High-speed motor hollow shaft rotary variable installation structure

Abstract

This utility model discloses a hollow shaft resolver mounting structure for a high-speed motor, comprising a resolver and a shaft. The resolver includes a resolver rotor and a resolver stator, and further includes a resolver mounting base, an end cover, a bearing, a bearing positioning ring, and a locking structure. The non-shaft extension end of the shaft is hollow. The bearing, bearing positioning ring, and locking structure are sequentially mounted on the shaft and located inside the end cover. One end of the locking structure extends axially to form a resolver rotor mounting shaft, on which the resolver rotor is mounted and axially fixed by an elastic retaining ring. The resolver stator is mounted on one end of the resolver mounting base, and the other end of the mounting base is connected to the end cover to form a sealed cavity. This utility model solves the problem of bearing nut loosening under high-speed vibration environments, ensuring the rigidity and reliability of the resolver structure.

Description

Technical Field

[0001] This utility model belongs to the field of motor rotary transformer technology, and in particular, relates to a high-speed motor hollow shaft rotary transformer mounting structure. Background Technology

[0002] A resolver is a sensor device specifically designed for detecting the angle and position of a rotating electric motor. It provides high-precision rotor angle feedback, facilitating motor control by the controller. The working principle of a resolver is similar to that of a traditional transformer. It consists of a stator and a rotor. The resolver rotor is fixed to the motor shaft, typically mounted on the non-shaft extension end. The resolver stator usually has an excitation winding; when alternating current is applied to this winding, a magnetic field is generated between the stator and rotor. The rotor has an induction winding; as the motor rotates, the rotor moves within the magnetic field, causing changes in the output signal. The resolver's output signal changes according to the rotor's angle and position. Through signal processing circuitry, the output can be converted into angle or speed signals, enabling precise angle and speed measurements.

[0003] High-speed motors offer advantages such as high power density, small size, high efficiency, and high reliability, making them widely applicable in the field of aerospace generators. Aerospace motors require high efficiency, high reliability, and lightweight design under extreme environments (high temperature, high vibration, high speed, etc.). Resolvers can be used for high-precision rotor position detection, ensuring the stability of the motor's closed-loop control and adapting to the extreme operating conditions of aerospace environments. However, because the resolver rotor is mounted on the motor shaft, its installation and selection become limited at high motor speeds. Due to the high motor speed, the rotor generates significant centrifugal force, requiring the resolver rotor to be as small as possible to meet strength requirements. However, for high-speed aerospace motors, to improve power density, the motor shaft is generally designed as a hollow shaft. For lightweighting, the inner diameter of the hollow shaft should be as large as possible while still meeting strength and rigidity requirements, which contradicts the installation and selection of high-speed resolvers. If the motor does not have power density requirements, a solid shaft can be used, simply requiring machining a small shaft diameter suitable for high-speed resolver installation. However, there are technical challenges in the hollow shaft resolver installation structure for high-speed aerospace motors.

[0004] Patent application CN108429410A discloses a resolver mounting structure for a hollow motor shaft, including a motor shaft, a resolver, and a motor end cover. The resolver includes a resolver stator assembly and a resolver rotor. The resolver stator assembly is fixed to the motor end cover, and the resolver rotor is fixed to the motor shaft. The key feature is that the motor shaft is composed of a main shaft and a connecting shaft fixedly connected. The main shaft is a hollow shaft manufactured using a cold forging process. The connecting shaft is fixedly connected to the main shaft by cold pressing or hot fitting. The resolver rotor is fixed to the connecting shaft by a pressure ring through cold pressing or hot fitting. This patent uses an interference fit between the connecting shaft and the hollow shaft's inner hole. This connecting shaft can be designed with a small diameter, and the resolver rotor is mounted on the connecting shaft. However, due to the high motor speed, interference fitting is unreliable, especially as the interference decreases at high speeds, leading to poor resolver stability, affecting the runout of the mounting shaft, and thus affecting resolver accuracy. If a large interference fit is used, the strength of the shaft is limited, and the amount of interference fit is also limited by the temperature of the heat fitting. Utility Model Content

[0005] This utility model primarily addresses existing resolver mounting structures. One type involves mounting the resolver inside the motor, utilizing its internal space but unsuitable for high-speed applications. Furthermore, for ordinary high-speed motors, where lightweighting is not a requirement, the shaft can be solid, with the resolver mounted on the smaller diameter end to meet high-speed requirements, but not high power density. Additionally, existing patents use interference-fit heat-shrink fittings for hollow shafts, which may be unreliable for higher-speed motors. Increasing the interference fit is limited by heat-shrink fitting temperature and shaft strength, and increases disassembly and assembly difficulties. This utility model proposes a hollow shaft resolver mounting structure for high-speed motors.

