Brushless motor with reverse drive holding torque

Abstract

The brushless motor comprises a stator structure, a rotor structure and a gear set, the rotor structure comprises a main drive rotor, a bidirectional spring and a driven gear, the stator structure provides a rotating magnetic field, the main drive rotor rotates under the action of the rotating magnetic field to convert electric energy into mechanical energy, and the gear set is driven by the bidirectional spring to rotate. The two-way spring is arranged between the main driving rotor and the driven gear as a torque transmission medium, the driven gear is installed on the main driving rotor through the two-way spring to be driven by the main driving rotor, and the gear set is meshed with the driven gear to adjust the output performance of the motor. According to the brushless motor with the reverse driving holding torque, the bidirectional spring of the rotor structure enables the actuator to provide high reverse driving holding torque when the actuator is reversely driven, and normal operation of the motor is not affected. The motor is high in space utilization rate, simple in structure and low in cost, and is applied to small-space occasions such as micromotors.

Description

Technical Field

[0001] The utility model relates to an actuator motor, and more particularly to a brushless motor with back-drive holding torque. Background Art

[0002] An actuator motor is a motor that converts electrical energy into mechanical energy and is used to drive an actuator to perform a specific action. Some actuator motors provide a back-drive holding torque through a worm gear or clutch design. Other actuator motors can use software electronic control to provide a back-drive holding torque when powered on. However, the above-mentioned known technical solutions cannot solve the following application scenarios with smaller spaces: such as charging door mechanisms, lifting mechanisms, etc., when the motor is not powered, there is a certain holding force but it is not completely self-locking. It is also impossible to achieve a certain holding force to maintain the posture of the mechanism when there is no power; and to protect the mechanism from damage when the back-drive force is too large, such as when the mechanism is manually pried open. Utility Model Content

[0003] In order to solve the problem in the prior art that the motor cannot provide a back-drive holding force when no power is supplied, the utility model provides a brushless motor with a back-drive holding torque.

[0004] According to the brushless motor with back-drive holding torque of the present invention, it includes a stator structure, a rotor structure and a gear set, wherein the rotor structure includes a main drive rotor, a bidirectional spring and a driven gear, the stator structure provides a rotating magnetic field, and the main drive rotor rotates under the action of the rotating magnetic field to convert electrical energy into mechanical energy. The bidirectional spring is arranged between the main drive rotor and the driven gear as a torque transmission medium, and the driven gear is installed on the main drive rotor through the bidirectional spring to be driven by the main drive rotor.

[0005] In a preferred embodiment, the main drive rotor supports the driven gear in the axial direction, and the main drive rotor does not directly contact the driven gear in the rotational direction.

[0006] In a preferred embodiment, the bidirectional spring has two spring arms that are spread apart and define a spring angle, and the two spring arms do not contact the main drive rotor and the driven gear at the same time.

[0007] In a preferred embodiment, the sides of the two spring arms facing the main drive rotor are in contact with the main drive rotor during active driving.

[0008] In a preferred embodiment, the main drive rotor has a main drive boss, which has two main drive side end surfaces respectively formed as the action surfaces of two spring arms to provide two main drive contact points. The central angle defined by the two main drive side end surfaces is smaller than the spring angle, thereby increasing the rotation drive spring angle of the main drive rotor.

[0009] In a preferred embodiment, the sides of the two spring arms facing the driven gear are in contact with the driven gear during passive driving.

[0010] In a preferred embodiment, the driven gear has a driven boss, which has two driven side end faces respectively formed as the action surfaces of two spring arms to provide two driven contact points. The central angle defined by the two driven side end faces is less than the difference between 360° and the spring angle, thereby reducing the rotation drive spring angle of the driven gear.

[0011] In a preferred embodiment, the main driving boss and the driven boss are fan-shaped bosses located on opposite sides of the two spring arms, and the axis of the installation shaft for installing the bidirectional spring is located at the center of the two fan-shaped bosses at the same time.

