JPH06194238A - Power transmission - Google Patents

Abstract

PURPOSE:To provide a highly reliable and high-strength power transmission which receives scarcely influence such as electric noise or external magnetic field and can detect torque in a highly precision. CONSTITUTION:Elastic bodies 60 and 62 are prepared between a first intermediate rotary body 15 and a second intermediate rotary body 32 that are rotated by an input-side rotary axis 11. The second body 32 is rotatable within a specific angle range against the first body 15. The bodies 60 and 62 will be deflected depending on the torque applied on the bodies 15 and 32. A first part 65 to be detected and a second part 66 to be detected are prepared on the first and second bodies 15 and 32, respectively. After the parts 65 and 66 are detected by sensors 70 and 71, the deflection and torque values of the bodies 60 and 62 can be detected on the basis of the changes in outputs sent from the sensors 70 and 71.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device used for transmitting a rotational force applied to an input side rotating shaft to an output side rotating shaft.

[0002]

2. Description of the Related Art In a power transmission device used for transmitting a rotational force applied to an input side rotating shaft to an output side rotating shaft, when the torque applied to the rotating shaft needs to be detected, the torque is not contacted. As one of the means for detecting the magnetic field, a torque detecting means utilizing the stress / magnetic effect of a magnetic material is known. This detecting means utilizes the fact that the magnetic permeability of the shaft itself made of a magnetic material or the magnetic material fixed to the shaft changes according to the magnitude of the torque, and the stress generated when a torsional stress is applied to the shaft. The magnetic effect detects the degree of change in magnetic permeability as a voltage value by an electromagnetic coil and converts it into a torque value.

[0003]

However, in the case of the above-mentioned prior art, there is a problem in reliability because it is easily affected by an external magnetic field, for example, a leakage flux of a motor, environmental changes such as temperature change or iron powder. . Further, since the amount of change in magnetic permeability is very small, it is necessary to take measures such as reducing the shaft diameter in order to generate a detectable torsional stress. In that case, since the shaft is easily bent, the mechanical strength is reduced,
This causes a loss of reliability as a power transmission device.

Further, in the above-mentioned prior art, as means for improving the detection sensitivity of the change in magnetic permeability, for example, the axis 4
Improvement measures have been proposed in which the direction of easy magnetization is aligned with the direction of 5 °, but such special axis processing is not a practical means because it causes high cost.

Therefore, an object of the present invention is that the degree of influence of environmental changes such as temperature, electrical noise or external magnetic field is small, the shaft diameter does not need to be made thin, and the torque can be detected with high accuracy. To provide a high power transmission device.

[0006]

The power transmission device of the present invention developed to achieve the above object rotates with the rotation of the input side rotating shaft rotated by a drive source and the input side rotating shaft. A first intermediate rotating body; a second intermediate rotating body provided so as to be relatively rotatable with respect to the first intermediate rotating body within a certain angle range in the rotation direction thereof; and the second intermediate rotating body Depending on the magnitude of the torque that is interposed between the output side rotating shaft that rotates integrally with the rotating body and the mutually opposing portion of the first intermediate rotating body and the second intermediate rotating body and that is applied to the intermediate rotating body. A flexible elastic body, a first detected portion provided on the side of the first intermediate rotating body, a second detected portion provided on the side of the second intermediate rotating body, and the first and second portions. Sensor means for detecting the detected portion of the, and the elasticity based on the output of the sensor means. And it includes a controller for determining the amount of deflection or bending torque change corresponding to the.

[0007]

When the input side rotating shaft is rotated by the drive source, the first intermediate rotating body is rotated, and the rotational force is transmitted to the second intermediate rotating body via the elastic body. And the output side rotation shaft rotate together. Then, the first detected portion and the second detected portion are detected by the sensor means.
In this case, if the torque applied to the intermediate rotating body is smaller than the force for bending the elastic body, the relative positional relationship between the first intermediate rotating body and the second intermediate rotating body in the rotation direction does not change, so that the sensor means Send a constant signal to the controller.

