Commutation torque ripple compensation device of brushless direct current motor

Abstract

The invention provides a brushless direct current motor commutation torque ripple compensation device, and relates to the technical field of brushless direct current motors, the brushless direct current motor commutation torque ripple compensation device comprises a shell, and further comprises a dynamic flux linkage compensation assembly, the dynamic flux linkage compensation assembly comprises a rotor arranged in the shell, and a bearing is arranged on the rotor. The torque sensor monitors torque changes in the motor commutation process in real time and transmits torque pulsation signals to the compensation current control module, the compensation current control module analyzes the signals and then generates adaptive compensation current instructions, current clutters are filtered out through the filter, stable compensation current is output to restrain basic torque pulsation, and the compensation current control module controls the compensation current control module to control the motor commutation. The rotary knob is rotated to drive the screw to rotate, the second connecting block in threaded connection pushes the rack to slide along the limiting grooves of the first supporting frame and the second supporting frame, the rack drives the permanent magnets to move, the positions of the permanent magnets are adjusted through the rotary shaft and the universal joint, dynamic flux linkage compensation is achieved, and commutation torque pulsation is further weakened.

Description

Technical Field

[0001] This invention relates to the field of brushless DC motor technology, and in particular to a brushless DC motor commutation torque pulsation compensation device. Background Technology

[0002] During operation, brushless DC motors (BLDC) often experience commutation torque pulsation due to sudden changes in current at the commutation point, which affects the motor's stability and performance. To solve this problem, a commutation torque pulsation compensation device can effectively reduce torque pulsation, improve the motor's efficiency and noise level, and enhance the stability of the drive system.

[0003] However, in practical use, the following shortcomings still exist. For example, existing brushless DC motors cannot achieve dynamic flux compensation, further weakening commutation torque pulsation. Periodic torque fluctuations lead to unstable motor speed, which can reduce motion control accuracy and cause machining deviations or inaccurate positioning in precision machine tools, robot joints, and other scenarios. Secondly, pulsation is converted into mechanical impact force, which aggravates motor vibration and noise, accelerates the wear of bearings, shafts, and other components, and may also be transmitted to the load equipment, shortening its lifespan. At the same time, in order to make up for the power gap caused by pulsation, the motor energy consumption increases and efficiency decreases. For example, in electric vehicle driving scenarios, this will shorten the driving range. In addition, it cannot meet the requirements of aerospace, semiconductor manufacturing, and other fields with extremely high requirements for torque stability, thus limiting its application scope.

[0004] Therefore, this invention proposes a brushless DC motor commutation torque pulsation compensation device to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and to propose a commutation torque pulsation compensation device for brushless DC motors.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a brushless DC motor commutation torque ripple compensation device, comprising a housing, and further comprising: A dynamic magnetic flux compensation component includes a rotor disposed within a housing, a bearing mounted on the rotor, a first support frame disposed within the housing, a second support frame connected within the first support frame, a rotating shaft rotatably connected to the first support frame, a universal joint mounted on the rotating shaft, a gear connected to the rotating shaft, a rack meshing with the gear, limit grooves formed on both the first and second support frames, the rack slidably connected within the limit grooves, a permanent magnet connected to one end of the rack, a screw rotatably connected to the housing, a second connecting block threaded onto the screw, the second connecting block being connected to the rack, and a knob connected to the top of the screw. A torque sensor, a compensation current control module, and a filter are installed on the housing. The signal output terminal of the torque sensor is electrically connected to the signal input terminal of the compensation current control module, and the current output terminal of the compensation current control module is electrically connected to the input terminal of the filter.

[0007] Furthermore, a first connecting block is connected to the first support frame, and a bolt is threaded onto the first connecting block, the bolt being threaded into the housing.

[0008] The beneficial effect of adopting the above-mentioned further solution is that by tightening the bolts, the huge fastening force generated by the threads is used to firmly press the first connecting block onto the inner wall of the housing, thereby achieving rigid fixation of the first support frame. This ensures that the support frame will not displace or vibrate when subjected to the reaction force from the internal magnetic flux compensation component, providing a stable and reliable installation foundation for the entire compensation device.

