Additional end cogging torque compensation and cooling integrated structure

Abstract

The invention discloses an additional end cogging torque compensation and cooling integrated structure which is installed at the end of a motor and comprises an end diversion cooling frame, a cogging torque compensation slot ring, a permanent magnet array and a phase locking mechanism. Spoke type blades are arranged on the outer edge of the frame, forced airflow is generated during rotation to cool the end of the winding, the compensation groove ring and the frame are in rigid connection and rotate synchronously, and compensation grooves distributed in the circumferential direction of the compensation groove ring and a permanent magnet array fixed to the end face of a pressing plate form axial air gap magnetic circuit coupling. Compensation torque opposite to the cogging torque of the body in phase is generated through order matching; the phase locking mechanism is connected through a fixing pin hole or a spline, and discrete adjustment and stable locking of the compensation phase are achieved. Additional installation is adopted, the electromagnetic structure of a motor body does not need to be changed, cogging torque is effectively restrained, end temperature rise is reduced, single-side or double-side installation flexibility is achieved, the technology is simple, cost is low, and the motor is suitable for the fields such as electric automobiles and servo motors with high requirements for low-speed stability and power density.

Description

An integrated structure for additional end cogging torque compensation and cooling Technical Field

[0001] This invention relates to the field of motor technology, specifically to an integrated structure for additional end cogging torque compensation and cooling, and a permanent magnet synchronous motor incorporating this structure. Background Technology

[0002] Cogging torque is a torque pulsation component caused by the periodic change of the air gap magnetic permeability of a motor with rotational angle. It is usually related to the combined effects of stator slot structure, rotor pole structure, and spatial harmonics of the air gap magnetic field. Cogging torque can lead to low-speed creep, increased noise and vibration, and deterioration of torque control performance. It may also induce additional losses and local temperature rise under certain operating conditions. Especially in applications with high requirements for low-speed smoothness and NVH performance, cogging torque suppression has become one of the important issues in motor design.

[0003] Commonly used methods for suppressing cogging torque in existing technologies mainly include stator skew, rotor skew, stator unequal teeth / slots, and structural optimization techniques such as non-uniform air gaps or pole shoe shaping. These methods typically reduce cogging effects and their harmonic components by altering the spatial distribution of air gap magnetic permeability or smoothing the air gap magnetic flux density. However, these methods generally involve direct modifications to the electromagnetic structure of the motor body, which can easily affect the distribution of the main magnetic field, leading to problems such as reduced main flux linkage, decreased back EMF, or decreased electromagnetic torque density, resulting in reduced output torque, decreased efficiency, or smaller design margins. Furthermore, skewed slots / pole configurations may increase processing and assembly difficulty, while non-uniform teeth / air gap configurations place higher demands on manufacturing consistency and tolerance control, resulting in higher engineering implementation costs. Meanwhile, excessive temperature rise in the motor end windings is one of the bottlenecks restricting the improvement of motor power density. Traditional end cooling relies on heat dissipation fins in the casing or external fans, which have limited heat dissipation efficiency and are not integrated with cogging torque suppression functions.

[0004] Therefore, there is an urgent need for a technical solution to effectively reduce cogging torque without altering the motor's main magnetic circuit and key structural components. Furthermore, if this solution can simultaneously improve heat dissipation at the motor ends, reduce end temperature rise and related losses, it will be even more beneficial for enhancing the motor's overall performance and reliability. Summary of the Invention

[0005] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide an integrated structure for additional end cogging torque compensation and cooling. This structure generates compensated cogging torque by adding a cogging torque compensation slot ring to the motor end and a coupling structure between the slot ring and the permanent magnet in the air gap, and achieves end cooling by forming a fan through an end-guided cooling frame. This solution does not require any modification to the stator slot shape, rotor pole shape, or main air gap, thus avoiding adverse effects on the main magnetic field and rated output torque, and improving end heat dissipation while suppressing cogging torque.