When the load on the output side rotating shaft increases for some reason, a torque corresponding to the magnitude of the load is applied to the intermediate rotating body and the elastic body bends. The relative positional relationship between the rotating body and the second intermediate rotating body in the rotation direction changes. As a result, the output of the sensor means changes, and the controller calculates the deflection of the elastic body based on this change. In this case, the torque value can be calculated from the flexure amount of the elastic body by previously obtaining the relationship between the flexure amount of the elastic body and the torque.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. In the power transmission device 10 shown in FIG. 1, the input side rotating shaft 1 located on the left side in the drawing
1 is given a rotational force by a drive source such as a motor (not shown). This input side rotary shaft 11 is
A bearing 12 rotatably supports one end of the housing 13. A first intermediate rotating body 15 is provided on the input side rotating shaft 11, and the first intermediate rotating body 15 rotates as the input side rotating shaft 11 rotates. At the end of the first intermediate rotating body 15, a pair of convex portions 20,
21 is provided. A recess 22 is provided at the center of the first intermediate rotating body 15.

A bearing 23 is provided on the other end side of the housing 13, and the driven side rotation unit 30 is rotatably supported by the bearing 23. The driven side rotation unit 30 includes an output side rotation shaft 31 located on the same axis as the input side rotation shaft 11 and a second intermediate rotating body 32 provided at an end of the output side rotation shaft 31. It is configured.

The second intermediate rotator 32 has a hollow disk shape, and is locked by the key 45 with respect to the output side rotary shaft 31, and is also stopped by the retaining ring 46 in the axial direction with respect to the output side rotary shaft 31. The position of is regulated.

As shown in FIG. 2, a pair of arcuate space portions 50 and 5 are provided on the lower side and the upper side of the second intermediate rotating body 32 in the figure.
1 is provided, and the convex portions 20 and 21 of the first intermediate rotating body 15 are inserted into the respective space portions 50 and 51. The convex portions 20 and 21 in the illustrated example are arranged in a 180 ° relationship with each other in the rotation direction of the first intermediate rotating body 15.

The convex portions 20 and 21 have the space portions 50 and 51.
In the inside of, the intermediate rotating body 32 can be rotated within a certain angle range in the circumferential direction. In other words, the first intermediate rotating body 15 and the second intermediate rotating body 32 are relatively rotatable in the circumferential direction within a certain angle range.

The protrusions 20 and 21 have spring seats 55 and 56 on both end faces thereof. And one spring seat 55
The first elastic body 60 is inserted between the first elastic body 60 and the rotation direction facing portion 57 of the second intermediate rotary body 32 in a state in which initial bending is applied (compressed state). Therefore, the first elastic body 60 is configured such that the first intermediate rotating body 15 is connected to the second intermediate rotating body 32.
2 is urged in the counterclockwise direction in FIG.

Further, the second elastic body 62 causes an initial deflection between the other spring seat 56 provided on the convex portion 20 or 21 and the rotationally facing portion 61 of the second intermediate rotating body 32. It is inserted in the given state. Therefore, the second elastic body 62 is
The first intermediate rotating body 15 is biased in the clockwise direction with respect to the second intermediate rotating body 32.

An example of the elastic bodies 60 and 62 is a compression coil spring, but a disc spring may be used instead of the coil spring, or a rubber-like elastic body such as synthetic rubber or elastomer may be used. In short, any member may be used as long as it is flexible and has elastic restoring force according to the magnitude of the load.

On the outer peripheral portion of the first intermediate rotating body 15, a plurality of projecting first detected portions 65 are provided at equal intervals in the circumferential direction. Further, on the outer peripheral portion of the second intermediate rotating body 32, a plurality of projecting second detected portions 66 are provided at the same intervals as the first detected portions 65.

The cylindrical portion 68 of the housing 13
Further, a first sensor 70 is provided at a position facing the first detected portion 65. In addition, the second detected portion 66
A second sensor 71 is provided at a position opposed to.
These sensors 70, 71 constitute a sensor means 72. An example of the sensors 70 and 71 is a magnetic proximity sensor, and each of the sensors 70 and 71 has, for example, an excitation coil and a detection coil (both not shown) built therein. In this case, the magnetic field generated by the exciting coil is applied to the detected parts 65 and 66, and the magnetic change occurring at that time is detected by the detection coils, whereby the detected parts 65 and 66 are detected by the sensors 70 and 71. When passing through, it outputs a pulse signal.