[0009] Furthermore, a heat dissipation assembly is provided at the bottom of the housing, the heat dissipation assembly including a support plate connected to the bottom of the housing, the top of the support plate being completely fitted to the bottom of the housing.

[0010] The beneficial effect of adopting the above-mentioned further solution is that by fully fitting the top of the support plate with the bottom of the housing, the contact area between the two is maximized, so that the heat generated by the motor and compensation device during operation can be efficiently transferred from the heat source to the starting point of the entire heat dissipation system through heat conduction, laying a solid foundation for the subsequent heat dissipation process and being the primary link of efficient thermal management.

[0011] Furthermore, heat dissipation fins are provided on the top of the support plate.

[0012] The beneficial effects of adopting the above-mentioned further solution are: the heat dissipation fins are fixed to the top of the support plate, which increases the effective surface area in contact with the surrounding air. After the heat is conducted from the support plate to the heat dissipation fins, the flowing air carries away the heat on the heat dissipation fins. The heat is continuously dissipated through air convection, thereby effectively reducing the overall temperature of the device and ensuring that the electronic components and permanent magnets operate within a safe temperature range.

[0013] Furthermore, a drainage pipe is provided inside the support plate, and an interface is provided on one side wall of the support plate corresponding to the inlet and outlet ends of the drainage pipe.

[0014] The beneficial effects of adopting the above-mentioned further solution are: the drainage pipe is embedded inside the support plate to form a closed liquid circulation channel. During operation, the coolant flows in from the inlet interface and absorbs the heat conducted by the support plate during the flow through the drainage pipe. The heated coolant then flows out from the outlet interface and carries away the heat through external circulation, forming an active and efficient heat dissipation method.

[0015] Furthermore, a vibration damping component is provided at the bottom of the support plate, the vibration damping component including a base plate disposed at the bottom of the support plate.

[0016] The beneficial effects of adopting the above-mentioned further solution are: the base plate serves as the installation platform and load-bearing foundation for the entire vibration damping assembly. Through its robust structure, it distributes the weight of the device, directly contacts the external mounting surface, and is responsible for bearing the force and vibration transmitted from all the vibration damping elements above, thus ensuring the stability and effectiveness of the vibration damping operation.

[0017] Furthermore, a first connecting plate is fixedly connected to each of the four sides of the base plate, and a vertically arranged buffer damper is fixedly connected to the top of each first connecting plate.

[0018] The beneficial effects of adopting the above-mentioned further scheme are as follows: the four first connecting plates fix the bottom ends of the four buffer dampers to the base plate. When the support plate is subjected to vibration impact, it will drive the second connecting plate to move up and down, thereby compressing or stretching the buffer damper. The viscous fluid or friction element inside the buffer damper will generate resistance in the opposite direction of movement, quickly converting the vibration impact energy into heat energy and dissipating it, thereby effectively suppressing and attenuating the vibration.

[0019] Furthermore, the other end of the buffer damper is connected to a second connecting plate, which is connected to the support plate.

[0020] The beneficial effects of adopting the above-mentioned further solution are: the second connecting plate is fixedly connected to the bottom of the support plate, and the vibration energy of the support plate and all components above it will be directly transmitted to the buffer damper and extension spring connected to it through the second connecting plate, thereby starting the entire vibration reduction process and ensuring that the vibration energy is efficiently guided to the vibration reduction element.

[0021] Furthermore, a telescopic spring is provided on the buffer damper, one end of the telescopic spring is connected to the first connecting plate, the other end of the telescopic spring is connected to the second connecting plate, and the natural length of the telescopic spring is consistent with the initial length of the buffer damper.

[0022] The beneficial effects of adopting the above-mentioned further scheme are: when the telescopic spring and the buffer damper are installed in parallel, the telescopic spring uses its own elastic deformation to absorb and store the impact energy when subjected to vibration and impact, playing a buffering and supporting role. After the impact, the telescopic spring releases energy to help reset. It works in conjunction with the buffer damper to achieve smooth vibration reduction.

