is restricted by a plurality of pins 19, and an oil seal 21 and a bearing 22 are provided between the B row side carrier 17 and the case 1.
is installed. Furthermore, the reference numeral 23 in the figure is a seal ring.

According to the above configuration, the rotation of the motor 3 is outputted via the rotation shaft 4, and the rotation of the rotation shaft 4 causes the row A side sun gear 10 to be rotated.
rotates. Due to this rotation of the A row side sun gear 10, the A
As the row side planet gear 11 rotates, the ring gear 9
It revolves around the A row side sun gear 10 along. The revolution of the A-row planet gear 11 causes the A-row carrier 13 to rotate. When the A-row carrier 13 rotates, the B-row sun gear 14 rotates, and as the B-row sun gear 14 rotates, the B-row planet gear 15 rotates around the B-row sun gear 14 along the ring gear 9. revolves around. The revolution of the B-row side planet gear 15 rotates the B-row side carrier 17, and further rotates the output shaft 5. Due to this action, the rotation of the motor 3 is transmitted to the output shaft 5 in a decelerated state.

(Problems to be solved by the invention) According to the above configuration, there are the following problems. For example, the motor 3 may fail and the motor rotation shaft 4 may become stuck. In such a case, the output shaft 5 side continues to rotate due to inertia, and there is a risk that a mechanical lock state will occur and the speed reduction mechanism 2 will be damaged. This also applies when the rotation of the output shaft 5 side is restricted.

To deal with this, the ring gear is installed so that it can rotate, and under normal conditions, the ring gear is pressed down by an elastic member via a pad to restrict its rotation. A structure has been proposed in which the ring gear is rotated against the biasing force of an elastic member to prevent the occurrence of a mechanical lock.

However, in this case, the temperature of the sliding surface between the ring gear and the pad will rise and there is a risk of seizure, and the slip torque value will change due to temperature changes, which may impair stable operation. there were.

The present invention was made based on the above points, and its purpose is not only to prevent the occurrence of a mechanical lock state and maintain the integrity of the reduction mechanism, but also to prevent the occurrence of a mechanical lock state. The object of the present invention is to provide a planetary gear type reducer that can prevent seizure and prevent changes in slip torque values due to temperature changes.

(Means for Solving the Problems) A sun gear on the row A side that has been installed and a ring gear that meshes with the sun gear on the row A side and is attached to the inner circumferential surface of the case for the reduction mechanism so that its rotation is not restricted. The A-row planet gear rotates on its own axis due to the rotation of the A-row sun gear and revolves around the A-row sun gear along the ring gear, and the A-row planet gear is connected to the A-row planet gear and rotates as the A-row planet gear revolves. A row A side carrier rotates with the A row carrier, a B row sun gear fixed to the A row carrier and rotates as the A row carrier rotates, and a B row sun gear that meshes with the B row sun gear and meshes with the ring gear. B rotates on its own axis due to the rotation of the row side sun gear and revolves around the B row side sun gear along the ring gear.
A planetary gear comprising a row-side planet gear, and a row-B side carrier that is connected to the sun gear on the row-B side and is connected to the output shaft and rotates as the row-B planet gear revolves to rotate the output shaft. In the type reducer, a friction type torque slip mechanism is installed on the outer periphery of the ring gear, and this friction type torque slip mechanism has a pad that is placed in contact with the outer periphery of the ring gear. It is equipped with an elastic member that biases in the direction of the ring gear to restrict the rotation of the ring gear, and when a load exceeding a preset value is applied, the elastic member deforms elastically to release the rotation restriction of the ring gear by the pad. , at least one of the pad and the elastic member is made of a shape memory alloy,
This is characterized in that it compensates for changes in torque slip value due to temperature changes.

Next, the planetary gear type reduction mechanism according to the second claim is as claimed in claim 1.
In the described planetary gear type reducer, the friction type torque slip mechanism increases the sliding contact area of the pad with respect to the ring gear and/or increases the load applied by the elastic member when the temperature exceeds a preset value. It is characterized by preventing a decrease in the frictional force between the

Furthermore, in the planetary gear type reduction mechanism according to a third aspect, in the planetary gear type reduction gear according to claim 1, the friction type torque slip mechanism reduces the sliding contact area of the pad with respect to the ring gear when the temperature exceeds a preset temperature. This feature is characterized in that the pad and the ring gear are prevented from seizing by increasing the pressure and/or reducing the load applied by the elastic member.

(Function) First, in the planetary gear type reduction mechanism according to the first aspect, under normal conditions, the rotation of the ring gear is restricted by the frictional force between the ring gear and the pad pressed by the elastic member. The rotation of the motor rotates the A-row sun gear, which causes the A-row planet gear to rotate and revolve around the A-row sun gear along the ring gear. The revolution of the A-row planet gear rotates the A-row carrier, which rotates the B-row sun gear. The rotation of the B-row sun gear causes the B-row planet gear to rotate and revolve around the B-row sun gear along the ring gear. The revolution of the B-row planet gear causes the B-row carrier to rotate, thereby rotating the output shaft while being decelerated to a predetermined value.