[0012] In a preferred embodiment, the brushless motor also includes a housing, a gear set and a control device. The gear set is engaged with the driven gear to adjust the output performance of the motor. The rotor structure and the gear set are rotatably mounted in the housing. The stator structure and the control device are fixedly mounted in the housing. The control device is connected to the stator structure to control the operating state of the motor.

[0013] In a preferred embodiment, the gear set comprises at least a linked primary gear and an output gear, wherein the primary gear meshes with the driven gear, and the output gear defines the motor output shaft and is connected to an external driven mechanism.

[0014] According to the brushless motor with reverse drive holding torque of the utility model, the bidirectional spring of the rotor structure enables the actuator to provide a high reverse drive holding torque when reverse driven, without affecting the normal operation of the motor. Even in the power-off state, when reverse driven, such as when the mechanism is manually actuated, a certain reverse drive holding torque can be provided to maintain the mechanism's posture and protect the mechanism from damage. In addition, the structure has a high space utilization rate and is applicable to small space applications such as micromotors. It has a simple structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the assembly of a brushless motor with back-drive holding torque according to a preferred embodiment of the present utility model.

[0016] Figure 2 yes Figure 1 Exploded diagram of the rotor structure.

[0017] Figure 3 yes Figure 2 Schematic diagram of the structure of the main drive rotor and bidirectional spring.

[0018] Figure 4 yes Figure 2 Schematic diagram of the structure of the driven gear and bidirectional spring.

[0019] Figure 5 yes Figure 1 The rotor structure and the transmission structure of the gear set.

[0020] Figure 6 yes Figure 1 Schematic diagram of the connection between the brushless motor and the external driven mechanism.

[0021] Figure 7 It is an exploded view of the rotor structure of a brushless motor according to another preferred embodiment of the present utility model.

[0022] Figure 8 It is an exploded view of the rotor structure of a brushless motor according to another preferred embodiment of the present utility model. DETAILED DESCRIPTION

[0023] The preferred embodiments of the present invention are given below in conjunction with the accompanying drawings and described in detail.

[0024] like Figure 1 As shown, according to a preferred embodiment of the present invention, a brushless motor with back-drive holding torque includes a housing 1, a stator structure 2, a rotor structure 3, a gear set 4 and a control device 5, wherein the stator structure 2 is fixedly mounted in the housing 1 to generate a rotating magnetic field, the rotor structure 3 is rotatably mounted in the housing 1 and rotates under the action of the rotating magnetic field provided by the stator structure 2 to convert electrical energy into mechanical energy, the gear set 4 is engaged with the rotor structure 3 in the housing 1 to adjust the output performance of the motor, and the control device 5 is connected to the stator structure 2 in the housing 1 to control the operating state of the motor.

[0025] like Figure 2 As shown, the rotor structure 3 includes a main drive rotor 31, a bidirectional spring 32 and a driven gear 33, wherein the main drive rotor 31 is in the stator structure 2 (see Figure 1 ) provides a rotating magnetic field, the driven gear 33 rotates with the gear set 4 (see Figure 1 ) is meshed and mounted on the main drive rotor 31 via a bidirectional spring 32 so as to be driven by the main drive rotor 31. Specifically, the main drive rotor 31 supports the driven gear 33 in the axial direction. The main drive rotor 31 does not directly contact the driven gear 33 in the rotational direction. The bidirectional spring 32 is provided between the main drive rotor 31 and the driven gear 33 as a torque transmission medium. Only one side of the spring arm of the bidirectional spring 32 contacts the main drive rotor 31 (when actively driven) or the driven gear 33 (when passively driven) and does not contact both at the same time. In other words, the two spring arms of the bidirectional spring 32 have opposite sides. The side facing the main drive rotor contacts the main drive rotor 31 when actively driven, and the side facing the driven gear 33 contacts the driven gear 33 when passively driven. The holding force can be adjusted to suit different applications by adjusting the wire diameter, pitch, number of turns, major diameter, torsion spring arm length, starting angle, and working angle of the bidirectional spring 32.

