JPS6010268B2 - Test method for the magnetic properties of the rotor of a hysteresis motor and equipment for carrying out the test method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for testing the magnetic properties of a rotor for a hysteresis motor, for example a high speed motor, by matching the rotor to a test stator.

In order to obtain the rated power and efficiency, the rotor of a hysteresis motor must have precisely defined magnetic properties, taking into account inconsistencies in the curing method and composition of the rotor material. , resulting in partially irreproducible failures.

The development of rotors therefore requires continuous measurements for testing the results obtained each time. If tolerance requirements are tight, testing of the magnetic properties of the rotor must be performed after flow production. Previously known test methods rely on the detection and evaluation of the magnetization curve of the rotor;
For this purpose, the test object is inserted into a test motor and rotated at high speed according to a predetermined program.

The testing times required in this method are relatively long, which in many cases makes testing quite uneconomical, for example in mass production. The problem underlying the invention is to make it possible, in the testing of rotors for hysteretic motors, to perform a sufficient test of the given electrical motor data, i.e. the magnetic properties, in a short time and at little expense in terms of measuring instruments. It is to be.

This problem is solved by the present invention as follows.

That is, the stator current generated when the stator winding is connected to a predetermined voltage having a predetermined frequency and the rotor is maintained in a stopped state by a braking action is measured and compared with a set value. The standstill current also has a predetermined relationship with the rotational moment and the area enclosed by the rotor hysteresis loop.

As a result, the stator current measurement of the invention provides a simple and readily implementable method for testing electrical motor data or rotors. Compared to previously known methods, therefore, the time for mounting the test device, the time for accelerating and starting the motor, and the time for carrying out special test programs can be saved. The test equipment measures the current in all phases of the stator winding without having to rotate the motor from a standstill as in conventional methods, and compares the measured value with the set value within a predetermined tolerance range. It is enough. In a series of operational tests, the inventive method of measuring standstill currents monitored the reproducibility of the response of characteristic motor data to standstill currents within measurement accuracy as well as the magnetic properties of the rotor for hysteresis motors. It becomes possible to do so.

The function or performance of a motor can be expressed by characteristic data such as torque, efficiency, and output power.

As is known, there are predetermined relationships between various motor data. For example, torque x rotation speed = shaft output, torque x rotation speed ÷ efficiency = active power, etc. FIG. 2 shows a predetermined relationship between motor torque and standstill current. When various relationships between various characteristic data of a certain (model) motor are known,
Characteristic curves showing the relationships between such characteristic mutual data can be created or drawn for different types of models. However, such a characteristic curve is created or drawn only once for each motor type. Thereafter, during testing of this motor type rotor, only the standstill current measurements need be made. Using the aforementioned characteristic curve and this measured current, the torque of the rotor under test is It is possible to immediately represent rut output, etc. with sufficient accuracy. Furthermore, it is possible to automatically express all the above-mentioned values as a test report via an automated test device. In this case, since the rotor does not rotate during the test, the rotor testing device can be fully automated without providing a vibration damping device. On the other hand, in the usual rotor testing method, the rotor is rotated to carry out the operational test, so the test stand must be equipped with a vibration damping device, especially when a data evaluation device is provided on the test stand. That is, in the secondary test method, the possible high rotational speed (approximately 1 rpm) when the rotor rotates
Therefore, damping or reinforcing measures must be taken to suppress (or in some cases completely eliminate) the vibrations that may occur due to this.

The same stator can be used for various rotor measurements in embodiments of the invention.

For example, for measurements of the entire motor, relatively large tolerances can be avoided by performing measurements on the same stator. Moreover, the configuration of the invention makes it possible to develop a testing device that uses rotors at the site where they are manufactured and thus prevents the supply of defective products. This is particularly important in the case of mass production. It is advantageous to have the voltage and frequency for rated operation of the hysteretic motor available for the stator winding.

This brings the test conditions closer to rated operation, thereby avoiding tolerances caused by further correspondence of measured values and rated values. In the present invention, the stator current when the rotor is at rest is used as the set value, so that the performance tested in the running test satisfies the requirements in a known manner.

