Brushless coreless motor

Abstract

The present invention relates to the technical field of motors. Provided is a brushless coreless motor, comprising a housing, a stator assembly arranged in the housing, and a rotor assembly supported on the housing, wherein the housing comprising a first cover plate, a second cover plate, and a housing body sandwiched between the cover plates; and the rotor assembly is supported on the first and second cover plates and forms rotatable connection. The brushless coreless motor further comprises a first bearing and a second bearing, the first bearing being a ball bearing, and the second bearing being an oil-impregnated bearing. The side of the first cover plate close to the housing body is recessed to form a first slot, and the side of the second cover plate close to the housing body is recessed to form a second slot; the outer peripheral side of the first bearing is fixed in the first slot, and the outer peripheral side of the second bearing is fixed in the second slot. Both ends of the rotor assembly are respectively inserted and fixed into the inner peripheral sides of the first and second bearings. Compared with the prior art, the present invention ensures that the axial and radial float of the motor rotor is maintained in a reasonable range, and improves the stability of motor rotation.

Description

Brushless Hollow Cup Motor Technical Field

[0001] This invention relates to the field of motor technology, and more particularly to a brushless hollow cup motor. Background Technology

[0002] Brushless coreless motors, due to their compact structure, high power density, high efficiency, and significant energy-saving benefits, have been widely used in electric motors and generators. In recent years, the industrial sector has seen an increasingly urgent demand for equipment that directly drives loads using brushless coreless motors. The widespread application of these brushless coreless motor direct-drive devices will generate immeasurable energy-saving benefits. Technical issues

[0003] In related technologies, most existing brushless coreless motors include a housing, a rotor, and a stator wound at intervals around the rotor. The housing consists of a cover plate and a housing body. The connection between the rotor and the housing in a brushless coreless motor typically uses bearings to provide axial and radial positioning of the rotor. However, existing brushless coreless motors use ball bearings at both the front and rear ends of the rotor for axial and radial positioning. The axial and radial runout is limited by the axial and radial runout of the inner and outer rings of the ball bearings. Insufficient axial and radial runout of the inner and outer rings of the ball bearings affects the rolling efficiency of the steel balls, leading to instability in motor rotation. Furthermore, the use of ball bearings places higher demands on the manufacturing processes of the inner and outer rings and the steel balls.

[0004] Therefore, it is necessary to provide a new brushless coreless motor to solve the above-mentioned technical problems. Technical solutions

[0005] The purpose of this invention is to provide a brushless hollow cup motor with better axial and radial movement control and rotational stability.

[0006] To achieve the above objectives, the present invention provides a brushless coreless motor, which includes a housing, a stator assembly fixed within the housing, and a rotor assembly supported by the housing and forming a rotatable connection.

[0007] The outer shell includes a first cover plate, a second cover plate, and a hollow outer shell body sandwiched between the first cover plate and the second cover plate;

[0008] The stator assembly is fixed to the inner circumference of the housing body and is spaced around the outer circumference of the rotor assembly;

[0009] The rotor assembly is supported at both ends by the first cover plate and the second cover plate, respectively, and is rotatably connected to the first cover plate and the second cover plate, respectively.

[0010] The brushless hollow cup motor further includes a first bearing and a second bearing. The first bearing is a ball bearing, and the second bearing is an oil-impregnated bearing. The first cover plate is recessed on the side near the outer shell to form a first groove, and the second cover plate is recessed on the side near the outer shell to form a second groove coaxially arranged with the first groove. The outer peripheral side of the first bearing is fixed in the first groove, and the outer peripheral side of the second bearing is fixed in the second groove. The two ends of the rotor assembly are respectively inserted and fixed to the inner peripheral side of the first bearing and the inner peripheral side of the second bearing.

[0011] Preferably, the first cover plate includes a first cover plate body and a first fixing ring extending from the side of the first cover plate body near the outer shell body, and a second fixing ring extending from the side of the first fixing ring near the outer shell body. The first fixing ring abuts against the outer shell body, the second fixing ring is inserted into the opening end of the outer shell, the first groove is formed on the inner circumferential side of the second fixing ring, and the outer circumferential side of the first bearing is welded and fixed in the first groove.

[0012] Preferably, the second cover plate includes a second cover plate body and a third fixing ring formed by protruding from the side of the second cover plate body near the outer shell body, the second groove is formed on the inner circumferential side of the third fixing ring, and the outer circumferential side of the second bearing is riveted and fixed in the second groove.

[0013] Preferably, the stator assembly includes a stator coil that is coaxially arranged with the housing body and fixed to the inner circumference of the housing body.

[0014] Preferably, the rotor assembly includes a rotating shaft that is rotatably connected to the first cover plate and the second cover plate respectively, an iron core sleeved and fixed to the rotating shaft, and a permanent magnet sleeved and fixed to the iron core; the permanent magnet is spaced apart from the stator assembly.

