Encapsulated high-precision sine and cosine rotary transformer and processing method

Abstract

The invention discloses a potting type high-precision sine and cosine rotary transformer and a processing method, and relates to the field of sine and cosine rotary transformer processing applied to an extreme environment, and the processing method comprises the following steps: potting and curing a rotor, and potting a part on the outer side of a rotor bracket with a potting material to obtain a rotor potting piece; potting and curing the stator, and potting the inner side part of the primary side iron core of the annular transformer by a potting material to obtain a stator potting piece; and grinding the outer circular surface of the rotor potting piece, and grinding the inner circular surface of the stator potting piece. And the rotary transformer functional parts are all tightly packaged, so that the working field of the rotary transformer is greatly widened, the capability of the rotary transformer for resisting severe environments such as hydraulic oil, moisture and mould is improved, and the explosion-proof reliability is improved.

Description

Technical Field

[0001] The invention relates to a sine-cosine rotary transformer for measuring mechanical rotation angles, which is applied to extreme environments such as oil pressure resistance, dust prevention, mildew prevention, salt spray prevention, explosion prevention, etc. Background Art

[0002] A resolver, or resolver for short, is an induction micromotor whose output voltage maintains a certain functional relationship with the rotor angle. The typical application of resolvers is to match servo motors to detect the motor rotor position in real time, so as to achieve high-precision control of motor performance parameters such as speed and torque; it is also used in other occasions where precise measurement of the rotation angle is required.

[0003] With the expansion of the application of resolver products, the special requirements of miniaturization and strong environmental resistance make it impossible for conventional resolver products to meet them; and as a batch product, the complicated and delicate winding coil winding work of resolver should be avoided as much as possible. Therefore, it is urgent to develop potting high-precision resolver products suitable for mechanized automatic production.

[0004] At present, the improvement of the environmental resistance of the rotary transformer depends on the potting and sealing structure design. The relevant patent of "potted rotary transformer" that can be retrieved is a rotary transformer potting device, method and application (CN106298217B) of Zhuzhou CSR Electromechanical Technology Co., Ltd., which takes the reluctance type rotary transformer as the potting object and mainly proposes innovation points and rights protection for the potting device, method and application of the rotary transformer. The above patents only pottage the rotary transformer stator, because its windings are all on the stator side, and there is no winding on the rotor side, so potting is not required.

[0005] Among the relevant patents of "sine-cosine resolver" that can be retrieved, the sealing structure of an oil-immersed sine-cosine resolver (patent number: CN218768946U) of Beijing Shuguang Aviation Electric Co., Ltd. and a high-voltage sealed sine-cosine resolver (patent number: CN217544296U) of Shaanxi Dongfang Aviation Instrument Co., Ltd. are related to oil immersion, sealing and other factors. However, the main method of both is to seal the resolver in a housing. Structurally, the housing and other related structures are added, making the overall shape of the resolver larger, which is limited in application under conditions of limited space. In terms of process, an additional docking interface needs to be set on the housing, which complicates the structure. Summary of the invention

[0006] The technical problem solved by the present application is to overcome the shortcomings of the prior art and provide a structure in which both sides of the stator and rotor of a sine-cosine resolver are potted, so as to solve the problem of low resistance to harsh environments of the sine-cosine resolver in the prior art, so that the resolver product is suitable for extreme environments such as resistance to oil pressure, dust, mildew and salt spray, and explosion-proof.

[0007] Secondly, the technical problem solved by the present invention is: to overcome the shortcomings of the prior art and provide a structure with higher roundness and roughness requirements for the inner circle of the stator and the outer circle of the rotor of a sine-cosine rotary transformer, so as to solve the problems of large electrical errors (greater than 10 arc minutes) and low batch qualification rate of sine-cosine rotary transformers in the prior art.

[0008] The technical solutions provided by this application are as follows:

[0009] A method for processing a potted high-precision sine-cosine rotary transformer is used for processing the sine-cosine rotary transformer. The sine-cosine rotary transformer comprises a rotor and a stator sleeved outside the rotor. The rotor comprises a rotor bracket, and a rotary transformer primary iron core, a rotary transformer primary winding, a toroidal transformer secondary iron core and a toroidal transformer secondary winding arranged outside the rotor bracket. The stator comprises a toroidal transformer primary iron core, and a toroidal transformer primary winding, a rotary transformer secondary iron core and a rotary transformer secondary winding arranged inside the toroidal transformer primary iron core. The processing method comprises:

[0010] The rotor is potted and cured, and the potting material is potted on the outer part of the rotor bracket to obtain a rotor potting part; the stator is potted and cured, and the potting material is potted on the inner part of the primary iron core of the toroidal transformer to obtain a stator potting part;

[0011] The outer cylindrical surface of the rotor potting part is ground, and the grinding size is the grinding allowance. The inner cylindrical surface of the stator potting part is ground.

