Equal-air-gap multi-antipode reluctance type rotary transformer capable of resisting eccentric interference

Abstract

The invention discloses an equal-air-gap multi-antipode reluctance type rotary transformer capable of resisting eccentric interference. The motor comprises a housing, an output coil arranged at one end of the housing, a first stator core and a second stator core arranged in the output coil, a plurality of stator teeth arranged on the first stator core, a rotor support arranged in the housing, a plurality of assembling grooves arranged on the rotor support, and rotor cores arranged in the assembling grooves. Wherein the rotor iron core is formed by stacking a plurality of square silicon steel sheets, the assembling grooves are inclined parallel straight grooves, the inclination angle is beta, the coupling area of the rotor iron core changes according to the cosine law, S3 = 2 * tan (beta) * R2 * sin (d / 2) * cos (theta0), theta0 is larger than or equal to 0 and smaller than or equal to pi, theta0 is the electrical angle under the number of unit pole pairs, and d is the tooth width of stator teeth; according to the invention, air gap magnetic flux with sine rule change is generated through axial magnetic conductance change, the circumferential air gap is uniform, the influence of precision on eccentricity is small, and high-precision processing of the rotor structure is easier to realize.

Description

Technical Field

[0001] The present invention relates to the field of resolver devices, and particularly to an equal air-gap multi-pole reluctance resolver resistant to eccentricity interference. Background Art

[0002] As an advanced electromagnetic modulation device, the reluctance resolver has important application value in the fields of power conversion and energy transmission. In the design of traditional rotating motors, the coupling relationship between the rotor and the stator is usually realized through simple mechanical motion, while the reluctance resolver realizes energy transfer through the action of the electromagnetic field. Its compact structure, high efficiency and fast response speed make it an important part of modern power systems.

[0003] The existing magnetic reluctance multi-stage resolver adopts a radial coupling structure design. Its rotor part adopts a salient pole arc structure. This design can not only effectively reduce the resistance of the magnetic circuit, but also improve the efficiency of energy transfer. In terms of air-gap design, an uneven air-gap layout can optimize the magnetic field distribution, reduce iron loss and improve the accuracy of the transformation ratio. However, the magnetic circuit coupling relationship between the stator and the rotor mainly depends on the change amount of the air gap. By precisely controlling the size and shape change of the air gap, the magnetic flux between the stator and the rotor can change according to the sine function law, so as to achieve the ideal resolver output characteristics. In the eccentric state, the non-uniform distribution of the air gap will lead to the asymmetry of the magnetic field, thereby affecting the output accuracy of the resolver.

[0004] Therefore, it is necessary to provide a new technical solution to overcome the above defects. Summary of the Invention

[0005] The purpose of the present invention is to provide an equal air-gap multi-pole reluctance resolver resistant to eccentricity interference that can effectively solve the above technical problems.

[0006] To achieve the purpose of the present invention, the following technical solutions are adopted:

[0007] An equal air-gap multi-pole reluctance resolver resistant to eccentricity interference, characterized in that it includes a housing, an output coil provided at one end of the housing, a first stator core and a second stator core provided in the output coil, a plurality of stator teeth provided on the first stator core, an input coil provided between the first stator core and the second stator core, a magnetic conductive ring provided on the input coil, a rotor bracket provided in the housing, a plurality of assembly grooves provided on the rotor bracket, and a rotor core provided in the assembly grooves;

[0008] Wherein, the rotor core is stacked by a plurality of square silicon steel sheets, the assembly grooves are inclined parallel straight grooves in the vertical direction, the inclination angle is β, and the coupling area S3 of the rotor core changes according to the cosine law, and it is S3 = 2·tan(β)·R2 ·sin(d / 2)·cos(θ0), where 0 ≤ θ0 ≤ π, θ0 is the electrical angle under the unit number of pole pairs, d is the stator tooth width, and R is the rotor core radius.

[0009] Furthermore, the coupling height h0 between the rotor core and the first stator core is h0 = R·tan(β)·cos(θ0).

