High-speed permanent magnet synchronous motor rotor for dynamometer

Abstract

The utility model discloses a high-speed permanent magnet synchronous motor rotor for a dynamometer, which comprises a rotor shaft, a plurality of axial ventilation holes along the axial direction of the rotor shaft and a plurality of radial ventilation holes along the radial direction of the rotor shaft are arranged in the rotor shaft, the axial ventilation holes are arranged at one end of the rotor shaft, and the radial ventilation holes are arranged at the other end of the rotor shaft. The axial ventilation holes are communicated with the radial ventilation holes, a plurality of magnetic isolation strips are uniformly arranged in the circumferential direction of the rotor shaft at intervals, permanent magnets are arranged among the magnetic isolation strips, and the outer surfaces of the permanent magnets are sleeved with carbon fiber sheaths; by means of the mode, the rotor can effectively dissipate heat under the conditions that cooling liquid is not used and the structure of the rotor is simplified.

Description

Technical Field

[0001] This utility model relates to the field of motor rotor cooling technology, and in particular to a high-speed permanent magnet synchronous motor rotor for dynamometers. Background Technology

[0002] In the field of high-speed permanent magnet synchronous motors for dynamometers, rotor cooling technology is crucial for ensuring the motor's efficient and stable operation. Currently, conventional cooling solutions mainly employ liquid cooling systems. These systems utilize the coordinated action of components such as cooling pipes, radiators, and electric pumps, employing coolant circulating within the pipes to absorb and remove the heat generated by the rotor's operation. Liquid cooling technology relies on the high specific heat capacity of the coolant, which can meet the heat dissipation requirements under high power density conditions, ensuring stable motor operation under high-speed and high-load conditions.

[0003] However, existing liquid cooling technology has significant shortcomings: First, the system structure is complex, involving the collaborative design and manufacturing of multiple components, resulting in high process difficulty and high cost. Not only is the initial investment high, but the cost of coolant replacement and system maintenance also increases significantly in the later stages. Second, it has stringent requirements for sealing performance. Once the seal fails and coolant leakage occurs, it may cause serious failures such as motor short circuits. Moreover, the corrosion of motor components by coolant during long-term use will shorten the equipment's lifespan. Utility Model Content

[0004] The main technical problem solved by this utility model is to provide a high-speed permanent magnet synchronous motor rotor for dynamometers, which can effectively dissipate heat without using coolant and with a simplified rotor structure.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a high-speed permanent magnet synchronous motor rotor for a dynamometer is provided, comprising: a rotor shaft, a plurality of axial ventilation holes along its axial direction and radial ventilation holes along its radial direction are provided inside the rotor shaft, the axial ventilation holes are provided at one end of the rotor shaft and the radial ventilation holes are provided at the other end of the rotor shaft, the axial ventilation holes and the radial ventilation holes are connected, a plurality of magnetic shielding strips are uniformly spaced around the rotor shaft, permanent magnets are provided between the magnetic shielding strips, and a carbon fiber sheath is provided on the outer surface of the permanent magnet.

[0006] Preferably, the rotor shaft is a hollow shaft.

[0007] Preferably, balance rings are provided at both ends of the rotor shaft.

[0008] Preferably, the balance ring has multiple screw holes evenly spaced radially.

[0009] Preferably, a positioning groove is provided on the rotor shaft, and the magnetic shielding strip is embedded in the positioning groove and fixed.

[0010] Preferably, the rotor shaft has positioning steps at both ends that cooperate with the balance ring, and the balance ring and the positioning steps are interference fit.

[0011] Preferably, the balance ring is made of stainless steel.

[0012] The beneficial effects of this invention are as follows: by opening axial and radial ventilation holes on the rotor shaft, the airflow penetrates the interior of the rotor shaft, thereby increasing the airflow channels passing through the inside of the rotor shaft and thus increasing the cooling efficiency of the rotor shaft. Furthermore, it significantly simplifies the complex structure of traditional liquid cooling systems, reducing manufacturing costs and maintenance difficulty. The precise fit design of the positioning steps and balance ring screw holes further enhances the mechanical fixation reliability and the ease of dynamic balance adjustment. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0014] Figure 2 This is a schematic diagram of the structure of this utility model after the carbon fiber sheath has been removed;

[0015] Figure 3 This is a schematic diagram of the rotor shaft of this utility model;

[0016] Figure 4 This is a cross-sectional view of the present invention.

