A magnetic resistance type rotary joint mounting structure resistant to electromagnetic interference

Abstract

The application discloses a kind of magnetoresistive rotary joint installation structures of anti-electromagnetic interference, to protect rotary joint, including rotating shaft, rotary joint rotor installation cylinder, rotary joint rotor, rotary joint stator, cover plate, shielding ground, connecting fastener, rotary joint stator installation base and end cover;Outer structure uses non-conductive non-magnetic material to directly isolate the magnetic field of rotary joint rotor and rotary joint stator, and inner structure forms the structure of metal cage to prevent external magnetic field interference, so that the output signal of rotary joint is not interfered by external electromagnetic field, not only can the installation of rotary joint stator and rotary joint rotor meet precision requirement, but also the signal of magnetoresistive rotary joint can be accurately output, so that motor can realize closed-loop operation.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of electric machines, and particularly relates to a magnetic resistance type rotary variable differential transformer installation structure with electromagnetic interference resistance. BACKGROUND

[0002] An electric machine generally performs closed-loop control through a rotary variable differential transformer to feed back a rotating speed signal, and the magnetic resistance type rotary variable differential transformer has poor electromagnetic interference resistance. When there is a strong electromagnetic field near the magnetic resistance type rotary variable differential transformer, such as a strong alternating current, a magnetic powder brake, an electromagnetic brake and other strong external magnetic fields, the signal output by the rotary variable differential transformer has large fluctuation, so that the electric machine cannot perform closed-loop operation. SUMMARY

[0003] In order to solve the above problems in the prior art, the application provides a magnetic resistance type rotary variable differential transformer installation structure with electromagnetic interference resistance, so that the output signal of the rotary variable differential transformer is not interfered by external electromagnetic fields, thereby solving the above problems.

[0004] The application adopts the technical scheme that a magnetic resistance type rotary variable differential transformer installation structure with electromagnetic interference resistance comprises a rotating shaft, a rotary variable differential transformer rotor fixed on the rotating shaft through a rotary variable differential transformer rotor installation cylinder, and a rotary variable differential transformer stator fixed on an end cover through a rotary variable differential transformer stator installation base; the rotating shaft is provided with a shaft shoulder and a circlip to position and fix the rotary variable differential transformer rotor; the rotary variable differential transformer rotor installation cylinder is composed of two layers of an installation cylinder outer side and an installation cylinder inner side in contact with the rotating shaft, the installation cylinder inner side is made of non-conductive and non-magnetic material to isolate direct conduction of electricity and magnetism caused by the rotating shaft; the rotary variable differential transformer stator installation base is composed of two layers of a base outer side and a base inner side in contact with the end cover, the base outer side is fixed with a cover plate through a connecting fastener, the base inner side and the connecting fastener are made of non-conductive and non-magnetic material to isolate direct conduction of electricity and magnetism caused by the end cover; the installation cylinder outer side, the base outer side and the cover plate are made of metal material to form a closed structure like a metal cage, and a shielding ground wire is led out to ground to shield external radiated electromagnetic fields.

[0005] The rotary variable differential transformer stator installation base of the magnetic resistance type rotary variable differential transformer installation structure with electromagnetic interference resistance is provided with a stop opening to limit the rotary variable differential transformer stator.

[0006] The end cover of the magnetic resistance type rotary variable differential transformer installation structure with electromagnetic interference resistance is provided with a stop opening to limit the rotary variable differential transformer stator installation base.

[0007] The non-conductive and non-magnetic material of the magnetic resistance type rotary variable differential transformer installation structure with electromagnetic interference resistance includes but is not limited to polytetrafluoroethylene and epoxy resin.

[0008] The metal of the magnetic resistance type rotary variable differential transformer installation structure with electromagnetic interference resistance includes but is not limited to copper, aluminum and iron.

[0009] The beneficial effects of the present application are: the outer layer structure of the present application directly isolates the magnetic field of the resolver rotor and resolver stator by using non-conductive and non-magnetic material, and the inner layer structure forms a metal cage structure to prevent external magnetic field interference, so that the output signal of the resolver is not disturbed by the external electromagnetic field, not only can the installation of the resolver stator and resolver rotor meet the accuracy requirements, but also the signal of the resolver can be accurately output, so that the motor can realize closed-loop operation. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is a structural schematic diagram of the present application;

[0011] Figure 2 is a schematic diagram of the shaft and resolver rotor installation cylinder of the present application;

[0012] Figure 3 is a schematic diagram of the resolver stator installation base of the present application;

[0013] Figure 4 is a schematic diagram of the resolver stator installation base mating surface of the present application;

[0014] Figure 5 is a description of the gap of the auxiliary installation structure of the present application.

