Inner rotor type resolver

Abstract

The invention discloses an inner rotor type rotary transformer which comprises a lower cover, and a lower cover pin is clamped and mounted on the right side of the top of the lower cover. The shape of the rotor is changed into an oval shape from a round shape, and the gap between the stator and the rotor is increased to 1.0 mm from 0.5 mm, so that the measurement accuracy of the rotary transformer can meet the specification requirement of 2 degrees under the condition that the stator and the rotor are eccentric, the performance is stable, and the problems that the working temperature of the rotary transformer generally ranges from-40 DEG C to 150 DEG C, and under the high-temperature condition, the measurement accuracy of the rotary transformer is low are solved. In the prior art, the resistance of the coil is increased, the voltage drop and the energy loss are increased, the magnetic conductivity of the iron core is changed along with the temperature, the performance of the transformer is further influenced, in addition, the stator and the rotor easily generate eccentricity at a high temperature, namely the centers of the rotary transformer rotor and the stator are not on the center of the motor rotor, and cos or sin signal front and back half-cycle peak values are inconsistent during eccentricity. Therefore, the measurement precision of the rotary transformer is influenced.

Description

Technical Field

[0001] The invention relates to the technical field of rotary transformers, in particular to an inner rotor type rotary transformer for measuring the rotation angle and rotation speed of a motor. Background Art

[0002] A rotary transformer is a sensor used to accurately measure the speed and rotation angle of a motor. Generally, the excitation coil and output coil of the rotary transformer are both located on the stator, and the rotor having an elliptical or multi-pole shape is located inside or outside the stator along the circumference of the stator. A rotary transformer with a rotor located outside the stator is called an outer rotor type rotary transformer, and a rotary transformer with a rotor located inside the stator is called an inner rotor type rotary transformer. Recently, rotary transformers are widely used in various technical fields, especially in high-precision control systems, such as electric power steering systems that need to measure and control the rotation angle and rotation speed with high precision. Therefore, it is necessary to accurately point out and analyze the various factors that affect the measurement performance of the rotary transformer, and reflect these factors in the design of the rotary transformer, so as to minimize the measurement error of the rotary transformer and maximize the measurement accuracy. The operating temperature of the rotary transformer is generally between -40℃ and 150℃. Under high temperature conditions, the resistance of the coil will increase, resulting in increased voltage drop and energy loss. The magnetic permeability of the core will also change with temperature, further affecting the performance of the transformer. In addition, the stator and rotor are easily eccentric at high temperatures, that is, the center of the rotary transformer rotor and the stator is not on the center of the motor rotor. When eccentric, the peak values ​​of the cos or sin signal before and after the half cycle are inconsistent, thereby affecting the measurement accuracy of the rotary transformer. This shortcoming is not reflected in the design of the rotary transformer in the prior art. In the prior art, the influence of the eccentricity of the stator and rotor on the measurement error of the rotary transformer at high temperature is not considered. Summary of the invention

[0003] In order to solve the problems raised in the above background technology, the purpose of the present invention is to provide an inner rotor type rotary transformer, which has the advantages of reducing the influence of stator and rotor eccentricity on measurement error at high temperature by changing the shape of the rotor and increasing the gap between the rotor and the stator, thereby improving the measurement accuracy of the rotary transformer, and solves the problem that the operating temperature of the rotary transformer is generally -40°C to 150°C. Under high temperature conditions, the resistance of the coil will increase, resulting in increased voltage drop and energy loss, and the magnetic permeability of the iron core will also change with temperature, further affecting the performance of the transformer. In addition, the stator and rotor are easily eccentric at high temperatures, that is, the center of the rotary transformer rotor and the stator is not on the center of the motor rotor. When eccentric, the peak values ​​of the cos or sin signal before and after the half cycle are inconsistent, thereby affecting the measurement accuracy of the rotary transformer. This shortcoming is not reflected in the design of the rotary transformer in the prior art. In the prior art, the problem of the influence of the eccentricity of the stator and rotor on the measurement error of the rotary transformer at high temperature is not considered.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solution: an inner rotor type rotary transformer, comprising a lower cover, a lower cover pin is snap-fitted on the right side of the top of the lower cover, an insulating cover pin is snap-fitted on the top of the lower cover pin, an insulating cover is fixedly installed on the left side of the insulating cover pin, a stator is fixedly installed on the outside of the insulating cover, a rotor is snap-fitted on the inside of the stator, and an upper cover is snap-fitted on the top of the insulating cover and the insulating cover pin.

[0005] As a preferred embodiment of the present invention, the shape of the rotor is elliptical, and the gap between the stator and the rotor is 1.0 mm.

[0006] Compared with the prior art, the present invention has the following beneficial effects:

[0007] 1. The present invention changes the shape of the rotor from circular to elliptical by setting, and increases the gap between the stator and the rotor from 0.5mm to 1.0mm. When the stator and the rotor are eccentric, the measurement accuracy of the rotary transformer can meet the specification requirement of 2°, and the performance is stable. The working temperature of the rotary transformer is generally -40℃~150℃. Under high temperature conditions, the resistance of the coil will increase, resulting in increased voltage drop and energy loss. The magnetic permeability of the iron core will also change with temperature, further affecting the performance of the transformer. In addition, the stator and rotor are easily eccentric at high temperatures, that is, the center of the rotary transformer rotor and the stator is not on the center of the motor rotor. When eccentric, the peak values ​​of the cos or sin signal before and after the half cycle are inconsistent, thereby affecting the measurement accuracy of the rotary transformer. This shortcoming is not reflected in the design of the rotary transformer in the prior art. In the prior art, the problem of the influence of the eccentricity of the stator and rotor on the measurement error of the rotary transformer at high temperature is not considered. The effect of reducing the influence of the eccentricity of the stator and rotor on the measurement error at high temperature by changing the shape of the rotor and increasing the gap between the rotor and the stator is achieved, thereby improving the measurement accuracy of the rotary transformer.

