JPS6221962Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hysteresis type dynamometer that applies a hysteresis type magnetic coupling of a permanent magnet field that operates on the principle of a hysteresis motor.

Magnetic couplings that use permanent magnets are classified into three types. There are three types: a synchronous type that uses attraction and repulsion between magnets, an eddy current type that uses eddy current, and a hysteresis type that uses magnetic hysteresis. Among these three types, the eddy current type is already applied to dynamometers (the large type uses a current-excited field), but other types are also used in dynamometers. There are none. Of the two models other than the eddy current type, the synchronous type has an extremely weak starting torque, causes disturbances during asynchronous operation, can hardly absorb the load torque, and in principle cannot function as a dynamometer. do not have. On the contrary,
Since the hysteresis type can in principle always transmit or absorb constant torque even during startup, non-synchronization, and synchronization, it is thought that it can operate as a dynamometer.

By the way, in the case of conventional dynamometers using eddy current type magnetic couplings, as can be seen from the principle of eddy current type, torque absorption at low speeds is extremely weak, and there is a drawback that torque cannot be absorbed at all when the vehicle is restrained. .

The present invention was developed by focusing on the excellent property of the hysteresis type magnetic coupling in that it is capable of absorbing constant torque even when the hysteresis type magnetic coupling is locked or at low speed. The present invention aims to provide a hysteresis type dynamometer that can easily measure the torque of an electric motor, etc. from the time of restraint to the time of startup to high speed.

Embodiments of the hysteresis type dynamometer according to the present invention will be described below with reference to the drawings.

As can be seen from FIGS. 1 and 2, the hysteresis type dynamometer of the embodiment has a structure similar to that of an axial gap type hysteresis magnetic coupling. 1 and 2, a permanent magnet rotating field 2 is fixed to a drive shaft 1 connected to a rotating shaft to be measured such as an electric motor (not shown), and this permanent magnet rotating field 2 is made of ferromagnetic material. 2 on the disk-shaped field side yoke 3 of the body
It has a structure in which a circular permanent magnet 4, which is pre-magnetized more than the pole, is fixed. As the permanent magnet 4, a ferrite magnet material is usually used. On the other hand, a support shaft 6 is mounted on the support stand 5 so as to be concentric with the drive shaft 1.
A ball bearing 7 is connected to the support shaft 6.
A hysteresis magnet rotor 8 is rotatably provided via the hysteresis magnet rotor 8. Here, hysteresis magnet rotor 8
In this example, a non-magnetized annular hysteresis magnet material 11 is fixed to a disc-shaped hysteresis side yoke 9 made of a ferromagnetic material so as to face the permanent magnet 4 with an air gap 10 interposed therebetween. This hysteresis magnet material 11
For example, a ferrite magnet material or an alnico magnet material having a high coercive force and a large specific resistance is used. The support shaft 6 supporting the ball bearing 7 has a threaded portion 12 and is screwed onto the support base 5, and a handle 13 is attached to the rear end of the support shaft 6. Therefore, by turning this handle 13, the length of the gap between the permanent magnet rotating field 2 and the hysteresis magnet rotor 8 can be adjusted. The hysteresis magnet rotor 8 has arms 14 attached to the left and right sides of its central axis, and one of the arms 14 is provided with a weight or other load measuring device 15 for measuring the load applied to the arm. There is.

Next, the operation of the hysteresis type dynamometer shown in FIGS. 1 and 2 will be explained. When the permanent magnet rotating field 2 on the drive side rotates, a rotating magnetic field is generated in the hysteresis magnet material 11 of the hysteresis magnet rotor 8 due to the magnetizing force it generates. This causes the hysteresis magnet material 11 to generate a magnetic flux density distribution according to its hysteresis magnetization characteristic, and a torque proportional to the loop area of the magnetization characteristic is generated. Therefore, the hysteresis magnet rotor 8 tries to rotate around the support shaft 6, but the arm 1
4. It is held still by a weight or other load measuring device 15 provided at the tip. If the load measuring device 15 is adjusted so that the rest position of the arm 14 is horizontal, the product of the load at that time and the length of the arm 14 (length from the center of the support shaft) is the value of the torque on the drive side. shows. In other words, it is equivalent to applying a load torque equal to this value to the motor under test that is directly connected to the drive shaft 1, and the output is absorbed as hysteresis loss in the hysteresis magnet rotor 8 and becomes heat. and dissipate.

According to the above embodiment, the following effects can be achieved.

