CN112467903A

CN112467903A - Motor rotor and permanent magnet motor

Info

Publication number: CN112467903A
Application number: CN202011319953.6A
Authority: CN
Inventors: 胡余生; 郭伟林; 张芳; 龚高
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-11-23
Filing date: 2020-11-23
Publication date: 2021-03-09

Abstract

The application provides a motor rotor and a permanent magnet motor. This electric motor rotor includes the pivot, fixed plate (1) and carbon fiber sheath (2), the pivot includes first axle (3) that sets gradually along the axial, permanent magnet (4) and second axle (5), the axial extension of fixed plate (1) along the pivot, the first end fixed connection of fixed plate (1) is on first axle (3), the second end fixed connection of fixed plate (1) is on second axle (5), fixed plate (1) are at least two, two at least fixed plate (1) set gradually along circumference in the periphery side of pivot, and splice into the drum, carbon fiber sheath (2) winding is at the periphery side of drum. According to the motor rotor, the phenomenon that the carbon fiber sheath is broken can be effectively avoided, and the structural safety of the permanent magnet when the motor rotor rotates at a high speed is guaranteed.

Description

Motor rotor and permanent magnet motor

Technical Field

The application relates to the technical field of motors, in particular to a motor rotor and a permanent magnet motor.

Background

With the vigorous promotion of the industry upgrading of the country, the field of motors can be continuously developed to high speed and miniaturization. The surface-mounted rotor is simple in structure and convenient to assemble, so that the surface-mounted rotor is commonly used in the field of high-speed motors, a sheath is usually required to be added on the outer surface of a permanent magnet due to the fact that the tensile strength of the permanent magnet is low, and the sheath is usually made of high-strength alloy or carbon fiber and the like.

Along with the gradual rise of the power and the rotating speed of the motor, the outer diameter of the permanent magnet of the surface-mounted motor rotor is increased, and the centrifugal force borne by the rotor is increased; the yield strength of the high-strength alloy sheath also has a limit and cannot ensure the structural safety of the rotor at a higher rotating speed; the radial and axial strength of the carbon fiber sheath is very low, so that the requirement on the rigidity of the rotor cannot be met, the rotor is easy to bend in the operation process, and the axial fracture phenomenon of the carbon fiber sheath can occur at the contact position of the multi-section permanent magnet and the contact position of the permanent magnet and the shaft; in addition, the initial winding tension provided by the existing carbon fiber winding technology is limited, the pressure stress provided by the carbon fiber sheath to a wrapping object is limited, and if the pressure stress of the carbon fiber maintenance sleeve does not directly act on the permanent magnet, the permanent magnet is difficult to be protected at a high rotating speed, so that the structural safety of the permanent magnet in high-speed rotation is difficult to be ensured by adopting a carbon fiber and high-strength alloy double-sheath mode.

Disclosure of Invention

Therefore, the technical problem that this application will be solved lies in providing a motor rotor and permanent-magnet machine, can effectively avoid carbon fiber sheath to take place the fracture phenomenon, guarantees the structure safety of permanent magnet when motor rotor is high-speed rotatory.

In order to solve the problem, the application provides a motor rotor, which comprises a rotating shaft, fixed plate and carbon fiber sheath, the pivot includes the primary shaft that sets gradually along the axial, permanent magnet and secondary shaft, the fixed plate extends along the axial of pivot, the first end fixed connection of fixed plate is epaxial at the primary shaft, the second end fixed connection of fixed plate is epaxial at the secondary, the fixed plate is at least two, two at least fixed plates set gradually along circumference in the periphery side of pivot, and splice into the drum, the carbon fiber sheath twines the periphery side at the drum.

Preferably, the first shaft and the second shaft both comprise a shaft extension end and a main shaft end, the shaft extension end and the main shaft end form a step structure, the permanent magnet is located between the main shaft end of the first shaft and the main shaft end of the second shaft, the first end of the fixing plate is fixedly connected to the main shaft end of the first shaft, and the second end of the fixing plate is fixedly connected to the main shaft end of the second shaft.

Preferably, the fixed plate comprises a plate body and end plates arranged at two ends of the plate body, the plate body is sleeved outside the rotating shaft, a first pin hole is formed in the end plate of the fixed plate, a second pin hole is formed in the end face of the main shaft end, and the fixed plate is fixedly connected with the first shaft and the second shaft through pins arranged in the first pin hole and the second pin hole respectively.