If an overload acts on this, for example, if the motor rotation shaft becomes stuck due to a motor failure, the ring gear will rotate against the biasing force of the elastic member acting through the pad, prevents a mechanical lock condition from occurring. Therefore, the integrity of each component constituting the speed reduction mechanism is not impaired.

In addition, at least one of the pad and the elastic member is made of a shape memory alloy, which compensates for changes in the torque slip value due to temperature changes, and prevents loss of function of the friction type torque slip mechanism due to temperature changes. Prevents damage to torque slip mechanism and ring gear. Note that the method of compensating the torque slip value is arbitrary and may be configured depending on the purpose. A decrease in the frictional force between the pad and the ring gear is prevented by at least one of four configurations in which the pad changes shape to increase the sliding contact surface and a configuration in which the load by the elastic member is increased.

Furthermore, the planetary gear type reducer according to a third aspect of the present invention has a configuration in which the pad changes shape to reduce the sliding surface between the pad and the ring gear when the temperature exceeds a preset value.
Seizing between the pad and the ring gear is prevented by at least one of the structures in which the load applied by the elastic member is reduced.

(Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. 1 to 4. Incidentally, the same parts as in the prior art are denoted by the same reference numerals, and the explanation thereof will be omitted.

The ring gear 101 is axially divided into two parts: a ring gear 102 on the A row side and a ring gear 103 on the B row side. The rotation of the B row side ring gear 103 is restricted by a plurality of pins 104. On the other hand, the rotation of the A row side ring gear 102 is restricted by a friction type torque slip mechanism 105.

The friction type torque slip mechanism 105 includes a box 106 formed by protruding a part of the case 1 to the outer circumferential side, and is arranged inside the box 106 so that its inner circumferential surface is brought into contact with the outer circumferential surface of the A-row side ring gear 102. The torque spring 108 is housed in the box 106 and urges the pad 107 toward the ring gear 102, and the adjustment screw 109 closes the opening of the box 106 and supports the torque spring 108. ing. Note that the reference numeral 110 in the figure is a seal ring. The pad 107 is pressed against the A row ring gear 102 by a torque spring 108, and the rotation of the A row ring gear 102 is restricted by the frictional force between the pad 107 and the pad 107. In addition, if the motor rotation shaft 4 becomes stuck due to a failure of the motor 3, a large overload will be applied, but in that case, the A-row side ring gear 102 will resist the biasing force of the torque spring 108. and rotate, thereby preventing a mechanical lock condition from occurring.

The pad 107 has a shape as shown in FIG. That is, the inner circumferential surface of the pad 107 is formed linearly, so that it comes into line contact with the A-row side ring gear 102 at three locations.However, the shape of the pad 107 is not limited to this. Rather, an appropriate one should be selected in consideration of slip torque stability, accuracy, reproducibility, etc. Also, the pad 107 is made of a shape memory alloy, and when the temperature exceeds a preset temperature, As shown in FIG. 3, it changes in an arc shape. This allows pad 10
This increases the sliding surface area between the ring gear 7 and the ring gear 102, and prevents a decrease in frictional force and thus a slip torque value due to a rise in temperature. The changing shape of the pad 107 may be as shown in FIG. 4, in which both end portions change into an arc shape.

Further, the slip torque value can be arbitrarily set by changing the torque spring 108 or changing the load using the adjustment screw 109.

The operation will be explained based on the above configuration.

First of all, in normal times, in this case, the A row side ring gear 10
The rotation of motor 2 is regulated by a friction type torque slip mechanism 105, so that the rotation of motor 3 is transmitted to output shaft 5 while being decelerated to a predetermined value by the same action as in the conventional case.

Next, a case where a large overload acts will be explained. For example, a case will be described in which the motor 3 breaks down and the motor rotating shaft 4 becomes stuck. In this case, since the output shaft 5 side tends to rotate due to inertia, a large load acts on the speed reduction mechanism 2. This load is the friction type torque slip mechanism 1
If the torque slip value exceeds the torque slip value according to
rotates against the urging force of the This prevents a large load from acting on the deceleration RtR2 due to the rotation of the A-row side ring gear 102 and damaging its integrity.

In addition, even if the output shaft 5 side stops for some reason and the motor 3 continues to rotate, the ring gear 102 on the A row side rotates due to the same action to provide a slip state and decelerate. The integrity of the mechanism 2 can be maintained.