[0010] Furthermore, the coupling area S1 between the rotor core and the first stator core is: S1 = R·∫h0·d·θ0 = ∫2tan(β)·R 2 ·sin(d / 2)·cos(θ0).

[0011] Furthermore, the coupling area S2 between the rotor core and the second stator core is: S2 = R·∫h0·d·θ0 = ∫2tan(β)·R 2 ·sin(d / 2)·cos(θ0); and S3 = S1 + S2.

[0012] Furthermore, the inclination angle of the assembly groove is β = arctan(lr / R), where lr is the maximum axial coupling height of the rotor core.

[0013] Furthermore, stator slots are provided between two adjacent stator teeth, and the number of stator slots is the same as that of the stator teeth and they are uniformly arranged along the axial direction on the first stator core.

[0014] Furthermore, the first stator core and the second stator core have the same shape and structure.

[0015] Furthermore, the rotor bracket is made of non-magnetic material.

[0016] Furthermore, magnetic isolation grooves are provided on the rotor core.

[0017] Furthermore, the height of the magnetic isolation groove is 1 / 3 of the thickness of the rotor core.

[0018] The present invention provides an axial magnetic circuit equal air-gap multi-pole reluctance resolver, which has the following advantages:

[0019] 1. The multi-pole reluctance resolver with an axial magnetic circuit involved in the present invention has a rotor structure with an axial structural change. Its radial dimensions are consistent, its circumferential air gap is uniform, and the influence of eccentricity on its output accuracy is small. It is applicable to more complex operating conditions.

[0020] 2. The multi-pole reluctance resolver with an axial magnetic circuit according to the present invention can effectively control the constant component of the residual electromotive force through a rotor structure with an axial structural change, and its rotor has an equal-size structure, which is more conducive to high-precision machining. Compared with the conventional multi-pole reluctance resolver, the precision can be increased by more than twice.

[0021] 3. For the conventional multi-pole reluctance resolver, its air gap is smaller than that of the conventional reluctance resolver, greatly reducing the radial space of the iron core, saving the radial space, and enabling a thinner and lighter design. Brief Description of the Drawings

[0022] The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention.

[0023] Figure 1 It is a schematic structural diagram of the multi-pole reluctance resolver with an axial magnetic circuit according to the present invention.

[0024] Figure 2 It is a sectional view of the structure of the multi-pole reluctance resolver with an axial magnetic circuit according to the present invention.

[0025] Figure 3 It is a first schematic diagram of the magnetic circuit coupling between the stator and rotor under the unit pole pair number of the multi-pole reluctance resolver with an axial magnetic circuit according to the present invention.

[0026] Figure 4 It is a second schematic diagram of the magnetic circuit coupling between the stator and rotor under the unit pole pair number of the multi-pole reluctance resolver with an axial magnetic circuit according to the present invention.

[0027] Figure 5 It is a diagram of the rotor of the multi-pole reluctance resolver with an axial magnetic circuit according to the present invention.

[0028] Figure 6 It is a developed view of the circumferential plane of the rotor of the multi-pole reluctance resolver with an axial magnetic circuit according to the present invention.

[0029] Figure 7 It is a diagram of the rotor bracket of the multi-pole reluctance resolver with an axial magnetic circuit according to the present invention.

[0030] In the figures: 1. First stator iron core; 2. Input coil; 3. Magnetic conduction ring; 4. Stator slot part; 5. Output coil; 6. Rotor bracket; 7. Rotor iron core; 10. Housing; 11. Stator tooth; 12. Stator slot; 60. Assembly slot; 71. Magnetic isolation slot. Detailed Embodiments

[0031] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention.

[0032] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "transverse", "longitudinal", "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present invention. When a component is referred to as being "fixed to" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component at the same time. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration.

