CN210404882U

CN210404882U - Rotor structure of small brushless direct current motor

Info

Publication number: CN210404882U
Application number: CN201921441097.4U
Authority: CN
Inventors: 丁刚; 罗永鸿; 李臻
Original assignee: Shenzhen Power Motor Industrial Co Ltd
Current assignee: Shenzhen Power Motor Industrial Co Ltd
Priority date: 2019-08-30
Filing date: 2019-08-30
Publication date: 2020-04-24
Anticipated expiration: 2029-08-30

Abstract

The utility model relates to a rotor structure of a small brushless DC motor, which comprises a shaft core, a plurality of cylindrical rare earth permanent magnets and a plurality of balance blocks; the shaft core comprises a first shaft body, a second shaft body, a third shaft body and two inner square holes, the second shaft body and the third shaft body are respectively arranged at two opposite side ends of the first shaft body, the diameters of cross section circles of the second shaft body and the third shaft body are equal, the diameters of the cross section circles of the second shaft body and the third shaft body are smaller than the diameter of the cross section circle of the first shaft body, and the two inner square holes are respectively arranged at two ends of the shaft core; the cylindrical rare earth permanent magnets are sleeved on the outer wall of the first shaft body at equal intervals; a plurality of balancing piece interference fit cup joint in on the first axis body outer wall, the balancing piece with the free end laminating setting of tombarthite permanent magnet, above-mentioned rotor structure can reduce the vibration and the noise that the motor produced when the operation.

Description

Rotor structure of small brushless direct current motor

Technical Field

The utility model belongs to the technical field of small-size brushless DC motor and specifically relates to a small-size brushless DC motor's rotor structure.

Background

The electric seat of the automobile is a seat which takes a motor as power and adjusts various positions of the seat through a transmission device and an actuating mechanism so that a driver or passengers can sit comfortably, a brushless direct current motor is an important component of the electric seat of the automobile, the weight reduction allowance of a motor rotor in the prior art in the field is small in the weight reduction balance process, the permanent magnet on the motor rotor is difficult to balance, and the motor generates great vibration and noise in the running process.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a can reduce vibration and the noise that the motor produced when the operation, improve the rotor structure of the small-size brushless DC motor of the whole balanced precision of rotor.

In order to solve the technical problem, the utility model provides a rotor structure of a small brushless direct current motor, which comprises a shaft core, a plurality of cylindrical rare earth permanent magnets and a plurality of balance blocks; the shaft core comprises a first shaft body, a second shaft body, a third shaft body and two inner square holes, the second shaft body and the third shaft body are respectively arranged at two opposite side ends of the first shaft body, the diameters of cross section circles of the second shaft body and the third shaft body are equal, the diameters of the cross section circles of the second shaft body and the third shaft body are smaller than the diameter of the cross section circle of the first shaft body, and the two inner square holes are respectively arranged at two ends of the shaft core; the cylindrical rare earth permanent magnets are sleeved on the outer wall of the first shaft body at equal intervals; a plurality of balancing pieces are sleeved on the outer wall of the first shaft body in an interference fit mode, and the balancing pieces are attached to the free ends of the rare earth permanent magnets.

Further, adjacent two the laminating of cylindrical rare earth permanent magnet sets up, two balancing piece interference fit cup joint in on the first axis body outer wall, follow first last two that first axis axial arranged in proper order the free end of cylindrical rare earth permanent magnet and one the laminating of balancing piece sets up.

Further, the axle core still includes fourth axis body and fifth axis body, the fourth axis body is located the second axis body is kept away from the one end of first axis body, the fifth axis body is located the third axis body is kept away from the one end of first axis body, the diameter of the cross section circle of fourth axis body and fifth axis body equals, the diameter of the cross section circle of fourth axis body and fifth axis body is less than the cross section circle diameter of second axis body.

Furthermore, the balancing piece is annular, and the excircle diameter of balancing piece is less than or equal to the excircle diameter of the free end of cylindrical rare earth permanent magnet.

Furthermore, a punching rib is arranged between the first shaft body and the cylindrical rare earth permanent magnet.

Furthermore, concave arc surface grooves are respectively arranged on the wall of each of the four sides of the inner square hole, and the concave arc surface grooves on the wall of each of the two opposite sides of the inner square hole correspond to each other in position.

The beneficial effects of the utility model reside in that:

1. the rotor shaft core adopts a plurality of step structures, so that the position pressed by the bearing can be accurately positioned, and the precision of the assembly position of the bearing is improved.

2. The balance blocks are arranged on the end surfaces of the two magnets, so that the weight reduction allowance of the rotor in the weight reduction and balance process is improved, the process difficulty of rotor balance is reduced, the overall balance precision of the rotor is improved, and the vibration and the noise generated when the motor operates can be reduced; the balance weight and the shaft core are in interference fit, so that the magnet can be effectively prevented from shifting.

