A brushless DC outer rotor motor with dual encoders

Abstract

The present invention relates to a DC brushless outer rotor motor with dual encoders, comprising a stator assembly, a rotor assembly, and dual encoders; the rotor assembly comprises a housing (2) and a front bearing (3); the stator assembly comprises a shaft (12), a rear bearing (13), and an end cover (14); one end of the housing (2) is connected to the shaft (12) via the front bearing (3), and the other end of the housing (2) is connected to the end cover (14) via the rear bearing (13); the dual encoders comprise a single code disk (7) mounted on the housing (2) and two encoder chips mounted on the end cover (14). Compared with the prior art, the present invention has the advantages of increasing the support rigidity of the motor structure, reducing the swing of the motor during rotor rotation, and achieving high position control accuracy.

Description

Technical Field

[0001] The present invention relates to a motor, in particular to a DC brushless outer rotor motor with a dual encoder. Background Art

[0002] The existing DC brushless outer rotor motor structure is that one end of the outer rotor housing is connected and fixed to the shaft and rotates synchronously. This structure has the disadvantage of insufficient support rigidity, which easily causes large rotor swing and reduces the motor position control accuracy.

[0003] At the same time, the encoder disc of existing brushless DC outer rotor motors is mounted on the rotating shaft at the rear of the motor, which increases the axial length of the motor. In addition, existing brushless DC outer rotor motors generally use a single encoder, which has low motor position or speed control accuracy. Summary of the Invention

[0004] The purpose of the present invention is to provide a brushless DC outer rotor motor with dual encoders in order to overcome the defects of the prior art.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] According to one aspect of the present invention, a brushless DC outer rotor motor with dual encoders is provided, comprising a stator assembly, a rotor assembly, and dual encoders; the rotor assembly comprises a housing and a front bearing, the stator assembly comprises a shaft, a rear bearing, and an end cover, one end of the housing being connected via the front bearing shaft, and the other end of the housing being connected to the end cover via the rear bearing;

[0007] The dual encoder comprises a single code disc mounted on the housing and two encoder chips mounted on the end cover.

[0008] As a preferred technical solution, the stator assembly also includes a corrugated spring and a shaft sleeve or shaft retaining spring for locking the relative position of the stator assembly and the rotor assembly after assembly. The upper end face of the corrugated spring contacts the shaft sleeve or shaft retaining spring, and the lower end face contacts the inner ring of the front bearing.

[0009] As a preferred technical solution, the stator assembly further includes screws, a PCB assembly and an insulating gasket. The PCB assembly is fixed to the end cover by screws, and an insulating gasket is installed in the middle.

[0010] As a preferred technical solution, the stator assembly further includes a light shielding member, which is mounted on the PCB assembly and fixed to the end cover by screws.

[0011] As a preferred technical solution, the stator assembly also includes a wound stator, the shaft is fixed in the center hole of the end cover, the wound stator is fixed on the shaft, and the three-phase lines of the wound stator are connected to the PCB assembly through the through holes of the end cover; the front bearing and the rear bearing are distributed on both sides of the wound stator.

[0012] As a preferred technical solution, the two ends of the casing have different diameters, the upper part has a smaller diameter and a longer length, and the lower part has a larger diameter and a shorter length.

[0013] As a preferred technical solution, the front bearing and the rear bearing have the same outer diameter and different inner diameters; the front bearing has a smaller inner diameter and the rear bearing has a larger inner diameter.

[0014] As a preferred technical solution, the rotor assembly also includes a connecting block, a mirror frame, a magnet and a steel sleeve, the mirror frame is fixed to the outside of the casing, the magnet is fixed inside the casing, the steel sleeve is fixed below the magnet inside the casing, and the connecting block is fixed above the front bearing inside the casing; the front bearing and the rear bearing are distributed on both sides of the magnet.

[0015] As a preferred technical solution, the housing or mirror frame rotates together with the laser lens or prism.