Preferably, the end face of the pin is lower than the end face of the spindle end near the shaft extension end, or the end face of the pin is flush with the end face of the spindle end.

Preferably, the end plate has an inner circular surface matched with the shaft extension end, and the diameter of the inner circular surface of the end plate is larger than that of the shaft extension end; and/or the plate body is provided with an inner arc surface matched with the peripheral surface of the rotating shaft, and the inner arc surface is attached to the peripheral surface of the rotating shaft.

Preferably, the shaft extension end is sleeved with a rotor baffle, and the rotor baffle is stopped outside the main shaft end.

Preferably, the rotor baffle is an interference fit with the shaft extension end.

Preferably, the rotor baffle is further externally provided with a nut, the nut is in threaded connection with the shaft extension end, and the nut axially limits the rotor baffle.

Preferably, the carbon fibre sheath is an interference fit with the cylinder.

Preferably, the outer circumferential surface of the cylinder is a smooth surface.

Preferably, the first and second shafts are made of a non-magnetically conductive material.

According to another aspect of the present application, there is provided a permanent magnet motor comprising a motor rotor as described above.

The application provides an electric motor rotor, which comprises a rotating shaft, fixed plate and carbon fiber sheath, the pivot includes the primary shaft that sets gradually along the axial, permanent magnet and secondary shaft, the axial extension of fixed plate edge pivot, the first end fixed connection of fixed plate is on the primary shaft, the second end fixed connection of fixed plate is on the secondary shaft, the fixed plate is at least two, two at least fixed plates set gradually along circumference at the periphery side of pivot to splice into the drum, the carbon fiber sheath winding is at the periphery side of drum. The motor rotor is sleeved with the segmented fixing plate outside a rotating shaft formed by the first shaft, the permanent magnet and the second shaft, two ends of the fixing plate are fixedly connected with the first shaft and the second shaft, the fixing plate can be used for providing radial strength and axial strength required by the permanent magnet and the matching of the permanent magnet and the shaft, the carbon fiber sheath is prevented from having larger radial and axial effects in the motion process of the motor rotor, meanwhile, the carbon fiber sheath can be used for providing larger circumferential strength for the permanent magnet, the whole shaft bending resistance of the motor rotor can be effectively improved through the matching of the fixing plate and the carbon fiber sheath, so that the carbon fiber sheath can directly act compressive stress on the first shaft, the second shaft and the permanent magnet through the segmented fixing plate, the structure safety of the permanent magnet when the motor rotor rotates at high speed is protected, the phenomenon of axial fracture of the carbon fiber maintenance sleeve in the, the power density of the motor is improved.

Drawings

FIG. 1 is a schematic cross-sectional structural view of a rotor of an electric machine according to an embodiment of the present application;

FIG. 2 is an exploded view of a rotor of an electric machine according to an embodiment of the present application;

fig. 3 is a perspective view of a first shaft of a rotor of a motor according to an embodiment of the present application;

fig. 4 is a perspective view of a fixing plate of a motor rotor according to an embodiment of the present disclosure;

fig. 5 is a force analysis diagram of a motor rotor according to an embodiment of the present application.

The reference numerals are represented as:

1. a fixing plate; 2. a carbon fiber sheath; 3. a first shaft; 4. a permanent magnet; 5. a second shaft; 6. a shaft extension end; 7. a main shaft end; 8. a plate body; 9. an end plate; 10. a first pin hole; 11. a second pin hole; 12. a pin; 13. a rotor baffle; 14. and (4) a nut.

Detailed Description

With reference to fig. 1 to 5, according to an embodiment of the present application, the motor rotor includes a rotating shaft, a fixing plate 1 and a carbon fiber sheath 2, the rotating shaft includes a first shaft 3, a permanent magnet 4 and a second shaft 5, which are sequentially arranged along an axial direction, the fixing plate 1 extends along the axial direction of the rotating shaft, a first end of the fixing plate 1 is fixedly connected to the first shaft 3, a second end of the fixing plate 1 is fixedly connected to the second shaft 5, the fixing plate 1 is at least two, the at least two fixing plates 1 are sequentially arranged along a circumferential direction on an outer circumferential side of the rotating shaft and are spliced into a cylinder, and the carbon fiber sheath 2 is.

The motor rotor is sleeved with the segmented fixing plate 1 on the rotating shaft formed by the first shaft 3, the permanent magnet 4 and the second shaft 5, two ends of the fixing plate 1 are fixedly connected with the first shaft 3 and the second shaft 5, the fixing plate 1 can be utilized to provide radial and axial strength required by the permanent magnet 4 and the permanent magnet 4 to be matched with the shafts, the carbon fiber sheath 2 is prevented from receiving larger radial and axial action in the motion process of the motor rotor, meanwhile, the carbon fiber sheath 2 can be utilized to provide larger circumferential strength for the permanent magnet 4, the whole shaft bending resistance of the motor rotor can be effectively improved through the matching of the fixing plate 1 and the carbon fiber sheath 2, so that the carbon fiber sheath 2 can directly act on the first shaft 3, the second shaft 5 and the permanent magnet 4 through the segmented fixing plate 1, the structural safety of the permanent magnet 4 when the motor rotor rotates at a high speed is protected, and the axial fracture phenomenon of the carbon, the limit rotating speed of the motor is further improved, and the power density of the motor is improved.

The first shaft 3 and the second shaft 5 respectively comprise a shaft extension end 6 and a main shaft end 7, the shaft extension end 6 and the main shaft end 7 form a step structure, the permanent magnet 4 is located between the main shaft end 7 of the first shaft 3 and the main shaft end 7 of the second shaft 5, the first end of the fixing plate 1 is fixedly connected to the main shaft end 7 of the first shaft 3, and the second end of the fixing plate 1 is fixedly connected to the main shaft end 7 of the second shaft 5.

First end and the first axle 3 fixed connection of fixed plate 1, second end and second axle 5 fixed connection, consequently can realize the fixed connection between first axle 3 and the second axle 5 through fixed plate 1, and simultaneously, because permanent magnet 4 is located between first axle 3 and the second axle 5, consequently, can form axial and radial spacing to permanent magnet 4 through fixed plate 1 equally, utilize fixed plate 1 to eliminate permanent magnet 4 to the axial and radial influence of carbon fiber sheath 2 in the electric motor rotor course of operation, avoid carbon fiber sheath 2 in electric motor rotor course of operation, the phenomenon of axial fracture takes place in the contact department position of permanent magnet 4 and first axle 3 or second axle 5.

The fixing plate 1 comprises a plate body 8 and end plates 9 arranged at two ends of the plate body 8, the plate body 8 is sleeved outside the rotating shaft, a first pin hole 10 is formed in the end plate 9 of the fixing plate 1, a second pin hole 11 is formed in the end face of the main shaft end 7, and the fixing plate 1 is fixedly connected with the first shaft 3 and the second shaft 5 through pins 12 arranged in the first pin hole 10 and the second pin hole 11.

The fixing plate 1 is made of a non-magnetic material, and can be specifically made of stainless steel or non-magnetic alloy. The fixed plate 1 is fixedly connected with the first shaft 3 and the second shaft 5 through the end plates 9 at two ends, so that the fixed plate 1 can axially limit the first shaft 3, the permanent magnet 4 and the second shaft 5 through the end plates 9 at two ends, and meanwhile, the fixed plate 1 can be fixedly connected with the first shaft 3, the permanent magnet 4 and the second shaft 5 in the radial direction and the circumferential direction through the pins 12.

The two sides of the fixing plate 1 are respectively provided with a first pin hole 10, the spindle ends 7 of the first shaft 3 and the second shaft 5 are respectively provided with a second pin hole 11, each spindle end 7 is provided with N (N is more than or equal to 2) second pin holes 11, the number of the fixing plates 1 is also N, and one end of each fixing plate 1 is provided with 1 first pin hole 10, so that the fixing connection between each fixing plate 1 and each spindle end 7 can be realized. The N fixing plates 1 can be spliced into a complete cylinder to realize installation and matching with the rotating shaft.

The end plate 9 has an inner circular surface matched with the shaft extension end 6, and the diameter of the inner circular surface of the end plate 9 is larger than that of the shaft extension end 6, so that the inner circular surface of the end plate 9 can be fully matched with the outer peripheral surface of the shaft extension end 6.

The plate body 8 is provided with an inner arc surface matched with the outer peripheral surface of the rotating shaft, the inner arc surface is attached to the outer peripheral surface of the rotating shaft, sufficient contact between the fixing plate 1 and the first shaft 3, the permanent magnet 4 and the second shaft 5 can be guaranteed, and structural integrity and consistency of the motor rotor are guaranteed.