[0017] The components in the attached diagram are labeled as follows:

[0018] 1. Rotor shaft; 11. Axial ventilation hole; 12. Radial ventilation hole; 13. Positioning groove; 14. Positioning step;

[0019] 2. Magnetic shielding strip;

[0020] 3. Permanent magnet;

[0021] 4. Carbon fiber sheath;

[0022] 5. Balance ring; 51. Screw hole. Detailed Implementation

[0023] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0024] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to 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 this utility model.

[0025] Furthermore, 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0026] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., 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 or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] In this utility model, unless otherwise explicitly specified and limited, "above" 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 with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0028] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0029] Unless otherwise specified, physical quantities in formulas should be understood as basic quantities of SI base units, or derived quantities derived from basic quantities through mathematical operations such as multiplication, division, differentiation, or integration.

[0030] Example:

[0031] refer to Figure 1 and Figure 2 A high-speed permanent magnet synchronous motor rotor for a dynamometer includes a rotor shaft 1. The rotor shaft 1 has multiple axial ventilation holes 11 along its axial direction and radial ventilation holes 12 along its radial direction. The axial ventilation holes 11 are located at one end of the rotor shaft 1, and the radial ventilation holes 12 are located at the other end of the rotor shaft 1. The axial ventilation holes 11 and radial ventilation holes 12 communicate with each other. If a through-hole axial ventilation hole 11 is used, the airflow may only pass through rapidly in a straight line, resulting in limited contact with the heat-generating areas inside the rotor shaft 1 and low heat dissipation efficiency. The design where the end of the axial ventilation hole 11 turns into a radial ventilation hole 12 forces the airflow to change direction within the rotor shaft 1 and diffuse into the radial holes, extending the contact time and path between the airflow and the high-temperature areas, thus improving the heat exchange effect.

[0032] refer to Figure 1 and Figure 2 The rotor shaft 1 has multiple magnetic isolation strips 2 evenly spaced around its circumference, and permanent magnets 3 are placed between each magnetic isolation strip 2. The permanent magnets are attached to the rotor shaft 1. A carbon fiber sheath 4 is fitted on the outer surface of the permanent magnet 3. The carbon fiber sheath 4 covers the outer surface of the permanent magnet 3. The high strength and low density characteristics of carbon fiber are used to resist the centrifugal force generated by high-speed rotation and prevent the permanent magnet 3 from breaking or falling off.

[0033] refer to Figure 1 and Figure 4 The rotor shaft 1 is a hollow shaft, thus forming a natural axial airflow channel inside. This significantly increases the contact area between the airflow and the rotor shaft 1, accelerating the convective transfer of heat from the permanent magnet 3, the sheath, and other heat-generating components to the air, thereby improving the overall heat dissipation capacity. Furthermore, there is an air gap between the rotor shaft 1 and the stator, which also provides a channel for gas flow, further enhancing heat dissipation. The radial ventilation holes 12 guide the axial airflow to the outer surface of the rotor or the air gap area, forming a synergistic internal and external heat dissipation with the external air-cooled airflow (such as the air gap path), covering a larger heat dissipation area and avoiding localized heat accumulation.

[0034] On the other hand, compared with a solid rotor shaft 1, a hollow rotor shaft 1 can significantly reduce the rotor mass, reduce inertial resistance during high-speed rotation, improve the dynamic response capability of the motor, and the lightweight design reduces the centrifugal force borne by the rotor during high-speed rotation, alleviates the mechanical load on components such as permanent magnet 3 and sheath, and extends service life.