(1) To measure the torque of an electric motor, etc., it is necessary to vary the load torque and actually measure the torque speed characteristics. The load torque can be easily varied by changing the length of the gap between 8 and 8.

(2) Conventional eddy current type dynamometers have extremely weak torque absorption at low speeds, as can be seen in principle, and cannot absorb torque at all when restrained. Since the dynamometer is based on the principle of the hysteresis magnetization phenomenon of the hysteresis magnet material 11, it is possible to absorb the torque generated on the drive side as load torque even at low speeds and when the vehicle is locked. Therefore, it has an excellent advantage that eddy current type dynamometers do not have, and can easily measure starting and stopping torques, which are relatively difficult to measure.

The hysteresis type dynamometers shown in Figures 1 and 2 have an axial gap type (disk type) magnetic path configuration, but in addition to this type, radial gap type (cylinder type) magnetic path configurations are also available. It can also be adopted. FIG. 3 shows another embodiment of the present invention, which is a hysteresis type dynamometer having such a radial gap type magnetic path configuration. In FIG. 3, a hysteresis magnet rotor 20 is fixed to the drive shaft 1, and this hysteresis magnet rotor 20 has a non-magnetized cylindrical hysteresis magnet material 22 on the outer periphery of a cylindrical hysteresis yoke 21 made of ferromagnetic material. is fixed. On the other hand, a support shaft 6 is provided on the support base 5 so as to be concentric with the drive shaft 1, and a permanent magnet rotating field 23 is connected to the support shaft 6 via a ball bearing 7.
is rotatably provided. Here, the permanent magnet rotating field 23 includes a cylindrical permanent magnet 25 magnetized in advance to have two or more poles on the inner circumference of a cylindrical field-side yoke 24 made of ferromagnetic material, and an air gap 26 with respect to the hysteresis magnet rotor 20. They are fixed so that they face each other with the two parts in between. Note that the points that a load measuring device is provided at the end of the arm on the side of the permanent magnet rotating field 23 and that the support shaft 6 is screwed to the support base 5 are similar to the embodiments shown in FIGS. 1 and 2. be.

In the case of the embodiment shown in FIG. 3, although the length of the air gap between the hysteresis magnet rotor 20 and the permanent magnet rotating field 23 cannot be adjusted, the load torque can be adjusted by changing the length of their overlap. can be made variable. Furthermore, the operation as a dynamometer is completely the same as that of the previous embodiment.

In the embodiments shown in FIGS. 1 and 2, the drive shaft side is a permanent magnet rotating field and the measurement side is a hysteresis magnet rotor, but the opposite may be used. Similarly, in the other embodiment shown in FIG. 3, the drive shaft side is a hysteresis magnet rotor, and the measurement side is a rotating permanent magnet field, but the reverse may be used.

As explained above, the hysteresis type dynamometer according to the present invention is capable of measuring torque during locking or at low speeds, which conventional eddy current type dynamometers could not measure. It is extremely useful as a dynamometer to measure the power of a motor.

[Brief explanation of the drawing]

Fig. 1 is a side cross-sectional view showing an embodiment of the hysteresis type dynamometer according to the present invention, Fig. 2 is a partially sectional front view showing the hysteresis magnet rotor and arm portion, and Fig. 3 is a cross-sectional side view showing an embodiment of the hysteresis type dynamometer according to the present invention. FIG. 7 is a side sectional view showing another embodiment. 1... Drive shaft, 2, 23... Permanent magnet rotating field, 3, 24... Field side yoke, 4, 25... Permanent magnet, 5... Support stand, 6... Support shaft, 7... Ball bearing, 8, 20...hysteresis magnet rotor,
9, 21...Hysteresis side yoke, 10, 26
... air gap, 11, 22 ... hysteresis magnet material,
12...screw part, 13...handle, 14...arm, 15...load measuring device.

Claims (1)

[Scope of utility model registration request] A permanent magnet rotating field magnet in which a pre-magnetized permanent magnet is fixed to a ferromagnetic field side yoke, and a hysteresis magnet rotor in which a non-magnetized hysteresis magnet material is fixed to a ferromagnetic rotor side yoke. It has a magnetic path configuration in which the permanent magnet and the hysteresis magnet material are opposed to each other with an air gap in between, and either one of the permanent magnet rotating field and the hysteresis magnet rotor is fixed to a drive shaft, and the other is fixed to the drive shaft. A hysteresis type dynamometer characterized by being equipped with a torque measurement mechanism.