[0016] As a preferred technical solution, the shaft of the motor is a fixed component, and the housing is a rotating component.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1. The motor of the present invention adopts a structure in which the rotor assembly rotates relative to a fixed shaft. The rotor assembly housing is connected to the shaft and the end cover at both ends through two bearings, which increases the support rigidity of the motor structure, makes the motor swing less during the rotation of the rotor, and has high position control accuracy.

[0019] 2. The motor encoder code disk of the present invention is assembled on the housing, and the encoder chip is assembled on the motor end cover. The encoder and the motor are well integrated, with a compact structure and a small motor size.

[0020] 3. The motor of the present invention adopts a dual encoder mode, which compensates each other and reduces the control accuracy error caused by the non-concentricity between the code disk and the chip, and the motor position or speed control accuracy is high;

[0021] 4. The motor power and rotational motion of the present invention are output to the user end through the housing or the mirror frame, and the use structure is compact and space-saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention;

[0023] Among them, 1 is the connecting block, 2 is the housing, 3 is the front bearing, 4 is the mirror frame, 5 is the magnet, 6 is the steel sleeve, 7 is the code disk, 8 is the screw, 9 is the bushing, 10 is the corrugated spring, 11 is the wound stator, 12 is the shaft, 13 is the rear bearing, 14 is the end cover, 15 is the light shielding part, 16 is the PCB assembly, and 17 is the insulating gasket. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0025] like Figure 1 As shown, a DC brushless outer rotor motor with dual encoders includes a stator assembly, a rotor assembly and dual encoders; the rotor assembly includes a housing 2 and a front bearing 3, the stator assembly includes a shaft 12, a rear bearing 13 and an end cover 14, one end of the housing 2 is connected to the shaft 12 through the front bearing 3, and the other end of the housing 2 is connected to the end cover 14 through the rear bearing 13; the dual encoder includes a single code disk 7 assembled on the housing 2 and two encoder chips assembled on the end cover 14. The encoder and the motor are well integrated, the structure is compact, and the motor is small.

[0026] The stator assembly also includes a sleeve 9 or a shaft retaining spring and a corrugated spring 10 for locking the relative position of the stator assembly and the rotor assembly after assembly. The upper end face of the corrugated spring 10 contacts the sleeve 9 or the shaft retaining spring, and the lower end face contacts the inner ring of the front bearing 3. The rotor assembly rotates relative to the fixed shaft, and the rotor assembly housing is connected to the shaft and end cover at both ends through two bearings.

[0027] The stator assembly further includes screws 8, a PCB assembly 16 and an insulating gasket 17. The PCB assembly 16 is fixed to the end cover 14 by means of the screws 8, and an insulating gasket 17 is installed in the middle.

[0028] The stator assembly also includes a wound stator 11. The shaft 12 is fixed in the center hole of the end cap 14. The wound stator 11 is fixed to the shaft 12. The three-phase wires of the wound stator 11 are connected to the PCB assembly 16 through the through holes of the end cap 14. The front bearing 3 and the rear bearing 13 are located on either side of the wound stator 11. The stator assembly also includes a light shield 15, which is mounted on the PCB assembly 16 and fixed to the end cap 14 via screws. The inner hole of the rear bearing is fixed to the end cap, and the shaft is fixed in the center hole of the end cap. The wound stator is fixed to the shaft, and the three-phase wires of the wound stator are connected to the PCB through the end cap.

[0029] The end cap has a shaft mounting hole in the center, a bearing mounting surface and stator three-phase wire holes on the top, a flat bottom surface with threaded holes, and motor mounting holes on the outer edge. The housing 2 has different diameters at both ends: the upper portion has a smaller diameter and a longer length, while the lower portion has a larger diameter and a shorter length. The front bearing 3 and rear bearing 13 have the same outer diameter but different inner diameters; the front bearing 3 has a smaller inner diameter, while the rear bearing 13 has a larger inner diameter.