[0023] Furthermore, a rubber pad is connected to the base plate, the top of the rubber pad is in close contact with the bottom surface of the support plate, and the height of the rubber pad is consistent with the initial height of the buffer damping.

[0024] The beneficial effects of adopting the above-mentioned further solutions are: the rubber pad, with its own elasticity and damping characteristics, provides auxiliary soft support for the main support structure when static, and absorbs high-frequency low-amplitude vibrations through small deformation when there is slight vibration. Its main function is to provide flexible limiting and buffering, prevent metal parts from rigidly colliding and generating noise, and absorb high-frequency resonance.

[0025] Compared with the prior art, the advantages and positive effects of the present invention are as follows: In this invention, during device operation, the torque sensor monitors the torque changes during the motor commutation process in real time and transmits the torque pulsation signal to the compensation current control module. After analyzing the signal, the compensation current control module generates an appropriate compensation current command. The current noise is filtered out by a filter, and a stable compensation current is output to suppress the basic torque pulsation. If further optimization of the magnetic flux is needed to reduce pulsation, the knob can be rotated to drive the screw to rotate, causing the threaded second connecting block to push the rack to slide along the limiting groove of the first support frame and the second support frame. The rack drives the permanent magnet to move, and at the same time, the rotating shaft can assist in adjusting the position of multiple permanent magnets through the cooperation of the universal joint to optimize the air gap magnetic field distribution, realize dynamic magnetic flux compensation, and further reduce commutation torque pulsation. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a brushless DC motor commutation torque ripple compensation device according to the present invention; Figure 2 This is a schematic diagram of the brushless DC motor structure for a brushless DC motor commutation torque ripple compensation device according to the present invention. Figure 3 This is a schematic diagram of the dynamic flux compensation component structure of a brushless DC motor commutation torque pulsation compensation device according to the present invention. Figure 4 This is a structurally disassembled schematic diagram of the dynamic flux compensation component of a brushless DC motor commutation torque ripple compensation device according to the present invention. Figure 5 This is a schematic diagram of the heat dissipation component structure of a brushless DC motor commutation torque ripple compensation device according to the present invention. Figure 6 This is a schematic diagram of the vibration reduction component structure of a brushless DC motor commutation torque pulsation compensation device according to the present invention.

[0027] Figure label: 1. Shell; 2. Dynamic flux compensation assembly; 21. Rotor; 22. Bearing; 23. First support frame; 24. First connecting block; 25. Bolt; 26. Second support frame; 27. Shaft; 28. Universal joint; 29. ​​Gear; 210. Rack; 211. Limiting groove; 212. Permanent magnet; 213. Screw; 214. Second connecting block; 215. Knob; 216. Torque sensor; 217. Compensation current control module; 218. Filter; 3. Heat dissipation components; 31. Support plate; 32. Heat dissipation fins; 33. Cooling pipes; 34. Interface; 4. Vibration damping components; 41. Base plate; 42. First connecting plate; 43. Buffer damping; 44. Second connecting plate; 45. Telescopic spring; 46. Rubber pad. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] like Figures 1-4 As shown, this embodiment provides a technical solution: a brushless DC motor commutation torque ripple compensation device, including a housing 1, and further comprising: The dynamic magnetic flux compensation component 2 includes a rotor 21 disposed within a housing 1, a bearing 22 disposed on the rotor 21, a first support frame 23 disposed within the housing 1, a second support frame 26 connected within the first support frame 23, a rotating shaft 27 rotatably connected to the first support frame 23, a universal joint 28 disposed on the rotating shaft 27, a gear 29 connected to the rotating shaft 27, a rack 210 meshing with the gear 29, a limit groove 211 provided on both the first support frame 23 and the second support frame 26, the rack 210 slidably connected within the limit groove 211, a permanent magnet 212 connected to one end of the rack 210, a screw 213 rotatably connected to the housing 1, a second connecting block 214 threadedly connected to the screw 213, the second connecting block 214 connected to the rack 210, and a knob 215 connected to the top of the screw 213. A torque sensor 216, a compensation current control module 217, and a filter 218 are all mounted on the housing 1. The signal output terminal of the torque sensor 216 is electrically connected to the signal input terminal of the compensation current control module 217, and the current output terminal of the compensation current control module 217 is electrically connected to the input terminal of the filter 218. During operation, the torque sensor 216 monitors the torque changes during the motor commutation process in real time and transmits the torque pulsation signal to the compensation current control module 217. After analyzing the signal, the compensation current control module 217 generates an appropriate compensation current. The current command is filtered by filter 218 to remove current noise and output a stable compensation current to suppress basic torque pulsation. If further optimization of the flux linkage is needed to reduce pulsation, the knob 215 can be rotated to drive the screw 213 to rotate, so that the threaded second connecting block 214 pushes the rack 210 to slide along the limiting groove 211 of the first support frame 23 and the second support frame 26. The rack 210 drives the permanent magnet 212 to move. At the same time, the rotating shaft 27 can assist in adjusting the position of multiple permanent magnets 212 through the cooperation of the universal joint 28 to optimize the air gap magnetic field distribution, realize dynamic flux linkage compensation, and further reduce commutation torque pulsation.