[0015] The reference signs are: 1-rotating shaft, 1-1-shoulder, 1-2-clamp spring, 2-resolver rotor installation cylinder, 2-1-installation cylinder inside, 2-2-installation cylinder outside, 3-resolver rotor, 4-resolver stator, 5-cover plate, 6-shielding ground wire, 7-connection fastener, 8-resolver stator installation base, 8-1-base inside, 8-2-base outside, 9-end cover. DETAILED DESCRIPTION

[0016] Hereinafter, the embodiments of the present application will be described in detail with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application, and are not intended to limit the protection scope of the present application. For example, although each component in the drawings is drawn in a specific proportion, these proportion relationships are only exemplary, and those skilled in the art can adjust them as needed to adapt to specific application occasions.

[0017] It should be noted that in the description of the present application, the terms "center", "upper", "lower", "left", "right", "inner", "outer" and the like indicate the direction or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed or operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0018] Furthermore, it needs to be explained that in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the connection inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0019] Referring to Figure 1 The application discloses a magnetic resistance type rotary variable mounting structure for protecting the rotary variable, which comprises a rotating shaft 1, a rotary variable rotor mounting cylinder 2, a rotary variable rotor 3, a rotary variable stator 4, a cover plate 5, a shielding ground wire 6, a connecting fastener 7, a rotary variable stator mounting base 8 and an end cover 9.

[0020] Referring to Figure 2 The rotating shaft 1 is provided with a shaft shoulder 1-1 and a circlip 1-2, so as to position and fix the rotary variable rotor 3. The rotary variable rotor mounting cylinder 2 is composed of two layers of a mounting cylinder outer side 2-2 and a mounting cylinder inner side 2-1 in contact with the rotating shaft 1 side. The mounting cylinder inner side 2-1 is made of non-conductive and non-magnetic material, so as to isolate the direct conduction of electricity and magnetism caused by the rotating shaft 1, and is one of the outer layer structures.

[0021] Referring to Figure 3 The rotary variable stator mounting base 8 is composed of two layers of a base outer side 8-2 and a base inner side 8-1 in contact with the end cover 9 side. The base outer side 8-2 is fixed with the cover plate 5 through the connecting fastener 7. The base inner side 8-1 and the connecting fastener 7 are made of non-conductive and non-magnetic material, so as to isolate the direct conduction of electricity and magnetism caused by the end cover 9, and are one of the outer layer structures. The mounting cylinder outer side 2-2, the base outer side 8-2 and the cover plate 5 are made of metal material to form a closed structure like a metal cage, and the shielding ground wire 6 is led out to be grounded, so as to shield the external electromagnetic field, and are the inner layer structures.

[0022] The mounting position of the rotary variable stator mounting base 8 and the rotary variable stator 4 should be limited by a stopper, so as to ensure the axial position of the rotary variable stator 4. The matching surface of the rotary variable stator mounting base 8 and the rotary variable stator 4 should have precision requirements, wherein the coaxiality and roughness are controlled according to the installation progress of the rotary variable, so as to ensure the radial positioning accuracy of the rotary variable stator 4. The end cover 9 is provided with a stopper for limiting the rotary variable stator mounting base 8. The mounting position of the rotary variable stator mounting base 8 and the end cover 9 should be limited by a stopper, so as to ensure the axial position of the rotary variable stator mounting base 8. The matching surface of the rotary variable stator mounting base 8 and the end cover 5 should have precision requirements, wherein the coaxiality and roughness are controlled according to the installation progress of the rotary variable, so as to ensure the radial positioning accuracy of the rotary variable stator 4.

[0023] Firstly, the rotary transformer rotor installation cylinder 2 and the rotating shaft 1 are positioned and fixed, the rotary transformer rotor installation cylinder 2 is positioned and connected, and the installation of the rotary transformer rotor 3 is completed. Then the rotary transformer stator installation base 8 is installed on the end cover 9, positioned by the stop port, and connected by the connecting fastener 7, the installation of the rotary transformer stator installation base 8 is completed, then the rotary transformer stator 4 is installed on the rotary transformer stator installation base 8, positioned by the stop port, and connected by the connecting fastener 7, the installation of the rotary transformer stator 4 is completed. Finally, the cover plate 5 is fixed on the rotary transformer stator installation base 8 by the connecting fastener 7, and the installation of the electromagnetic interference resistant magnetic resistance rotary transformer structure is completed.

[0024] In order to eliminate the direct conduction of electromagnetic brake, magnetic powder brake or other electromagnetic field on the side of the end cover 9, the inside of the installation cylinder 2-1 is made of non-conductive and non-magnetic material to isolate the direct conduction of electricity and magnetism caused by the rotating shaft 1. There may be shaft current and other electromagnetic fields in the rotating shaft 1. In order to eliminate the direct conduction of electromagnetic field of the rotating shaft 1, the inside of the base 8-1 and the connecting fastener 7 are made of non-conductive and non-magnetic material to isolate the direct conduction of electricity and magnetism caused by the end cover 9. The non-conductive and non-magnetic material includes but is not limited to polytetrafluoroethylene, epoxy resin and other materials.