[0030] The rotor assembly also includes a connecting block 2, a mirror frame 4, a magnet 5, and a steel sleeve 6. The mirror frame 4 is fixed to the outside of the housing 2, the magnet 5 is fixed to the inside of the housing 2, the steel sleeve 6 is fixed to the bottom of the magnet 5 in the housing 2, and the connecting block 2 is fixed to the top of the front bearing 3 in the housing; the front bearing 3 and the rear bearing 13 are distributed on both sides of the magnet 5. The housing 2 or the mirror frame 4 rotates together with the laser lens or prism. The light shielding member is a thin-walled member that can prevent external light from entering the motor through the gap between the rotor assembly and the stator assembly and interfering with the operation of the encoder; the power and rotational motion of the motor or the mirror frame are output to the user end through the housing; the stator assembly is the stationary component of the motor, and the rotor assembly is the rotating component of the motor.

[0031] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A brushless DC outer rotor motor with dual encoders, characterized in that: The invention comprises a stator assembly, a rotor assembly and a dual encoder; the rotor assembly comprises a housing (2) and a front bearing (3); the stator assembly comprises a shaft (12), a rear bearing (13) and an end cover (14); one end of the housing (2) is connected to the shaft (12) via the front bearing (3); the other end of the housing (2) is connected to the end cover (14) via the rear bearing (13); The dual encoder comprises a single code disc (7) mounted on the housing (2) and two encoder chips mounted on the end cover (14); The stator assembly further comprises a corrugated spring (10) and a shaft sleeve (9) or a shaft retaining spring for locking the relative position of the stator assembly and the rotor assembly after assembly. The upper end surface of the corrugated spring (10) contacts the shaft sleeve (9) or the shaft retaining spring, and the lower end surface contacts the inner ring of the front bearing (3); The stator assembly further comprises screws (8), a PCB assembly (16) and an insulating gasket (17); the PCB assembly (16) is fixed to the end cover (14) by means of the screws (8), and an insulating gasket (17) is installed in the middle; The stator assembly further comprises a wound stator (11), the shaft (12) is fixed in the center hole of the end cover (14), the wound stator (11) is fixed on the shaft (12), and the three-phase lines of the wound stator (11) are connected to the PCB assembly (16) through the through holes of the end cover (14); the front bearing (3) and the rear bearing (13) are distributed on both sides of the wound stator (11).

2. A brushless DC outer rotor motor with dual encoders according to claim 1, characterized in that: The stator assembly further comprises a light shielding member (15), which is mounted on the PCB assembly (16) and fixed to the end cover (14) via screws.

3. A brushless DC outer rotor motor with dual encoders according to claim 1, characterized in that: The casing (2) has different diameters at both ends, with the upper portion having a smaller diameter and a longer length, and the lower portion having a larger diameter and a shorter length.

4. A brushless DC outer rotor motor with dual encoders according to claim 1, characterized in that: The front bearing (3) and the rear bearing (13) have the same outer diameter but different inner diameters; the front bearing (3) has a smaller inner diameter, while the rear bearing (13) has a larger inner diameter.

5. A brushless DC outer rotor motor with dual encoders according to claim 1, characterized in that: The rotor assembly further comprises a connecting block (2), a mirror frame (4), a magnetic steel (5) and a steel sleeve (6), wherein the mirror frame (4) is fixed on the outside of the housing (2), the magnetic steel (5) is fixed in the housing (2), the steel sleeve (6) is fixed below the magnetic steel (5) in the housing (2), and the connecting block (2) is fixed above the front bearing (3) in the housing; the front bearing (3) and the rear bearing (13) are distributed on both sides of the magnetic steel (5).

6. A brushless DC outer rotor motor with dual encoders according to claim 5, characterized in that: The housing (2) or the mirror frame (4) rotates together with the laser lens or the prism.

7. A brushless DC outer rotor motor with dual encoders according to claim 1, characterized in that: The shaft (12) of the motor is a fixed component, and the housing (2) is a rotating component.

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