[0006] A hollow shaft resolver mounting structure for a high-speed motor includes a resolver and a shaft. The resolver includes a resolver rotor and a resolver stator, and also includes a resolver mounting base, an end cover, a bearing, a bearing positioning ring, and a locking structure. The non-shaft extension end of the shaft is hollow. The bearing, bearing positioning ring, and locking structure are sequentially mounted on the shaft and located inside the end cover. One end of the locking structure extends axially to form a resolver rotor mounting shaft, and the resolver rotor is mounted on the resolver rotor mounting shaft and axially fixed by an elastic retaining ring. The resolver stator is mounted on one end of the resolver mounting base, and the other end of the resolver mounting base is connected to the end cover to form a sealed cavity.

[0007] Furthermore, the locking structure adopts a bearing locking nut, which is connected to the rotating shaft by a thread. The bearing locking nut is equipped with a locking nut thread, and the locking nut thread rotates in the opposite direction to the rotating shaft, so that the bearing locking nut and the rotating shaft are securely installed.

[0008] Furthermore, the bearing locking nut is also provided with a set screw, which is arranged radially along the bearing locking nut and its end abuts against the rotating shaft to prevent the bearing locking nut from rotating relative to the rotating shaft.

[0009] Furthermore, the bearing is a high-speed ceramic ball bearing, with its outer ring having a clearance fit with the inner circle of the end cover and its inner ring having an interference fit with the shaft.

[0010] Furthermore, the high-speed ceramic ball bearing is disposed between the bearing positioning ring and the locking structure, and the high-speed ceramic ball bearing is axially positioned on the rotating shaft by the bearing positioning ring and the locking structure.

[0011] Furthermore, the elastic retaining ring is installed in an annular groove on the resolver rotor mounting shaft to restrict the axial movement of the resolver rotor.

[0012] Furthermore, an inner oil seal is provided on the inner side of the end cover. The inner oil seal is fitted onto the hollow rotating shaft and is located on the side of the bearing near the shaft extension end, for the purpose of achieving a seal between the end cover and the rotating shaft.

[0013] Furthermore, the shaft extension end is a solid structure, and the hollow inner diameter of the non-shaft extension end is 40mm.

[0014] Furthermore, the diameter of the locking structure is 55mm, and the shaft diameter of the resolver rotor mounting shaft is 30mm.

[0015] Furthermore, the resolver mounting base is detachably connected to the end cover for adjusting the circumferential position of the resolver stator.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model includes a rotary transformer and a rotating shaft. The rotary transformer includes a rotary rotor and a rotary stator, as well as a rotary transformer mounting base, an end cover, a bearing, a bearing positioning ring, and a locking structure. The non-shaft extension end of the rotating shaft is a hollow structure. The bearing, bearing positioning ring, and locking structure are sequentially fitted onto the rotating shaft and located inside the end cover. The precision locking structure of this utility model transmits the locking force to the bearing through the bearing positioning ring, ensuring uniform force distribution on the high-speed bearing and improving its service life. The locking nut and the rotating shaft are threaded together. Furthermore, after the locking nut is tightened to the correct position, it is locked to the rotating shaft by a set screw, solving the problem of nut loosening under high-speed vibration environments and ensuring the rigidity, precision, and long-term reliability of the spindle support system.

[0017] 2. The locking structure of this utility model is equipped with a resolver rotor mounting shaft for mounting the resolver rotor. After the resolver rotor is installed in place, it is axially fixed by an elastic retaining ring. This utility model provides an independent and precise mounting reference surface for the resolver rotor, ensuring its high coaxiality with the shaft, while eliminating the axial clearance between the rotor and the shaft, preventing axial micro-movement during high-speed start-stop or load changes, and ensuring the stability of the air gap.