[0012] The potting and curing of the rotor includes: placing the rotor on a first potting tool, a first annular groove is provided on the top of the first potting tool, a first positioning column is formed in the middle of the first annular groove, the inner diameter of the rotor bracket is matched with the outer diameter of the first positioning column, so that the rotor is sleeved outside the first positioning column and is located in the first annular groove, and the outer diameter of the first annular groove is larger than the outer diameter of the rotor.

[0013] The first potting tool is provided with an annular receiving groove at the bottom of the first annular groove near the first positioning column, and the depth of the receiving groove is consistent with the height of the end of the rotor support protruding from the end of the secondary iron core of the annular transformer.

[0014] The stator is potted and solidified, comprising: placing the stator on a second potting tool, a second annular groove is provided on the top of the second potting tool, a second positioning column is formed in the middle of the second annular groove, the outer diameter of the primary iron core of the annular transformer is matched with the outer diameter of the second annular groove, so that the stator is sleeved in the second annular groove and fits with the inner wall of the second annular groove, and the outer diameter of the second positioning column is smaller than the inner diameter of the stator.

[0015] The dimensions of the primary iron core of the rotary transformer and the secondary iron core of the rotary transformer before grinding are the design dimensions plus the grinding allowance, and the design dimensions are the dimensions of the primary iron core of the rotary transformer and the secondary iron core of the rotary transformer after grinding.

[0016] It also includes grinding both ends of the rotor potting part and the stator potting part. The two ends of the rotor potting part and the stator potting part are mechanical interface mounting surfaces to ensure the accuracy of the mechanical interface mounting surfaces.

[0017] A potted high-precision sine-cosine rotary transformer is obtained according to any of the above-mentioned methods for processing a potted high-precision sine-cosine rotary transformer.

[0018] In summary, this application at least includes the following beneficial technical effects:

[0019] 1. The stator and rotor potting method of the sine-cosine resolver proposed in the present invention is aimed at resolver products with windings on both the stator and rotor sides, and the resolver functional components (i.e., the stator and rotor sides) are tightly sealed, which greatly broadens the working field of the resolver, improves the resolver's ability to withstand harsh environments such as hydraulic oil, moisture, and mold, and improves explosion-proof reliability; and the method proposed in the present invention achieves good potting for resolver products with small structures and great difficulty in potting operations.

[0020] 2. The inner and outer cylindrical grinding of the stator and rotor of the sine-cosine resolver proposed in the present invention (including the allowance design before grinding) improves the magnetic field distortion caused by the partial core lamination structure of the resolver, thereby improving the electrical error accuracy and batch qualification rate of the resolver; at the same time, the improvement of the resolver accuracy also means that the resolver can be applied to fields with higher precision requirements;

[0021] 3. The potting and grinding of the sine-cosine resolver proposed in the present invention do not change the original mechanical interface and electrical interface of the resolver, and can be replaced in situ with a non-potted resolver, but its working accuracy and reliability are significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the basic structure of the sine-cosine rotary transformer according to an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the overall potting of the rotor of the sine-cosine resolver according to an embodiment of the present invention;

[0024] Figure 3 Schematic diagram of grinding the outer shape of the potting layer of the rotor of the sine-cosine rotary transformer according to an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the overall potting of the stator of the sine-cosine rotary transformer according to an embodiment of the present invention;

[0026] Figure 5The figure is a schematic diagram of the outer shape grinding of the stator potting layer of the sine-cosine rotary transformer according to an embodiment of the present invention.

[0027] Explanation of the figure numbers: 1. Rotor bracket; 2. Primary iron core of toroidal transformer; 3. Secondary iron core of toroidal transformer; 4. Primary winding of toroidal transformer; 5. Secondary winding of toroidal transformer; 6. Primary iron core of rotary transformer; 7. Secondary iron core of rotary transformer; 8. Primary excitation winding and compensation winding of rotary transformer; 9. Secondary winding of rotary transformer. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0029] The embodiment of the present application discloses a potted high-precision sine-cosine rotary transformer. Taking a small sine-cosine rotary transformer with an outer diameter of 20 mm, a rotor installation diameter of 4 mm, and a total length of 18 mm as an example, a high thermal conductivity epoxy potting glue is selected as the potting material.

