ELECTROMAGNETIC TORQUE MOTOR WITH HIGH TORQUE AND LIMITED ANGLE

Abstract

The torque motor in this patent depends on decreasing the gap between a surface on a fixed part and a corresponding inclined facing surface on a rotating part, where the gap width is proportional to its distance from the angle vertex, in magnifying the electromagnetic force and its resulting torque. Therefore, the surface on the fixed part starts directly ator close toa point in align with the rotating part center of rotation, and hence the gap width is minimum at the start point and increases away from this point due to the inclination angle. The motor may have various features such as utilizing many pairs of facing surfaces, many electromagnetic circuits; arrange the surfaces in pairs for balanced forces, works in one or two directions, the two directions electromagnetic circuits installed in one or two levels. Precautions and ways to avoid magnetic field interference and leakage should be considered.

Claims

1. An electromagnetic torque motor with limited angular displacement consists of a rotating part and one of more fixed parts, each fixed part with two or more ends, the fixed part(s) ends' surfaces face one or more corresponding surfaces on the rotating part. The facing surfaces are separated with gaps which are preferred to be of zero value when the surfaces are in the closest position, and when the rotating part is displaced, the gap is generated between them

2. The electromagnetic torque motor with limited angular displacement as in item 1, in which the fixed part facing surface at its end starts at a point in align with the rotating part center of rotation, or close to it, and extends in one side of the center of rotation in such a way that its generated pulling electromagnetic forces produce torques in one direction

3. The electromagnetic torque motor with limited angular displacement as in items 1 and 2, where the two facing pair surfaces that generate pulling forces are distributed in such a way that they generate torques in the same direction and doesn't oppose each other

4. The electromagnetic torque motor with limited angular displacement as in item 1, 2 and 3, wherein the closeness between the facing surfaces of the fixed and rotating parts due to their inclination and existence near the angle vertex are utilized. The gap width between the two facing surfaces is smallest at the vertex side and largest at the other side

5. The electromagnetic torque motor with limited angular displacement as in item 1 to 4 wherein the two facing surfaces at the two fixed part ends are facing two surfaces on the rotating part in such a way that the resultant of the electromagnetic pulling forces is zero force and a pure torque couple

6. The electromagnetic torque motor with limited angular displacement as in item 1 to 5 wherein more than one facing surfaces pair and one electromagnetic circuits are utilized

7. The electromagnetic torque motor with limited angular displacement as in item 6 wherein surface pairs are arranged in such a way that no contradiction between torques as in item 3, and all forces are balanced as in item 5

8. The electromagnetic torque motor with limited angular displacement as in item 1 to 7 wherein more than one electromagnetic group can be used to generate torques in one direction or in the two directions of rotation

9. The electromagnetic torque motor with limited angular displacement as in item 1 to 8 wherein the groups can be built in one level or in several levels

10. The electromagnetic torque motor with limited angular displacement as in item 1 to 9 wherein flux isolators or else can be used to prevent flux leakage or interference

11. The electromagnetic torque motor with limited angular displacement as in item 1 to 10 wherein any means such as permanent magnets or else can be used to improve the performance without considering it a new idea

Description

BRIEF DESCRIPTION OF DRAWINGS

[0015] FIG. 1 Shows the main parts of an electromagnetic torque motor example that applies the invention idea

[0016] FIG. 2 shows a closeup of rotating part in the example shown in FIG. 1 with the fixed part two ends and the facing surfaces

[0017] FIG. 3 shows a closeup of the facing surfaces in FIG. 1 and the position of the rotating part at its stroke end

[0018] FIG. 4 shows an example of how the torque motor can work in the two directions of rotation.

[0019] FIG. 5 shows how to use more than two pairs of facing surfaces, and electromagnetic circuits as well in order to increase the torque. It also shows some improvement examples such as force balancing, avoiding facing surfaces area reduction and decreasing the magnetic flux leakage.

[0020] FIG. 6 shows an example of using two force balanced groups to turn the electromagnetic torque motor in the two directions, and using flux isolators to reduce leakage and interference at intersections

[0021] FIG. 7 shows other examples for the fixed and rotating parts arrangements.

INDUSTRIAL APPLICABILITY

[0022] The torque motor generates high torque at small stroke angles, where the torque increases with the decrease of the inclination angle between the corresponding faces of the fixed and rotating parts. These motors are suitable for machine such as wire forming machines. Current machine use cams for certain product, or electric servo motors with speed reducers or pneumatic and hydraulic actuators for programmable multipurpose machines. If the powerful torque motors are used, simple, of low cost and easy to be controlled multipurpose programmable machines can be built.

[0023] Other important application is the torque motor of servovalves. Prevailing motors can't directly drive them without intermediate amplifiers. This motor can provide the required driving torque for many of such applications. Besides, it can be built as integrated part of the device in order to reduce the inertia and increase the speed of response.