Motor with one-way buffer structure

Abstract

The invention discloses a motor with a one-way buffer structure, belongs to the field of motors, and solves the problem in the prior art that self-locking force always exists to influence the operation of the motor, the technical scheme for solving the problem comprises a shell and a rotating shaft, the rotating shaft is rotatably mounted on the shell, a first magnet is fixed on the rotating shaft, and a second magnet is fixed on the rotating shaft; a second magnet spaced from the first magnet is fixed to the shell, a coil is wound around the periphery of the second magnet, the coil and a driving circuit of the motor are connected to the same power source, when the coil is not powered on, the first magnet and the second magnet attract each other magnetically so as to apply self-locking force to the rotating shaft in the static state, and when current in the first direction is supplied to the coil, self-locking force is applied to the rotating shaft in the static state. And when the coil is electrified with the current in the second direction, the polarity of the generated magnetic field is opposite to that of the magnetic field of the second magnet so as to reduce the self-locking force to the rotating shaft, and when the coil is electrified with the current in the second direction, the polarity of the generated magnetic field is the same as that of the magnetic field of the second magnet so as to increase the self-locking force to the rotating shaft. According to the invention, adjustable self-locking is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electric machines, and in particular to an electric machine with a one-way buffering structure. BACKGROUND

[0002] An electric machine generally comprises a housing and a rotating shaft rotatably supported by the housing. In application scenarios such as electric lifting tables, medical lifting devices, etc., the electric machine often needs to drive the load to frequently start and stop or rapidly lift. When the rotating shaft is running at high speed, if it suddenly slows down or stops, a significant inertial impact will be generated due to the inertia of the load, which not only affects the positioning accuracy, but also can cause mechanical vibration, noise and even structural damage.

[0003] To suppress such impact and achieve reliable holding after stopping, the prior art usually adds a brake or a self-locking device in the electric machine. For example, the utility model patent CN222884472U discloses a magnetic self-locking structure, which sets a first magnet assembly on the housing and a second magnet assembly spaced from the first magnet assembly on the rotating shaft or rotor, and the two are attracted by opposite magnetic poles to provide a static holding force, thereby achieving self-locking when stopping. However, the magnetic attraction force in this type of scheme always exists, and the self-locking force cannot be dynamically adjusted. This results in the electric machine continuously bearing additional magnetic resistance during normal operation, which not only increases the driving load and reduces energy efficiency, but also can exacerbate heating and wear. SUMMARY

[0004] The purpose of the present application is to provide an electric machine with a one-way buffering structure, which solves the problem of the self-locking force always existing in the prior art and affecting the operation of the electric machine, and realizes adjustable self-locking.

[0005] To achieve the above purpose, the present application adopts the following technical scheme: an electric machine with a one-way buffering structure, comprising a housing and a rotating shaft, the rotating shaft being rotatably mounted on the housing, a first magnet being fixed on the rotating shaft, a second magnet being fixed on the housing and spaced from the first magnet, a coil being arranged around the outer periphery of the second magnet, the coil and the driving circuit of the electric machine being connected to the same power supply, when the coil is not powered, the first magnet and the second magnet are magnetically attracted to exert a self-locking force on the rotating shaft in a static state, when the coil is powered with a first direction current, the magnetic field polarity generated thereby is opposite to that of the second magnet to reduce the self-locking force on the rotating shaft, and when the coil is powered with a second direction current, the magnetic field polarity generated thereby is the same as that of the second magnet to increase the self-locking force on the rotating shaft.