[0030] The basic structure and working principle of the sine-cosine resolver are as follows:

[0031] The sine-cosine resolver is functionally composed of two parts: a toroidal transformer and a resolver. Figure 1 . In the figure, 1 is a rotor support, which is used to support and connect in series the rotating part of the sine-cosine rotary transformer (the rotating part includes the secondary iron core 3 of the toroidal transformer and the primary iron core 6 of the rotary transformer); 2 is the primary iron core of the toroidal transformer, which also serves as the stator housing; 3 is the secondary iron core of the toroidal transformer; 4 is the primary winding of the toroidal transformer, 5 is the secondary winding of the toroidal transformer; 6 is the primary iron core of the rotary transformer, 7 is the secondary iron core of the rotary transformer; 8 is the primary winding of the rotary transformer (or the excitation winding and the compensation winding); 9 is the secondary winding of the rotary transformer (or the sine winding and the cosine winding). The primary iron core 6 of the rotary transformer and the secondary iron core 7 of the rotary transformer are composed of multiple annular laminations.

[0032] The rotor support 1 is cylindrical in shape. The multiple laminations of the primary iron core 6 of the rotary transformer are sequentially sleeved outside the rotor support 1 and connected to the rotor support 1. The primary iron core 6 of the rotary transformer is provided with a slotted structure for winding the primary winding 8 of the rotary transformer. The secondary iron core 3 of the toroidal transformer is sleeved outside the rotor support 1 and is located at one end of the primary iron core 6 of the rotary transformer. The outer side of the secondary iron core 3 of the toroidal transformer is provided with an annular groove along the circumferential direction, and the secondary winding 5 of the toroidal transformer is wound in the outer annular groove. The rotor support 1 and the primary iron core 6 of the rotary transformer installed outside the rotor support 1, the primary winding 8 of the rotary transformer, the secondary iron core 3 of the toroidal transformer, and the secondary winding 5 of the toroidal transformer constitute a rotor. The primary iron core 2 of the toroidal transformer is sleeved on the outside of the rotor support 1, and an inner annular groove is provided on the inner side of the primary iron core 2 of the toroidal transformer. The primary winding 4 of the toroidal transformer is provided in the inner annular groove. The primary winding 4 of the toroidal transformer is opposite to the secondary winding 5 of the toroidal transformer. The secondary iron core 7 of the rotary transformer is installed on the inner side of the primary iron core 2 of the toroidal transformer. The secondary iron core 7 of the rotary transformer is provided with a slotted structure for winding the secondary winding 9 of the rotary transformer. The secondary iron core 7 of the rotary transformer is opposite to the primary iron core 6 of the rotary transformer. The primary iron core 2 of the toroidal transformer, the primary winding 4 of the toroidal transformer installed on the inner side of the primary iron core 2 of the toroidal transformer, the secondary iron core 7 of the rotary transformer and the secondary winding 9 of the rotary transformer constitute a stator.

[0033] The coupling relationship between the primary and secondary sides of the toroidal transformer does not change with the rotation of the rotor, and the primary AC voltage signal can be stably transmitted to the secondary side. The secondary winding of the toroidal transformer is electrically connected to the primary winding of the rotary transformer to provide electrical energy to the latter, that is, to form an excitation current in the primary winding of the rotary transformer. The primary winding of the rotary transformer is wound on the iron core according to a specific combination of turns and arrangement. The iron core is slotted. Under the action of the excitation current, a pulsating magnetic field can be formed on the surface of the rotary transformer rotor core and coupled to the secondary side of the rotary transformer in real time. The secondary core of the rotary transformer is also slotted accordingly, and two sets of output signal windings are wound according to a specific combination of turns and arrangement, and the two sets of windings are orthogonal to each other. The accurate calculation of the rotor position is achieved by analyzing the voltage amplitude and phase information of the two sets of signal windings. In addition, there is a set of rotary transformer compensation windings, which are orthogonally wound with the rotary transformer excitation windings to compensate for the distortion of the primary pulsating magnetic field caused by the secondary current of the rotary transformer.

[0034] Sincos resolver insulation design includes:

[0035] The sine-cosine resolver has a total of 6 sets of windings: the primary winding 4 of the toroidal transformer, the secondary winding 5 of the toroidal transformer, the primary winding 8 of the resolver (including the excitation winding of the resolver and the compensation winding of the resolver), and the secondary winding 9 of the resolver (including the sine winding of the resolver and the cosine winding of the resolver), which are wound on the corresponding iron cores. Before the resolver is potted as a whole, its electrical insulation should be designed:

[0036] 1) The primary winding of the toroidal transformer, the sine winding and the cosine winding of the rotary transformer are wound on a non-metallic insulating frame and have no contact with metal materials;

[0037] 2) Due to space limitations, the secondary transformer winding of the toroidal transformer, the excitation winding of the rotary transformer and the compensation winding are directly wound on the metal magnetic conductive material. Before winding, the secondary iron core of the toroidal transformer and the primary iron core of the rotary transformer are coated with non-metallic materials to form a dense insulation layer;

[0038] 3) After the above 6 sets of windings are completed, non-metallic impregnation materials are used uniformly for insulation protection.