[0018] 3. This utility model highly integrates bearing positioning, locking, and resolver installation functions at the end of the rotating shaft, resulting in a very compact structure that greatly shortens the axial dimension of the motor and facilitates the miniaturization of the entire machine. Furthermore, the locking nut uses a threaded connection, making the resolver installation structure easy to assemble and disassemble. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is an enlarged schematic diagram of the bearing locking nut structure of this utility model; Figure 3 This is a schematic diagram of the overall structure of this utility model; In the above figure, 1. Shaft, 2. Inner oil seal, 3. End cover, 4. Resolver mounting base, 5. Bearing, 6. Bearing locating ring, 7. Bearing lock nut, 8. Resolver rotor, 9. Elastic retaining ring, 10. Resolver stator, 101. Shaft extension end, 102. Shaft non-extension end, 701. Lock nut thread, 702. Set screw, 703. Resolver rotor mounting shaft. Detailed Implementation

[0020] To clearly illustrate the technical features of this utility model, the following detailed description, in conjunction with the accompanying drawings, provides a comprehensive overview of the present utility model. Many specific details are set forth in the following description to facilitate a thorough understanding of the present utility model. However, the present utility model can also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present utility model is not limited to the specific embodiments disclosed below. Furthermore, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the present utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined as "first" and "second" can explicitly or implicitly include one or more of those features. In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified. In this utility model, unless otherwise explicitly specified and limited, terms such as "installed," "connected," "joined," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. In this utility model, unless otherwise explicitly specified and limited, "on" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0021] Example 1 like Figure 1 and Figure 2As shown, a high-speed motor hollow shaft resolver mounting structure includes a resolver and a rotating shaft 1. The resolver includes a resolver rotor 8 and a resolver stator 10, and also includes a resolver mounting base 4, an end cover 3, a bearing 5, a bearing positioning ring 6, and a locking structure. The non-shaft extension end of the rotating shaft 1 is a hollow structure. The bearing 5, the bearing positioning ring 6, and the locking structure are sequentially fitted onto the rotating shaft 1 and located inside the end cover 3. One end of the locking structure extends axially to form a resolver rotor mounting shaft 703. The resolver rotor 8 is mounted on the resolver rotor mounting shaft 703 and axially fixed by an elastic retaining ring 9. The resolver stator 10 is mounted on one end of the resolver mounting base 4, and the other end of the resolver mounting base 4 is connected to the end cover 3 to form a sealed cavity.

[0022] In this embodiment, the rotating shaft 1 is made of high-strength alloy steel to reduce weight and withstand high speeds, making it suitable for high-speed operating conditions. The non-shaft extension end 102 of the rotating shaft 1 is machined into a hollow shape with an inner diameter of 40mm, effectively reducing the weight of the rotating shaft 1 without affecting its structural strength under high-speed rotation, thus contributing to improving the overall power density of the motor. The shaft extension end 101 is used for external interfaces, while the shaft extension end is a solid structure to ensure the reliability and stability of the connection with other components of the centrifuge. Furthermore, the resolver mounting structure can only be installed on the non-shaft extension end 102 of the rotating shaft, and the non-shaft extension end 102 is a stepped shaft, facilitating the installation of the resolver and bearing 5.

[0023] like Figure 1 and Figure 2 As shown, in this embodiment, the locking structure uses a bearing locking nut 7 with a diameter of 55mm. One end of the bearing locking nut 7 extends axially to form a resolver rotor mounting shaft 703 with a shaft diameter of 30mm. The resolver rotor mounting shaft 703 has an annular groove for mounting and fixing the resolver rotor 8. The bearing locking nut 7 is threaded to the rotating shaft 1, and the locking nut thread 701 is opposite in direction to the rotating shaft 1. This design can effectively prevent the bearing locking nut 7 from loosening due to vibration and other factors during high-speed rotation of the motor. In addition, a set screw 702 is also provided on the bearing locking nut 7. The set screw 702 is arranged radially, and its end abuts tightly against the rotating shaft 1. The axis of the set screw 702 is perpendicular to the axis of the rotating shaft 1, providing the most direct radial locking force, forming a strong mechanical anti-loosening, further enhancing the connection stability between the bearing locking nut 7 and the rotating shaft 1, and preventing relative rotation between the two. With its dual locking and anti-loosening design, it provides double protection through "threaded tightening + mechanical clamping", completely solving the problem of bearing nut loosening under high-speed vibration environment and ensuring the rigidity, accuracy and long-term reliability of the spindle support system.