Next, a case where the temperature exceeds a preset temperature will be explained. When the temperature becomes high, the pad 107 and ring gear 10
There is a concern that the frictional force between the pad 107 and the pad 107 may decrease, but in the case of this embodiment, when the temperature exceeds a predetermined temperature, the shape of the pad 107 changes to an arc shape as shown in FIG. The sliding surface between pad 107 and ring gear 102 increases. This compensates for the decrease in the frictional force between the two. Therefore, the ring gear 102 will not rotate unexpectedly.

According to this embodiment, the following effects can be achieved.

First of all, even if the motor rotation shaft 4 becomes stuck due to a failure of the motor 3, or even if the output shaft 5 side stops rotating for some reason, the rotation of the A-row side ring gear 102 will cause slippage. Therefore, damage to the speed reduction mechanism 2 can be prevented. In particular, it is possible to compensate for a decrease in the frictional force between the ring gear 102 and the pad 107 due to a rise in temperature, thereby making it possible to obtain stable operation of the friction-type torque slip mechanism.

Further, the friction type torque slip mechanism 105 of this embodiment has a simpler structure and is less expensive than, for example, an electromagnetic clutch type.

Furthermore, since the structure utilizes the frictional force between the outer circumferential surface of the A-row side ring gear 102 and the inner circumferential surface of the pad 107, there is less slippage compared to other structures, such as those using balls, rollers, claws, etc. Further, the torque slip value can be easily changed by selecting the torque spring 107 or changing the load using the adjustment screw 108.

Next, a second embodiment will be described with reference to FIG. In this embodiment, the ring gear 101 is not divided into two parts in the axial direction, but is integrated as a conventional unit, and a friction two-lux slip mechanism 10 is provided.
5 was installed.

Furthermore, the third embodiment shown in FIG. 6 employs an integral ring gear 101 and has friction type torque slip mechanisms 105 installed at a plurality of locations. The other configurations of both the second and third embodiments are the same as those of the first embodiment, and the explanation thereof will be omitted.

Next, a fourth embodiment will be described. This pad is made of a shape memory alloy, and when the temperature exceeds a preset temperature, the pad changes shape to reduce the sliding contact area between the pad and the ring gear. This prevents burning due to sliding contact between the ring gear and the pad.

It should be noted that the present invention is not limited to the above embodiments,
For example, the torque spring may be made of a shape memory alloy to provide the compensation function, or both the pad and the torque spring may be made of the shape memory alloy to provide the compensation function.

(Effects of the Invention) As detailed above, according to the planetary gear reducer according to the present invention, when the torque exceeds a preset torque slip value, the ring gear rotates to provide a slip state. In addition to being able to maintain the health of the speed reduction mechanism and thus the speed reducer, it is also possible to provide stable operation regardless of temperature changes because it has a compensation function for temperature changes.

[Brief explanation of the drawing]