[0006] After adopting the above technical solution, the present invention has the following advantages: When the motor stops running, the coil and the motor drive circuit are simultaneously de-energized. Relying on the permanent magnet attraction between the first magnet and the second magnet, a reliable self-locking force is provided for the rotating shaft in the stationary state, ensuring that the load is stable and does not slip after stopping, thus improving safety. When the motor starts or runs normally, the power supply supplies current in the first direction to the coil, and the coil generates a magnetic field with the opposite polarity to the second magnet, effectively weakening or even canceling the attraction of the second magnet, thereby significantly reducing the magnetic resistance during operation, significantly reducing the drive load of the motor, improving starting performance, and minimizing the additional energy consumption, temperature rise, and mechanical wear caused by continuous magnetic attraction resistance. When facing frequent start-stop, rapid lifting, or load inertial impact, the power supply can quickly switch to supply current in the second direction to the coil. At this time, the magnetic field of the coil and the second magnet are superimposed in the same direction, enhancing the overall magnetic attraction, thereby dynamically improving the self-locking / braking force, effectively absorbing impact energy, suppressing shaft rebound or vibration, realizing active buffering and rapid stopping, and better adapting to start-stop scenarios such as electric lifting tables and medical lifting equipment.

[0007] Furthermore, the first magnet is a ring-shaped magnet with alternating unweakened magnet regions and weakened magnet regions distributed around its circumference. The weakened magnet regions are areas with partial structural defects, non-magnetic filling, or covered by non-magnetic structural components. The housing is provided with at least two second magnets, which are respectively arranged opposite to the unweakened magnet regions.

[0008] Using the aforementioned technical solution, due to the limitations of the installation structure of the shaft and the first magnet, the first magnet forms alternating unweakened and weakened regions circumferentially. This results in the magnetic induction intensity generated in the weakened region on the air gap side being significantly lower than that in the unweakened region. If the second magnet adopts a complete ring structure, its continuous magnetic conduction path will guide the magnetic flux in the unweakened region to bypass the air gap corresponding to the weakened region circumferentially. This not only leads to a reduction in the effective air gap magnetic flux density and the static self-locking force being constrained by the weakest coupling position, but also generates high cogging torque and continuous magnetic resistance during operation due to global magnetic coupling. This results in difficulties in starting, high vibration and noise, and reduced energy efficiency. In this solution, at least two second magnets are set opposite to the unweakened area, effectively cutting off the circumferential bypass path of the magnetic flux and achieving strong-strong alignment and weak-weak alignment. This spatially cuts off the bypass path of the magnetic flux, causing the magnetic flux to concentrate in the high-coupling area to form a high-density local magnetic circuit. In the static state, the magnetic flux is constrained to the strong-strong alignment to form a high-density local magnetic circuit, significantly improving the actual self-locking force. In the dynamic state, the magnetic attraction only exists in the alignment area of ​​the unweakened magnets, and the magnetic resistance in other areas is extremely low, which suppresses cogging torque as much as possible and reduces the average operating load.

[0009] Furthermore, the magnetic field polarity of all the second magnets is in the same direction.

[0010] By adopting the aforementioned technical solution, the magnetic attraction between each second magnet and the first magnet maintains a consistent polarity relationship in the circumferential direction, minimizing local magnetic repulsion or magnetic cancellation caused by staggered magnetic pole arrangement. This ensures a stable opposite-polarity attraction state at the alignment positions in areas where the magnets are not weakened, effectively improving the magnitude and stability of the static self-locking force. Furthermore, when used in conjunction with the coil for electromagnetic control, the second magnets of the same polarity can respond synergistically to the coil current in the same direction. When a reverse current is applied, the magnetic attraction force is simultaneously weakened, and when a forward current is applied, the magnetic attraction force is simultaneously strengthened, thereby achieving uniform and efficient adjustment of the self-locking force.

[0011] Furthermore, the coils on the outer periphery of each of the second magnets are wound in the same direction, and all the coils on the outer periphery of the second magnets are connected in series.

[0012] Using the aforementioned technical solution, the coils on the outer periphery of each of the second magnets are wound in the same direction, and all the coils are connected in series. This ensures that when a control current in a single direction is applied, the magnetic field polarity generated by each coil is consistent, which can synchronously apply magnetization or demagnetization in the same direction to their respective second magnets. This achieves uniform and coordinated control of multiple magnetic attraction pairs in the circumference. At the same time, the series connection only requires one drive current, which greatly simplifies the drive circuit structure and reduces control complexity.

[0013] Furthermore, the coil includes a winding wire wound around the periphery of each second magnet, and a connecting wire connecting adjacent winding wires, the connecting wires being arranged adjacent to the surface of the second magnet and / or the surface of the housing.

[0014] By adopting the aforementioned technical solution, the connecting wires are attached to the outer edge of the second magnet or the inner wall of the housing, avoiding the wires from protruding in the radial or axial center area of ​​the motor as much as possible. This reduces the encroachment on the rotation space of the shaft. In addition, the wiring method close to the fixed surface facilitates reliable fixation of the connecting wires by means of adhesive, slotting, or potting processes, significantly enhancing vibration and fatigue resistance, preventing wear, short circuits, or open circuits caused by wire shaking during operation, and shortening the bridging distance of the connecting wires, reducing the loop area, and helping to reduce parasitic inductance and electromagnetic interference. On the one hand, during the switching process of the drive circuit, it can suppress back EMF spikes, reduce voltage stress on the insulation layer of the winding wire, and prevent inter-turn breakdown as much as possible. On the other hand, reducing electromagnetic radiation helps improve the electromagnetic compatibility of the system and avoids induced noise interference with the control signal as much as possible, thereby ensuring the accuracy of self-locking force regulation.

[0015] Furthermore, the rotating shaft is provided with a fixing bracket for mounting the first magnet, the circumferential surface of the first magnet is provided with at least one groove, and / or the fixing bracket at least partially covers the circumferential surface of the first magnet, and the magnet weakening area of ​​the first magnet corresponds to the position where the groove is provided and / or the position covered by the fixing bracket.

[0016] Using the aforementioned technical solution, the first magnet can be reliably positioned and securely connected on the rotating shaft through the fixing frame. At the same time as the installation is completed, the groove and / or the part blocked by the fixing frame will naturally form a magnet weakening area in the circumferential direction due to the partial lack of magnet material or the magnetic field being diverted / shielded by the magnetic guiding structure. The magnet weakening area is generated naturally as an incidental result of the installation structure, without the need for additional segmented magnets, special magnetization processes or independent magnetic shielding measures.

[0017] Furthermore, the fixing frame has a mounting hole at its center, and the fixing frame is sleeved on the rotating shaft through the mounting hole and is interference-fitted and / or keyed to the rotating shaft.

[0018] Using the aforementioned technical solution, the interference fit can form a uniform radial clamping force between the fixed frame and the rotating shaft, eliminating assembly gaps and preventing the fixed frame from fretting or shifting in the axial and circumferential directions as much as possible, thereby ensuring the stability of the position of the first magnet installed on it; the key connection transmits torque through the cooperation of the key and keyway, avoiding relative slippage of the fixed frame due to insufficient friction when the rotating shaft rotates, especially under conditions of frequent start-stop or sudden load changes, it can still maintain the circumferential phase of the magnet unchanged; when the interference fit and key connection are used simultaneously, the interference fit undertakes the positioning and anti-loosening functions, ensuring high coaxiality and gapless installation, while the key connection is dedicated to torque transmission. The two have clear division of labor and complement each other, which not only improves the reliability and vibration resistance of the connection, but also avoids the failure risk of a single connection method under high dynamic loads as much as possible.

[0019] Furthermore, the housing is provided with raised reinforcing ribs, and a recessed area is formed between adjacent reinforcing ribs, and each of the second magnets is respectively installed in the recessed area.

[0020] Using the aforementioned technical solution, the reinforcing ribs, while improving the overall rigidity and deformation resistance of the shell, will divide the shell space into multiple recessed areas. If only a single second magnet is set, it will be difficult to span the arrangement of multiple reinforcing ribs, which may result in the second magnet being suspended, insufficient support, or the need for additional supports, thus wasting space. However, by using multiple second magnets, the existing structural layout of the shell can be adapted to achieve a compact integration of the second magnet and the shell.

[0021] Furthermore, the motor also includes a stator winding, with the second magnet and coil located on the side of the first magnet away from the stator winding.

[0022] By adopting the aforementioned technical solution, the self-locking coil and the stator winding are kept axially far apart, thus minimizing electromagnetic coupling and electrical interference between them.