[0024] like Figure 1 and Figure 3As shown, the bearing 5 uses a high-speed ceramic ball bearing as the support unit. Its outer ring is clearance-fitted with the inner circle of the end cover 3, and its inner ring is interference-fitted with the shaft 1. This high-speed ceramic ball bearing is positioned between the bearing locating ring 6 and the bearing locking nut 7, achieving axial positioning on the shaft 1 through these two components. Specifically, the inner ring of the bearing 5 is axially positioned on one side by the shaft shoulder and the bearing locating ring 6, while the other side is locked by the bearing locking nut 7. The high-speed ceramic ball bearing possesses characteristics such as low friction, high speed adaptability, and good wear resistance, meeting the requirements for stable high-speed operation of the motor.

[0025] In this embodiment, the resolver rotor 8 is mounted on the resolver rotor mounting shaft 703 and is axially fixed by an elastic retaining ring 9 installed in an annular groove on the resolver rotor mounting shaft 703, ensuring that the resolver rotor 8 will not undergo axial displacement during motor operation. The resolver stator 10 is mounted on one end of the resolver mounting base 4, and the other end of the resolver mounting base 4 is connected to the end cover 3 to form a sealed cavity, effectively protecting the internal resolver components from external environmental interference.

[0026] In practical applications of the resolver mounting structure in high-speed centrifuges, this high-speed motor hollow shaft resolver mounting structure demonstrated excellent performance. Due to the high stability of the resolver mounting structure, the resolver can accurately detect the position and speed information of the motor shaft, providing accurate data support for the control system of the high-speed centrifuge.

[0027] Example 2 like Figure 1 and Figure 2 As shown, a high-speed motor hollow shaft resolver mounting structure includes a resolver and a rotating shaft 1. The resolver includes a resolver rotor 8 and a resolver stator 10, and also includes a resolver mounting base 4, an end cover 3, a bearing 5, a bearing positioning ring 6, and a locking structure. The non-shaft extension end of the rotating shaft 1 is a hollow structure. The bearing 5, the bearing positioning ring 6, and the locking structure are sequentially mounted on the rotating shaft 1 and located inside the end cover 3. One end of the locking structure extends axially to form a resolver rotor mounting shaft 703. The resolver rotor 8 is mounted on the resolver rotor mounting shaft 703 and is axially fixed by an elastic retaining ring 9. The resolver stator 10 is mounted on one end of the resolver mounting base 4, and the other end of the resolver mounting base 4 is connected to the end cover 3 to form a sealed cavity.

[0028] In this embodiment, an inner oil seal 2 is also provided between the end cover 3 and the rotating shaft 1. The inner oil seal 2 is fitted onto the rotating shaft 1 and is located on the side of the bearing 5 near the shaft extension end of the rotating shaft 1. It is used to achieve a seal between the end cover 3 and the rotating shaft 1, effectively preventing contaminants such as lubricating oil and coolant inside the motor from entering the resolver chamber and contaminating or damaging the resolver. It also prevents external impurities from entering the motor, thus improving the adaptability of the entire system in harsh environments.

[0029] like Figure 3 As shown, in this embodiment, two high-speed ceramic ball bearings are used for support, and the positional dimension of the two bearings 5 ​​is set to 60mm. The bearings 5 ​​are pre-filled with high-temperature long-life grease. The bearing rings have undergone black anodizing treatment to improve corrosion resistance and operational stability.

[0030] An annular sealing ring was added at the mating surface between the resolver mounting base 4 and the end cover 3 to form a secondary seal, ensuring complete isolation between the motor interior and the external environment.

[0031] This embodiment is applicable to high-speed motors in new energy vehicle drive motors or aerospace fields, where the requirements for reliability and environmental adaptability are extremely stringent.

[0032] Example 3 like Figure 1 and Figure 2 As shown, a high-speed motor hollow shaft resolver mounting structure includes a resolver and a rotating shaft 1. The resolver includes a resolver rotor 8 and a resolver stator 10, and also includes a resolver mounting base 4, an end cover 3, a bearing 5, a bearing positioning ring 6, and a locking structure. The non-shaft extension end of the rotating shaft 1 is a hollow structure. The bearing 5, the bearing positioning ring 6, and the locking structure are sequentially fitted onto the rotating shaft 1 and located inside the end cover 3. One end of the locking structure extends axially to form a resolver rotor mounting shaft 703. The resolver rotor 8 is mounted on the resolver rotor mounting shaft 703 and axially fixed by an elastic retaining ring 9. The resolver stator 10 is mounted on one end of the resolver mounting base 4, and the other end of the resolver mounting base 4 is connected to the end cover 3 to form a sealed cavity.

