JPS60157514A - Rotary bearing provided with rotary displacement detector - Google Patents

Abstract

PURPOSE:To enable to apply the titled detector to a rotary part of an industrial robot by making the titled detector possess both a bearing function of a rotary shaft and a rotary position detecting function, by providing a rotary displacement detector on a rotary bearing unitarily, in the rotary bearing provided with an inner and outer rings. CONSTITUTION:A rotary bearing, for example, a ball bearing is provided with an outer and inner rings 1, 7. In this case, the outer ring 1 is provided with a magnetism detecting head 9, the inner ring 7 is provided with a coded ring 6 to which a code based on the magnetism is recorded and a groove part of the outer ring 1 is provided with a stress detecting mechanism based on a strain gauge 12. With this construction, the titled bearing can detect highly accurately a rotary position, bending stress and thrust stress while it is functioning as the rotary bearing of a joint part and a rotary part of a robot especially.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to the bearing function of a rotating body and the detection of rotational displacement of a rotating shaft, and is particularly suitable for detecting rotational displacement for use in rotating parts and joints of industrial robots, etc. Regarding rotary bearings with equipment.

[Background of the invention]

An example of using an encoder or potentiometer that detects rotational displacement in conventional units is shown at the 8th robot joint.
This will be explained with reference to FIG.

In FIG. 8, reference numeral 41 is a rotation detector, which is a rotary encoder or potentiometer.A gear 42 attached to the shaft of the rotation detector 41 is rotated by a gear 44 attached to a rotation shaft 43. 40 is the mounting bracket. FIG. 9 shows an example in which the rotation detector 47 is a built-in type and is attached to the rotating shaft 46. As mentioned above, conventional rotation detectors require parts such as claw metal fittings and gears for transmitting rotation, and also require space to install the rotation detector, which limits the design around robot joints. There was a drawback to giving. Furthermore, special measures were required to detect bending stress, thrust stress, etc. of the rotating shaft.

[Purpose of the invention]

The object of the present invention is that it can be easily attached to the joints and rotating shafts of industrial robots, etc., and has a bearing function of the rotating shaft and a rotational position detection function, and can also detect rotational bending stress, thrust stress, etc. The present invention provides a rotating bearing with a rotational displacement detector.

[Summary of the invention]

The present invention enables direct detection of the rotational position and stress of the rotating shaft by simply installing the bearing, provided that the bearing used in the rotating parts and joints of industrial b-pots etc. is equipped with a rotational displacement detection function. Compared to systems that transmit rotation to potentiometers or encoders using gears, steps, etc., this system provides highly accurate direct displacement detection, simplifies the mechanism, and saves space.

[Embodiments of the invention]

Examples of the present invention are shown in FIGS. 1, 2, and 3 below.

This will be explained with reference to FIGS. 4B, 5, 6, and 7.

1 and 2 show a first embodiment of the present invention, in which a magnetic detection head 9 is provided on the outer ring portion 1 of a ball bearing, a code ring 6 on which a magnetic code is recorded is provided on the inner ring portion 7, and a magnetic detection head 9 is provided on the inner ring portion 7. This structure has a stress detection function using a strain gauge 12 in the groove part @1. FIG. 2 is a plan view of this embodiment.

FIG. 3 shows a second embodiment of the present invention, in which an electrically resistive film 19 is provided on the inner peripheral surface of the outer ring portion l of a ball bearing, and an electric brush 17 that slides on the electrically resistive film 19 is provided on the inner ring portion 7. , is provided with a ring 18 that is electrically connected to the electric brush 17. Further, the ring 18 slides into contact with the electric brush 16 attached to the outer ring portion 1, and is electrically connected thereto. FIG. 4 is a schematic diagram of the electrical circuit of this embodiment.

Figures 5 and 6 show a third embodiment, in which uloB is provided on both sides of the ball raceway of the outer ring 1 of the ball bearing, and furthermore, a wide groove with a diameter d is provided on the outer peripheral surface, and a narrow groove is provided at the center of the wide groove. A groove 11A is provided,
A strain gauge 1 is installed on the outer circumferential surface above the two inner circumferential grooves.
2A and 12B are attached in parallel at multiple locations, eight locations in this embodiment.

The rotational displacement detector of this embodiment detects only the stress of the rotating shaft.

FIG. 7 shows an application example in which the rotary bearing with a rotational displacement detector of the first embodiment is applied to a joint of a robot.