[0035] refer to Figures 1-4 Balance rings 5 ​​are fitted at both ends of the rotor shaft 1. Multiple screw holes 51 are evenly spaced radially on the balance rings 5, serving to adjust the mass distribution. By increasing or decreasing the number of screws or adjusting their installation positions (e.g., installing counterweight screws or screws of different masses), the local mass distribution of the balance rings 5 ​​is altered, compensating for mass imbalances in the rotor shaft 1 caused by manufacturing tolerances, assembly errors, or uneven distribution of the permanent magnets 3. Dynamic balancing significantly reduces vibration and noise caused by rotor shaft 1 eccentricity, extending the service life of critical components such as bearings and shaft systems. Furthermore, it complements dynamic calibration; during motor assembly or maintenance, by detecting the vibration characteristics of the rotor shaft 1 and using the screw holes to install counterweights or adjust the screw distribution, precise dynamic balancing of the rotor shaft 1 is achieved, ensuring uniform distribution of centrifugal force during high-speed rotation.

[0036] refer to Figure 2 and Figure 3 The rotor shaft 1 has a positioning groove 13. The magnetic shielding strip 2 is sequentially embedded into the positioning groove 13 by screws and then sealed with glue. The magnetic shielding strip 2 is used to block the leakage magnetic path between adjacent permanent magnets 3, optimize the magnetic field distribution, and reduce magnetic flux loss. By embedding the permanent magnets 3 into the positioning groove 13 of the rotor shaft 1 with screws and sealing them with glue, the circumferential fixation of the permanent magnets 3 is enhanced, preventing displacement caused by centrifugal force during high-speed rotation.

[0037] refer to Figures 1-3 The rotor shaft 1 has positioning steps 14 at both ends that mate with the balance ring 5. The balance ring 5 and the positioning steps 14 are interference-fitted, thus fixing the balance ring 5 to both ends of the rotor shaft 1. The positioning steps 14 provide a clear mechanical reference surface for the balance ring 5. During installation, simply aligning the end face of the balance ring 5 with the step quickly determines its axial position. To further facilitate the assembly of the balance ring 5 and the rotor shaft 1, a chamfer can be made on the outer end face of the positioning steps 14. The balance ring 5 is made of stainless steel, giving it excellent tensile strength and yield strength, enabling it to withstand the enormous centrifugal force and vibration loads generated during high-speed rotation. This also ensures that the balance ring 5 does not undergo plastic deformation or breakage at high speeds (such as dynamometer conditions), guaranteeing the long-term stability of dynamic balance adjustment. Furthermore, the coefficient of thermal expansion of stainless steel is similar to that of commonly used materials for the rotor shaft 1, and it maintains high mechanical properties even at high temperatures.

[0038] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A rotor for a high-speed permanent magnet synchronous motor used in a dynamometer, characterized in that, include: The rotor shaft (1) has multiple axial ventilation holes (11) along its axial direction and radial ventilation holes (12) along its radial direction. The axial ventilation holes (11) are opened at one end of the rotor shaft (1), and the radial ventilation holes (12) are opened at the other end of the rotor shaft (1). The axial ventilation holes (11) and the radial ventilation holes (12) are connected. Multiple magnetic shielding strips (2) are evenly spaced around the rotor shaft (1). Permanent magnets (3) are arranged between the magnetic shielding strips (2). The outer surface of the permanent magnets (3) is covered with a carbon fiber sheath (4).

2. The rotor of a high-speed permanent magnet synchronous motor for a dynamometer according to claim 1, characterized in that: The rotor shaft (1) is a hollow shaft.

3. The rotor of a high-speed permanent magnet synchronous motor for a dynamometer according to claim 2, characterized in that: Balance rings (5) are provided at both ends of the rotor shaft (1).

4. A high-speed permanent magnet synchronous motor rotor for a dynamometer according to claim 3, characterized in that: The balance ring (5) has multiple screw holes (51) evenly spaced radially.

5. A high-speed permanent magnet synchronous motor rotor for a dynamometer according to claim 1, characterized in that: The rotor shaft (1) is provided with a positioning groove (13), and the magnetic shielding strip (2) is embedded in the positioning groove (13) and fixed.

6. A high-speed permanent magnet synchronous motor rotor for a dynamometer according to claim 3 or 4, characterized in that: The rotor shaft (1) has positioning steps (14) at both ends that cooperate with the balance ring (5), and the balance ring (5) and the positioning steps (14) are interference fit.

7. A high-speed permanent magnet synchronous motor rotor for a dynamometer according to claim 6, characterized in that: The balance ring (5) is made of stainless steel.

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