[0023] Furthermore, the coil is connected in parallel with the motor's drive circuit and is detachably connected.

[0024] By adopting the aforementioned technical solution, the coil and the motor drive circuit are connected in parallel to the same power supply, which simplifies the power supply structure, realizes the synchronous power supply and disconnection of the coil and the motor, ensures as much as possible that the self-locking is automatically released during operation and the permanent magnet lock is restored when the machine stops, and by setting the coil to be detachable, the user can easily switch the connection polarity with the power supply by reversing the two terminals of the coil, thereby selectively passing current in the first direction or the second direction through the coil under the premise of fixed winding direction, generating magnetic fields that weaken or enhance the self-locking force respectively. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings:

[0026] Figure 1 This is a schematic diagram of the motor with a unidirectional buffer structure in this invention;

[0027] Figure 2 This is a cross-sectional view of the motor with a unidirectional buffer structure in this invention;

[0028] Figure 3 This is a partial structural diagram of the motor with a unidirectional buffer structure in this invention;

[0029] Figure 4 This is a schematic diagram of the structure of the first magnet and the fixing frame in this invention;

[0030] Figure 5 This is a schematic diagram of the structure of the second magnet and the end cap in this invention;

[0031] Figure 6 This is a schematic diagram of the structure of the first magnet in this invention;

[0032] Figure 7 This is a schematic diagram of the coil in the present invention when a current in the first direction is applied;

[0033] Figure 8 This is a schematic diagram of the coil in the present invention when a current in the second direction is applied;

[0034] In the figure, 1 is the shell; 10 is the sleeve; 11 is the end cap; 12 is the reinforcing rib; 13 is the recessed area; 2 is the rotating shaft; 3 is the stator; 4 is the first magnet; 41 is the groove; 5 is the second magnet; 6 is the coil; 61 is the winding wire; 62 is the connecting wire; 7 is the fixing frame; 71 is the support part; 72 is the clamping part. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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.

[0036] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein.

[0037] It should be understood that in the various embodiments of the present invention, the number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0038] It should be understood that in this invention, "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0039] It should be understood that in this invention, "multiple" refers to two or more. "And / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, X and / or Y can represent: X alone, X and Y simultaneously, or Y alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "Contains X, Y, and Z", "Contains X, Y, and Z" means that all three X, Y, and Z are contained; "Contains X, Y, or Z" means that one of X, Y, and Z is contained; "Contains X, Y, and / or Z" means that any one, two, or three of X, Y, and Z are contained.

[0040] The technical solution of the present invention will be described in detail below with reference to specific embodiments. The following specific embodiments may be combined or substituted with each other according to the actual situation, and the same or similar concepts or processes may not be described again in some embodiments.

[0041] like Figures 1 to 8As shown, the present invention provides a motor with a unidirectional buffer structure, including a housing 1 and a rotating shaft 2. The rotating shaft 2 is rotatably mounted on the housing 1. A first magnet 4 is fixed on the rotating shaft 2, and a second magnet 5 spaced apart from the first magnet 4 is fixed on the housing 1. A coil 6 is wound around the outer periphery of the second magnet 5. The coil 6 and the motor's drive circuit are both connected to the same power source. When the coil 6 is not energized, the first magnet 4 and the second magnet 5 are magnetically attracted to apply a self-locking force to the rotating shaft 2 in a stationary state. When a first-direction current is applied to the coil 6, the polarity of the magnetic field it generates is opposite to the polarity of the magnetic field of the second magnet 5, thereby reducing the self-locking force on the rotating shaft 2. When a second-direction current is applied to the coil 6, the polarity of the magnetic field it generates is the same as the polarity of the magnetic field of the second magnet 5, thereby increasing the self-locking force on the rotating shaft 2.