[0006] The technical solution adopted by this invention to solve the technical problem is as follows: An additional end-coiling torque compensation and cooling integrated structure is installed at the axial end of a rotating electric motor. The motor includes a stator, a rotor, a shaft, and an end pressure plate. The structure includes an end-guided cooling frame, a coiling torque compensation slotted ring, a permanent magnet array, and a phase locking mechanism. The end-guided cooling frame is a rotating body composed of spoke-type blades, coaxially fixed to the shaft and rotating synchronously with the shaft. The blades have a preset tilt angle relative to the axial direction, generating axial and radial airflow to cool the motor end windings during rotation. The coiling torque compensation slotted ring is a ring-shaped component made of magnetically conductive material, rigidly connected to the lower end of the end-guided cooling frame and rotating synchronously. The slotted ring faces the motor. A circumferentially distributed compensation slot is provided on one side of the end. The number of compensation slots, Ns, is equal to the least common multiple of the number of stator slots, Z, and the number of rotor poles, 2P. The permanent magnet array is fixedly installed on the axial end face of the end pressure plate and located on the axial opposite side of the cogging torque compensation slot ring. An axial air gap is formed between the permanent magnet array and the compensation slot. The number of pole pairs, pm, of the permanent magnet array is equal to Ns divided by 2, and each permanent magnet is arranged with alternating polarities along the circumference. The phase locking mechanism is set between the end flow cooling frame and the rotating shaft to lock the cogging torque compensation slot ring and the rotating shaft to a selected phase among multiple discrete phase relationships, so that the compensation cogging torque generated by the compensation slot is out of phase with the fundamental component of the motor body cogging torque.

[0007] Preferably, the compensation slot is a sinusoidal slot or an equivalent magnetic permeability modulation slot to reduce slot harmonics.

[0008] Preferably, the permanent magnet array is composed of a plurality of permanent magnet units, and the permanent magnet units are fixed to the axial end face of the end pressure plate.

[0009] Preferably, the phase locking mechanism includes a fixing pin and fixing pin holes. There are multiple fixing pin holes, which are equally spaced at the hub of the end flow cooling frame. The number of fixing pin holes is an integer multiple of the rotor pole number 2P. The fixing pin can be selectively inserted into any of the fixing pin holes and cooperate with the rotating shaft to lock the relative angular position of the end flow cooling frame and the rotating shaft.

[0010] Preferably, the phase locking mechanism is a spline connection, which is disposed between the end cooling frame and the rotating shaft, and the number of spline teeth is an integer multiple of the rotor pole number 2P.

[0011] Preferably, the blades of the end-flow cooling frame have an angle relative to the axial direction, and the number of blades is an integer multiple of the rotor pole number 2P.

[0012] Preferably, the toothed torque compensation groove ring is integrally connected to the end guide cooling frame or is rigidly connected.

[0013] Preferably, the structure is installed only at one axial end of the motor.

[0014] Preferably, the structure is symmetrically installed at both axial ends of the motor to counteract the axial unbalanced magnetic pull when installed on one side.

[0015] Furthermore, the present invention also provides a permanent magnet synchronous motor, which includes the above-described additional end cogging torque compensation and cooling integrated structure.

[0016] Furthermore, the magnetic material can be conventional silicon steel sheets for motors, such as low-loss oriented silicon steels like DW310 and DW470, or other soft magnetic materials with high permeability and low iron loss.

[0017] Based on the synergistic mechanism of end air gap magnetic circuit coupling modulation and forced convection of rotating blades, this invention adopts an additional installation method to simultaneously achieve the dual functions of cogging torque suppression and end cooling without changing the electromagnetic structure of the motor body.

[0018] The core innovative mechanism is as follows: I. Cogging Torque Compensation Principle: 1. Order Matching: The number of compensation slots Ns = LCM(Z, 2P), and the number of permanent magnet pole pairs pm = Ns / 2, ensuring that the spatial period of the permanent magnet magnetic field is strictly matched with the magnetic permeability modulation period of the slot ring, generating a compensation torque component with the same frequency and opposite phase as the cogging torque of the main body. Where: Z is the number of stator slots, 2P is the number of rotor poles (or equivalent to 2p), and LCM(Z,2P) is the least common multiple of Z and 2P.

[0019] 2. Magnetic circuit coupling: An axial air gap is formed between the permanent magnet array fixed on the end face of the pressure plate and the rotating compensation groove ring. The Ns compensation grooves of the groove ring periodically modulate the permanent magnet magnetic field, so that the air gap magnetic resistance changes sinusoidally, thereby generating a controllable compensation cogging torque on the rotating shaft.

[0020] 3. Phase locking: The compensation groove ring is rigidly connected to the rotating shaft through the phase locking mechanism (fixed pin hole or spline structure) to ensure that the phase difference between the compensation torque and the cogging torque of the main body is stable at 180°, so that the torque pulsation is canceled.

[0021] II. End Cooling Principle: 1. Fan Effect: The spoke blades of the end guide cooling frame rotate with the shaft. Because the blades have an angle relative to the axis, they generate axial-radial coupled airflow, which performs forced convection heat transfer on the winding end, pressure plate and pressure finger.