[0015] Preferably, the brushless hollow cup motor further includes a circuit board, which is fixed to the side of the second cover plate away from the first cover plate. The stator assembly is electrically connected to the circuit board, and the circuit board is provided with output terminals.

[0016] Preferably, the brushless hollow cup motor further includes a hollow housing, which is fitted and fixed to the outer periphery of the outer shell, and the housing is made of magnetically conductive material.

[0017] Preferably, one side of the housing has a through hole, through which the wire for connecting the output terminal extends to the outside of the housing.

[0018] Preferably, the brushless hollow cup motor further includes a sensor assembly for detecting the rotation data of the rotor assembly. The sensor assembly includes a sensor magnet sleeved and fixed to one end of the rotor assembly away from the second bearing and a Hall sensor fixed to one side of the circuit board near the second cover plate. The Hall sensor and the sensor magnet are arranged at a distance from each other. Beneficial effects

[0019] Compared with the prior art, the brushless coreless motor of the present invention includes a housing, a stator assembly fixed within the housing, and a rotor assembly supported by the housing and rotatably connected thereto. The housing includes a first cover plate, a second cover plate, and a hollow housing body sandwiched between the first cover plate and the second cover plate. The stator assembly is fixed to the inner circumference of the housing body and spaced around the outer circumference of the rotor assembly. The two ends of the rotor assembly are respectively supported by the first cover plate and the second cover plate and rotatably connected to the first cover plate and the second cover plate. The brushless coreless motor also includes a first bearing and a second bearing. The first bearing is a ball bearing, and the second bearing is an oil-impregnated bearing. The first cover plate is recessed on the side near the housing body to form a first groove, and the second cover plate is recessed on the side near the housing body to form a second groove coaxially arranged with the first groove. The outer circumference of the first bearing is fixed in the first groove, and the outer circumference of the second bearing is fixed in the second groove. The two ends of the rotor assembly are respectively inserted and fixed to the inner circumference of the first bearing and the inner circumference of the second bearing. In the above structure, the axial movement of the motor is controlled by the ball bearing at the front end of the rotor, and the radial movement of the motor is controlled by the oil-impregnated bearing at the rear end of the rotor. The combination of the two types of bearings ensures that the axial and radial movement of the motor rotor is kept within a reasonable range, reducing abnormal noise caused by unstable motor rotation and improving the stability of motor rotation. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0021] Figure 1 is a three-dimensional structural schematic diagram of the brushless hollow cup motor provided in an embodiment of the present invention;

[0022] Figure 2 is an exploded three-dimensional view of the brushless hollow cup motor provided in an embodiment of the present invention;

[0023] Figure 3 is an exploded three-dimensional view of the brushless hollow cup motor provided in an embodiment of the present invention.

[0024] Figure 4 is a cross-sectional view along line AA in Figure 1;

[0025] Figure 5 is a schematic diagram of the assembly structure of the first bearing and the second bearing provided in an embodiment of the present invention. Embodiments of the present invention

[0026] 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 a part of the embodiments of the present invention, and not all of them. 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.

[0027] Please refer to Figures 1 to 5. Figure 1 is a three-dimensional structural schematic diagram of the brushless hollow cup motor provided in an embodiment of the present invention. Figure 2 is an exploded three-dimensional structural diagram of the brushless hollow cup motor provided in an embodiment of the present invention. Figure 3 is an exploded three-dimensional structural diagram of the brushless hollow cup motor provided in an embodiment of the present invention from another perspective. Figure 4 is a cross-sectional view along line AA of Figure 1. The present invention provides a brushless hollow cup motor 100, which includes a housing 1, a stator assembly 2 fixed in the housing 1, and a rotor assembly 3 supported in the housing 1 and forming a rotatable connection.

[0028] The outer shell 1 includes a first cover plate 11, a second cover plate 12, and a hollow outer shell body 13 sandwiched between the first cover plate 11 and the second cover plate 12;

[0029] The stator assembly 2 is fixed to the inner circumference of the outer casing 13 and is spaced around the outer circumference of the rotor assembly 3;

[0030] The rotor assembly 3 is supported at both ends by the first cover plate 11 and the second cover plate 12 respectively, and is rotatably connected to the first cover plate 11 and the second cover plate 12 respectively.

[0031] Specifically, referring to Figures 2 and 3, the brushless hollow cup motor 100 further includes a first bearing 4 and a second bearing 5. The first bearing 4 is a ball bearing, and the second bearing 5 is an oil-impregnated bearing. The first cover plate 11 is recessed on the side near the outer shell body 13 to form a first groove 111, and the second cover plate 12 is recessed on the side near the outer shell body 13 to form a second groove 121 coaxially arranged with the first groove 111. The outer peripheral side of the first bearing 4 is fixed in the first groove 111, and the outer peripheral side of the second bearing 5 is fixed in the second groove 121. The two ends of the rotor assembly 3 are respectively inserted and fixed to the inner peripheral side of the first bearing 4 and the inner peripheral side of the second bearing 5.