[0042] When the motor stops, the coil 6 and the motor's drive circuit are simultaneously de-energized. Relying on the permanent magnet attraction between the first magnet 4 and the second magnet 5, a reliable self-locking force is provided for the stationary shaft 2, ensuring the load remains stable and does not slip after shutdown, thus improving safety. When the motor starts or runs normally, the power supply provides current in the first direction to the coil 6. The coil 6 generates a magnetic field with the opposite polarity to the second magnet 5, effectively weakening or even canceling the attraction of the second magnet 5. This significantly reduces magnetic resistance during operation, substantially reducing the motor's drive load, improving starting performance, and minimizing additional energy consumption, temperature rise, and mechanical wear caused by continuous magnetic resistance. In situations involving frequent starts and stops, rapid lifting, or load inertial impacts, the power supply can quickly switch to providing current in the second direction to the coil 6. At this time, the magnetic field of the coil 6 and the second magnet 5 are superimposed in the same direction, enhancing the overall magnetic attraction and dynamically increasing the self-locking / braking force. This effectively absorbs impact energy, suppresses the rebound or vibration of the shaft 2, and achieves active buffering and rapid shutdown, better adapting to start-stop scenarios such as electric lifting tables and medical lifting equipment.

[0043] It should be noted that the coil 6 is connected in parallel with the motor drive circuit, which simplifies the power supply structure and enables the coil 6 and the motor to be powered on and off synchronously. This ensures that the self-locking is automatically released during operation and the permanent magnet lock is restored when the machine stops. In addition, the coil 6 and the motor drive circuit are detachably connected, allowing the user to easily switch the polarity of its connection with the power supply by reversing the two terminals of the coil 6. Thus, under the premise of fixed winding direction, the coil 6 can be selectively supplied with current in the first direction or the second direction, which will generate magnetic fields that weaken or strengthen the self-locking force, respectively.

[0044] It should be noted that in this embodiment, the first magnet 4 and the second magnet 5 are arranged along the axial direction of the rotating shaft 2. The housing 1 includes a sleeve 10 located in the circumferential direction of the rotating shaft 2 and an end cap 11 located at the end of the rotating shaft 2. The second magnet 5 is fixed on the end cap 11.

[0045] It should be noted that the motor also includes a stator 3 and a rotor. The stator 3 is equipped with stator windings, and the rotor is fixed on the rotating shaft 2 and cooperates with the stator windings to generate driving torque. The first magnet 4 is a ring-shaped magnet, fixed circumferentially on the rotating shaft 2. Its physical shape is complete and continuous, which facilitates reliable installation and positioning. Due to the structural limitations of the rotating shaft 2, such as slotting and bracket obstruction, the circumferential magnetic field of the first magnet 4 often has a weakened magnetic field region. Specifically, in this invention, the first magnet 4 has alternating unweakened and weakened regions distributed around its circumference. This results in the magnetic induction intensity generated in the weakened region on the air gap side being significantly lower than that in the unweakened region. The weakened region is a region with localized structural defects, non-magnetic filling, or coverage by non-magnetic structural components. The housing 1 has at least two second magnets 5, which are respectively arranged opposite to the unweakened regions. This effectively cuts off the circumferential bypass path of the magnetic flux, achieving strong-strong alignment and weak-weak alignment, thereby spatially cutting off the bypass path of the magnetic flux. This concentrates the magnetic flux in the high-coupling region to form a high-density local magnetic circuit. In a static state, the magnetic flux is constrained at the strong-strong alignment to form a high-density local magnetic circuit, significantly improving the actual self-locking force. In a dynamic state, the magnetic attraction only exists at the alignment of the unweakened regions, while the magnetic resistance in other regions is extremely low, minimizing cogging torque and reducing the average operating load.

[0046] Specifically, the rotating shaft 2 is provided with a fixing frame 7 for mounting the first magnet 4. The circumferential surface of the first magnet 4 is provided with at least one groove 41 and the fixing frame 7 at least partially covers the circumferential surface of the first magnet 4. The magnet weakening area of ​​the first magnet 4 corresponds to the position where the groove 41 is provided and the position covered by the fixing frame 7. The magnet weakening area is naturally generated as an incidental result of the mounting structure, without the need for additional segmented magnets, special magnetization processes or independent magnetic shielding measures. Other parts of the first magnet 4 form the magnet unweakened area.