[0030] The above solutions still have the problem of not being able to reduce the heat and vibration generated by the brushless DC motor during use, such as... Figures 3-4 As shown: A first connecting block 24 is connected to the first support frame 23, and a bolt 25 is threaded onto the first connecting block 24. The bolt 25 is threaded into the housing 1. By tightening the bolt 25, the huge fastening force generated by the thread is used to firmly press the first connecting block 24 onto the inner wall of the housing 1, thereby achieving rigid fixation of the first support frame 23. This ensures that the support frame will not displace or vibrate when subjected to the reaction force from the internal magnetic flux compensation component, providing a stable and reliable installation foundation for the entire compensation device. like Figure 1 as well as Figure 5As shown, a heat dissipation assembly 3 is provided at the bottom of the housing 1. The heat dissipation assembly 3 includes a support plate 31 connected to the bottom of the housing 1. The top of the support plate 31 is completely attached to the bottom of the housing 1. By completely attaching the top of the support plate 31 to the bottom of the housing 1, the contact area between the two is maximized, allowing the heat generated by the motor and compensation device during operation to be efficiently transferred from the heat source to the starting point of the entire heat dissipation system through heat conduction. This lays a solid foundation for the subsequent heat dissipation process and is the primary step in efficient thermal management. A heat dissipation fin 32 is provided on the top of the support plate 31. The heat dissipation fin 32 is fixed to the top of the support plate 31, and its function is to increase the effective surface area in contact with the surrounding air. Heat is conducted from the support plate 31 to the surrounding air. Behind the heat dissipation fins 32, the flowing air carries away the heat from the heat dissipation fins 32, and the heat is continuously dissipated through air convection, thereby effectively reducing the overall temperature of the device and ensuring that the electronic components and permanent magnets 212 operate within a safe temperature range. A drain pipe 33 is provided inside the support plate 31. An interface 34 is provided on one side wall of the support plate 31 corresponding to the inlet and outlet of the drain pipe 33. The drain pipe 33 is embedded inside the support plate 31 to form a closed liquid circulation channel. During operation, the coolant flows in from the inlet interface 34. In the process of flowing through the drain pipe 33, it absorbs the heat conducted from the support plate 31. The heated coolant then flows out from the outlet interface 34 and carries away the heat through external circulation, forming an active and efficient heat dissipation method. like Figure 1 as well as Figure 6As shown, a vibration damping assembly 4 is provided at the bottom of the support plate 31. The vibration damping assembly 4 includes a base plate 41 at the bottom of the support plate 31. The base plate 41 serves as the mounting platform and load-bearing foundation for the entire vibration damping assembly 4. Through its robust structure, it distributes the weight of the device, directly contacts the external mounting surface, and is responsible for bearing the force and vibration transmitted from all the vibration damping elements above, ensuring the stability and effectiveness of the vibration damping operation. First connecting plates 42 are fixedly connected to the four sides of the base plate 41, and each first connecting plate 42 has a vertically arranged buffer damper 43 fixedly connected to its top. The four first connecting plates 42 connect the four buffer dampers 43. The bottom end of the support plate 31 is fixed to the base plate 41. When the support plate 31 is subjected to vibration and impact, it will drive the second connecting plate 44 to move up and down, thereby compressing or stretching the buffer damper 43. The viscous fluid or friction element inside the buffer damper 43 will generate resistance in the opposite direction of movement, quickly converting the vibration and impact energy into heat energy and dissipating it, thereby effectively suppressing and attenuating the vibration. The other end of the buffer damper 43 is connected to the second connecting plate 44, which is connected to the support plate 31 and fixedly connected to the bottom of the support plate 31. The vibration energy of the support plate 31 and all components above it will be transmitted through the second connecting plate 44. Plate 44 directly transmits the energy to the connected damper 43 and telescopic spring 45, thereby initiating the entire vibration reduction process and ensuring that the vibration energy is efficiently guided to the vibration reduction element. The damper 43 is equipped with a telescopic spring 45, one end of which is connected to the first connecting plate 42, and the other end to the second connecting plate 44. The natural length of the telescopic spring 45 is the same as the initial length of the damper 43. The telescopic spring 45 and the damper 43 are installed in parallel. When subjected to vibration impact, the telescopic spring 45 uses its own elastic deformation to absorb and store the impact energy, thus providing buffering and support. The spring 45 provides support; after an impact, the spring releases energy to help the body return to its original position. It works in conjunction with the damping buffer 43 to achieve smooth vibration reduction. A rubber pad 46 is connected to the base plate 41. The top of the rubber pad 46 is in close contact with the bottom surface of the support plate 31, and the height of the rubber pad 46 is consistent with the initial height of the damping buffer 43. With its own elasticity and damping characteristics, the rubber pad 46 provides auxiliary soft support to the main support structure when static. When there is slight vibration, it absorbs high-frequency low-amplitude vibration through small deformation. Its main function is to provide flexible limit and buffer, prevent metal parts from rigidly colliding and generating noise, and absorb high-frequency resonance.