[0033] As Figures 1 to 7 shown, an equal air-gap multi-pole reluctance resolver resistant to eccentric interference includes a housing 10, an output coil 5 provided at one end of the housing 10, a first stator core 1 and a second stator core 4 provided in the output coil 5, a plurality of stator teeth 11 provided on the first stator core 1, an input coil 2 provided between the first stator core 1 and the second stator core 4, a magnetic conductive ring 3 provided on the input coil 2, a rotor bracket 6 provided in the housing 10, a plurality of assembly grooves 60 provided on the rotor bracket 6, and a rotor core 7 provided in the assembly grooves 60; wherein, the first stator core 1 and the second stator core 4 have the same shape and structure, and a stator slot 12 is provided between any two adjacent stator teeth 11.

[0034] Specifically, the first stator core 1, the second stator core 4 and 3 together form a stator magnetic circuit structure. The first stator core 1 and the second stator core 4 form a winding core structure for the output coil 5. The number of stator slots 12 is the same as that of stator teeth 11 and they are evenly arranged axially in the winding core structure. By axially arranging the stator teeth 11 and the stator slots 12, the circumferential air gap between the winding core and the rotor core 7 can be effectively ensured to be uniform. In one embodiment of the present invention, there are Zs stator teeth 11 in the winding core structure, the number of pole pairs of the resolver in the stator magnetic circuit structure is P, and Zs = P. The cosine-phase output winding and the sine-phase output winding are wound on the stator teeth 11 at intervals. The axially evenly arranged stator teeth 11 cooperate with the cosine-phase output winding and the sine-phase output winding to generate a stable axial magnetic circuit.

[0035] Furthermore, as Figure 3 and Figure 6 shown, the rotor bracket 6 is made of non-magnetic material, and a plurality of assembly grooves 60 for assembling the rotor core 7 are evenly distributed on the rotor bracket 6. In one embodiment of the present invention, the number of assembly grooves is Zr, and the assembly grooves 60 are parallel straight grooves with an inclined angle, where Zr = P and P is the number of pole pairs of the resolver.

[0036] It should be noted that the rotor core 7 is stacked by rotor punching sheets of square and other dimensions. By setting the stacking of square silicon steel sheets of equal dimensions, the machining error of the curved surface of the traditional salient pole can be avoided, and the high-precision machining is easier to achieve through the equal-dimension structure. In addition, the material of the rotor punching sheet is silicon steel sheet, which is a kind of silicon-iron soft magnetic alloy with extremely low carbon content, having high resistivity and magnetic permeability, being beneficial to reducing the coercive force and iron loss, and improving the performance of the reluctance multi-pole resolver.

[0037] Furthermore, the rotor core 7 is axially inclined on the rotor bracket 6 through the assembly groove 60, and the inclined angle of the rotor core 7 in the assembly groove 60 is expressed as β = arctan(lr / R). It should be noted that lr is the maximum axial coupling height of the rotor core 7; R is the radius of the rotor core. The air gap of the traditional radial magnetic circuit resolver is unevenly distributed along the circumference, resulting in a significant change in magnetic resistance when eccentric, affecting the accuracy. The present invention adopts an axial magnetic circuit, and the axial inclination structure of the rotor core in the assembly groove 60 can make the air gap evenly distributed along the circumferential direction.

[0038] In actual operation, when the rotor core 7 rotates by an angle of θ0 from the zero position, the coupling height between the rotor core and the upper core of the stator is h0 = R·tan(β)·cos(θ0), where θ0 is the electrical angle under the unit number of pole pairs. At this time, the coupling area S1 between the rotor core 7 and the first stator core 1 through the stator teeth 11 is: S1 = R·∫h0·d·θ0 = ∫2tan(β)·R 2·sin(d / 2)·cos(θ0); where d is the tooth width of the stator tooth 11, with the unit of radian; similarly, the coupling area S2 between the rotor core 7 and the second stator core 4 through the stator tooth 11 can be obtained as: S2 = R·∫h0·d·θ0 = ∫2tan(β)·R 2 ·sin(d / 2)·cos(θ0); thus, it can be obtained that within each electrical cycle, the coupling area between the wound core structure and the rotor core changes according to the cosine law, which is: S3 = S1 + S2 = 2·tan(β)·R 2 ·sin(d / 2)·cos(θ0), 0 ≤ θ0 ≤ π; according to Faraday's law of electromagnetic induction and the above, the change in the magnetic flux of the coupling magnetic field causes a corresponding change in the induced voltage. The change law of the coupling area is reflected in the output voltage of the resolver. When the coupling area between the stator and rotor in this embodiment changes according to the cosine law, an axial magnetic conductance will be generated. Through the change of the axial magnetic conductance, a sinusoidal air-gap magnetic flux is generated, and its circumferential air gap is uniform. Therefore, even if there is eccentricity in the present invention, the magnetic flux distribution can still maintain symmetry, effectively maintaining the output accuracy, reducing the influence of eccentricity on the output accuracy, and enhancing the applicable range.