In order to test the rotor, it is no longer necessary to consider theoretical relationships or to carry out running tests during rotation; instead, the rotor is tested as follows. That is, for each rotor, only the stator current that occurs when the rotor is maintained in a stopped state by a control action is measured; ) and compares the motor characteristic data with set values obtained from a known stator. Furthermore, the invention is to provide an apparatus for implementing the test method according to the invention that is as simple and inexpensive to implement as possible. This problem is solved by the present invention as follows.

That is, the device has at least a stator and a centering spacer, the top surface of the spacer being formed to center and fix the rotor. The electromagnetic properties of the centered spacer material are equal to those of the medium filling the air gap between the stator and rotor during operation. When using a high speed rotation motor, the characteristics have a high vacuum. The thickness of the spacer must then correspond exactly to the thickness of the cavity. If the spacer becomes worn out or damaged, the measurement stator can be used as is and replaced with another spacer. In this case, the previously measured rotor can be used for the correction of various scales. In the design of the device according to the invention, the stator of the hysteresis motor associated with the rotor is used as the test stator.

In this case, the best reproducibility of the measurement results is guaranteed; in addition, among a large number of mass-produced stators, a large number of precision homogeneous stators are selected, which are used in the production of a large number of similar precision test devices. be able to. The expensive production of rigorous and as identical test stators as possible is therefore omitted; identical test stators however allow a single nominal value test valid for all test stators. . Next, the present invention will be described in detail with reference to the drawings. A test stator 2 is provided in the base 1 and is cast in it.

A spacer 3 is inserted into the center of the stator 2, and the spacer 3 accommodates the rotor 4 to be tested in a centered manner parallel to the plane. The stator winding is connected to a generator 5. Furthermore, a measuring device 6 is provided for measuring the stator current. During the test process, the test object is iron-plated onto the surfacer 3 and set under braking action, unless the static friction caused by its own weight is sufficient to counteract the torque generated during the measurement by the magnetic field.

After connecting a voltage of a predetermined frequency to the stator windings, the adjusted stator current, which corresponds to the magnetic properties of the test object, is measured and compared with a set value in order to determine the characteristics of the rotor.
The setpoint value is determined, for example, in a test rig using a standard rotor that has already been tested. The so-called standstill current measured via the device S has a certain relationship to the electromagnetic properties characterizing a hysteresis motor equipped with a corresponding rotor. Thus, for example, the correspondence is shown by curve 7 in FIG. 2 between motor torque M and standstill current 1. Curve 8 shows the corresponding tolerance limit.

[Brief explanation of the drawing]

FIG. 1 is a schematic circuit diagram of an embodiment of the present invention, and FIG. 2 is a graph showing the relationship between motor torque and stop state current. 2...Stator, 3...Subasa, 4...Rotor. FIG. I Fig. 2

Claims (1)

[Claims] 1. A method for testing the magnetic characteristics of a rotor of a hysteresis motor by associating the rotor with a test stator, in which the stator winding is connected to a predetermined voltage having a predetermined frequency, and the rotor is rotated. A method for testing the magnetic characteristics of a rotor of a hysteresis motor, characterized in that the stator current generated when the child 4 is maintained in a stopped state by a braking action is measured and compared with a set value. 2. A method according to claim 1, in which the same test stator 2 is used for measurements on different rotors. 3. A method according to claim 1 or 2, wherein a predetermined voltage and frequency for the rated operation of the hysteresis motor is used for the stator winding. 4. The method according to any one of claims 1 to 3, wherein the stator current when the rotor 4 having the rated performance is stopped in the operating test is used as the set value. 5 Match the rotor to the test stator, connect the stator winding to a predetermined voltage with a predetermined frequency in order to test the magnetic characteristics of the rotor of the hysteresis motor, and bring the rotor to a stopped state by braking the rotor. A device for carrying out a test method for measuring a stator current generated when the stator is maintained at a fixed value and comparing it with a set value, comprising at least a stator 2 and a spacer 3 arranged in a centered manner, the spacer An apparatus for carrying out a method for testing the magnetic characteristics of a rotor of a hysteresis motor, characterized in that the upper surface of the rotor is formed to center and fix the rotor. 6. Device according to claim 5, characterized in that the stator of a hysteresis motor associated with the rotor is used as the test stator.