The sensors 70 and 71 are, in addition to the magnetic proximity sensor described above, an optical sensor or an ultrasonic sensor.
In short, it is sufficient that the detected parts 65 and 66 can be detected in a non-contact manner, and a suitable one for the use environment may be appropriately selected. Further, the detected parts 65 and 66 may be any marks that can be detected by the sensors 70 and 71, and therefore, other than the convex part is applied according to the detection principle of the sensors 70 and 71.

The sensors 70, 71 are connected to the signal lines 75, 7
It is connected to the controller 77 via 6. The controller 77 includes an arithmetic circuit using a microcomputer or the like, and based on the phase shift of the pulses output from the first sensor 70 and the second sensor 71, the elastic bodies 60, 62 are generated as will be described later. A series of data processing programs for calculating the amount of flexure and torque that have occurred are incorporated.

Next, the operation of the power transmission device 10 having the above structure will be described. When the input-side rotating shaft 11 is rotated by a drive source (not shown), the rotational force is transmitted to the first intermediate rotating body 15, whereby the first intermediate rotating body 15
Rotates. For example, in FIG. 2, the first intermediate rotating body 1
When 5 rotates in the clockwise direction, the torque is transmitted to the second intermediate rotating body 32 while being applied in the direction of compressing the first elastic body 60, so that the second intermediate rotating body 32 and the output side rotating shaft 31 are separated. Rotate clockwise.

Here, if the torque is smaller than the repulsive force due to the initial bending of the first elastic body 60, the first elastic body 60 does not substantially bend and the second intermediate rotating body 32 moves in the above direction. Rotate to. In this case, the relative positional relationship between the first intermediate rotating body 15 and the second intermediate rotating body 32 does not change,
Therefore, the pulses sent from the first sensor 70 and the second sensor 71 are synchronized with each other as shown in FIG.

When the first intermediate rotating body 15 rotates in the counterclockwise direction, torque is transmitted to the second intermediate rotating body 32 while being applied in the direction of compressing the second elastic body 62. The rotating body 32 and the output side rotation shaft 31 rotate counterclockwise. Also in this case, if the torque is smaller than the repulsive force due to the initial deflection of the second elastic body 62, the second
The second intermediate rotating body 32 rotates in the above-described direction without substantially bending the elastic body 62. Therefore, also in this case, the output is as shown in FIG.

When the load on the output side increases due to some reason and the torque applied to the output side rotating shaft 31 increases, the elastic body 60 (or 62) flexes according to the magnitude of the torque. And in this case, the elastic body 60 (or 62)
Since the relative positional relationship in the rotation direction between the first intermediate rotating body 15 and the second intermediate rotating body 32 changes according to the amount of bending of the output, the output detected by the first sensor 70 and the second sensor 71 The relationship causes a phase shift as shown in FIG. 4, for example.

The phase shift is input to the arithmetic circuit of the controller 77, and the amount of flexure of the elastic bodies 60, 62 is calculated based on the relationship between the phase shift and the flexure which is obtained in advance.
If the load / deflection characteristics of the elastic bodies 60 and 62 are linear characteristics, the flexure of the elastic bodies 60 and 62 is proportional to the load, and thus the load (torque) is obtained from the magnitude of the flexure.

In the case of the above embodiment, since the digital signal is used to detect the torque, it is less susceptible to the influence of electrical noise and external magnetic field. Further, if the spring constants of the elastic bodies 60 and 62 are changed, various torque ranges and detection resolutions can be dealt with. And in the said Example, the rotating shaft 11,31
The torque transmitting parts such as those having the same strength as the conventional products can be used, and no special treatment is required. Therefore, the cost is not increased and the reliability is high.

The intermediate rotors 15 and 32 shown in FIG.
In the modified example, the stopper 80 is provided inside the elastic bodies 60 and 62. In this case, the intermediate rotor 15,
When the flexure of the elastic bodies 60, 62 reaches a predetermined amount due to the torque applied to the elastic body 32, the stopper 80 causes the elastic bodies 60, 62 to move.
Further flexion of 62 is prevented.

