JPH0220499A - Holding device for rotation of motor for mounting space navigation body - Google Patents

Abstract

PURPOSE:To stop the rotation of a motor without needing a power supply at the motor stopping time and to enable the rotation without any trouble at the motor rotation time by forming the material of either a rotor or stator by a permanent magnet by equipping with magnetic body made rotor and stator on the rotation holding device of a motor. CONSTITUTION:At the time of the rest state of a motor an attraction force by a magnetic force is exerted between the projection parts of a rotor 1 and stator 2 and the rotor 1 is held for the stator 2. The both projection parts fix the relative size of B-B' part, C-C' part so that the attraction force between B part and B' part, C part and C' part does not give a trouble at the motor rotation time with the relative face of the rotor 1 and stator 2 being in the shape of U groove. In case of a driving force being given by a motor, the rotor 1 is continued to be held for the stator 2 while the driving force is smaller than the holding forces of the B, B'/C, C' parts. However the rotor starts to rotate with the increase of the driving force and a rotation unevenness if caused on the rotor 1 while under low speed rotation but in such a normal zone as rotating at high speed the rotation unevenness can be neglected.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotation holding device for a motor mounted on a spacecraft, and particularly to a device for holding a motor shaft mounted on a spacecraft that holds the motor shaft against external force when the motor is stopped. This invention relates to a rotation holding device.

[Conventional technology]

Normally, motors mounted on spacecraft are used to deploy and drive solar array paddles, rotate antennas, etc.
If no power is supplied when the machine is stopped, it will be rotated by an external force, so some kind of holding mechanism is required to stop this rotation. Conventionally, an electromagnetic friction clutch type device has been used as a rotation holding device for a motor mounted on a spacecraft. In this electromagnetic friction clutch type, as shown in the sectional view of FIG. 3, the electromagnetic plate 6 is an electromagnet, and the motor shaft 5 is directly connected and held to the casing 10 by attracting and pressing the friction plate 7. On the other hand, if no current flows through coil 4,
The friction plate 7 is pushed away from the electromagnetic plate 6 by the compression spring 8, and the motor shaft 5 becomes free. [Problem to be Solved by the Invention] The above-mentioned conventional rotation holding device for a motor mounted on a spacecraft uses an electromagnet. It requires a power source to drive it, and uses frictional forces that are difficult to predict, especially in the high vacuum of space.
This has the disadvantage that the reliability of the entire system driven by the motor is extremely low.

An object of the present invention is to provide a rotation holding device for a motor mounted on a spacecraft, which can stop the rotation of the motor without requiring power supply when the motor is stopped, and can rotate without any trouble when the motor is rotating.

[Means to solve the problem]

A rotation holding device for a spacecraft mounting motor according to the present invention is a rotation holding device for a spacecraft mounting motor that is attached to a rotating shaft of a motor and holds the rotating shaft with a predetermined force when the motor is stopped. a rotor made of a magnetic material that is fixed to a rotating shaft, rotates in conjunction with the center of the rotating shaft, divides the circumference into equal parts, and has a plurality of protrusions at positions; a stator made of a magnetic material and having a plurality of second protrusions arranged concentrically with the shaft and facing the plurality of first protrusions at predetermined intervals, and connected to a fixed part of the motor; The material of either the rotor or the stator is made of a permanent magnet.

[Actual example]

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view of one embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA in FIG. 31. The material of the rotor 1 is a permanent magnet, and the direction of magnetization is the direction of the rotation axis of the rotor shown in FIG.

A stator made of magnetic material is installed around the outer periphery of the rotor. First, when the motor is in a stationary state as shown in the figure, an attractive force due to magnetic force acts between the protrusions of the rotor 1 and the protrusions of the stator 2, and the rotor 1 is held against the stator 2. be done. Furthermore, as shown in the cross-sectional view of FIG. 2, the protrusions of the rotor and the protrusions of the stator 2 have U-shaped grooves on the opposing surfaces of the rotor 1 and the stator 2. B-B so that the suction force between the C' section and the C' section does not interfere with the rotation of the motor, which will be described later.
The relative sizes of the ' part and the C-C part are determined.

Next, when a driving force is applied by a motor (not shown), the rotor 1 moves to the stator 2 while this driving force is smaller than the holding force due to the magnetic force of the B, B, and C2C' sections mentioned in Air. However, as the driving force increases, the rotor 1 begins to rotate.During low-speed rotation, the rotor 1 causes uneven rotation due to magnetic force, but at high-speed rotation, that is, several tens of tens of seconds per second. In a normal use area where the rotor rotates at the rotational speed, this rotational unevenness can be ignored.In this embodiment, the magnetization direction of the rotor 1 is the rotational axis direction.
Parts B and C in the diagram are magnetic poles N and S (or S and N), respectively.
However, it is also possible to make the adjacent protrusions of the I rotor 1 shown in FIG. 1 so as to correspond to the N and S magnetic poles. It is also possible to use the stator 2 as a magnet.

〔Effect of the invention〕

As explained above, according to the present invention, the holding force is obtained by the magnetic force of the permanent magnet, so there is no need to supply special power from the outside, and there is no mechanical moving part or contact part for holding. In addition, since the number of parts is small, it is possible to construct a highly reliable rotation holding device for a motor mounted on a spacecraft.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of one embodiment of the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 is a vertical sectional view of a conventional rotation holding device for a motor mounted on a spacecraft. be. ], ... rotor, 2 ... stator, 3 ... motor shaft, 4 ... coil, 5 ... motor shaft, 6 ... electromagnetic plate, 7 ... friction plate, 8 ... - Compression spring, 9... Support spring, 1o... Casing, 11... Center ring.

Claims (1)

[Claims] In a rotation holding device for a spacecraft-mounted motor that is attached to a rotating shaft of a motor and holds the rotating shaft with a predetermined force when the motor is stopped, the rotating shaft is fixed to the rotating shaft and rotates in conjunction with the center of the rotating shaft. a rotor made of a magnetic material having a plurality of first protrusions at equally divided positions on the circumference; a plurality of second portions facing the protrusion;
and a stator made of a magnetic material and connected to a fixed part of the motor, wherein either the rotor or the stator is made of a permanent magnet. Rotation holding device for mounting motor.