[0022] 2. Reusable structure: The same mechanical component (end cooling frame) has both magnetic circuit support and cooling flow guidance functions, eliminating the need for an additional fan and reducing additional losses.

[0023] III. Double-sided cancellation principle: Axial force balance: This structure is symmetrically installed at both ends of the motor. The permanent magnet arrays on both sides generate axial magnetic pull forces of equal magnitude and opposite direction. The resultant force is close to zero, avoiding additional load on the bearing.

[0024] A. Single-sided installation scheme working process: Stage 1, Synchronous rotation: After the motor is powered on, the stator winding establishes a rotating magnetic field to drive the shaft to rotate; the end guide cooling frame achieves angular positioning and torque transmission with the shaft through fixed pins or splines, the frame and the cogging torque compensation slot ring are relatively stationary and rotate synchronously with the shaft; the permanent magnet array fixed to the end face of the pressure plate remains stationary, forming a relative motion relationship between the rotating slot ring and the stationary permanent magnet; Stage 2, Forced end cooling: As the shaft rotates, the spoke blades of the guide cooling frame form a fan effect, generating axial and radial airflow, which performs convective heat transfer on the winding end, pressure plate and pressure fingers, reducing the end temperature rise and suppressing the increase in copper loss caused by the temperature rise; Stage 3, Real-time cogging torque compensation: The cogging torque compensation slot ring rotates synchronously with the shaft. The Ns circumferentially distributed compensation slots periodically modulate the magnetic field of the permanent magnet, causing the end-coupled magnetic energy to change sinusoidally with the rotation angle, generating compensation cogging torque on the shaft. By selecting the indexing hole position or spline phase combination of the fixed pin hole, the angular phase between the compensation slot ring and the permanent magnet is set, so that the compensation cogging torque is out of phase with the fundamental component of the motor body cogging torque. The two are superimposed to achieve cogging torque cancellation or reduction, reducing torque pulsation, noise and vibration. Stage 4, Phase Adjustment and Locking: In the assembly stage, the phase between the compensation slot ring and the shaft is roughly adjusted and precisely positioned by using the multi-indexing hole position of the fixed pin hole or the discrete tooth profile of the spline. After the phase is determined, the locking mechanism ensures that the compensation phase remains stable during operation, so that the compensation effect is continuously effective.

[0025] B. Working process of the dual-side installation scheme: Two sets of the integrated structure of this invention are symmetrically installed on the drive end and the non-drive end of the motor. The permanent magnet arrays on both sides are arranged with the same polarity, and the axial magnetic pull generated are opposite in direction and cancel each other out. The airflow field on both sides forms a pressure balance in the middle of the motor, and the end temperature rise is further reduced. The compensation torque generated by the two sets of compensation devices is superimposed in phase, which has a better effect on suppressing torque pulsation in the middle of the long motor.

[0026] The positive and beneficial effects of this invention are as follows: 1. This invention adopts an additional installation structure, which does not require any modification to the motor's stator slot shape, rotor pole shape, or main air gap length and other main electromagnetic structures, fundamentally avoiding adverse effects on the main magnetic circuit. After installation, the motor's core performance parameters such as rated torque, efficiency, and power factor remain unchanged, completely solving the inherent defects of traditional skewed slot / skewed pole schemes that lead to a decrease in main magnetic flux and a reduction in torque density, effectively ensuring the motor's rated output capacity and design margin.

[0027] 2. This invention generates a compensation torque that is out of phase with the main body's tooth cogging torque through end air gap magnetic circuit coupling, concentrating the compensation energy at the target order; the order matching design of the compensation slot ring and the permanent magnet array ensures that the generated compensation torque waveform is precisely superimposed in opposite phase with the main body's tooth cogging torque waveform, achieving a significant reduction in the peak-to-peak value of the tooth cogging torque; at low speeds, speed fluctuations are significantly reduced, torque pulsation is effectively suppressed, noise and vibration levels are greatly improved, and low-speed stability meets the stringent requirements of high-performance application scenarios.

[0028] 3. The rotating spoke blades of the end-guided cooling frame in this invention also function as fans, generating axial and radial coupled airflow during operation, which directly scours the winding ends, pressure plates, and pressure finger areas, forming forced convection heat transfer. This design integrates structural support and airflow guidance functions into one unit, eliminating the need for an additional cooling fan. While achieving cogging torque compensation, it effectively reduces end temperature rise, suppresses copper loss increase and local hot spots caused by temperature rise, extends winding insulation life, and improves motor overload capacity and operational reliability.