Therefore, according to this modification, the elastic body 60,
Even if 62 is damaged, torque can be transmitted to the second intermediate rotating body 32 via the stopper 80, so that reliability of power transmission is improved. In addition, since the amount of bending of the elastic bodies 60 and 62 can be set to the allowable value or less, the elastic body 6
The 0 and 62 can be prevented from sagging, and the durability of the elastic bodies 60 and 62 can be improved. Further, by adjusting the length of the stopper 80, the bending range of the elastic bodies 60 and 62 can be adjusted.

Next, a second embodiment of the present invention will be described with reference to FIGS. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 6, the first intermediate rotating body 15 is provided with the disk-shaped first rotating member 91, and the second intermediate rotating body 32 is also provided with the disk-shaped second rotating member 91. A rotating member 92 is provided. Then, the first rotating member 91
Rotates together with the first intermediate rotating body 15, and the second rotating member 92 rotates together with the second intermediate rotating body 32.

A plurality of first rotating members are provided on the outer peripheral portion of the first rotating member 91.
The detected part 65 is provided. These detected parts 6
5 is provided so as to project in the direction of the second rotating member 92. These detected parts 65 are arranged at equal intervals in the circumferential direction of the first rotating member 91, and a gap of a predetermined pitch P (see FIG. 8) is provided between the detected parts 65, 65 adjacent to each other. ing.

Further, a plurality of second detected portions 66 are provided on the outer peripheral portion of the second rotating member 92 at equal intervals in the circumferential direction. As shown in FIGS. 7 and 8, the first detected portion 65
The second detected portion 66 and the second detected portion 66 are arranged so as to alternately enter in the circumferential direction of the rotating members 91 and 92. The width W of the second detected portion 66 is smaller than the pitch P between the first detected portions 65, 65. Therefore, the first rotating member 91 and the second rotating member 92 are in a state of being relatively rotatable in the circumferential direction with respect to each other by the dimensional difference between P and W.

As described above, in the second embodiment, the first detected portion 65 and the second detected portion 66 are alternately arranged on the same circumference in the direction in which the intermediate rotors 15 and 32 rotate. It is arranged. Then, one sensor 7 is used as the sensor means 72 at a position where these detected parts 65 and 66 can be detected.
0 is placed.

In the second embodiment having the above-mentioned structure, when the input side rotating shaft 11 is rotated by the driving source (not shown), the first intermediate rotating body 15 and the first rotating member 91 rotate in the same direction. For example, in FIG. 7, when the first intermediate rotating body 15 rotates clockwise, the torque becomes the first
Since the elastic body 60 is transmitted to the second intermediate rotating body 32 while being applied in the direction of compressing the elastic body 60, the second intermediate rotating body 32 rotates in the clockwise direction.

If the torque is smaller than the repulsive force due to the initial bending of the first elastic body 60, the first elastic body 60 does not substantially bend and the second intermediate rotating body 32 moves in the above direction. Rotate to. In this case, since the first intermediate rotating body 15 and the second intermediate rotating body 32 are kept in the neutral position with respect to each other, the pulse sent from the sensor 70 is directed to the upper side (during light load) of FIG. As shown, they appear at approximately equal intervals. In FIG. 9, when the sensor 70 detects the detected portions 65 and 66, it is turned off, and the sensor 70 detects the detected portions 65 and 66.
This is an example in which it is turned on when 6 is not detected.

When the output load increases for some reason and the torque applied to the output rotary shaft 31 increases, the elastic body 60 (or 62) bends according to the magnitude of the torque.
In this case, the relative positional relationship in the rotation direction between the first intermediate rotating body 15 and the second intermediate rotating body 32 changes according to the amount of bending of the elastic body 60 (or 62). By changing the positional relationship between 65 and the second detected portion 66, an output such as that shown in the lower side (under heavy load) of FIG. 9 is generated according to the change amount. This output is input to the controller 77, and information regarding the amount of bending or the load (torque value) of the elastic bodies 60 and 62 is obtained.