[0032] In the above structure, the side where the first bearing 4 is located is the front end of the brushless hollow cup motor 100, and the side where the second bearing 5 is located is the rear end of the brushless hollow cup motor 100. The front ball bearing controls the axial movement of the motor, and the rear oil-impregnated bearing controls the radial movement of the motor. The combination of the two types of bearings ensures that the axial and radial movement of the motor rotor is kept within a reasonable range, which improves the stability of the motor rotation and reduces the abnormal noise caused by the unstable rotation of the motor.

[0033] Preferably, referring to the assembly structure diagram shown in Figure 5, in this embodiment of the invention, the first cover plate 11 includes a first cover plate body 112 and a first fixing ring 113 protruding from the side of the first cover plate body 112 near the outer shell body 13, and a second fixing ring 114 protruding from the side of the first fixing ring 113 near the outer shell body. The first fixing ring 113 abuts against the outer shell body 13, and the second fixing ring 114 is inserted into the opening end of the outer shell 1. The first groove 111 is formed on the inner circumferential side of the second fixing ring 114, and the outer circumferential side of the first bearing 4 is welded and fixed in the first groove 111.

[0034] The second cover plate 12 includes a second cover plate body 122 and a third fixing ring 123 protruding from the side of the second cover plate body 122 near the outer shell body. The second groove 121 is formed on the inner circumferential side of the third fixing ring 123, and the outer circumferential side of the second bearing 5 is riveted and fixed in the second groove 121. For the ball bearing type, welding fixation can ensure the stability of the connection and fixation between the outer ring of the bearing and the first cover plate 11, and does not affect the rotation of the inner ring of the bearing, so as to ensure the axial stability of the ball bearing in the motor. For the oil-impregnated bearing type, riveting fixation can ensure that the gap between the bearing and the groove of the second cover plate 12 is controlled, so as to ensure the radial stability of the oil-impregnated bearing in the motor.

[0035] Referring to Figures 2 and 3, the stator assembly 2 includes a stator coil 21 coaxially disposed with and fixed to the inner circumference of the housing body 13. In this embodiment of the invention, the stator coil 21 and the rotor assembly 3 generate a magnetic field with each other, thereby driving the rotor assembly 3 to rotate.

[0036] The rotor assembly 3 includes a rotating shaft 31 rotatably connected to the first cover plate 11 and the second cover plate 12, an iron core 32 fixed to the rotating shaft 31, and a permanent magnet 33 fixed to the iron core 32. The permanent magnet 33 is spaced apart from the stator assembly 2. The stator assembly 2 and the stator coil 21 generate a magnetic field with each other, driving the rotating shaft 31 to rotate between the first cover plate 11 and the second cover plate 12, thereby achieving the motor rotation effect.

[0037] The brushless hollow cup motor 100 also includes a circuit board 6, which is fixed to the side of the second cover plate 12 away from the first cover plate 11. The stator assembly 2 is electrically connected to the circuit board 6, and the circuit board 6 is provided with a wire output terminal 61.

[0038] The brushless hollow cup motor 100 also includes a hollow housing 7, which is fitted and fixed to the outer periphery of the outer shell. The housing 7 is made of magnetic material, and the design of the magnetic material of the housing is conducive to improving the magnetic strength of the stator assembly 2, thereby improving the motor performance.

[0039] The housing 7 has a through hole 71 on one side, through which the wire for connecting the output terminal 61 extends to the outside of the housing 7.

[0040] In this embodiment of the invention, the position of the through hole 71 makes the motor output position clear, which facilitates assembly and reduces the complexity of motor assembly.

[0041] The brushless hollow cup motor 100 also includes a sensor assembly 8, which is used to detect the rotation data of the rotor assembly 3. The sensor assembly 8 includes a sensor magnet 81 sleeved and fixed to one end of the rotor assembly 3 away from the second bearing 5 and a Hall sensor 82 fixed to one side of the circuit board 6 near the second cover plate 12. The Hall sensor 82 and the sensor magnet 81 are arranged at a distance from each other.

[0042] In this embodiment of the invention, the rotation data of the rotating shaft 31 is collected by the sensor magnet 81, and the data is collected by the Hall sensor 82 sensing the sensor magnet 81. The Hall sensor 82 processes the rotation data. After the circuit board 6 collects the sensor data, it transmits the processed data to an external device for display, which facilitates motor control.