[0029] 4. This invention, through the multi-division hole positions of the fixed pin holes or the discrete tooth profile connected by splines, can achieve flexible adjustment of the compensation phase during the assembly stage. This design allows for optimization of the angular phase relationship between the compensation slot ring and the permanent magnet array to meet the individual differences of different motors or specific operating conditions, so that each motor can obtain the best compensation effect. The phase locking mechanism ensures that the adjusted phase relationship remains stable during operation, which solves the limitation of the traditional body structure being unadjustable and significantly improves the adaptability and product consistency of mass production.

[0030] 5. This invention is an add-on structure that can be directly modified on existing motors without redesigning the stator and rotor dies or changing the core manufacturing process. For performance upgrades of existing motors, there is no need to replace the entire machine; performance can be improved simply by adding an end structure. It has excellent economic efficiency and market promotion value.

[0031] 6. This invention, through an additional, adjustable end-integrated structure, achieves effective suppression of cogging torque and simultaneous improvement of end heat dissipation without sacrificing the performance of the motor itself. It has significant advantages such as simple process, low cost, flexible debugging, and strong scalability, providing a non-intrusive performance upgrade solution for high-performance permanent magnet motors. It is particularly suitable for applications such as drive motors and servo motors with stringent requirements for low-speed stability, NVH performance, and power density.

[0032] 7. When this invention is symmetrically installed at both axial ends of the motor, the axial magnetic pull generated by the permanent magnet arrays on both sides is in opposite directions and cancels each other out, resulting in minimal residual axial force. This design eliminates the additional bearing load that may result from unilateral installation, making it suitable for motors with a large length-to-diameter ratio or support systems sensitive to axial forces, ensuring the reliability and operational stability of the mechanical structure. Attached Figure Description

[0033] Figure 1 is a three-dimensional structural diagram of the integrated structure of the present invention at the motor end; Figure 2 is a three-dimensional structural diagram of Figure 1 from another direction; Figure 3 is a structural diagram of the present invention without a rotating shaft and a spoke-type end cooling frame; Figure 4 is a structural diagram of the end cogging torque compensation mechanism of the present invention; Figure 5 is a plan view of the end cogging torque compensation mechanism of the present invention; Figure 6 is a curve of the cogging torque suppression result when the axial compensation permanent magnet is 20.15mm thick, taking a permanent magnet synchronous motor with an axial length of 800mm and 144 slots as an example. The horizontal axis is the rotor position angle and the vertical axis is the cogging torque amplitude, which intuitively shows the suppression effect; In each figure, the figure numbers represent: 1--end cooling frame, 2--rotating shaft, 3--pressure plate, 4--winding, 5--permanent magnet, 6--stator, 7--pressure finger, 8--fixing pin, 9--fixing pin hole, 10--cogging torque compensation slot ring. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The scope of protection of the present invention is not limited to the described embodiments.

[0035] As shown in Figures 1 to 6, this embodiment is applied to a 144-slot 32-pole permanent magnet synchronous motor; the motor body includes a stator 6, a rotor, a shaft 2, windings 4, and an end pressure plate 3; the additional end cogging torque compensation and cooling integrated structure of the present invention is installed at the non-driving end of the motor, mainly including an end flow cooling frame 1, a cogging torque compensation slot ring 10, a permanent magnet array, and a phase locking mechanism.

[0036] The end cooling frame 1 is a rotating body composed of spoke blades. It is formed by stamping magnetic steel components. The hub part is machined with multiple fixed pin holes 9 at equal angles for connecting with the rotating shaft 2. Multiple spoke blades are evenly distributed on the outer edge of the frame. The blades have a preset tilt angle relative to the axial direction. When the rotating shaft 2 rotates, the frame 1 rotates synchronously and generates axial and radial airflow to force convection cooling of the winding end and the vicinity of the pressure plate 3.

[0037] The toothed torque compensation groove ring 10 is a ring-shaped component made of magnetic material and is rigidly connected (welded or bolted) to the lower end of the end flow cooling frame 1. The groove ring has circumferentially distributed compensation grooves on the side facing the motor end. The groove shape of the compensation groove can be a sinusoidal groove or an equivalent magnetic permeability modulation groove. The number of compensation grooves Ns is equal to the least common multiple of the number of stator slots Z and the number of rotor poles 2P to ensure that the order of the compensation torque is consistent with the toothed torque of the main body.

