JPH01152993A - Squirrel-cage induction motor - Google Patents

Abstract

PURPOSE:To assemble a motor into an automatic controller and to quicken response, by rotating a second stator through a cylinder drive mechanism which employs a motor as a drive source. CONSTITUTION:A rolling rod 21 is secured to a part of outer circumference of a second stator B. Tip of a motor cylinder 23 is coupled through a universal joint 22 with the rolling rod 21. Furthermore, a universal joint 25 for coupling a brake device 24 and a frame seat 26 with the motor cylinder 23 is provided. Control circuit 32 of the motor cylinder 23 controls the motor cylinder 23 to displace the second stator B by a predetermined amount or hold the second stator B. When the second stator B is required to be fixed at a predetermined position, the brake device 24 associated with the motor cylinder 23 functions to hold the second stator B.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is characterized in that a first stator and a second stator having the same number of poles and the same number of slots are opposed to a common squirrel cage rotor. The present invention relates to a squirrel-cage induction motor in which the second stator is disposed in parallel in a range corresponding to one pole pitch and is movable in the circumferential direction.

[Conventional technology]

FIG. 4 is a sectional view showing a conventional squirrel cage induction motor disclosed in, for example, Japanese Unexamined Patent Publication No. 59-191461. In the figure, 1 is a bracket, 2 is a bearing, and 3 is supported on the bracket 1 by the bearing 2. 4 is a rotor core fixed to the rotor shaft 3, 5 is a rotor conductor provided on the rotor core 4, and 6 is an end that constitutes a squirrel-cage winding by short-circuiting both ends of the rotor conductor 5. The ring A is a first stator which is fixed to the frame 9 and has a stator winding 8A.

B is a second stator, which has a stator winding 8B like the first stator, but with a frame 9
It is mounted so that it can rotate in the circumferential direction.

That is, a ring-shaped washer 10 is attached to the outer periphery of the second stator, and a support metal 11 for supporting the washer 10 is provided on the frame 9 over the entire circumference of the frame.
The support metal 11 and the washer 10 are configured to be able to slide against each other.

12 is a rolling rod fixed to the second stator and protrudes from the outer periphery of the frame 9; 13 is a hydraulic system consisting of a piston 14 coupled to the rolling rod and a cylinder device 15 for driving this piston. By supplying pressure oil from either one of the pressure oil supply ports 16 and 17 provided at both ends of the cylinder device, the second stator B can be rotated in the circumferential direction of the frame 9. It is something.

Note that the second stator B is configured to be able to rotate within a range corresponding to the l-pole pitch of the magnetic poles generated by applying three-phase alternating current from the outside.

When three-phase alternating current is applied to the first and second stators of the squirrel-cage induction motor configured in this way so that the directions of the rotating magnetic fields are the same, the squirrel-cage winding 5 of the rotor An electromotive force corresponding to the deflection angle of the first and second stators A and B is induced, and the torque characteristic with respect to the speed shown in Fig. 4 (a) is obtained, and the starting current with respect to the speed shown in Fig. 4 (b) is It is known that properties can be obtained. In this case, Fig. 4 (a
The starting current shown in FIG. 4(b) corresponds to the torques T1 to T4 shown in ).

[Problem that the invention seeks to solve]

Since the conventional induction motor is constructed as described above, it is difficult to easily control the relationship between the characteristics required by the load and the amount of displacement of the second stator, and the motor lacks responsiveness. Furthermore, since it is not possible to manually control the amount of displacement of the stator when the hydraulic mechanism fails, there is a problem that it cannot be incorporated into an automatic control system.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain a squirrel cage induction motor that can be incorporated into an automatic control device and can provide a quick response.

[Means for Solving the Problems] The squirrel cage induction motor according to the present invention includes a second stator rotatably provided opposite to the squirrel cage quantum trochanter, and an outer surface of the second stator. A piston of a cylinder mechanism driven by a motor is connected to the protruding rolling rod, and a brake is installed to stop and hold the second stator at a predetermined rotational position, and a calculation is performed based on the conditions required by the load. and a control circuit that provides the motor with command signals for the amount of forward rotation and the amount of reverse rotation of the second stator.

[Effect]

In the squirrel cage induction motor of this invention, the motor is actuated by a command signal from a control circuit, the second stator is rotated by a cylinder mechanism using this motor as a driving source, and the second stator is stopped at a predetermined rotational position by a brake. By holding the cylinder mechanism, the response is quick, and since the cylinder mechanism uses a motor as a driving source, it can be manually operated, and it can be incorporated into an automatic control device.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. In Fig. 1, in which the same parts as in Fig. 3 are given the same reference numerals,
21 is a rolling rod and a universal joint fixed to a part of the outer periphery of the second stator B; 23 is a known motor cylinder as a cylinder mechanism; It is connected to the rolling rod 21. 24 is a brake device for the motor cylinder, 25 is a frame seat 26
This is a universal joint that connects the motor cylinder 23 and the motor cylinder 23.