[0026] like Figure 3As shown, the main drive rotor 31 has a fan-shaped main drive boss 311. The axis of the mounting shaft for mounting the bidirectional spring 32 is located at the center of the fan. The bidirectional spring 32 has two open spring arms 321, which define a spring angle α. The main drive boss 311 has two main drive side end surfaces that form the active surfaces of the two spring arms 321, respectively, to provide two main drive contact points 34. The central angle defined by the two main drive side end surfaces of the main drive boss 311 is smaller than the spring angle α, thereby increasing the rotation drive spring angle α of the main drive rotor 31.

[0027] like Figure 4 As shown, the driven gear 33 has a sector-shaped driven boss 331. The axis of the mounting shaft for mounting the bidirectional spring 32 is also located at the center of the sector. The driven boss 331 has two driven-side end surfaces that form the active surfaces of two spring arms 321, respectively, to provide two driven contact points 35. The central angle defined by the two driven-side end surfaces of the driven boss 331 is less than the difference between 360° and the spring angle α, thereby reducing the spring angle α as the driven gear 33 rotates.

[0028] like Figure 5 As shown, the gear set 4 includes a first-stage gear 41, a second-stage gear 42, a third-stage gear 43 and an output gear 44, which are rotatably mounted in the housing 1. The first-stage gear 41 is connected to the driven gear 33 of the rotor structure 3 (see FIG. Figure 2 ) meshes with the second-stage gear 42 and the first-stage gear 41, the third-stage gear 43 meshes with the second-stage gear 42, and the output gear 44 meshes with the third-stage gear 43 and ultimately defines the motor output shaft. The motor output shaft is connected to the external driven mechanism 6 to drive the external driven mechanism 6 through the stator structure 2, such as Figure 6 It should be understood that the specific structure of the gear set 4 here can be adjusted according to the torque increase requirement or speed reduction requirement of the external driven mechanism 6.

[0029] The following briefly describes the principle of unlocking the forward drive holding torque of the brushless motor according to the present invention.

[0030] When the motor is powered on and operates normally, the motor is driven in the forward direction by the rotor structure 3. Due to the setting of the contact point position of the bidirectional spring 32 and the main drive rotor 31 (see Figure 3 ), regardless of whether the main drive rotor 31 rotates forward or reverse, the torque increases the angle α between the arms of the bidirectional spring 32, enlarging the inner diameter of the bidirectional spring 32. Because the bidirectional spring 32 is directly threaded onto the mounting shaft, the increased inner diameter reduces friction to zero, completing the unlocking process. The torque is then transmitted via the bidirectional spring 32 to the driven gear 33, passing through the primary gear 41, the secondary gear 42, the tertiary gear 43, the output gear 44, and finally the external driven mechanism 6. The entire mechanism is now operating normally.

[0031] The following briefly introduces the principle of back-drive holding torque triggering of the brushless motor according to the present invention.

[0032] When the motor is not powered and the external driven mechanism 6 is under force, the torque is transmitted to the driven gear 33 of the rotor structure 3 via the external driven mechanism 6 → output gear 44 → third gear 43 → second gear 42 → first gear 41. Due to the setting of the contact point between the two-way spring 32 and the driven gear 33 (see Figure 4 ), when torque is transmitted from the driven gear 33, regardless of forward or reverse rotation, the torque consistently reduces the included angle α of the bidirectional spring 32, tightening the inner diameter of the bidirectional spring 32. Because the bidirectional spring 32 is directly threaded onto the mounting shaft, the contraction in the inner diameter increases the shaft-holding force and friction torque, placing the entire mechanism in a locked state and maintaining a high reverse drive torque. If the external drive torque acting on the external driven mechanism 6 continues to increase, the torque will exceed the torque limit provided by the bidirectional spring 32, forcing the rotor structure 3 to rotate without damaging the mechanism.

[0033] Thus, according to the brushless motor of the present invention, when the motor is operating normally, the active-side transmission mechanism operates, reducing the structural shaft-holding force. The frictional torque generated between the active-side transmission mechanism and the shaft is less than the torque output by the motor, allowing the motor to output torque normally. When the passive-side mechanism is manually pushed, the shaft-holding force increases due to the characteristics of the rotor structure, and the frictional force generated between the active-side transmission mechanism and the shaft is greater than the thrust transmitted by the passive side, thereby increasing the backdrive holding torque.