3. The axle core adopts interior square hole structure, and the square hole shape is unanimous with customer end size, and the customer end flexible axle disect insertion goes out the axle end square hole during the installation, simple to operate, swift.

4. The multi-section cylindrical permanent magnet structure reduces the forming difficulty of the permanent magnet and improves the forming precision of the permanent magnet on the premise of ensuring the stable excitation magnetic field.

5. The diameter of the cross section circle of the fourth shaft body and the diameter of the cross section circle of the fifth shaft body are smaller than the diameter of the cross section circle of the second shaft body, so that the rotor bearing can be prevented from being pressed and damaged on the surface of the shaft and the inner surface of the bearing due to overlong interference assembly distance during assembly.

Drawings

Fig. 1 is a schematic view of the overall structure of the embodiment of the present invention.

Fig. 2 is a schematic view of the shaft core structure of the embodiment of the present invention.

Fig. 3 is a schematic view of another perspective structure of the shaft core structure according to the embodiment of the present invention.

In the figure, a shaft core 100, a first shaft body 110, a second shaft body 120, a third shaft body 130, an inner square hole 140, a concave arc groove 141, a fourth shaft body 150, a fifth shaft body 160, a cylindrical rare earth permanent magnet 200 and a balance weight 300.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the following description, with reference to the accompanying drawings and embodiments, will explain the rotor structure of a small brushless dc motor in further detail. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

Referring to fig. 1, a rotor structure of a small brushless dc motor according to an embodiment of the present invention includes a shaft core 100, a plurality of cylindrical rare earth permanent magnets 200, and a plurality of balance blocks 300; the shaft core 100 comprises a first shaft body 110, a second shaft body 120, a third shaft body 130 and two inner square holes 140, wherein the second shaft body 120 and the third shaft body 130 are respectively arranged at two opposite side ends of the first shaft body 110, the diameters of cross section circles of the second shaft body 120 and the third shaft body 130 are equal, the diameters of the cross section circles of the second shaft body 120 and the third shaft body 130 are smaller than the diameter of the cross section circle of the first shaft body 110, and the two inner square holes 140 are respectively arranged at two ends of the shaft core 100; a plurality of cylindrical rare earth permanent magnets 200 are sleeved on the outer wall of the first shaft body 110 at equal intervals; a plurality of balancing pieces 300 interference fit cup joints on first axis body 110 outer wall, balancing piece 300 and rare earth permanent magnet 200's free end laminating setting, it needs to point out the utility model discloses rare earth permanent magnet 200's that recite free end indicates that rare earth permanent magnet 200 does not laminate the terminal surface that sets up rather than adjacent another rare earth permanent magnet 200.

The rotor shaft core adopts a plurality of step structures, so that the pressed-in position of the bearing can be accurately positioned, and the precision of the assembly position of the bearing is improved; the shaft core adopts an inner square hole structure, the shape of the square hole is consistent with the size of the client, and the client flexible shaft is directly inserted into the inner square hole of the shaft end during installation, so that the installation is convenient and rapid; the balance blocks are arranged on the end surfaces of the two magnets, so that the weight reduction allowance of the rotor in the weight reduction and balance process is improved, the process difficulty of rotor balance is reduced, the overall balance precision of the rotor is improved, and the vibration and the noise generated when the motor operates can be reduced; the balance weight and the shaft core are in interference fit, so that the magnet can be effectively prevented from shifting; the multi-section cylindrical permanent magnet structure reduces the forming difficulty of the permanent magnet and improves the forming precision of the permanent magnet on the premise of ensuring the stable excitation magnetic field.

Further, two adjacent cylindrical rare earth permanent magnets 200 laminate and set up, two balancing pieces 300 interference fit cup joint on first axis body 110 outer wall, follow first axis body 110 axial two first last cylindrical rare earth permanent magnets 200's that arrange in proper order free end and a balancing piece 300 laminating setting.

It can be understood that two adjacent cylindrical rare earth permanent magnets 200 are arranged in a fitting manner, so that the use amount of the balance weight 300 is reduced, and the magnetic conductance is more stable.

Further, the shaft core 100 further includes a fourth shaft body 150 and a fifth shaft body 160, the fourth shaft body 150 is disposed at one end of the second shaft body 120 far away from the first shaft body 110, the fifth shaft body 160 is disposed at one end of the third shaft body 130 far away from the first shaft body 110, the diameters of the cross-sectional circles of the fourth shaft body 150 and the fifth shaft body 160 are equal, and the diameters of the cross-sectional circles of the fourth shaft body 150 and the fifth shaft body 160 are smaller than the diameter of the cross-sectional circle of the second shaft body 120.