32 is a control circuit for this motor cylinder, and this control circuit 32 is a squirrel cage induction motor (hereinafter abbreviated as motor).
A current signal detection device 27 that detects a current signal of the motor, a speed signal detection device 28 that detects a speed signal of the motor, an automatic control signal device 30 that provides a control signal from a device in which the motor is incorporated, and a setting signal that sets the operation of the motor. Device 31, first
The motor cylinder 23 is controlled in response to a signal from a displacement detection device 29 or the like that measures the amount of displacement of the second stator B with respect to the stator A, and the second stator B is displaced or held by a predetermined amount. If it is necessary to fix the displacement at a certain position, the brake device 24 attached to the motor cylinder 23 can be operated to hold it.

Next, the operation will be explained. When starting the electric motor,
The control circuit 32 operates so that the starting current is minimized, that is, the relative positions of the first stator A and the second stator B are shifted by one pole pitch, that is, the displacement is the maximum amount.
A signal is given to the motor cylinder 23 from the motor cylinder 23. Then,
Since the starting current is suppressed, the starting torque of the motor is small, so the load (pump or fan) is accelerated little by little.

When the detected current value from the current signal detection device 26 is greater than or equal to the set value, the control circuit 31 issues a command signal to reduce the current (to reduce the rotational speed of the squirrel cage induction motor), and the motor cylinder 23 The above ↑ command signal is input to rotate the second stator B so that the deviation with respect to the first stator A increases.

Further, when the detected speed value from the speed signal detection device 27 deviates from the set speed value, the control circuit 31 compares the voltage corresponding to the detected speed value with the voltage corresponding to the set speed value, and responds according to the detected speed value. If the voltage is larger than the voltage corresponding to the set speed value, a command signal is issued to decelerate, and if it is smaller than the voltage corresponding to the set speed value, a command signal is issued to speed up. Rotate so that the deviation of the stator A relative to the stator A increases or decreases.

Further, when the control circuit 31 receives a command signal from the automatic control signal device 28 to reduce the production amount of the process, the control circuit 31 operates the motor cylinder 23 so that the rotation speed corresponds to the degree of the reduction.

Originally, the starting current value of a squirrel cage induction motor decreases as the speed increases, so the displacement of the second stator B is gradually changed so that the starting current is started with the set current. If the torque required by the load is large and the motor does not accelerate, the motor completes starting by gradually loosening the displacement of the second stator B until the motor accelerates.

Next, when it is necessary to change the speed during operation, a speed command is given and the motor cylinder 23 is operated until the speed reaches that speed without comparing the speed signal and the design value.

Further, when a failure occurs in the cylinder mechanism, control circuit 32, etc., the rotational displacement of the second stator can be manually operated by manually rotating the motor shaft serving as the drive source.

In the above embodiment, the second stator B is rotated by the motor cylinder, but instead of the motor cylinder, a known mechatronic cylinder whose expansion/contraction amount, expansion/contraction speed, etc. can be numerically controlled may be used. .

In the above embodiment, one motor cylinder or mechatronic cylinder is provided, but these may be provided at several locations on the circumference and controlled simultaneously.

[Effects of the Invention] As described above, according to the present invention, since the second stator is configured to be rotated by the cylinder mechanism driven by the motor as the drive source, a quick response can be obtained and the cylinder If a failure occurs in the mechanism or the like, the rotational displacement of the second stator can be manually operated, so it can be incorporated into an automatic control circuit. In addition, the cylinder mechanism can directly rotate the stator of the box 2, and since a power transmission device such as a gear is not required, the structure can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a squirrel cage induction motor according to an embodiment of the present invention, FIG. 2 is a front view showing a motor cylinder for rotating a second stator, and FIG. 3 is a conventional squirrel cage induction motor. FIG. 4(a) is a longitudinal sectional view showing a type induction motor, FIG. 4(a) is a torque characteristic diagram with respect to speed, and FIG. 4(b) is a starting current characteristic diagram with respect to speed. A and B are the first. Second stator, 18 is a squirrel cage trochanter, 2
1 is a rolling rod, 23 is a motor cylinder, 24 is a brake device, and 32 is a control circuit. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. a2N Figure 4 (a) ■, and

Claims (1)

[Claims] A first stator and a second stator having the same number of poles and the same number of slots are arranged side by side facing a common squirrel cage rotor, and the second stator has a pitch equivalent to one pole. A squirrel cage induction motor capable of rotation in the circumferential direction includes a cylinder mechanism in which a motor is used as a drive source and a piston is connected to a rolling rod protruding from the outer surface of the second stator; The motor is equipped with a brake that stops and holds the motor at a predetermined rotational position, and a control circuit that calculates based on the conditions required by the load and provides command signals for the amount of forward rotation and the amount of forward rotation of the second stator to the motor. A squirrel cage induction motor characterized by: