Motor rotor structure

Abstract

The utility model discloses a motor rotor structure, which belongs to the technical field of motors, a motor rotor is arranged in a stator and comprises a shaft, the shaft is of a split structure and comprises a shaft head, a shaft body and a shaft tail which are sequentially connected end to end, the shaft head and the shaft tail are symmetrically arranged on two axial sides of the shaft body, and a liquid cooling loop is formed in an inner cavity of a motor. According to the motor rotor structure, the shaft head, the shaft body and the shaft tail are split, so that the centering of the bearing is ensured, the roughness and the hardness of the circumferential surface and the end surface matched with the bearing are also ensured, the abrasion of the bearing is reduced, and the service life of the bearing is further prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to a motor rotor structure. Background Art

[0002] When designing and using a brushless DC motor for a pump, the coolant is used to cool the inside of the motor. Since ordinary ball bearings have large turbulence losses when the rolling elements rotate when working in the coolant, many designs use graphite bearings. Graphite is an excellent self-lubricating and anti-wear material that can work in high-temperature, high-viscosity media, and is particularly suitable for use in media working conditions such as water, fuel, and gasoline.

[0003] In order to improve the service life of the bearing, the roughness and hardness of the grinding surface of the shaft are usually required to be high. However, it is difficult to ensure that the circumferential surface of the shaft shoulder and the end face of the shaft shoulder of the bearing can reach high roughness and hardness at the same time during processing. Utility Model Content

[0004] The utility model aims to provide a motor rotor structure to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the utility model provides the following technical solutions: a motor rotor structure is arranged in a stator, and the motor rotor structure includes: a shaft, which is a split structure, including a shaft head, a shaft body and a shaft tail connected end to end in sequence, and the shaft head and the shaft tail are symmetrically arranged on both sides of the axial direction of the shaft body to form a liquid cooling circuit in the inner cavity of the motor.

[0006] Preferably, the shaft body and the shaft head are fitted by interference fit.

[0007] Preferably, the shaft body and the shaft tail are fitted by interference fit.

[0008] Preferably, after the shaft head and the shaft body, as well as the shaft tail and the shaft body are heat-fitted, pins are symmetrically and evenly provided on the circumference.

[0009] Preferably, the motor rotor structure further comprises a graphite bearing, and the graphite bearing comprises a front graphite bearing arranged at the shaft head and a rear graphite bearing arranged at the shaft tail.

[0010] Preferably, the graphite bearing inner ring contacts the bearing mating circumferential surface, and the graphite bearing outer ring is fitted with the stator by interference fit.

[0011] Preferably, the front end of the front graphite bearing along the direction of the lubrication groove cooling oil circuit of the graphite bearing itself contacts the bearing matching shoulder peripheral end surface of the shaft body, and the rear end of the rear graphite bearing along the direction of the lubrication groove cooling oil circuit of the rear graphite bearing itself contacts the bearing matching shoulder peripheral end surface of the shaft body.

[0012] Preferably, the motor rotor structure further comprises a magnetic steel, wherein the magnetic steel is half-embedded in the magnetic steel embedding groove of the shaft body, and the outer cylindrical surface of the magnetic steel is interference fit with a sleeve.

[0013] Preferably, the liquid cooling circuit includes: a gap between the shaft head and the stator, a lubrication groove of the front graphite bearing itself, a gap between the shaft body and the sleeve and the stator, a lubrication groove of the rear graphite bearing itself, a gap between the shaft tail and the stator, and hollow oil guide grooves of the shaft head, the shaft body and the shaft tail themselves.

[0014] Beneficial effects: The split shaft head, shaft body and shaft tail structure of the motor rotor shaft ensures the alignment of the bearing while also ensuring the roughness and hardness of the circumferential surface and end surface matching the bearing, thereby reducing the wear of the bearing and thus increasing the life of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0016] Figure 1 It is a schematic diagram of the rotor structure of this motor;

[0017] Figure 2 This is a schematic diagram of the rotor shaft mating surface of this motor;

[0018] Figure 3 It is a schematic diagram of the circumferential cross-section of the motor rotor pin fastening.

[0019] The reference numerals in the figure are: shaft head 1, stator 2, front graphite bearing 3, shaft body 4, pin 5, magnetic steel 6, sleeve 7, shaft tail 8, rear graphite bearing 9, bearing matching shoulder peripheral end face 10, bearing matching circumferential surface 11. DETAILED DESCRIPTION

[0020] In the following description, a large number of specific details are given to provide a more thorough understanding of the utility model. However, it is obvious to those skilled in the art that the utility model can be implemented without one or more of these details. In other examples, in order to avoid confusion with the utility model, some technical features known in the art are not described.

[0021] Reference Figure 1 , Figure 2 , Figure 3The motor rotor structure provided by the utility model includes a shaft. The shaft is a split structure, including a shaft head 1, a shaft body 4 and a shaft tail 8 which are connected in sequence from head to tail, and a liquid cooling circuit is formed inside the motor. The shaft head 1, the shaft body 4 and the shaft tail 8 are processed separately. The separately processed shaft head 1 and the shaft tail 8 ensure the runout of the circular rotating surface, the coaxiality of the shaft center, the roughness, the hardness and other requirements during processing, and also facilitate the flatness, roughness and hardness of the two end faces of the shaft body 4. After ensuring the processing dimensions, form and position tolerances and other requirements of the parts respectively, the shaft head 1 and the shaft body 4, the shaft tail 8 and the shaft body 4 are all installed by interference hot-fitting. During hot-fitting, the shaft body is first heated and expanded, thereby increasing the diameter of the shaft body 4. The shaft head 1 and the shaft tail 8 are symmetrically placed in the measuring assembly position of the shaft body 4 through the action of force. When the temperature is cooled to room temperature, the shaft body 4 will shrink, thereby achieving precise assembly. The circumferential connections between the shaft head 1 and the shaft body 4, and between the shaft tail 8 and the shaft body 4 are circumferentially fixed by means of pins 5 to prevent relative rotation of the connections, and the pins 5 are symmetrically and evenly distributed on the circumferential surface.