[0039] In addition, in one embodiment of the present invention, a magnetic isolation groove 71 is also provided on the outer circumference of the stacked rotor core 7. The magnetic isolation groove 71 is 1 / 3 of the thickness of the rotor core 7. By providing the magnetic isolation groove 71, the leakage magnetic flux at the end of the stator core can be effectively reduced, and the resolver accuracy can be further improved.

[0040] It is worth further explaining that in one embodiment of the present invention, both the cosine-phase output winding and the sine-phase output winding are concentrated equal-turn windings. By setting the concentrated equal-turn windings, the winding is simple and has good consistency, which is convenient for users to realize fully automated winding through automated equipment, can reduce process fluctuations, and improve the overall accuracy to more than twice that of conventional reluctance resolvers.

[0041] It should be noted that in traditional resolvers, there is partial coupling between the input and output magnetic fields, resulting in a fixed voltage at the output end when static (the rotor is stationary). To further optimize the present invention, in one embodiment of the present invention, the magnetic conductive ring 3 is arranged between the first stator core 1 and the second stator core 4; the input coil 2 is wound radially on the magnetic conductive ring 3, and its magnetic field direction is distributed radially; the output coil 5 is wound axially through the stator teeth 11 on the first stator core 1 and the second stator core 4 respectively, so its magnetic field is distributed axially; the function of the magnetic conductive ring 3 is to concentrate and guide the input magnetic field, resulting in a natural 90° orthogonal relationship between the axial magnetic path of the input magnetic field on the magnetic conductive ring 3 and the radial magnetic path of the output magnetic field on the stator core structure. The magnetic force line directions of the two are perpendicular to each other. When the input and output magnetic fields are orthogonal, the coupling coefficient approaches zero, and the theoretical voltage at the output end is zero at this time. Therefore, the static residual potential can be effectively suppressed.

[0042] It should be noted that the cosine output voltage expression of the axial magnetic circuit multi-pole resolver of the present invention is: Ucos = Ku·U0·sin(ωt)cos(pθ), and the sine output voltage expression is: Usin = Ku·U0·sin(ωt)sin(pθ), where Ucos is the cosine output voltage; Usin is the sine output voltage; Ku is the voltage ratio; U0 is the excitation voltage; ω is the excitation frequency; P is the resolver pole pair number; θ is the mechanical angle of rotor rotation.

[0043] During the actual use process, when resolving, the input magnetic field passes through the input coil 2 and then successively through the magnetic conduction ring 3, the air gap, the rotor iron core, the air gap, and the magnetic conduction ring 3 to form a closed loop in a cycle, while the output magnetic field passes through the output coil 5 and then successively through the first stator iron core 1, the air gap, the rotor iron core 7, the air gap, and the second stator iron core 4 to form a closed loop in a cycle. Since the magnetic conduction ring 3 is arranged between the first stator iron core 1 and the second stator iron core 4, the input and output magnetic fields are restricted in independent magnetic circuits, which can avoid cross-coupling, reduce dynamic interference, and improve the signal purity.

[0044] In one embodiment of the present invention, the axial length of the first stator iron core 1 is La, the axial length of the second stator iron core 4 is Lb, and the axial length of the magnetic conduction ring 3 is Lc, and La = Lb = Lc. By setting the same axial length, when the input coil 2 is embedded in the magnetic conduction ring 3 and the output coil 5 is wound on the inner surfaces of the upper and lower iron cores, the axial space can be fully utilized, making the internal structure of the present invention more compact and effectively saving the radial space.