[0038] The permanent magnet 5 is fixedly bonded to the axial end face of the end pressure plate 3, and the permanent magnet array is formed by alternating magnetic poles along the circumference. The permanent magnet array is located on the opposite side of the toothed torque compensation groove ring 10 in the axial direction, and a preset axial air gap is formed between the two. The number of pole pairs pm of the permanent magnet array is equal to Ns divided by 2, so that the period of the permanent magnet magnetic field is precisely matched with the magnetic permeability modulation period of the compensation groove.

[0039] The phase locking mechanism includes a fixing pin 8 and fixing pin holes 9. The fixing pin holes 9 are evenly spaced at angles on the hub of the end guide cooling frame 1, and their number is an integer multiple of the rotor pole number 2P. The fixing pin 8 can be selectively inserted into any fixing pin hole 9 and cooperate with the rotating shaft 2 to achieve rigid angular positioning between the frame and the rotating shaft 2. Alternatively, a spline connection can be used to achieve angular positioning and torque transmission, and the number of spline teeth is also an integer multiple of the rotor pole number 2P.

[0040] Working process: When the motor is running, after the stator 6 is energized, a rotating magnetic field is established in the winding 4 in the stator slot, driving the shaft 2 to rotate; the end guide cooling frame 1 is rigidly connected to the shaft 2 through the fixing pin 8 and rotates synchronously with the shaft; the rotating spoke blades generate axial and radial airflow to force cooling the end of the winding 4; at the same time, the magnetic field generated by the permanent magnet array is modulated by the rotating cogging torque compensation slot ring 10, generating a compensation torque that is opposite in phase to the cogging torque of the main body. The superposition of the two significantly weakens the cogging torque; by selecting different fixing pin holes 9 or spline misalignment, the compensation phase can be adjusted to achieve the optimal suppression effect.

[0041] Phase adjustment method: ① Pre-assembly: Fit the end guide cooling frame 1 into the rotating shaft 2 without locking the fixing pin 8; ② Phase scanning: Rotate the motor at low speed under no load, record the cogging torque waveform with the torque sensor, and at the same time manually rotate the end guide cooling frame 1 to find the angular position that minimizes the combined cogging torque; ③ Locking: Align with the nearest indexing hole, insert the fixing pin 8 and tighten it; ④ Verification: Remeasure the cogging torque to confirm that the suppression effect meets the standard.

[0042] For motors with a large axial length, two identical integrated end structures are symmetrically installed at the two axial ends of the motor; the permanent magnet arrays on both sides are arranged in the same polarity direction, and the axial magnetic pull generated cancels each other out; dual-sided cooling further reduces the end temperature rise, and the axial load of the bearing does not increase significantly.

[0043] Instead of fixed pin holes, spline connections are used to achieve angular positioning; the spline can be designed with equally divided tooth profiles to provide discrete phase indexing, or a multi-segment staggered spline structure can be used to achieve more phase combination options and improve phase adjustment accuracy.

[0044] For small and medium-sized motors, the cogging torque compensation groove ring 10 and the end guide cooling frame 1 are made of integrated magnetic material components, and the permanent magnet 5 is selected as a small magnet unit. By optimizing the magnetic circuit design, the weight is reduced, and the material cost is reduced while ensuring the compensation effect.

[0045] The above four embodiments together constitute the complete technical solution system of the present invention: Embodiment 1, as the basic solution, elaborates in detail the typical structural composition, working principle, and phase adjustment method of single-sided installation, establishing the core technical framework of the present invention; Embodiment 2, addressing the axial magnetic pull problem of long motors, proposes a double-sided symmetrical installation strategy to achieve double-sided cancellation and synergistic effect; Embodiment 3, by replacing the fixed pin with a spline connection, improves the phase adjustment resolution and torque transmission capability, suitable for high-power precision adjustment applications; Embodiment 4, addressing the lightweight requirements of small motors, adopts an integrated composite structure and a volume-optimized permanent magnet unit, reducing cost and weight while ensuring performance. These four embodiments expand the scope of application of the present invention from different dimensions, fully demonstrating the flexibility, scalability, and scenario adaptability of the technical solution, providing a complete solution from standard to customized for various permanent magnet motors.