[0031] Working principle: like Figures 1-6As shown, in terms of dynamic flux compensation, during device operation, the torque sensor 216 on the housing 1 monitors the torque changes during the motor commutation process in real time and transmits the torque pulsation signal to the compensation current control module 217. After analyzing the signal, the compensation current control module 217 generates an appropriate compensation current command. The current noise is filtered out by the filter 218, and a stable compensation current is output, which initially suppresses the basic torque pulsation. If further optimization is needed, rotating the knob 215 drives the screw 213 to rotate, causing the threaded second connecting block 214 to push the rack 21. 0. Sliding along the limiting grooves 211 of the first support frame 23 and the second support frame 26, the rack 210 drives the permanent magnet 212 to move. At the same time, the rotating shaft 27, through the universal joint 28, assists in adjusting the position of multiple permanent magnets 212, optimizing the air gap magnetic field distribution, realizing dynamic flux compensation, and further reducing commutation torque pulsation. Moreover, the first support frame 23 is rigidly fixed in the housing 1 through the first connecting block 24 and bolts 25, ensuring no displacement vibration during operation and providing a stable foundation for compensation. In the heat dissipation assembly 3, the top of the support plate 31 at the bottom of the housing 1 and the... The housing 1 fits perfectly, efficiently conducting the heat generated by the motor and compensation device. Part of the heat is dissipated through the heat dissipation fins 32 on the top of the support plate 31 via air convection, while the other part is absorbed by the coolant in the drainage pipe 33 inside the support plate 31. The coolant flows in from the inlet port 34 and flows out from the outlet port 34, carrying away heat through external circulation. This dual heat dissipation ensures that the electronic components and permanent magnet 212 operate at a safe temperature. In the vibration damping assembly 4, the base plate 41 serves as the load-bearing foundation, and the first connecting plates 42 on its four sides fix the bottom of the buffer damping 43. At the end, the top of the buffer damper 43 is connected to the support plate 31 through the second connecting plate 44, and the two ends of the telescopic spring 45 sleeved on the buffer damper 43 are respectively connected to the first connecting plate 42 and the second connecting plate 44. The initial length is the same as that of the buffer damper 43. When the support plate 31 is subjected to vibration impact, the buffer damper 43 dissipates the vibration energy through internal resistance, and the telescopic spring 45 buffers and assists in the reset with elastic deformation. At the same time, the rubber pad 46 on the bottom plate 41 is in contact with the support plate 31 to absorb high-frequency low-amplitude vibration, prevent rigid collision noise, and achieve vibration reduction effect.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A commutation torque ripple compensation device for a brushless DC motor, comprising a housing (1), characterized in that, Also includes: A dynamic magnetic flux compensation component (2) includes a rotor (21) disposed within a housing (1), a bearing (22) disposed on the rotor (21), a first support frame (23) disposed within the housing (1), a second support frame (26) connected within the first support frame (23), a rotating shaft (27) rotatably connected to the first support frame (23), a universal joint (28) disposed on the rotating shaft (27), a gear (29) connected to the rotating shaft (27), and teeth meshing on the gear (29). The rack (210), the first support frame (23) and the second support frame (26) are provided with limit grooves (211), the rack (210) is slidably connected in the limit groove (211), one end of the rack (210) is connected to a permanent magnet (212), the housing (1) is rotatably connected to a screw (213), the screw (213) is threadedly connected to a second connecting block (214), the second connecting block (214) is connected to the rack (210), and the top of the screw (213) is connected to a knob (215). A torque sensor (216) is provided on the housing (1), a compensation current control module (217) is provided on the housing (1), and a filter (218) is provided on the housing (1). The signal output terminal of the torque sensor (216) is electrically connected to the signal input terminal of the compensation current control module (217), and the current output terminal of the compensation current control module (217) is electrically connected to the input terminal of the filter (218).