[0043] Compared with the prior art, the brushless coreless motor of the present invention includes a housing, a stator assembly fixed within the housing, and a rotor assembly supported by the housing and rotatably connected thereto. The housing includes a first cover plate, a second cover plate, and a hollow housing body sandwiched between the first cover plate and the second cover plate. The stator assembly is fixed to the inner circumference of the housing body and spaced around the outer circumference of the rotor assembly. The two ends of the rotor assembly are respectively supported by the first cover plate and the second cover plate and rotatably connected to the first cover plate and the second cover plate. The brushless coreless motor also includes a first bearing and a second bearing. The first bearing is a ball bearing, and the second bearing is an oil-impregnated bearing. The first cover plate is recessed on the side near the housing body to form a first groove, and the second cover plate is recessed on the side near the housing body to form a second groove coaxially arranged with the first groove. The outer circumference of the first bearing is fixed in the first groove, and the outer circumference of the second bearing is fixed in the second groove. The two ends of the rotor assembly are respectively inserted and fixed to the inner circumference of the first bearing and the inner circumference of the second bearing. In the above structure, the axial movement of the motor is controlled by the ball bearing at the front end of the rotor, and the radial movement of the motor is controlled by the oil-impregnated bearing at the rear end of the rotor. The combination of the two types of bearings ensures that the axial and radial movement of the motor rotor is kept within a reasonable range, reducing abnormal noise caused by unstable motor rotation and improving the stability of motor rotation.

[0044] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A brushless coreless motor, comprising a housing, a stator assembly fixed within the housing, and a rotor assembly supported on the housing and rotatably connected thereto; The outer shell includes a first cover plate, a second cover plate, and a hollow outer shell body sandwiched between the first cover plate and the second cover plate; The stator assembly is fixed to the inner circumference of the housing body and is spaced apart around the outer circumference of the rotor assembly. The rotor assembly is supported at both ends by the first cover plate and the second cover plate, respectively, and forms a rotatable connection with the first cover plate and the second cover plate, respectively; characterized in that, The brushless hollow cup motor further includes a first bearing and a second bearing. The first bearing is a ball bearing, and the second bearing is an oil-impregnated bearing. The first cover plate is recessed on the side near the outer shell to form a first groove, and the second cover plate is recessed on the side near the outer shell to form a second groove coaxially arranged with the first groove. The outer peripheral side of the first bearing is fixed in the first groove, and the outer peripheral side of the second bearing is fixed in the second groove. The two ends of the rotor assembly are respectively inserted and fixed to the inner peripheral side of the first bearing and the inner peripheral side of the second bearing.

2. The brushless hollow cup motor according to claim 1, characterized in that, The first cover plate includes a first cover plate body, a first fixing ring extending from the side of the first cover plate body near the outer shell body, and a second fixing ring extending from the side of the first fixing ring near the outer shell body. The first fixing ring abuts against the outer shell body, the second fixing ring is inserted into the opening end of the outer shell, the first groove is formed on the inner circumferential side of the second fixing ring, and the outer circumferential side of the first bearing is welded and fixed in the first groove.

3. The brushless hollow cup motor according to claim 1, characterized in that, The second cover plate includes a second cover plate body and a third fixing ring formed by protruding from the side of the second cover plate body near the outer shell body. The second groove is formed on the inner circumferential side of the third fixing ring, and the outer circumferential side of the second bearing is riveted and fixed in the second groove.

4. The brushless hollow cup motor according to claim 1, characterized in that, The stator assembly includes a stator coil that is coaxially arranged with the housing body and fixed to the inner circumference of the housing body.

5. The brushless hollow cup motor according to claim 1, characterized in that, The rotor assembly includes a rotating shaft that is rotatably connected to the first cover plate and the second cover plate, an iron core that is sleeved and fixed to the rotating shaft, and a permanent magnet that is sleeved and fixed to the iron core; the permanent magnet is spaced apart from the stator assembly.

6. The brushless hollow cup motor according to claim 1, characterized in that, The brushless hollow cup motor also includes a circuit board, which is fixed to the side of the second cover plate away from the first cover plate. The stator assembly is electrically connected to the circuit board, and the circuit board is provided with output terminals.

7. The brushless hollow cup motor according to claim 6, characterized in that, The brushless hollow cup motor also includes a hollow housing, which is fitted and fixed to the outer periphery of the outer shell, and the housing is made of magnetic material.

8. The brushless hollow cup motor according to claim 7, characterized in that, One side of the housing has a through hole, through which the wire for connecting the output terminal extends to the outside of the housing.

9. The brushless hollow cup motor according to claim 6, characterized in that, The brushless hollow cup motor also includes a sensor assembly for detecting the rotation data of the rotor assembly. The sensor assembly includes a sensor magnet sleeved and fixed to one end of the rotor assembly away from the second bearing and a Hall sensor fixed to one side of the circuit board near the second cover plate. The Hall sensor and the sensor magnet are arranged at a distance from each other.

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