CN218678788U

CN218678788U - Large-torque outer rotor brushless motor for electric screwdriver

Info

Publication number: CN218678788U
Application number: CN202222875885.2U
Authority: CN
Inventors: 陆亚洲; 徐亚青; 孔令国
Original assignee: Zhangjiagang Huajie Electronics Co Ltd
Current assignee: Zhangjiagang Huajie Electronics Co Ltd
Priority date: 2022-10-31
Filing date: 2022-10-31
Publication date: 2023-03-21
Anticipated expiration: 2032-10-31

Abstract

The utility model relates to a big moment of torsion external rotor brushless motor for electric screwdriver, including stator module and rotor subassembly and base, integrative taking shape has the registration arm on the base, stator module cup joints on the registration arm, the rotor subassembly includes the pivot, the protecgulum, casing and multi-disc magnet steel, the pivot tip passes the protecgulum and stretches out in the place ahead of protecgulum, the pivot is rotated and is pegged graft in the registration arm, the casing cup joints at stator module periphery, each magnet steel is just right with stator module, the cross-section of magnet steel is the rectangle, form inhomogeneous air gap between arbitrary magnet steel and the stator module. The utility model discloses a set up the rotor subassembly outside in order to increase the power arm to under the condition that does not change the motor size, effectively improved the output torque of rotor.

Description

Large-torque outer rotor brushless motor for electric screwdriver

Technical Field

The utility model belongs to the technical field of the motor, concretely relates to big moment of torsion external rotor brushless motor for electric screwdriver.

Background

At present, the electric screwdriver motors used in the market are two types, namely a brush direct current motor and a common inner rotor brushless motor, the brush motor is large in size, heavy in weight and high in noise, and the use experience of a user is poor; compared with a brush motor, the brushless inner rotor motor has the advantages of long service life, low noise, higher rotating speed than that of a brush motor, wide speed-adjustable range, capability of realizing accurate torque control and large-range working condition application, but in practical application, the output torque of the brushless inner rotor motor is smaller, and the requirements of the market on large torque and small-sized screwdrivers cannot be met.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is: the large-torque outer rotor brushless motor for the electric screwdriver is provided to solve the technical problem that the torque of the existing screwdriver motor is small.

In order to solve the technical problem, the utility model discloses a technical scheme is: a big moment of torsion external rotor brushless motor for electric screwdriver, including stator module and rotor subassembly, still include a base, integrated into one piece has the registration arm that the perpendicular to base set up on the base, stator module cup joints on the registration arm, and the bearing pilot hole of setting coaxial with the registration arm centre bore is seted up to the base bottom surface, the rotor subassembly includes pivot, fixed connection at the protecgulum of pivot one end, connects casing and the multi-disc subsides of following outside the protecgulum and establish the magnet steel on the casing inner wall, and the pivot tip passes the protecgulum and stretches out in the place ahead of protecgulum, and the pivot is rotated and is pegged graft in the registration arm, and the casing cup joints at stator module periphery, and each magnet steel is just right with stator module, stator module includes the stator core and a plurality of coils around establishing on stator core with registration arm fixed connection, the cross-section of magnet steel is the rectangle, forms inhomogeneous air gap between arbitrary magnet module and the stator module.

As a preferred scheme, all magnet steel are dispersed evenly along the inner wall of the machine shell in the circumferential direction, and insulating glue is filled in gaps among the magnet steel.

As a preferable scheme, a plurality of fan-shaped holes are uniformly distributed in the circumferential direction on the front cover, a plate-shaped fan blade is formed between any two adjacent fan-shaped holes, the fan-shaped holes extend outwards along the radial direction of the front cover to the outer circumferential surface of the front cover, an axially-raised conical flow guide body is integrally formed in the center of the inner top surface of the front cover, and the inclined surface of the flow guide body guides airflow to flow into the fan-shaped holes.

Preferably, the number of the fan blades is a prime number greater than 5.

The beneficial effects of the utility model are that: the utility model discloses a set up the rotor subassembly in order to increase the power arm outside the stator module to under the condition that does not change motor size, effectively improved the output torque of rotor, simultaneously, adopt the cross-section to make and form inhomogeneous air gap between magnet steel and the stator module for the magnet steel of rectangle, make the back electromotive force curve of motor tend to the sine, reduce the torque ripple of motor, tooth's socket torque and noise improve the rotational stability of motor, improve the efficiency.

Drawings

The following detailed description of embodiments of the present invention is provided with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of a half-section structure of the present invention;

FIG. 2 is a left side view of the rotor assembly shown in FIG. 1;

in fig. 1 and 2: 1. stator module, 1a, stator core, 1b, coil, 2, rotor subassembly, 3, base, 4, registration arm, 5, bearing pilot hole, 6, pivot, 7, protecgulum, 8, casing, 9, magnet steel, 10, insulating cement, 11, fan-shaped hole, 12, flabellum, 13, baffle.

Detailed Description

The following describes in detail a specific embodiment of the present invention with reference to the drawings.