[0039] Sincos resolver potting design, including:

[0040] After the resolver is designed and assembled according to the basic structure, working principle and insulation design of the above-mentioned sine-cosine resolver, it has met the normal use conditions. On this basis, the resolver stator and rotor are potted and ground respectively, as shown in the attached Figures 2 to 5 shown.

[0041] like Figure 2 As shown, the rotor is placed on the first potting tool, a first annular groove is provided on the top of the first potting tool, a first positioning column is formed in the middle of the first annular groove, the inner diameter of the rotor bracket 1 matches the outer diameter of the first positioning column, so that the rotor is sleeved outside the first positioning column and is located in the first annular groove, the outer diameter of the first annular groove is larger than the outer diameter of the rotor, so that the outer cylindrical surface of the rotor has a processing allowance after curing, and the first potting tool is provided with an annular receiving groove at the bottom of the first annular groove near the first positioning column, the depth of the receiving groove is consistent with the height of the end of the rotor bracket 1 protruding from the end of the secondary iron core 3 of the annular transformer, so that the end of the rotor bracket 1 is located in the receiving groove. Figure 1 The potting material is injected from the upper end and covers the potting part (i.e. the rotor); then, according to the requirements for the use of the potting material, a certain temperature and vacuum degree are maintained so that the potting material evenly fills the potting part until the curing is completed.

[0042] As attached Figure 4 As shown, the stator is placed on the second potting tool, a second annular groove is provided on the top of the second potting tool, a second positioning column is formed in the middle of the second annular groove, the outer diameter of the primary iron core 2 of the annular transformer matches the outer diameter of the second annular groove, so that the stator is sleeved in the second annular groove and fits with the inner wall of the second annular groove, and the outer diameter of the second positioning column is smaller than the inner diameter of the stator, so that the inner surface of the stator has a processing allowance after curing. Figure 1The potting material is injected from the upper end and covers the potting part (i.e., the stator); then, according to the requirements for the use of the potting material, a certain temperature and vacuum degree are maintained so that the potting material evenly fills the potting part until the curing is completed.

[0043] like Figure 3 As shown, after the rotor is potted and cured according to the potting material usage requirements, the potting layer shape should be ground, and the grinding surface is the outer cylindrical surface and both ends of the potting layer. Among them, the two ends of the potting layer are ground, as shown in the two sizes of 0.1mm and 0.6mm in the figure, which are the heights of the protruding ring transformer secondary core 3 and the rotary transformer primary winding 8 at both ends of the rotor bracket 1, respectively, to remove the excess potting material attached to the mechanical interface mounting surface without affecting the accuracy and reliability of the rotor; the cylindrical surface of the potting layer is ground, as shown in the Φ12 size in the figure, in addition to ensuring the accuracy requirements, that is, not affecting the rotation of the rotor, its roundness and surface roughness are also required, which are generally guaranteed by the accuracy of the grinder or lathe.

[0044] As attached Figure 5 As shown, after the stator is potted and cured according to the potting material usage requirements, the shape of the potting layer should be ground, and the grinding surface is the inner cylindrical surface and both ends of the potting layer. Among them, the two ends of the potting layer are ground, as shown in the 18 size in the figure, to remove the excess potting material attached to the mechanical interface installation surface, without affecting the accuracy and reliability of the stator; the inner cylindrical surface of the potting layer is ground, as shown in the Φ12.5 size in the figure, in addition to ensuring the accuracy requirements, that is, not interfering with the rotor, its roundness and surface roughness are also required, which are generally guaranteed by the accuracy of the grinder or lathe.

[0045] Finally, check the quality of the stator and rotor potting. The surface should be uniform and smooth without cracks or slag, and it should be able to withstand a certain hydraulic pressure of 3-50MPa without rupture or deformation.

[0046] The original secondary iron core of the traditional rotary transformer (attached Figure 1 6 and 7) are made of stacked silicon steel sheets, and the outer surface of the primary core and the inner surface of the secondary core are irregular cylindrical surfaces; and the magnetic field distortion caused by this irregularity cannot be calculated, which has a great impact on the overall electrical error of the resolver. Often, in a batch of resolver products, the qualified rate of those that meet the requirements, taking 10 arc minutes as an example, is less than 20%.