[0033] In this embodiment, the bearing locking nut 7 is made of high-strength alloy steel and nitrided, significantly improving the precision of the locking nut thread 701 on its surface to ensure a perfect fit with the shaft thread. In addition to the self-tightening effect of the reverse thread, a radial threaded hole is additionally machined at the flange of the nut, and a high-strength set screw 702 is installed. During assembly, after tightening the nut, the set screw 702 is screwed in, ensuring its tip firmly presses against the surface of the shaft 1, forming a double anti-loosening mechanism and improving vibration resistance.

[0034] The resolver mounting base 4 and the end cover 3 are connected by a snap-fit ​​detachable connection. When it is necessary to adjust the circumferential position of the resolver stator, simply press the snap-fit ​​to quickly remove the resolver mounting base for adjustment, which greatly improves the convenience of operation and is especially suitable for application scenarios that require frequent adjustment of the resolver position.

[0035] Obviously, the above-described embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A high-speed motor hollow shaft resolver mounting structure, comprising a resolver and a rotating shaft, wherein the resolver comprises a resolver rotor and a resolver stator, characterized in that, It also includes a resolver mounting base, an end cover, a bearing, a bearing positioning ring, and a locking structure. The non-shaft extension end of the rotating shaft is a hollow structure. The bearing, bearing positioning ring, and locking structure are sequentially fitted onto the rotating shaft and located inside the end cover. One end of the locking structure extends axially to form a resolver rotor mounting shaft. The resolver rotor is mounted on the resolver rotor mounting shaft and axially fixed by an elastic retaining ring. The resolver stator is mounted on one end of the resolver mounting base, and the other end of the resolver mounting base is connected to the end cover to form a sealed cavity.

2. The high-speed motor hollow shaft resolver mounting structure according to claim 1, characterized in that, The locking structure uses a bearing locking nut, which is connected to the rotating shaft by a thread. The bearing locking nut is equipped with a locking nut thread, and the locking nut thread rotates in the opposite direction to the rotating shaft.

3. The high-speed motor hollow shaft resolver mounting structure according to claim 2, characterized in that, The bearing locking nut is also provided with a set screw, which is arranged radially along the bearing locking nut and its end abuts against the rotating shaft to prevent the locking nut from rotating relative to the rotating shaft.

4. The high-speed motor hollow shaft resolver mounting structure according to claim 1, characterized in that, The bearing is a high-speed ceramic ball bearing, with its outer ring having a clearance fit with the inner circle of the end cover and its inner ring having an interference fit with the shaft.

5. The high-speed motor hollow shaft resolver mounting structure according to claim 4, characterized in that, The high-speed ceramic ball bearing is disposed between the bearing positioning ring and the locking structure, and the high-speed ceramic ball bearing is axially positioned on the rotating shaft by the bearing positioning ring and the locking structure.

6. The high-speed motor hollow shaft resolver mounting structure according to claim 1, characterized in that, The elastic retaining ring is installed in an annular groove on the resolver rotor mounting shaft to restrict the axial movement of the resolver rotor.

7. The high-speed motor hollow shaft resolver mounting structure according to claim 1, characterized in that, The inner side of the end cover is provided with an inner oil seal, which is fitted onto the hollow rotating shaft and located on the side of the bearing near the shaft extension end, for the purpose of achieving a seal between the end cover and the rotating shaft.

8. The high-speed motor hollow shaft resolver mounting structure according to claim 1, characterized in that, The shaft extension end is a solid structure, while the hollow inner diameter of the non-shaft extension end is 40mm.

9. The high-speed motor hollow shaft resolver mounting structure according to claim 1, characterized in that, The locking structure has a diameter of 55mm, and the shaft diameter of the resolver rotor mounting shaft is 30mm.

10. The high-speed motor hollow shaft resolver mounting structure according to claim 1, characterized in that, The resolver mounting base is detachably connected to the end cover and is used to adjust the circumferential position of the resolver stator.

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