[0047] The mounting bracket 7 is fitted onto the rotating shaft 2 through its central mounting hole, and the bracket and shaft 2 are interference-fitted. The interference fit generates a uniform radial clamping force between the mating surfaces, eliminating assembly gaps and minimizing axial and circumferential movement, slippage, or rotational displacement of the mounting bracket 7. This ensures that the first magnet 4 mounted on it maintains stable position and phase during motor operation. To further enhance the reliability of the connection structure under high torque or dynamic loads, a keyed connection is added to the interference fit. The key directly transmits rotational torque through its engagement with the keyway on the rotating shaft 2, minimizing the risk of slippage that can occur when relying solely on friction to transmit torque. This ensures the magnet's circumferential alignment accuracy, especially under frequent start-stop or sudden load changes. When combined, the interference fit provides precise positioning and anti-loosening functions, while the keyed connection is dedicated to torque transmission, forming a dual guarantee mechanism of positioning and torque transmission separation. This significantly improves the overall connection's stability, vibration resistance, and long-term service reliability.

[0048] It should be noted that in other embodiments, the groove 41 may not be provided in the circumferential direction of the first magnet 4. In this case, only the part blocked by the fixing frame 7 is the magnet weakening area. The fixing frame 7 includes a support part 71 that supports the first magnet 4 and a clamping part 72 that clamps the first magnet 4 in the circumferential direction. The blocked part refers to the part of the first magnet 4 that is blocked by the clamping part 72 in the circumferential direction.

[0049] To ensure the self-locking stability of the rotating shaft 2, the magnetic field polarity of all the second magnets 5 is the same, so that the magnetic attraction between each second magnet 5 and the first magnet 4 maintains a consistent polarity relationship in the circumferential direction. This avoids local magnetic repulsion or magnetic force cancellation caused by the staggered arrangement of magnetic poles as much as possible, and ensures that a stable opposite attraction state is formed at the alignment position in the unweakened area of ​​the magnets. This effectively improves the magnitude and stability of the static self-locking force. At the same time, when used in conjunction with the coil 6 for electromagnetic control, the second magnets 5 with the same polarity can generate a coordinated response to the current of the coil 6 in the same direction. When a reverse current is applied, the magnetic attraction force is weakened simultaneously, and when a forward current is applied, the magnetic attraction force is strengthened simultaneously, thereby achieving uniform and efficient adjustment of the self-locking force.

[0050] Correspondingly, the coils 6 on the outer periphery of each second magnet 5 are wound in the same direction, and all the coils 6 on the outer periphery of the second magnet 5 are connected in series. This ensures that when a control current in a single direction is applied, the magnetic field generated by each coil 6 has the same polarity, which can synchronously apply the same direction of magnetization or demagnetization to their respective second magnets 5. This achieves uniform and coordinated control of multiple magnetic attraction pairs in the circumference. At the same time, the series connection only requires one drive current, which greatly simplifies the drive circuit structure and reduces the control complexity.

[0051] To achieve a more compact structure, the coil 6 includes winding wires 61 wound around the outer periphery of each second magnet 5, and connecting wires 62 connecting adjacent winding wires 61. The connecting wires 62 are arranged near the surfaces of the second magnets 5 and the housing 1, minimizing the possibility of the wires protruding in the radial and axial central regions of the motor, thereby reducing the encroachment on the rotation space of the shaft 2. Furthermore, the close proximity of the wiring to the fixed surface facilitates reliable fixation of the connecting wires 62 through adhesive bonding, slotting, or potting processes, significantly enhancing vibration and fatigue resistance, minimizing wear, short circuits, or open circuits caused by wire movement during operation, and shortening the bridging distance of the connecting wires 62, reducing the loop area, and helping to reduce parasitic inductance and electromagnetic interference. On the one hand, during the switching process of the drive circuit, it can suppress back EMF spikes, reduce voltage stress on the insulation layer of the winding wires 61, and minimize inter-turn breakdown. On the other hand, reducing electromagnetic radiation helps improve the electromagnetic compatibility of the system and minimizes the interference of induced noise with the control signal, thereby ensuring the accuracy of self-locking force regulation.