[0045] It should be noted that both the first stator iron core 1 and the second stator iron core 4 are formed by stamping and stacking multiple stator laminations, and the material of the stator laminations is silicon steel sheet, which is beneficial to reducing the coercive force and iron loss and improving the performance of the reluctance multi-pole resolver.

[0046] The standard parts used in the present invention can all be purchased from the market. The special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part all adopt conventional means such as bolts, rivets, and welding that are mature in the prior art. The machines, parts, and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be elaborated here. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0047] It should be understood that for those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of the present invention.

Claims

1. An equal air-gap multi-pole reluctance resolver resistant to eccentric interference, characterized in that: It includes a housing (10), an output coil (5) provided at one end of the housing (10), a first stator core (1) and a second stator core (4) provided in the output coil (5), a plurality of stator teeth (11) provided on the first stator core (1), an input coil (2) provided between the first stator core (1) and the second stator core (4), a magnetic conductive ring (3) provided on the input coil (2), a rotor bracket (6) provided in the housing (10), a plurality of assembly grooves (60) provided on the rotor bracket (6), and a rotor core (7) provided in the assembly grooves (60); Among them, the rotor core (7) is formed by stacking a plurality of square silicon steel sheets. The assembly groove (60) is an inclined parallel straight groove in the vertical direction, with an inclination angle of β. The coupling area S3 of the rotor core (7) changes according to the cosine law, and it is S3 = 2·tan(β)·R 2 ·sin(d / 2)·cos(θ0), 0 ≤ θ0 ≤ π, where θ0 is the electrical angle under the unit pole pair number, d is the tooth width of the stator tooth (11), and R is the radius of the rotor core.

2. The equal air-gap multi-pole reluctance resolver for anti-eccentric interference according to claim 1, characterized in that: The coupling height h0 between the rotor core (7) and the first stator core (1) is h0 = R·tan(β)·cos(θ0).

3. The equal air-gap multi-pole reluctance resolver for anti-eccentricity interference according to claim 2, wherein: The coupling area S1 between the rotor core (7) and the first stator core (1) is: S1 = R·∫h0·d·θ0 = ∫2tan(β)·R 2 ·sin(d / 2)·cos(θ0).

4. The equal air-gap multi-pole reluctance resolver for anti-eccentricity interference according to claim 3, characterized in that: The coupling area S2 between the rotor core (7) and the second stator core (4) is: S2 = R·∫h0·d·θ0 = ∫2tan(β)·R 2 ·sin(d / 2)·cos(θ0); and S3 = S1 + S2.

5. The equal air-gap multi-pole reluctance resolver for anti-eccentric interference according to claim 4, characterized in that: The inclination angle of the assembly groove (60) is β = arctan(lr / R), where lr is the maximum coupling height of the rotor core in the axial direction.

6. The equal air-gap multi-pole reluctance resolver for anti-eccentricity interference according to claim 1, characterized in that: A stator slot (12) is provided between two adjacent stator teeth (11). The stator slots (12) are the same in number as the stator teeth (11) and are uniformly arranged along the axial direction on the first stator core (1).

7. An air-gap-equal multi-pole reluctance resolver against eccentric interference as claimed in claim 6, characterized in that: The first stator core (1) and the second stator core (4) have the same shape and structure.

8. The equal air-gap multi-pole reluctance resolver for anti-eccentric interference according to claim 7, wherein: The rotor bracket (6) is made of a non-magnetic conductive material.

9. The equal air-gap multi-pole reluctance resolver for anti-eccentricity interference according to claim 1, characterized in that: A magnetic isolation groove (71) is provided on the rotor core (7).

10. A kind of equal air-gap multi-pole reluctance resolver resistant to eccentric interference as described in claim 9, characterized in that: The height of the magnetic isolation groove (71) is 1 / 3 of the thickness of the rotor core (7).

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