[0047] The present invention grinds the cylindrical surface of the potting layer of the stator and rotor of the sine-cosine rotary transformer, and also grinds the primary and secondary iron cores of the annular transformer part and the rotary transformer part. Figure 3 , 5As shown in . In particular, the roundness of the inner and outer round cores of the primary and secondary sides of the resolver is improved, and the magnetic field distortion caused by the laminated structure is reduced, thereby improving the overall accuracy and pass rate of the resolver. Taking 10 arc minutes as an example, the batch pass rate reaches more than 95%. Under the processing method of this patent, the accuracy and pass rate of the sine-cosine resolver are improved.

[0048] There are two points that need to be supplemented: 1) In order not to increase the overall working air gap of the resolver, the corresponding core should be designed with a grinding allowance to ensure that the relevant dimensions still meet the requirements after grinding, as shown in the attached Figure 3 Φ12 and attached Figure 5 Φ12.5; 2) Commonly used sine-cosine resolvers (without potting) can also be ground accordingly to improve the accuracy level and batch qualification rate.

[0049] The contents not described in detail in this application specification belong to the common knowledge of those skilled in the art.

[0050] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. A method for processing a potted high-precision sine-cosine rotary transformer, characterized in that: Used for processing a sine-cosine rotary transformer, the sine-cosine rotary transformer comprising a rotor and a stator sleeved outside the rotor, the rotor comprising a rotor support (1), and a rotary transformer primary iron core (6) arranged outside the rotor support (1), a rotary transformer primary winding (8), a toroidal transformer secondary iron core (3) and a toroidal transformer secondary winding (5), the stator comprising a toroidal transformer primary iron core (2), and a toroidal transformer primary winding (4) arranged inside the toroidal transformer primary iron core (2), a rotary transformer secondary iron core (7) and a rotary transformer secondary winding (9); Processing methods include: The rotor is potted and cured, and the potting material is potted on the outer part of the rotor bracket (1) to obtain a rotor potting part; the stator is potted and cured, and the potting material is potted on the inner part of the primary iron core (2) of the toroidal transformer to obtain a stator potting part; The outer cylindrical surface of the rotor potting part is ground, and the grinding size is the grinding allowance. The inner cylindrical surface of the stator potting part is ground.

2. The method for processing a potted high-precision sine-cosine resolver according to claim 1, characterized in that: The potting and curing of the rotor comprises: placing the rotor on a first potting tool, the top of the first potting tool is provided with a first annular groove, the middle of the first annular groove forms a first positioning column, the inner diameter of the rotor bracket (1) matches the outer diameter of the first positioning column, so that the rotor is sleeved outside the first positioning column and is located in the first annular groove, and the outer diameter of the first annular groove is larger than the outer diameter of the rotor.

3. The method for processing a potted high-precision sine-cosine resolver according to claim 2, characterized in that: The first potting tool is provided with an annular receiving groove at a position near the first positioning column at the bottom of the first annular groove, and the depth of the receiving groove is consistent with the height of the end of the rotor support (1) protruding from the end of the secondary iron core (3) of the annular transformer.

4. The method for processing a potted high-precision sine-cosine resolver according to claim 1, characterized in that: The stator is potted and solidified, comprising: placing the stator on a second potting tool, a second annular groove is arranged on the top of the second potting tool, a second positioning column is formed in the middle of the second annular groove, the outer diameter of the primary iron core (2) of the annular transformer matches the outer diameter of the second annular groove, so that the stator is sleeved in the second annular groove and fits with the inner wall of the second annular groove, and the outer diameter of the second positioning column is smaller than the inner diameter of the stator.

5. The method for processing a potted high-precision sine-cosine resolver according to claim 1, characterized in that: The dimensions of the primary iron core (6) and the secondary iron core (7) of the rotary transformer before grinding are the design dimensions plus the grinding allowance, and the design dimensions are the dimensions of the primary iron core (6) and the secondary iron core (7) of the rotary transformer after grinding.

6. The method for processing a potted high-precision sine-cosine resolver according to claim 1, characterized in that: It also includes grinding both ends of the rotor potting part and the stator potting part. The two ends of the rotor potting part and the stator potting part are mechanical interface mounting surfaces to ensure the accuracy of the mechanical interface mounting surfaces.

7. A potted high-precision sine-cosine rotary transformer, characterized in that: The method for processing a potted high-precision sine-cosine rotary transformer is obtained according to any one of claims 1-6.

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