[0052] It should be noted that in this invention, since the second magnet 5 is disposed on the end cover 11, the connecting wire 62 is disposed adjacent to the end cover 11 and does not pass through the stator winding area or rotor space inside the motor.

[0053] It should be noted that the connecting wire 62 can also be arranged only adjacent to the surface of the second magnet 5 or the surface of the housing 1, which facilitates the fixing and routing of the wire.

[0054] To improve the structural strength of the motor, the housing 1 is provided with raised reinforcing ribs 12. While improving the overall rigidity and deformation resistance of the housing 1, a recessed area 13 is formed between adjacent reinforcing ribs 12. If only a single second magnet 5 is provided, it is difficult to arrange it across multiple reinforcing ribs 12, which may cause the second magnet 5 to be suspended, insufficiently supported, or require additional supports, thus wasting space. Therefore, in this invention, each second magnet 5 is installed in the recessed area 13, which can conform to the existing structural layout of the housing 1 and realize the integrated and compact integration of the second magnet 5 and the housing 1.

[0055] It should be noted that the second magnet 5 can be provided in appropriate quantities such as two, three, or four. In this embodiment, the end cap 11 is provided with reinforcing ribs 12 in a cross shape. The reinforcing ribs 12 divide the inner surface of the end cap 11 into four symmetrically distributed recessed areas 13. There are four second magnets 5, which are individually set in the four recessed areas 13. Each second magnet 5 is evenly distributed along the circumference of the rotating shaft 2 and is arranged opposite to the first magnet 4 on the rotating shaft 2 in the axial direction.

[0056] Since the stator winding generates an alternating magnetic field when energized, in order to reduce the electromagnetic coupling between coil 6 and the stator winding, the second magnet 5 and coil 6 are located on the side of the first magnet 4 away from the stator winding, so that the self-locking coil 6 and the stator winding are kept axially far apart, thereby effectively reducing the mutual interference of their magnetic fields and minimizing the impact on the normal operation of the motor and the stability of the self-locking function.

[0057] It should be noted that both the first magnet 4 and the second magnet 5 are neodymium iron boron. To facilitate the distinction between the magnetic poles of the first magnet 4 and the second magnet 5, the N pole and S pole are used for differentiation in the figure. The top of the first magnet 4 is the N pole and the bottom of the first magnet 4 is the S pole. The top of the second magnet 5 is the N pole and the bottom of the second magnet 5 is the S pole. When the coil 6 is not energized, the first magnet 4 and the second magnet 5 are magnetically attracted to each other to apply a self-locking force to the rotating shaft 2 in a stationary state.

[0058] like Figure 7As shown, when the current enters from the first direction, that is, flows in from the direction of the arrow, according to Ampere's law, the upper part of coil 6 is macroscopically represented as the S pole, and the lower part of coil 6 is macroscopically represented as the N pole. The magnetic field of coil 6 is opposite to the magnetic field of the second magnet 5, which effectively weakens or even cancels the attraction of the second magnet 5, thereby greatly reducing the magnetic resistance during operation and thus minimizing the impact on the normal rotation of the motor.

[0059] like Figure 8 As shown, when the current enters from the second direction, that is, from the direction of the arrow, according to Ampere's law, the upper part of coil 6 is macroscopically represented as the N pole, and the lower part of coil 6 is macroscopically represented as the S pole. The magnetic field of coil 6 is the same as the magnetic field of the second magnet 5. The magnetic field of coil 6 and the second magnet 5 are superimposed in the same direction, which enhances the overall magnetic attraction force, thereby dynamically improving the self-locking / braking force, reducing the motor speed, and achieving the buffering effect.

[0060] When the motor stops running, coil 6 and the motor are de-energized simultaneously, and the first magnet 4 and the second magnet 5 attract each other, achieving a static self-locking effect.

[0061] When the direction of the motor changes, the positive and negative terminals of coil 6 and the motor drive circuit need to be reversed to ensure that the current enters from the first direction to cancel the magnetic field and minimize interference with the motor operation, and the current enters from the second direction to achieve a buffering effect.