As can be appreciated, the diameter of the cross-sectional circle of the four shaft bodies and the diameter of the cross-sectional circle of the fifth shaft body are smaller than the diameter of the cross-sectional circle of the second shaft body, so that the rotor bearing can avoid the pressure injury on the surface of the shaft and the inner surface of the bearing caused by the overlong interference assembly distance during assembly.

Further, the balance weight 300 is annular, and the diameter of the outer circle of the balance weight 300 is smaller than or equal to that of the outer circle of the free end of the cylindrical rare earth permanent magnet 200.

It can be understood that the balance weight 300 is in an annular structure, so that the service life of the balance weight can be prolonged, the size of the balance weight 300 is smaller than or equal to that of the cylindrical rare earth permanent magnet 200, the bearing load of the shaft core 100 is reduced, and the rotor structure is more compact.

Further, a punching rib is arranged between the first shaft body 110 and the cylindrical rare earth permanent magnet 200.

It can be understood that the punched ribs on the first shaft body 110 ensure that the cylindrical rare earth permanent magnet 200 is fixed on the first shaft body 110, and the function of preventing rotation is achieved.

Furthermore, the hole walls of the four sides of the inner square hole 140 are respectively provided with a concave arc surface groove 141, and the concave arc surface grooves 141 on the hole walls of the two opposite sides of the inner square hole 140 are corresponding in position.

It can be understood that the arrangement of the concave arc groove 141 makes the connection between the rotating shaft and the flexible shaft more stable when rotating.

The above description is only a preferred embodiment of the present invention, and the present invention is not limited to the above description in any form, and although the present invention has been disclosed with reference to the preferred embodiment, it is not limited to the present invention, and any skilled person in the art can make modifications or changes equivalent to the equivalent embodiment of the above embodiments without departing from the scope of the present invention.

Claims

1. The utility model provides a rotor structure of small-size brushless DC motor which characterized in that: comprises a shaft core (100), a plurality of cylindrical rare earth permanent magnets (200) and a plurality of balance blocks (300);

the axle core (100) comprises a first axle body (110), a second axle body (120), a third axle body (130) and two inner square holes (140), wherein the second axle body (120) and the third axle body (130) are respectively arranged at two opposite side ends of the first axle body (110), the diameters of cross-section circles of the second axle body (120) and the third axle body (130) are equal, the diameters of the cross-section circles of the second axle body (120) and the third axle body (130) are smaller than the diameter of the cross-section circle of the first axle body (110), and the two inner square holes (140) are respectively arranged at two ends of the axle core (100);

the cylindrical rare earth permanent magnets (200) are sleeved on the outer wall of the first shaft body (110) at equal intervals;

a plurality of balancing pieces (300) are sleeved on the outer wall of the first shaft body (110) in an interference fit mode, and the balancing pieces (300) are attached to the free end of the rare earth permanent magnet (200).

2. A rotor structure of a small brushless dc motor as set forth in claim 1, wherein: adjacent two laminating setting of cylindrical rare earth permanent magnet (200), two balancing piece (300) interference fit cup joint in on first axis body (110) outer wall, follow first last two that first axis body (110) axial was arranged in proper order the free end and one of cylindrical rare earth permanent magnet (200) the laminating setting of balancing piece (300).

3. A rotor structure of a small brushless dc motor as set forth in claim 1, wherein: the axle core (100) further comprises a fourth axle body (150) and a fifth axle body (160), the fourth axle body (150) is arranged at one end, far away from the first axle body (110), of the second axle body (120), the fifth axle body (160) is arranged at one end, far away from the first axle body (110), of the third axle body (130), the diameters of cross-section circles of the fourth axle body (150) and the fifth axle body (160) are equal, and the diameters of the cross-section circles of the fourth axle body (150) and the fifth axle body (160) are smaller than the diameter of the cross-section circle of the second axle body (120).

4. A rotor structure of a small brushless dc motor as set forth in claim 1, wherein: the balance weight (300) is annular, and the diameter of the outer circle of the balance weight (300) is smaller than or equal to that of the outer circle of the free end of the cylindrical rare earth permanent magnet (200).

5. A rotor structure of a small brushless dc motor as set forth in claim 1, wherein: and a punching rib is arranged between the first shaft body (110) and the cylindrical rare earth permanent magnet (200).

6. A rotor structure of a small brushless dc motor as set forth in claim 1, wherein: concave arc surface grooves (141) are respectively arranged on the wall of the four sides of the inner square hole (140), and the positions of the concave arc surface grooves (141) on the wall of the two opposite sides of the inner square hole (140) are corresponding.