[0025] In order to eliminate the external radiation electromagnetic field, the outside of the base 8-2, the outside of the installation cylinder 2-2 and the cover plate 5 are made of metal material to form a metal shielding shell, and the shielding ground wire 6 is grounded to shield the external radiation electromagnetic field. The metal includes but is not limited to copper, aluminum, iron and other materials, but the material should be selected according to the shielding requirement.

[0026] The rotary transformer stator installation base 8 is connected with the end cover 9 and the rotary transformer stator 4, in order to ensure the accuracy of the rotary transformer output speed signal, the installation of the rotary transformer should meet the accuracy requirements of axial and radial directions. The matching surface of the rotary transformer stator installation base 8 is shown in Figure 4 , wherein A is the axial matching contact surface A of the rotary transformer stator installation base 8 and the body end cover 9, and the corresponding contact surface should meet the requirements of flatness and roughness; B is the radial matching contact surface of the rotary transformer stator installation base 8 and the body end cover 9, B and the corresponding contact surface should meet the coaxiality requirement; C is the radial matching contact surface of the rotary transformer stator installation base 8 and the rotary transformer rotor 3, C and the corresponding contact surface should meet the coaxiality requirement; D is the radial contact matching surface of the rotary transformer stator installation base 8 and the rotary transformer rotor 3, D and the corresponding contact surface should meet the requirements of flatness and roughness.

[0027] When electromagnetic wave passes through any metal object, there are two types of losses, absorption and reflection, the calculation formula of shielding effectiveness S is: S=A+R+B (dB), wherein A is the absorption loss; R is the reflection loss, which changes with the ratio of wave resistance and shielding impedance, and depends on the distance between the shielding shell and the wave source; B is a positive or negative correction term formed by the reflection wave in the shielding shell, when A is greater than 15 dB, B can be ignored.

[0028]

[0029] Wherein, d is the thickness of the shield, σ is the electrical conductivity relative to copper material, μ is the magnetic permeability relative to copper material, f is the frequency, r is the distance between the wave source and the shield. Preferably, the shielding material is selected as iron, the electrical conductivity of iron relative to copper material is 0.17, the magnetic permeability of iron relative to copper material is 1000, and the thickness is selected according to the shielding effectiveness requirement. When other materials are selected, the electrical conductivity and the magnetic permeability can be referred to.

[0030] Referring to Figure 5 As shown in the figure, d1 is the axial distance between the rotary variable resistor stator mounting base 8 and the rotary variable resistor stator 4, d2 is the radial distance between the rotary variable resistor stator mounting base 8 and the rotary variable resistor stator 4, which is appropriately selected according to the installation space. d3 is the radial distance between the rotary variable resistor rotor mounting cylinder 2 and the rotary variable resistor stator mounting base 8 and the cover plate 5. Preferably, d3 is suggested to be less than 1mm, the smaller the distance, the better the shielding effect.

[0031] The above embodiments only exemplarily illustrate the principles and effects of the present application, and part of the applied embodiments, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application.

Claims

1. A magnetoresistive resolver mounting structure resistant to electromagnetic interference, characterized by: The utility model relates to a rotary transformer, which comprises a rotating shaft (1), a rotary transformer rotor (3) fixed on the rotating shaft (1) through a rotary transformer rotor mounting cylinder (2), a rotary transformer stator (4) fixed on an end cover (9) through a rotary transformer stator mounting base (8), an axle shoulder (1-1) and a circlip (1-2) arranged on the rotating shaft (1), the rotary transformer rotor mounting cylinder (2) comprising a mounting cylinder outer side (2-2) and a mounting cylinder inner side (2-1) in contact with the rotating shaft (1), the mounting cylinder inner side (2-1) being made of non-conductive and non-magnetic material, the rotary transformer stator mounting base (8) comprising a base outer side (8-2) and a base inner side (8-1) in contact with the end cover (9), the base outer side (8-2) being provided with a cover plate (5) fixed through a connecting fastener (7), the base inner side (8-1) and the connecting fastener (7) being made of non-conductive and non-magnetic material, the mounting cylinder outer side (2-2), the base outer side (8-2) and the cover plate (5) forming a metal cage closed structure, and a shielding ground wire (6) is led out to be grounded.

2. The electromagnetic interference resistant magnetoresistive rotary switch mounting structure of claim 1, wherein, The rotary transformer stator mounting base (8) is provided with a stop opening for limiting the rotary transformer stator (4).

3. The electromagnetic interference resistant magnetoresistive rotary switch mounting structure of claim 1, wherein, The end cover (9) is provided with a stop opening for limiting the rotary transformer stator mounting base (8).

4. The electromagnetic interference resistant magnetoresistive rotary switch mounting structure according to claim 1 or 2 or 3, wherein The non-conductive and non-magnetic material is polytetrafluoroethylene or epoxy resin.

5. The electromagnetic interference resistant magnetoresistive rotary switch mounting structure according to claim 1 or 2 or 3, wherein The metal is copper, aluminum or iron.

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