JPH028536Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a motor unit that drives manipulators, joints of robots, etc.

Generally, to drive the joints of these manipulators, robots, etc., a motor unit is used, which is an integral assembly of a motor, a brake mechanism, a speed reducer, an encoder for detecting rotation, and the like. Performance requirements for such a motor unit include small size and high reliability. For this reason, conventional motor units of this type are equipped with a torsion detector to detect the torque load on the output shaft, and it is possible to detect the output of the motor unit and manage the life of the motor unit based on the torque of the output shaft. It is configured.

By the way, in the conventional device, the signal from the torsion detector is transmitted to the outside via a slip ring provided on the output shaft. Therefore, this slip ring caused the problem that the entire motor unit became larger.

The present invention was developed based on the above circumstances, and its purpose is to provide a motor unit that can be made smaller overall.

That is, the present invention includes a reducer having a hollow input shaft and an output shaft arranged coaxially, a motor and a brake mechanism connected to the input shaft, a torsion detector provided in the hollow output shaft, A lead wire connected to the torsion detector is formed into a spiral shape and led out through the hollow input shaft. Therefore, the torsion detector and the lead wires are all accommodated within the hollow output shaft and input shaft of the speed reducer, and the motor unit does not become large. Further, since the lead wire is formed into a spiral shape, the twisting of the lead wire allows rotation of the torsion detector provided within the output shaft.

An embodiment of the present invention will be described below with reference to the drawings. This embodiment is a motor unit for driving joints of a manipulator or the like. That is, in the figure, 1 is an internally revolving gear type reduction gear, and this reduction gear 1 has an output shaft 10 and an input shaft 11 arranged coaxially. A motor 2 and a brake mechanism 3 are housed in a motor case 12 provided on the input shaft 11 side of the reducer 1. and,
The rotor 2a of the motor 2 is attached to the input shaft 11, and the stator 2b is attached to the motor case 12.
installed on. In addition, the brake mechanism 3
The rotor 3b is attached to the input shaft 11,
Further, the stator 3a is attached to the motor case 12 described above. Note that the input shaft 11 has a bearing 1.
9 is supported on this motor case 12. Further, an encoder 4 is provided on the output shaft 10 side of the reduction gear 1, and this encoder 4 is attached to the output shaft 10 via a tapered ring 15, and is configured to detect rotation of the output shaft 10. ing.

The output shaft 10 and input shaft 11 are formed hollow. A torsion detector 21 is provided within the output shaft 10 and is configured to detect the torsion of the output shaft 10 and its torque load. Further, a lead wire 22 is connected to this torsion detector 21, and this lead wire 22 is led out through the inside of the hollow input shaft 11. In addition, a spiral portion 22 is formed in a spiral manner in the middle of the lead wire 22.
a is formed, and the torsion detector 21 is configured to be able to rotate together with the output shaft 10 due to the twist of the spiral portion 22a. Note that the above-mentioned torsion detector 21
In this case, the cylindrical parts at both ends are fixed to the inner surface of the hollow output shaft 10 by means such as gluing or pinning,
It is assumed that a strain gauge is attached to the narrow center part and the strain output is led to the outside through a lead wire 22. Also, the lead wire 22
In order to obtain the torque load from the strain output derived to the outside, calculation may be performed using a conversion coefficient between the strain amount and the torque load determined in advance.

As mentioned above, the present invention includes a reducer having a hollow input shaft and an output shaft arranged coaxially, a motor and a brake mechanism connected to the input shaft, and a torsion detector provided in the hollow output shaft. and a lead wire connected to the torsion detector and formed into a spiral shape and led out through the hollow input shaft. Therefore, the torsion detector and the lead wires are all accommodated within the hollow output shaft and input shaft of the speed reducer, and the motor unit does not become large. Further, since the lead wire is formed into a spiral shape, the twisting of the lead wire has great effects such as allowing the rotation of the torsion detector provided within the output shaft.

[Brief explanation of the drawing]

The figure is a longitudinal sectional view of an embodiment of the present invention. 1... Reduction gear, 2... Motor, 3... Brake mechanism, 4... Encoder, 10... Output shaft, 11
...Input shaft, 21...Torsion detector, 22...Lead wire, 22a...Spiral portion.

Claims (1)

[Scope of utility model registration request] A speed reducer having a hollow input shaft and an output shaft arranged coaxially, a motor and a brake mechanism connected to the input shaft, a torsion detector provided in the hollow output shaft, and this torsion detector. A motor unit characterized by comprising: a lead wire connected to the input shaft, formed into a spiral shape, and led out through the hollow input shaft.