[0046] The above four embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. The core of the present invention lies in the integration of cogging torque compensation and cooling functions through an additional end structure. Its specific structural form, material selection, installation method, and phase locking mechanism can be adaptively adjusted according to the motor type, power level, and application scenario. For example, in addition to sinusoidal slots, the compensation slot type of the cogging torque compensation slot ring 10 can also be trapezoidal, rectangular, or other magnetic permeability modulation slot types; in addition to fan-shaped, the magnet shape of the permanent magnet array can be tile-shaped, rectangular, or annular magnetic rings; in addition to fixed pins and splines, the phase locking mechanism can use bolt clamping, elastic positioning pins, or other mechanical locking methods; in addition to spoke type, the cooling blades can be designed as centrifugal, mixed-flow, or composite structures with guide shields.

[0047] The scope of protection of this invention is defined by the claims and their equivalents. Any non-substantial modifications or equivalent substitutions made based on the concept of this invention shall fall within the scope of protection of this invention.

Claims

1. An integrated structure for additional end cogging torque compensation and cooling, installed at the axial end of a rotating electric motor, the motor comprising a stator, a rotor, a shaft, and an end pressure plate, characterized in that: The additional end-coiling torque compensation and cooling integrated structure includes an end-flow cooling frame, a coiling torque compensation slot ring, a permanent magnet array, and a phase locking mechanism. The end-flow cooling frame is a rotating body composed of spoke-type blades, coaxially fixed to the rotating shaft and rotating synchronously with it. The blades have a preset tilt angle relative to the axial direction, generating axial and radial airflow to cool the motor end windings during rotation. The coiling torque compensation slot ring is a ring-shaped component made of magnetically conductive material, rigidly connected to the lower end of the end-flow cooling frame and rotating synchronously. The slot ring has circumferentially distributed compensation slots on the side facing the motor end, and the number of compensation slots, Ns, is equal to a fixed value. The least common multiple of the number of sub-slots Z and the number of rotor poles 2P; the permanent magnet array is fixedly installed on the axial end face of the end pressure plate and located on the axial opposite side of the cogging torque compensation slot ring, and an axial air gap is formed between the permanent magnet array and the compensation slot; the number of pole pairs pm of the permanent magnet array is equal to Ns divided by 2, and each permanent magnet is arranged with alternating polarity along the circumference; the phase locking mechanism is set between the end flow cooling frame and the rotating shaft, and is used to lock the cogging torque compensation slot ring and the rotating shaft to a selected phase among multiple discrete phase relationships, so that the compensation cogging torque generated by the compensation slot is opposite in phase to the fundamental component of the motor body cogging torque.

2. The integrated structure for additional end cogging torque compensation and cooling according to claim 1, characterized in that: The compensation slot is a sinusoidal slot or an equivalent magnetic permeability modulation slot to reduce slot harmonics.

3. The integrated structure for additional end cogging torque compensation and cooling according to claim 1, characterized in that: The permanent magnet array is composed of several permanent magnet units, which are fixed to the axial end face of the end pressure plate.

4. The integrated structure for additional end cogging torque compensation and cooling according to claim 1, characterized in that: The phase locking mechanism includes a fixing pin and fixing pin holes. There are multiple fixing pin holes, which are equally spaced at the hub of the end flow cooling frame. The number of fixing pin holes is an integer multiple of the rotor pole number 2P. The fixing pin can be selectively inserted into any of the fixing pin holes and cooperate with the rotating shaft to lock the relative angular position of the end flow cooling frame and the rotating shaft.

5. The integrated structure for additional end cogging torque compensation and cooling according to claim 1, characterized in that: The phase locking mechanism is a spline connection, which is located between the end cooling frame and the rotating shaft, and the number of spline teeth is an integer multiple of the rotor pole number 2P.

6. The integrated structure for additional end cogging torque compensation and cooling according to claim 1, characterized in that: The blades of the end-guided cooling frame have an angle relative to the axial direction, and the number of blades is an integer multiple of the rotor pole number 2P.

7. The integrated structure for additional end cogging torque compensation and cooling according to claim 1, characterized in that: The toothed torque compensation groove ring is connected to the end guide cooling frame as a whole or in a rigid connection.

8. The integrated structure for additional end cogging torque compensation and cooling according to claim 1, characterized in that: The additional end-cog torque compensation and cooling integrated structure is installed only on one axial end of the motor.

9. The integrated structure for additional end cogging torque compensation and cooling according to claim 1, characterized in that: The additional end cogging torque compensation and cooling integrated structure is symmetrically installed at both axial ends of the motor to counteract the axial unbalanced magnetic pull when installed on one side.

10. A permanent magnet synchronous motor, characterized in that: The invention includes the additional end cogging torque compensation and cooling integrated structure as described in any one of claims 1 to 9.

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