2. The brushless DC motor commutation torque ripple compensation device according to claim 1, characterized in that: The first support frame (23) is connected to a first connecting block (24), and the first connecting block (24) is threaded with a bolt (25), which is threaded inside the housing (1).

3. The brushless DC motor commutation torque ripple compensation device according to claim 1, characterized in that: The bottom of the housing (1) is provided with a heat dissipation assembly (3), which includes a support plate (31) connected to the bottom of the housing (1), and the top of the support plate (31) is completely attached to the bottom of the housing (1).

4. The brushless DC motor commutation torque ripple compensation device according to claim 3, characterized in that: The top of the support plate (31) is provided with heat dissipation fins (32).

5. The brushless DC motor commutation torque ripple compensation device according to claim 3, characterized in that: The support plate (31) is provided with a drainage pipe (33), and the side wall of the support plate (31) is provided with an interface (34) corresponding to the water inlet and water outlet of the drainage pipe (33).

6. The brushless DC motor commutation torque ripple compensation device according to claim 3, characterized in that: The bottom of the support plate (31) is provided with a vibration damping component (4), which includes a base plate (41) provided at the bottom of the support plate (31).

7. The brushless DC motor commutation torque ripple compensation device according to claim 6, characterized in that: The base plate (41) is fixedly connected to the four sides of the base plate (42), and each of the first connecting plates (42) is fixedly connected to the top of the vertically arranged buffer damper (43).

8. The brushless DC motor commutation torque ripple compensation device according to claim 7, characterized in that: The other end of the buffer damper (43) is connected to a second connecting plate (44), which is connected to the support plate (31).

9. A brushless DC motor commutation torque ripple compensation device according to claim 8, characterized in that: A telescopic spring (45) is provided on the buffer damper (43). One end of the telescopic spring (45) is connected to the first connecting plate (42), and the other end of the telescopic spring (45) is connected to the second connecting plate (44). The natural length of the telescopic spring (45) is consistent with the initial length of the buffer damper (43).

10. A brushless DC motor commutation torque ripple compensation device according to claim 6, characterized in that: A rubber pad (46) is connected to the base plate (41). The top of the rubber pad (46) is in close contact with the bottom surface of the support plate (31), and the height of the rubber pad (46) is consistent with the initial height of the buffer damping (43).

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