JPH0216102B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a permanent magnet type synchronous motor, and relates to a one-way rotation device that limits the rotational direction of a rotor and rotates the rotor in a predetermined direction. be.

Conventional structure and its problems Traditionally, a ratchet mechanism, etc., was used to restrict the rotation of the rotor of a permanent magnet synchronous motor in one direction, but since the motor rotates at high speed, it cannot be used for continuous rotation etc. Noise and durability were issues.

Purpose of the Invention The present invention solves the above-mentioned drawbacks of the conventional motor, and is capable of regulating the rotation direction of a permanent magnet type synchronous motor with a simple structure without using a complicated mechanism such as a ratchet mechanism. An object of the present invention is to provide a unidirectional rotating device of a permanent magnet type synchronous motor that does not generate noise and can withstand continuous operation.

Composition of the Invention In order to achieve the above object, the unidirectional rotation device for a permanent magnet type synchronous motor of the present invention fixes a worm gear that meshes with a wheel gear on a rotor shaft, and uses a reaction force that the worm gear receives from the wheel gear to The motor body of a permanent magnet synchronous motor, in which the rotor can freely move in the thrust direction within a bearing according to its rotational direction, is provided with an electrical contact that opens and closes the drive power circuit of the motor. This is performed in conjunction with the movement of the child in the thrust direction, thereby ensuring that the rotor of the permanent magnet type synchronous motor can be rotated in a predetermined direction.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 illustrate a permanent magnet type synchronous motor according to the present invention, which consists of a motor body 1 and a permanent magnet rotor 2. A coil 4 is wound around it.
The permanent magnet rotor 2 has a rotor shaft 7 mounted on bearings 6, 6 provided on the side of the bracket 5 that holds the stator core 3.
A worm gear 9 is fixedly disposed at the end of the rotor shaft 7 to mesh with a wheel gear 8 on the load side.

In a permanent magnet type synchronous motor having such a basic configuration, the present invention provides an electric contact 10 for opening and closing the drive power circuit of the motor on the motor main body 1 side, and opening and closing of this electric contact 10 is controlled by the permanent magnet rotor 2.
It is characterized in that the movement is performed in conjunction with the movement in the thrust direction.

The electrical contact 10 includes a swinging piece 11 and a fixed piece 12, both of which are made of conductive material. The swinging piece 11 has its upper end fixed to the bracket 5 side, and contacts the fixed piece 12 fixed to the bracket 5 side via the abutment 13 provided at its lower end, so that no external force acts on it. In this case, the swinging piece 11 maintains the state of contact with the fixed piece 12 due to its own elasticity. Note that cords and the like connected to the swinging piece 11 and the fixed piece 12 are not shown.

The operation of the above configuration will be explained below.

The permanent magnet rotor 2 of the electric motor has a play that allows it to move in the thrust direction inside the bracket 5, and when it is not in operation, the permanent magnet rotor 2 is moved to the center of the stator core 3 by magnetic absorption force. positioned. When the permanent magnet rotor 2 starts to rotate due to the alternating magnetic field generated in the stator core 3 by the coil 4, the rotation of the permanent magnet rotor 2 is caused by the rotation of the rotor shaft 7.
The force is transmitted to the wheel gear 8 via the worm gear 9 fixed to the worm gear 8, but during the transmission, the worm gear 9 receives a reaction force from the wheel gear 8. Now, if the direction of the teeth of the worm gear 9 is to the left as shown in the figure, when the permanent magnet rotor 2 starts rotating in the A direction, it is positioned at the center of the stator core 3 due to magnetic absorption force before rotating. The permanent magnet rotor 2 that was
The reaction force from the wheel gear 8 causes the rotor shaft 7 to move in the thrust direction shown by arrow A' (leftward in FIG. 2), and the end surface 7a of the rotor shaft 7 contacts and presses the swinging piece 11 of the electric contact 10. Then, the rocking piece 1 resists the elastic force.
1, the contact state between the oscillating piece 11 and the fixed piece 12 is released, the drive power circuit of the motor is opened, the rotation of the permanent magnet rotor 2 in the direction A is stopped, and the wheel gear 8 is rotated. Since the reaction force from the permanent magnet rotor 2 is no longer applied, the permanent magnet rotor 2 returns to its original neutral position due to the magnetic attraction force, and the oscillating piece 11 and the fixed piece 1
2 come into contact again, current flows through the circuit, and the rotor 2 is restarted.

Conversely, when the permanent magnet rotor 2 rotates in the direction B, the direction of the reaction force that the worm gear 9 receives from the wheel gear 8 is reversed, and the permanent magnet rotor 2 rotates in the direction of the arrow.
Thrust direction indicated by B' (rightward in Figure 2)
Therefore, the swinging piece 11 and the fixed piece 12 of the electric contact 10 maintain a contact state, and the rotor 2 continuously rotates in the B direction.

Effects of the Invention As described above, according to the present invention, the worm gear meshing with the wheel gear is fixed on the rotor shaft, and the reaction force that the worm gear receives from the wheel gear causes the rotor to move in the thrust direction within the bearing according to the direction of rotation. The motor body of the permanent magnet type synchronous motor, which is freely movable, is provided with an electrical contact for opening and closing the drive power circuit of the motor, and the opening and closing of this electrical contact is performed in conjunction with the movement in the thrust direction. , it is possible to reliably and continuously rotate the permanent magnet rotor only in a predetermined direction, and since there is no member that comes into mechanical contact with the rotor during continuous rotation, it does not generate noise even when rotating at high speed. It has the advantage of being able to withstand continuous rotation.

[Brief explanation of drawings]

FIG. 1 is a principle diagram of a permanent magnet type synchronous motor to which the present invention is directed, and FIG. 2 is a schematic diagram showing an embodiment of a unidirectional rotation device for a permanent magnet type synchronous motor of the present invention. 1...Electric motor body, 2...Permanent magnet rotor, 3
... Stator core, 5 ... Bracket, 6 ... Bearing, 7 ... Rotor shaft, 8 ... Wheel gear, 9 ...
...worm gear, 10...electrical contact.

Claims (1)

[Claims] 1 A worm gear that meshes with a wheel gear is fixed on the rotor shaft, and an electric contact that opens and closes the drive power circuit of this motor is attached to the motor body, which allows the rotor shaft to move freely in the thrust direction within the bearing according to the rotation direction of the rotor shaft. unidirectional rotation of a permanent magnet type synchronous motor, characterized in that the electrical contacts are opened and closed in conjunction with the movement of the worm gear of the rotor shaft in the thrust direction due to the reaction force received from the wheel gear. Device.