[0062] Understandably, in other embodiments, the coil and the motor drive circuit are connected in parallel to the same power supply and connected to the power supply through a double-pole double-throw switch. The switch has two stable states, corresponding to two connection polarities of the coil: when the switch is in the first position, the coil is supplied with current in the first direction, generating a magnetic field opposite to the polarity of the second magnet, thereby reducing the self-locking force on the shaft and enabling the motor to start and run smoothly; when the switch is in the second position, the coil is supplied with current in the second direction, generating a magnetic field with the same polarity as the second magnet, thereby increasing the self-locking force, which is suitable for working conditions that require enhanced braking or pre-locking.

[0063] Understandably, in other embodiments, the second magnet may also be arranged around the first magnet, that is, the first magnet and the second magnet are arranged radially along the axis of rotation, thereby effectively reducing the axial length occupied by the motor and making the overall structure more compact, especially suitable for application scenarios that are sensitive to axial dimensions.

[0064] In addition to the preferred embodiments described above, the present invention has other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection claimed by the present invention.

Claims

1. An electric motor having a one-way buffering structure, comprising a housing and a rotating shaft, the rotating shaft being rotatably installed in the housing, characterized in that, The first magnet is fixed on the rotating shaft, the second magnet is fixed on the shell and spaced from the first magnet, a coil is arranged around the second magnet, the coil and the driving circuit of the motor are connected to the same power supply, when the coil is not powered, the first magnet and the second magnet are magnetically attracted to exert a self-locking force on the rotating shaft in a static state, when the coil is powered with a first direction current, the magnetic field generated by the coil is opposite to the magnetic field of the second magnet to reduce the self-locking force on the rotating shaft, when the coil is powered with a second direction current, the magnetic field generated by the coil is the same as the magnetic field of the second magnet to increase the self-locking force on the rotating shaft.

2. The electric machine with unidirectional buffering structure according to claim 1, characterized in that, The first magnet is a ring-shaped magnet, and a magnet non-weakened area and a magnet weakened area are alternately arranged around the first magnet, the magnet weakened area is a region with structural defects, non-magnetic filling or covered by a non-magnetic structural member, and at least two second magnets are arranged on the shell, and each second magnet is arranged opposite to the magnet non-weakened area.

3. The electric machine with unidirectional buffering structure according to claim 2, characterized in that, The magnetic field polarities of all the second magnets are the same.

4. The electric machine with unidirectional buffering structure according to claim 2, characterized in that, The coil around each second magnet has the same winding direction, and all the coils around the second magnets are connected in series.

5. The electric machine with unidirectional buffering structure according to claim 4, characterized in that, The coil includes a winding wire arranged around each second magnet, and a connecting wire connecting adjacent winding parts, and the connecting wire is arranged adjacent to the surface of the second magnet and / or the surface of the shell.

6. The electric machine with unidirectional buffering structure according to claim 3, characterized in that, The rotating shaft is provided with a fixing frame for mounting the first magnet, the circumferential surface of the first magnet is provided with at least one groove, and / or the fixing frame at least partially covers the circumferential surface of the first magnet, and the magnet weakened area of the first magnet corresponds to the position provided with the groove and / or the position covered by the fixing frame.

7. The electric machine with unidirectional buffering structure according to claim 6, characterized in that, The center of the fixing frame is provided with a mounting hole, the fixing frame is sleeved on the rotating shaft through the mounting hole, and the fixing frame is interference fit and / or key connected with the rotating shaft.

8. The electric machine with unidirectional buffering structure according to claim 2, characterized in that, The shell is provided with a protruding reinforcing rib, and a recessed area is formed between adjacent reinforcing ribs, and each second magnet is mounted in the recessed area.

9. The electric machine with unidirectional buffering structure according to claim 1, characterized in that, The motor further comprises a stator winding, and the second magnet and the coil are located on the side of the first magnet away from the stator winding.

10. The electric machine with unidirectional buffering structure according to claim 1, characterized in that, The coil and the driving circuit of the motor are connected in parallel and detachably connected.

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