Carry out the back chipping at the inboard apex angle department of fixed plate 1 and handle, avoid fixed plate 1 to take place to interfere between inboard apex angle department and the primary shaft 3 or secondary shaft 5, guarantee fully to cooperate in place between fixed plate 1 and the primary shaft 3 and the secondary shaft 5, make the medial surface of two end plates 9 of fixed plate 1 hug closely on the terminal surface of the main shaft end 7 of the primary shaft 3 and secondary shaft 5, make and to compress tightly the cooperation between primary shaft 3 and secondary shaft 5 and the permanent magnet 4, fixed plate 1 can play effectual connection fixed action.

In one embodiment, the end surface of the pin 12 is lower than the end surface of the spindle end 7 close to the shaft extension end 6, or the end surface of the pin 12 is flush with the end surface of the spindle end 7, so that the pin 12 can effectively connect the rotating shaft with the fixing plate 1, and meanwhile, the interference of the use of the pin 12 on the whole assembly of the motor rotor is avoided.

The first shaft 3 and the second shaft 5 are supported by non-magnetic-conductive materials such as stainless steel or non-magnetic-conductive alloy, and therefore axial magnetic flux leakage of the permanent magnet 4 can be effectively reduced.

The rotor baffle 13 is sleeved on the shaft extension end 6, the rotor baffle 13 stops outside the main shaft end 7, the pin 12 can be axially limited, the pin 12 is prevented from being separated from the first pin hole 10 of the fixing plate 1, and the stability and reliability of the overall structure of the motor rotor are improved.

In one embodiment, the rotor baffle 13 and the shaft extension end 6 are in interference fit, so that the stability of the fit structure between the rotor baffle 13 and the shaft extension end 6 can be effectively ensured.

The rotor baffle 13 is also externally provided with a nut 14, the nut 14 is in threaded connection with the shaft extension end 6, and the nut 14 axially limits the rotor baffle 13, so that the rotor baffle 13 is kept at a locking position, and the rotor baffle 13 is prevented from generating axial displacement. An external thread can be arranged on the shaft extension end 6, and the external thread of the shaft extension end 6 is matched with the nut 14, so that the nut 14 is locked and fixed on the first shaft 3 or the second shaft 5.

Interference fit between carbon fiber sheath 2 and the drum can guarantee that the compressive stress of carbon fiber sheath 2 can fully transmit to fixed plate 1.

The outer peripheral surface of the cylinder is a smooth surface, so that the problem that the carbon fiber sheath 2 is axially broken due to the friction effect generated on the carbon fiber sheath 2 in the working process of the motor rotor can be avoided.

The first shaft 3 and the second shaft 5 are made of a non-magnetic material.

The assembly process of the motor rotor is as follows: after the first shaft 3, the permanent magnet 4 and the second shaft 5 are spliced, the fixing plate 1 is installed, and the fixing plate 1, the first shaft 3 and the second shaft 5 are locked into an integral structure through the pins 12; the heating temperature of the rotor baffle 13 is calculated according to the interference, the rotor baffle 13 is respectively assembled on the first shaft 3 and the second shaft 5, so that the rotor baffle 13 is in interference fit with the first shaft 3 and the second shaft 5, then the screw caps 14 are assembled, and the inner end surfaces on two sides of the fixing plate 1 are tightly locked to the end surfaces of the main shaft ends 7 of the first shaft 3 and the second shaft 5 through the screw caps 14, so that the whole motor rotor has the anti-bending capability, and the radial acting force (namely the compressive stress) between the fixing plate 1 and the first shaft 3, the permanent magnet 4 and the second shaft 5 is very small. And finally, carbon fibers are wound on the outer surface of the fixing plate 1 in the circumferential direction, and the tension of the carbon fibers needs to be ensured to be consistent in the whole winding process. After winding, baking the whole motor rotor at a certain temperature to shape the carbon fiber sheath 2, and after natural cooling, manufacturing the whole motor rotor.

Referring to fig. 5, due to the adoption of a partitioned fixing plate structure, the pressure stress of the carbon fiber sheath 2 on the fixing plate 1 can directly act on the first shaft 3, the permanent magnet 4 and the second shaft 5 through the force transmission effect, and according to the force interaction principle, the centrifugal force applied to the permanent magnet 4 when the rotor rotates at a high speed can also directly act on the carbon fiber sheath 2, so that when the motor rotor rotates, the actual centrifugal force applied to the permanent magnet 4 is F2-F1, wherein F1 is the centrifugal force applied to the motor rotor when the motor rotor rotates, and F2 is the pressure of the carbon fiber sheath 2 on the permanent magnet when the motor rotor rotates.