[0022] The stator 2 includes a housing, an end cover, an armature, etc., and the figure only illustrates the main body of the motor related to the utility model.

[0023] The graphite bearing includes a front graphite bearing 3 arranged at the shaft head 1 and a rear graphite bearing 9 arranged at the shaft tail 4. The inner ring of the graphite bearing contacts the bearing mating circumferential surface 11. The outer rings of the front graphite bearing 3 and the rear graphite bearing 9 are assembled with the housing and the end cover in the stator 2 by means of interference shrink fitting. The front end of the front graphite bearing 3 along the direction of the lubrication groove cooling oil path of the graphite bearing itself contacts the bearing mating shoulder peripheral end surface 10 of the shaft body 4, and the rear end of the rear graphite bearing 9 along the direction of the lubrication groove cooling oil path of the graphite bearing itself contacts the bearing mating shoulder peripheral end surface 10 of the shaft body 4.

[0024] A magnetic steel embedding groove is provided on the outer circumferential surface of the shaft body 4 , and the magnetic steel 6 is embedded in the magnetic steel embedding groove, leaving only the outer circumferential surface of the magnetic steel 6 exposed, and the sheath 7 is interference fit and covers the outer circumferential surface of the magnetic steel 6 .

[0025] The liquid flow path in the inner cavity of the motor is composed of the gap between the shaft head 1 and the stator 2, the lubrication groove of the front graphite bearing 3 itself, the gap between the shaft body 4 and the sleeve 7 and the stator 2, the lubrication groove of the rear graphite bearing 9 itself, the gap between the shaft tail 8 and the stator 2, and the hollow oil guide grooves of the shaft head 1, the shaft body 4 and the shaft tail 8 themselves. When the DC brushless motor is in use, the coolant circulates through the liquid flow path to cool the inside of the motor.

[0026] The rotor structure of the motor adopts a split shaft head 1, shaft body 4, and shaft tail 8 structure, which is convenient for ensuring the runout of the circular rotating surface, the coaxiality of the shaft center, roughness, hardness and other requirements of the shaft head 1 and the shaft tail 8 during processing, and is also convenient for ensuring the flatness, roughness, and hardness of the two end surfaces of the shaft body 4, reducing the wear of the bearing mating surface, and thus improving the bearing life.

[0027] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be interpreted as limiting the present invention itself. Various changes can be made to it in form and detail without departing from the spirit and scope of the present invention defined in the appended claims.

Claims

1. A motor rotor structure, arranged in a stator, characterized in that: The motor rotor structure includes: a shaft, which is a split structure, including a shaft head, a shaft body and a shaft tail connected end to end in sequence, and the shaft head and the shaft tail are symmetrically arranged on both sides of the shaft body in the axial direction to form a liquid cooling circuit in the inner cavity of the motor.

2. The motor rotor structure according to claim 1, characterized in that: The shaft body and the shaft head are in interference fit.

3. The motor rotor structure according to claim 1, characterized in that: The shaft body and the shaft tail are in interference fit.

4. The motor rotor structure according to claim 1, characterized in that: Pins are symmetrically and evenly arranged at the circumferences where the shaft head and the shaft body are connected, and where the shaft tail and the shaft body are connected.

5. The motor rotor structure according to claim 1, characterized in that: The motor rotor structure also includes a graphite bearing, and the graphite bearing includes a front graphite bearing arranged at the shaft head and a rear graphite bearing arranged at the shaft tail.

6. The motor rotor structure according to claim 5, characterized in that: The inner ring of the graphite bearing is in contact with the matching circumferential surface of the bearing, and the outer ring of the graphite bearing is fitted with the stator by means of interference fit.

7. The motor rotor structure according to claim 5, characterized in that: The front end of the front graphite bearing along the direction of the lubrication groove cooling oil circuit of the graphite bearing itself contacts the bearing matching shoulder peripheral end surface of the shaft body, and the rear end of the rear graphite bearing along the direction of the lubrication groove cooling oil circuit of the rear graphite bearing itself contacts the bearing matching shoulder peripheral end surface of the shaft body.

8. The motor rotor structure according to claim 5, characterized in that: The motor rotor structure also includes a magnetic steel, which is half-embedded in the magnetic steel embedding groove of the shaft body, and the outer cylindrical surface of the magnetic steel is interference-fitted with a sleeve.

9. The motor rotor structure according to claim 8, characterized in that: The liquid cooling circuit includes: a gap between the shaft head and the stator, a lubrication groove of the front graphite bearing itself, a gap between the shaft body and the sleeve and the stator, a lubrication groove of the rear graphite bearing itself, a gap between the shaft tail and the stator, and hollow oil guide grooves of the shaft head, the shaft body and the shaft tail themselves.

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