According to the second embodiment, one sensor 7
Since the first detected portion 65 and the second detected portion 66 are detected by 0, the structure is simplified as compared with the case where a plurality of sensors are used. Further, when the elastic bodies 60, 62 bend to a predetermined amount, the first detected portion 65 and the second detected portion 66 are in contact with each other in the rotational direction to function as a stopper, and a torque larger than that is generated. When is loaded, the rotational force of the first intermediate rotating body 15 is directly transmitted to the second intermediate rotating body 32, so that the elastic bodies 60 and 62 are prevented from bending beyond an allowable limit.

[0038]

According to the present invention, since the torque is detected based on the change in the bending amount of the elastic body, it is possible to achieve high accuracy without being affected by electrical noise, external magnetic field, temperature change or dust. Torque can be detected. Further, it is not necessary to take measures such as reducing the shaft diameter as in the case of detecting a change in magnetic permeability, so that mechanical strength and reliability are not impaired. Further, since no special processing is required for the torque transmitting parts such as the rotating shaft, it can be implemented at low cost and has high operation reliability.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a power transmission device showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a diagram showing an example of an output of a sensor in the device shown in FIG.

FIG. 4 is a diagram showing an example of output when torque is increased in the device shown in FIG.

FIG. 5 is a vertical cross-sectional view of a power transmission device showing a modified example of an intermediate rotating body.

FIG. 6 is a vertical cross-sectional view of a power transmission device showing a second embodiment of the present invention.

7 is a sectional view taken along line VII-VII in FIG.

8 is a perspective view showing a detected part in the apparatus shown in FIG.

9 is a diagram showing an example of an output of a sensor in the device shown in FIG.

[Explanation of symbols]

10 ... Power transmission device, 11 ... Input side rotating shaft, 15 ... 1st
Intermediate rotating body, 31 ... output side rotating shaft, 32 ... second intermediate rotating body, 60, 62 ... elastic body, 65 ... first detected part,
66 ... 2nd detected part, 70 ... 1st sensor, 71 ... 2nd sensor, 72 ... Sensor means, 77 ... Controller,
80 ... Stopper.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Soho Sakauchi 3-10 Fukuura, Kanazawa-ku, Yokohama, Kanagawa Prefecture

Claims (5)

[Claims] 1. An input-side rotating shaft rotated by a drive source, a first intermediate rotating body that rotates with the rotation of the input-side rotating shaft, and a rotating direction with respect to the first intermediate rotating body. A second intermediate rotating body that is relatively rotatable within a certain angle range; an output-side rotating shaft that rotates integrally with the second intermediate rotating body; and the first intermediate rotating body. An elastic body that is interposed between parts facing each other with the second intermediate rotating body and that bends according to the magnitude of the torque applied to the intermediate rotating body, and a first covered member provided on the first intermediate rotating body side. A detection part, a second detected part provided on the second intermediate rotating body side, a sensor means for detecting the first and second detected parts, and the elasticity based on the output of the sensor means. Equipped with a controller that determines the amount of flexure of the body or the torque change according to the flexure Power transmission device according to claim and. 2. The power transmission device according to claim 1, wherein a compression coil spring is used for the elastic body. 3. The first detected part and the second detected part are arranged so as to be separated from each other in the axial direction of the intermediate rotating body, and the sensor means sets the first detected part. It comprises a first sensor for detecting and a second sensor for detecting the second detected portion. Depending on the output of the first sensor and the second sensor, the amount of bending or the bending of the elastic body is determined. The power transmission device according to claim 1, wherein the torque change is obtained. 4. A stopper is provided between portions of the first intermediate rotating body and the second intermediate rotating body that face each other in the rotational direction, and a stopper that prevents the elastic body from bending by a predetermined amount or more. 1
The power transmission device described. 5. The first detected portion and the second detected portion are alternately arranged on the same circumference in the rotation direction of the intermediate rotating body, and change depending on the bending of the elastic body. The power transmission device according to claim 1, wherein the relative positional relationship between the first detected portion and the second detected portion is detected by the sensor means having one sensor.