1 to 4 are diagrams showing a first embodiment of the present invention, in which FIG. 1 is a cross-sectional view of a planetary gear type reducer, FIGS. 2 to 4 are top views of pads, and FIG. 6 is a sectional view of the planetary gear type reducer according to the second embodiment, and FIG. 6 is a sectional view of the planetary gear type reducer according to the second embodiment. 1... Case, 2... Reduction mechanism, 3... Motor,
4...Motor rotating shaft, 5...Output shaft, 10...A
Row side sun gear, 11...A row side planet gear, 13
...A row side carrier, 14...B row side sun gear, 1
5...B row side planet gear, 17...B row side carrier, 101...ring gear, 102...A row side ring gear, 103...B row side ring gear, 105...
・Friction type torque slip mechanism, 107...pad, 1
08...torque spring. 9* 1 Zuko 2 [! 1 No. 4 Diagrams and Procedures Ne. 11) Correct placement (spontaneous) 1 Indication of the case 1986 Patent Application No. 149501, Name of the invention Planetary gear type reducer 3 Relationship with the person making the amendment Case Patent applicant address Tokyo 2-4-1 Hamamatsucho, Miyakominato-ku World Trade Center Building Name (092) Kayabae Gyo Co., Ltd. Representative Exhibitor Ken4 Agent Address: 150 ffi (409) 5040
Address: 3-28-15 Shibuya, Shibuya-ku, Tokyo Claims column and Detailed description of the invention column of the specification. The details of amendment No. 6 are as shown in the attached sheet. (1) Amend the Scope of Claims column as follows. Claims (1) A sun gear on the A row side fixed to the rotating shaft of the motor;
It meshes with this sun gear on the A row side, and also meshes with a ring gear attached to the inner circumferential surface of the reduction mechanism case in a state where its rotation is restricted, and rotates due to the rotation of the sun gear on the A row side, and rotates along the ring gear. A row-A planet gear that revolves around the row-side sun gear, a row-A carrier that is connected to the row-A planet gear and rotates as the row-A planet gear revolves, and a row-A carrier that is fixed to the row-A carrier. A sun gear on the row B side rotates as the row A side carrier rotates, and a sun gear on the row B side meshes with the sun gear on the row B side and meshes with the ring gear, rotates on its own axis due to the rotation of the sun gear on the row B side, and moves along the ring gear on the row B side. The B row side planet gear revolves around the sun gear,
In the planetary gear reducer, the planetary gear reducer includes a B-row side carrier that is connected to the B-row sun gear and is also connected to the output shaft and rotates as the B-row planet gear revolves to rotate the output shaft. A friction type torque slip mechanism is installed on the outer circumferential side of the ring gear, and this f-IP'A type torque slip mechanism has a pad that is placed in contact with the outer circumferential side of the ring gear, and normally the pad is moved toward the ring gear. and an elastic member that is energized to restrict the rotation of the ring gear, and elastically deforms to release the rotation restriction of the ring gear by the pad when a load exceeding a preset value is applied. and at least one of the elastic members is made of a shape memory alloy to compensate for changes in torque slip value due to temperature changes. (2) In the planetary gear type reducer according to claim 1, F'
The I-therapeutic torque slip mechanism increases the sliding contact area of the pad against the ring gear and/or increases the load applied by the elastic member when the temperature exceeds a preset value, thereby reducing the F! between the pad and the ring gear. A planetary gear type speed reducer characterized by preventing a decrease in frictional force. (3) In the planetary gear type reducer according to claim 1, the friction type torque slip mechanism reduces the sliding contact area of the pad with respect to the ring gear and/or reduces the load caused by the elastic member when the temperature exceeds a preset temperature. A planetary gear reducer characterized in that the pad and ring gear are prevented from seizing. (2) Line 2 of page 10 of the specification, line 10 of page 10 of the specification, line 8 of page 12 of the specification, line 14 of page 12 of the specification, and line 2 of page 18 of the specification. Correct "weight" to "load". Above Procedures - 7i'11 Official Book (Method) 1 Indication of Case 1986 Patent Application No. 149501, Name of Invention Planetary Gear Reducer 3 Relationship with 41 Amendments Patent Applicant Address Hamamatsu, Minato-ku, Tokyo 2-4-1 World Trade Center Building Name (092) Kayabae Gyo Co., Ltd. Representative Ken Enbe 4 Agent 150 tx (409) 504G Address 3-28-156 Shibuya, Shibuya-ku, Tokyo Subject to amendment Statement of A field for a brief description of the drawing. 7. In the first line of page 20 of the specification of contents of the amendment, the phrase "This is a cross-sectional view." has been replaced with "A cross-sectional view. FIG. 7 is a cross-sectional view showing the configuration of a conventional planetary gear type speed reducer." to correct. that's all

Claims (3)

[Claims] (1) A row side sun gear fixed to the rotating shaft of the motor;
It meshes with this sun gear on the A row side, and also meshes with a ring gear attached to the inner circumferential surface of the reduction mechanism case in a state where its rotation is restricted, and rotates due to the rotation of the sun gear on the A row side, and rotates along the ring gear. A row-A planet gear that revolves around the row-side sun gear, a row-A carrier that is connected to the row-A planet gear and rotates as the row-A planet gear revolves, and a row-A carrier that is fixed to the row-A carrier. A sun gear on the row B side rotates as the row A side carrier rotates, and a sun gear on the row B side meshes with the sun gear on the row B side and meshes with the ring gear, rotates on its own axis due to the rotation of the sun gear on the row B side, and moves along the ring gear on the row B side. A B-row side planet gear that revolves around the sun gear, and a B-row side that is connected to the B-row sun gear and connected to the output shaft and rotates as the B-row planet gear revolves to rotate the output shaft. In the planetary gear type reducer equipped with a carrier, a friction type torque slip mechanism is installed on the outer circumference side of the ring gear, and the friction type torque slip mechanism has a pad disposed in contact with the outer circumference side of the ring gear; An elastic member that normally biases the pad in the direction of the ring gear to restrict the rotation of the ring gear, and when a load exceeding a preset value is applied, elastically deforms to release the pad from restricting the rotation of the ring gear. A planetary gear type reduction mechanism, characterized in that at least one of the pad and the elastic member is made of a shape memory alloy and compensates for changes in torque slip value due to temperature changes. . (2) In the planetary gear type reducer according to claim 1, the friction type torque slip mechanism increases the sliding contact area of the pad with respect to the ring gear and/or increases the load applied by the elastic member when the temperature exceeds a preset temperature. A planetary gear type speed reducer characterized in that the reduction in frictional force between a pad and a ring gear is thereby prevented. (3) In the planetary gear type reducer according to claim 1, the friction type torque slip mechanism reduces the sliding contact area of the pad with respect to the ring gear and/or reduces the load applied by the elastic member when the temperature exceeds a preset temperature. A planetary gear reducer characterized in that the pad and ring gear are prevented from seizing.