[0008] 2. The present invention sets the shape of the rotor to be elliptical, the gap between the stator and the rotor to 1.0 mm, the shape of the rotor is changed from circular to elliptical, and the gap between the stator and the rotor is increased from 0.5 mm to 1.0 mm. In the case of eccentricity between the stator and the rotor, the measurement accuracy of the rotary transformer can meet the specification requirement of 2°, and the performance is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention from a first viewing angle;

[0010] Figure 2 This is a schematic diagram of the overall three-dimensional structure of the present invention from a second viewing angle;

[0011] Figure 3 It is a schematic diagram of the overall three-dimensional structure from a third viewing angle of the present invention.

[0012] In the figure: 1. rotor; 2. upper cover; 3. stator; 4. insulating cover; 5. insulating cover pin; 6. lower cover; 7. lower cover pin. DETAILED DESCRIPTION

[0013] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0014] like Figures 1 to 3 As shown, the inner rotor type rotary transformer provided by the present invention includes a lower cover 6, a lower cover pin 7 is snap-fitted to the right side of the top of the lower cover 6, an insulating cover pin 5 is snap-fitted to the top of the lower cover pin 7, an insulating cover 4 is fixedly installed on the left side of the insulating cover pin5, a stator 3 is fixedly installed on the outer side of the insulating cover 4, a rotor 1 is snap-fitted to the inner side of the stator 3, and an upper cover 2 is snap-fitted to the top of both the insulating cover 4 and the insulating cover pin5.

[0015] refer to Figure 1 , the shape of the rotor 1 is elliptical, and the gap between the stator 3 and the rotor 1 is 1.0 mm.

[0016] As a technical optimization solution of the present invention, by setting the shape of the rotor 1 to be elliptical, the gap between the stator 3 and the rotor 1 is 1.0 mm, the shape of the rotor 1 is changed from circular to elliptical, and the gap between the stator 3 and the rotor 1 is increased from 0.5 mm to 1.0 mm. In the case of eccentricity between the stator 3 and the rotor 1, the measurement accuracy of the rotary transformer can meet the specification requirement of 2°, and the performance is stable.

[0017] The working principle and use process of the present invention are as follows: when in use, the lower cover 6, the lower cover pin 7, the insulating cover 4, the insulating cover pin 5, the stator 3 and the rotor 1 are installed. After the installation is completed, the gap between the stator 3 and the rotor 1 is increased, so that the gap between the stator 3 and the rotor 1 is increased from 0.5mm to 1.mm, and the shape of the rotor 1 is changed from circular to elliptical. When the stator 3 and the rotor 1 are eccentric, the measurement accuracy of the rotary transformer can meet the specification requirement of 2°, and the performance is stable. By changing the shape of the rotor 1 and increasing the gap between the rotor 1 and the stator 3, the influence of the eccentricity of the stator and rotor 1 on the measurement error at high temperature is reduced, thereby improving the measurement accuracy of the rotary transformer.

[0018] In summary: the inner rotor type rotary transformer changes the shape of the rotor 1 from circular to elliptical by setting, and the gap between the stator 3 and the rotor 1 is increased from 0.5mm to 1.0mm. When the stator 3 and the rotor 1 are eccentric, the measurement accuracy of the rotary transformer can meet the specification requirement of 2°, and the performance is stable, which solves the problem that the operating temperature of the rotary transformer is generally -40℃~150℃. Under high temperature conditions, the resistance of the coil will increase, resulting in increased voltage drop and energy loss, and the magnetic permeability of the iron core will also change with temperature, further affecting the performance of the transformer. In addition, the stator and rotor are easily eccentric at high temperatures, that is, the center of the rotary transformer rotor and the stator is not on the center of the motor rotor. When eccentric, the peak values ​​of the cos or sin signals in the front and rear half cycles will be inconsistent, thereby affecting the measurement accuracy of the rotary transformer. This shortcoming is not reflected in the design of the rotary transformer in the prior art. In the prior art, the problem of the influence of the eccentricity of the stator and rotor at high temperatures on the measurement error of the rotary transformer is not considered.

[0019] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0020] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An inner rotor type rotary transformer, comprising a lower cover (6), characterized in that: A lower cover pin (7) is snap-fitted and installed on the right side of the top of the lower cover (6); an insulating cover pin (5) is snap-fitted and installed on the top of the lower cover pin (7); an insulating cover (4) is fixedly installed on the left side of the insulating cover pin (5); a stator (3) is fixedly installed on the outer side of the insulating cover (4); a rotor (1) is snap-fitted and installed on the inner side of the stator (3); and an upper cover (2) is snap-fitted and installed on the top of both the insulating cover (4) and the insulating cover pin (5).

2. The inner rotor type rotary transformer according to claim 1, characterized in that: The shape of the rotor (1) is elliptical, and the gap between the stator (3) and the rotor (1) is 1.0 mm.

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