As shown in fig. 1 and 2, the high-torque outer rotor brushless motor for the electric screwdriver includes a stator assembly 1, a rotor assembly 2 and a base 3, a positioning tube 4 perpendicular to the base 3 is integrally formed on the base 3, the stator assembly 1 is sleeved on the positioning tube 4, a bearing assembly hole 5 coaxially disposed with a central hole of the positioning tube 4 is formed in a bottom surface of the base 3, the rotor assembly 2 includes a rotating shaft 6, a front cover 7 fixedly connected to one end of the rotating shaft 6, a casing 8 connected to an outer edge of the front cover 7, and a plurality of pieces of magnetic steel 9 attached to an inner wall of the casing 8, an end of the rotating shaft 6 passes through the front cover 7 and extends out of a front side of the front cover 7, the rotating shaft 6 is rotatably inserted into the positioning tube 4, the casing 8 is sleeved on a periphery of the stator assembly 1, each magnetic steel 9 is directly opposite to the stator assembly 1, the stator assembly 1 includes a stator core 1a fixedly connected to the positioning tube 4 and a plurality of coils 1b wound around the stator core 1a, a cross section of the magnetic steel 9 is rectangular, an uneven air gap is formed between any one of the magnetic steel 9 and the stator assembly 1a stator assembly 1, so that a back electromotive force curve of the motor is curved, a sine torque of the motor is reduced, a torque of the motor, a rotating torque and a noise of the motor is increased, and a stability of the motor is increased, and a ripple efficiency of the motor is increased.

All the magnetic steels 9 are distributed discretely and uniformly along the circumferential direction of the inner wall of the machine shell 9, and insulating glue 10 is filled in gaps among the magnetic steels 9.

As a further optimized scheme, in this embodiment, a plurality of fan-shaped holes 11 are uniformly distributed in the circumferential direction on the front cover 7, a plate-shaped fan blade 12 is formed between any two adjacent fan-shaped holes 11, the fan-shaped holes 11 extend outward along the radial direction of the front cover 7 to the outer circumferential surface of the front cover 7, an axially protruding conical flow guide body 13 is integrally formed in the center of the inner top surface of the front cover 7, and the inclined surface of the flow guide body 13 guides the airflow to flow to the fan-shaped holes 11. This embodiment reforms into a centrifugal fan with protecgulum 7, can effectively improve the inside air mass flow of motor, reduces motor operating temperature, improves motor job stabilization nature.

The number of fan blades 12 in this embodiment is preferably a prime number greater than 5, preferably 11 or 13. So as to prevent the motor from generating resonance in the running process and entering the vibration and noise which affect the motor, and further improve the working stability of the motor.

The utility model discloses the theory of operation is: this embodiment is through setting up the rotor subassembly in order to increase the power arm outside stator module to under the condition that does not change motor size, effectively improved the output torque of rotor, simultaneously, adopt the cross-section to make and form inhomogeneous air gap between magnet steel and the stator module for the magnet steel of rectangle, make the back electromotive force curve of motor tend to the sine, reduce the torque ripple of motor, tooth's socket torque and noise improve the rotational stability of motor, improve the efficiency. Simultaneously, this embodiment still improves the air current flux in the motor, reduces motor operating temperature, improves the job stabilization nature of motor through designing protecgulum 7 into fan structure. And the quantity of flabellum designs for the matter number piece to eliminate flabellum and the resonant problem of rotor subassembly, further improve the job stabilization nature of motor.

The foregoing embodiments are merely illustrative of the principles and effects of the present invention, as well as some embodiments, and are not intended to limit the invention; it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the inventive concept of the present invention, and these changes and modifications belong to the protection scope of the present invention.

Claims

1. A high-torque outer rotor brushless motor for an electric screwdriver comprises a stator component (1) and a rotor component (2), it is characterized by also comprising a base (3), a positioning pipe (4) which is vertical to the base (3) is integrally formed on the base (3), the stator component (1) is sleeved on the positioning pipe (4), the bottom surface of the base (3) is provided with a bearing assembly hole (5) which is coaxial with the center hole of the positioning pipe (4), the rotor component (2) comprises a rotating shaft (6), a front cover (7) fixedly connected to one end of the rotating shaft (6), a machine shell (8) connected to the outer edge of the front cover (7) and a plurality of pieces of magnetic steel (9) attached to the inner wall of the machine shell (8), the end part of the rotating shaft (6) penetrates through the front cover (7) to extend out of the front part of the front cover (7), the rotating shaft (6) is rotatably inserted into the positioning pipe (4), the machine shell (8) is sleeved on the periphery of the stator component (1), each piece of magnetic steel (9) is right opposite to the stator component (1), the stator component (1) comprises a stator core (1 a) fixedly connected with the positioning pipe (4) and a plurality of coils (1 b) wound on the stator core (1 a), the section of the magnetic steel (9) is rectangular, and an uneven air gap is formed between any magnetic steel (9) and the stator assembly (1).

2. A high-torque brushless motor with an outer rotor as defined in claim 1, wherein all the magnetic steels (9) are circumferentially distributed uniformly and discretely along the inner wall of the housing (8), and the gaps between the magnetic steels (9) are filled with insulating glue (10).

3. The high-torque outer rotor brushless motor according to claim 1, wherein the front cover (7) is provided with a plurality of fan-shaped holes (11) uniformly distributed in the circumferential direction, a plate-shaped fan blade (12) is formed between any two adjacent fan-shaped holes (11), the fan-shaped holes (11) extend outwards along the radial direction of the front cover (7) to the outer circumferential surface of the front cover (7), an axially protruding conical guide body (13) is integrally formed at the center of the inner top surface of the front cover (7), and the inclined surface of the guide body (13) guides airflow to the fan-shaped holes (11).

4. A high torque outer rotor brushless electric machine according to claim 3, wherein the number of fan blades (12) is a prime number larger than 5.