A stator 25 of a direct drive motor fitted into a link 25, a rotor 30 attached to a shaft 33, a ball bearing 32 that rotatably holds the shaft 33, a rotary bearing 28 with a rotational displacement detector, and a rotor 30 fixed to both ends of the shaft 33. A drive that can directly detect rotational displacement and stress with high precision with a simple configuration such as the second link 31, the wiring 26 of the direct drive motor, the lead wire 34 of the strain gauge 12, and the lead wire 27° or more of the rotational position detector. You can get motorized joints.

〔Effect of the invention〕

According to the present invention, it is possible to function as a rotation bearing for the joints and rotating parts of a robot, and also to detect direct rotational position with high precision, bending stress, thrust stress, etc., and further simplify the area around the joints and save space. , it is effective in reducing costs by reducing the number of parts, etc., and greatly contributes to higher precision and cost reduction of robots.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the first embodiment, and FIG. 2 is a front view of one part of the first embodiment. Figures 3 and 4 are a cross-sectional view of the second embodiment and a schematic diagram of its electric circuit, and Figures 5 and 6 are a cross-sectional view of the third embodiment and a front view of the cross section in the direction of the arrows. be. FIG. 7 is an applied view of the rotary bearing with a rotational displacement detector according to the first embodiment. FIGS. 8 and 9 are explanatory diagrams of the joints of a robot equipped with a conventional rotation detector. DESCRIPTION OF SYMBOLS 1...Outer ring, 2...Corundum, 3...Detector lead wire, 4...Detection head body, 5...Stopping shaft, 6...
Code ring, 7...Inner shaft, 8...Seal, 9...
Magnetic detection head, 10... Inner circumferential groove, 11... Outer circumferential groove, 12... Strain gauge, d... Wide 1] Groove diameter, 1
6.17...electronic brush, 18...ring, 19...
Electrical resistance film, 25...1st link. 29...Motor rotor, 30...Stator,
28... Rotating bearing with rotational displacement detector, 40... Mounting bracket, 41... Potentiometer or encoder, 42. 43... Gear, 45... Rotating metal fitting, 4
1...Figure 7X

Claims (1)

[Scope of Claims] 1. A rotating bearing equipped with a rotational displacement detector, characterized in that the rotational bearing includes an inner shaft and an outer ring, and a rotational displacement detector is attached integrally with the rotational bearing. 2. A rotary bearing having an inner shaft and an outer ring, characterized in that a code ring recording a rotational position is attached to the inner shaft, and a displacement detecting section is further attached to the outer ring. Rotary bearing with rotational displacement detector as described. 3. A rotary bearing having an inner ring and an outer ring, characterized in that the inner ring is provided with a code ring recording a magnetic code, and the outer ring is further provided with a magnetic detector. A rotating bearing with a rotational displacement detector as described in . 4. In a rotating bearing with an inner shaft and an outer ring, the inner ring is provided with a code ring that transmits or reflects light to change the light, and the outer ring is provided with a code ring that emits or receives light and detects changes in light. A rotary bearing with a rotational displacement detector according to claim 1 or 2, characterized in that a detector is provided. 5. In a rotating bearing having an inner ring and an outer ring, the outer ring is provided with an electric brush that is electrically connected to an electrically resistive film and an output terminal, and a sliding ring attached to the inner ring that slides on the electric brush and the sliding ring are connected to the electric brush. 2. The rotary bearing with a rotational displacement detector according to claim 1, wherein the output electric brush that is electrically connected slides on the electrical resistance film. 6. In a rotating ball bearing that has a code ring that records rotational displacement on the inner ring and a displacement detection section on the outer ring, a groove is provided at the center of the ball orbit in the outer ring, and a groove is provided just above the groove on the outer periphery. A wide circumferential groove is provided at the center. A rotary bearing with a rotational displacement detector according to claim 1 or 2, characterized in that a strain gauge is attached to the stress circumferential groove. 7. In a rotating ball bearing, grooves are provided on both sides of the ball raceway on the inner circumferential surface of the outer ring, a wide groove is provided on the outer circumferential surface centered just above the ball raceway, and a narrow groove is further provided at the center of the wide groove, Claim 1, characterized in that a plurality of strain gauges are provided in parallel on the outer peripheral surface of the upper portions of the two circumferential grooves.
A rotating bearing with a rotational displacement detector as described in .