[0034] In summary, according to the brushless motor of the present invention, the rotor structure 3 includes only three parts (i.e., the main drive rotor 31, the bidirectional spring 32, and the driven gear 33). The bidirectional spring 32 is used to provide the back-drive holding torque. By rationally designing the parameters and contact points of the bidirectional spring 32, the back-drive holding force is improved. The structure is simple and space-saving. Moreover, according to the brushless motor of the present invention, the rotor structure 3 is at the head of the transmission chain and is used in conjunction with the actuator externally to improve the back-drive holding torque. It is not completely self-locking. The back-drive holding torque is adjusted by adjusting the bidirectional spring design to meet external requirements.

[0035] It should be understood that the specific structure of the bidirectional spring 32 of the rotor structure 3 in the above embodiment is only an example and not a limitation, and replacing it with a C-shaped spring 32a can also meet the requirements, such as Figure 7 In this alternative embodiment, the C-shaped spring 32a is a plastic spring or a metal spring. In addition, the bidirectional spring 32 can also be replaced by a double spring C-shaped ring 32b, as shown in FIG. Figure 8 shown.

[0036] The above merely describes preferred embodiments of the present application, and is not intended to limit the scope of the present application, and the above embodiments of the present application can be variously changed. That is, simple, equivalent changes and modifications made according to the content of the claims and the specification of the present application fall within the scope of the claims of the present application. The present application is not described in detail, and is conventional technical content.

Claims

1. A brushless motor with back-drive holding torque, comprising a stator structure, a rotor structure and a gear set, characterized in that: The rotor structure includes a main drive rotor, a bidirectional spring and a driven gear. The stator structure provides a rotating magnetic field. The main drive rotor rotates under the action of the rotating magnetic field to convert electrical energy into mechanical energy. The bidirectional spring is provided between the main drive rotor and the driven gear as a torque transmission medium. The driven gear is installed on the main drive rotor through the bidirectional spring to be driven by the main drive rotor.

2. The brushless motor according to claim 1, wherein: The main drive rotor supports the driven gear in the axial direction, and the main drive rotor does not directly contact the driven gear in the rotation direction.

3. The brushless motor according to claim 1, wherein: The bidirectional spring has two open spring arms that limit a spring angle, and the two spring arms do not contact the main drive rotor and the driven gear at the same time.

4. The brushless motor according to claim 3, characterized in that The sides of the two spring arms facing the main drive rotor are in contact with the main drive rotor during active driving.

5. The brushless motor according to claim 4, characterized in that: The main drive rotor has a main drive boss, which has two main drive side end surfaces formed as the action surfaces of two spring arms to provide two main drive contact points. The central angle defined by the two main drive side end surfaces is smaller than the spring angle, thereby increasing the rotation drive spring angle of the main drive rotor.

6. The brushless motor according to claim 5, characterized in that The sides of the two spring arms facing the driven gear are in contact with the driven gear during passive driving.

7. The brushless motor according to claim 6, characterized in that The driven gear has a driven boss, which has two driven side end faces respectively formed as the action surfaces of two spring arms to provide two driven contact points. The central angle defined by the two driven side end faces is less than the difference between 360° and the spring angle, thereby reducing the rotation driving spring angle of the driven gear.

8. The brushless motor according to claim 7, characterized in that: The main driving boss and the driven boss are fan-shaped bosses located on opposite sides of the two spring arms, and the axis of the installation shaft for installing the bidirectional spring is located at the center of the two fan-shaped bosses at the same time.

9. The brushless motor according to claim 1, wherein: The brushless motor also includes a housing, a gear set and a control device. The gear set engages with the driven gear to adjust the output performance of the motor. The rotor structure and the gear set are rotatably mounted in the housing. The stator structure and the control device are fixedly mounted in the housing. The control device is connected to the stator structure to control the operating state of the motor.

10. The brushless motor according to claim 9, characterized in that The gear set comprises at least a linked primary gear and an output gear, wherein the primary gear is meshed with the driven gear, and the output gear defines the motor output shaft and is connected to an external driven mechanism.

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