The circumferential strength of the carbon fiber sheath 2 is more than or equal to 1800MPa (far higher than that of the conventional high-strength alloy sheath), so that the structure safety of the fixing plate 1 and the permanent magnet 4 can be effectively protected; because the carbon fiber is wound on the smooth outer surface of the fixing plate 1 and cannot be subjected to additional friction or cutting action, the problem of axial fracture of the carbon fiber sheath 2 can be effectively solved.

According to an embodiment of the application, a permanent magnet motor comprises a motor rotor, which is the motor rotor described above.

It is readily understood by a person skilled in the art that the advantageous ways described above can be freely combined, superimposed without conflict.

The present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed. The foregoing is only a preferred embodiment of the present application, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present application, and these modifications and variations should also be considered as the protection scope of the present application.

Claims

1. The utility model provides a motor rotor, its characterized in that, includes pivot, fixed plate (1) and carbon fiber sheath (2), the pivot includes along axial primary shaft (3), permanent magnet (4) and second shaft (5) that set gradually, fixed plate (1) is followed the axial extension of pivot, the first end fixed connection of fixed plate (1) is in on primary shaft (3), the second end fixed connection of fixed plate (1) is in on second shaft (5), fixed plate (1) is at least two, at least two fixed plate (1) is in the periphery side of pivot sets gradually along circumference to splice into the drum, carbon fiber sheath (2) winding is in the periphery side of drum.

2. The electric motor rotor as recited in claim 1, characterized in that the first shaft (3) and the second shaft (5) each comprise a shaft extension end (6) and a spindle end (7), the shaft extension end (6) and the spindle end (7) forming a step structure, the permanent magnet (4) being located between the spindle end (7) of the first shaft (3) and the spindle end (7) of the second shaft (5), the first end of the fixing plate (1) being fixedly connected to the spindle end (7) of the first shaft (3), the second end of the fixing plate (1) being fixedly connected to the spindle end (7) of the second shaft (5).

3. The motor rotor as recited in claim 2, wherein the fixing plate (1) comprises a plate body (8) and end plates (9) disposed at two ends of the plate body (8), the plate body (8) is sleeved outside the rotating shaft, a first pin hole (10) is disposed on the end plate (9) of the fixing plate (1), a second pin hole (11) is disposed on an end surface of the spindle end (7), and the fixing plate (1) and the first shaft (3) and the fixing plate (1) and the second shaft (5) are fixedly connected through pins (12) disposed in the first pin hole (10) and the second pin hole (11), respectively.

4. An electric machine rotor according to claim 3, characterised in that the end faces of the pins (12) are lower than the end face of the spindle end (7) near the shaft end (6), or that the end faces of the pins (12) are flush with the end face of the spindle end (7).

5. An electric machine rotor, according to claim 3, characterized in that said end plate (9) has an inner circular surface cooperating with said shaft extension end (6), the diameter of the inner circular surface of said end plate (9) being greater than the diameter of said shaft extension end (6); and/or the plate body (8) is provided with an inner arc surface matched with the peripheral surface of the rotating shaft, and the inner arc surface is attached to the peripheral surface of the rotating shaft.

6. An electric machine rotor according to claim 2, characterised in that the shaft extension end (6) is sleeved with a rotor baffle (13), and the rotor baffle (13) stops outside the main shaft end (7).

7. An electric machine rotor according to claim 6, characterised in that the rotor baffle (13) is an interference fit with the shaft extension (6).

8. The motor rotor as recited in claim 6, characterized in that a nut (14) is further arranged outside the rotor baffle (13), the nut (14) is screwed with the shaft extension end (6), and the nut (14) axially limits the rotor baffle (13).

9. An electric machine rotor as claimed in any one of claims 1 to 8, characterized in that the carbon fibre sheath (2) has an interference fit with the cylinder.

10. The electric machine rotor as recited in any one of claims 1 to 8, wherein the outer peripheral surface of the cylinder is a smooth surface.

11. An electric machine rotor according to any of claims 1-8, characterized in that the first shaft (3) and the second shaft (5) are made of non-magnetically conductive material.

12. A permanent magnet electrical machine comprising an electrical machine rotor, characterized in that the electrical machine rotor is an electrical machine rotor according to any of claims 1-11.