CN-122001123-A - Rotor with self-fixing end plate

Abstract

The present disclosure provides a "rotor with self-securing end plates". A permanent magnet synchronous motor includes a rotor. The rotor is formed by sliding a rotor plate and an end plate onto a rotor shaft. At least one of the end plates is axially secured to the rotor shaft by rotating the at least one end plate such that a key engages a circumferential keyway in the shaft. An axial keyway allows the end plate to slide into the circumferential keyway. The axial keyway may also be used to rotationally fix the rotor plate to the shaft. The second end plate may be axially fixed in a similar manner or may be axially fixed by a shoulder.

Inventors

• M. SCHMIDT

Assignees

• 福特全球技术公司

Dates

Publication Date

20260508

Application Date

20251021

Priority Date

20241029

Claims (15)

1. 1. A rotor, comprising: A shaft defining a first circumferential keyway and a first axial keyway extending from a first step in the shaft at least to the first circumferential keyway; a first end plate having a first inner key positioned in the first circumferential keyway to prevent axial movement of the first end plate, and At least one rotor plate rotationally fixed to the shaft on a side of the first end plate opposite the step in the shaft.
2. 2. The rotor of claim 1, wherein: the first circumferential keyway defining a recess in the shaft facing the first step, and The first inner key is located in the recess.
3. 3. The rotor of claim 1, further comprising a second end plate having a second inner key located in a second circumferential keyway, wherein the first end plate and the second end plate are on opposite sides of the at least one rotor plate.
4. 4. A rotor as claimed in claim 3, wherein: The first axial keyway extending from the first step in the shaft to at least the second circumferential keyway, and Each of the at least one rotor plate has a third inner key located in the first axial keyway.
5. 5. A rotor as claimed in claim 3, wherein the shaft defines a second axial keyway extending from a second step in the shaft to at least the second circumferential keyway, the first step in the shaft and the second step in the shaft being located on opposite ends of the shaft relative to the at least one rotor plate.
6. 6. The rotor of claim 1, further comprising a second end plate abutting a shoulder in the shaft, and wherein the first end plate and the second end plate are on opposite sides of the at least one rotor plate.
7. 7. The rotor of claim 1, wherein the first end plate is made of a different material than the at least one rotor plate.
8. 8. A method of assembling a rotor, comprising: Sliding at least one rotor plate onto a shaft, the shaft having a first axial keyway and a first circumferential keyway; sliding a first end plate onto the shaft, the first end plate having a first key sliding within the first axial keyway, and After sliding the first end plate onto the shaft, the first end plate is rotated such that the first key engages the first circumferential keyway.
9. 9. The method of claim 8, further comprising: sliding a second end plate onto the shaft, the second end plate having a second key sliding within the first axial keyway, and After sliding the second end plate onto the shaft, the second end plate is rotated such that the second key engages a second circumferential keyway in the shaft.
10. 10. The method of claim 8, further comprising: Sliding a second end plate onto the shaft, the second end plate having a second key sliding within a second axial keyway in the shaft, and After sliding the second end plate onto the shaft, the second end plate is rotated such that the second key engages a second circumferential keyway in the shaft.
11. 11. The method of claim 8, further comprising sliding a second end plate onto the shaft such that the second end plate abuts a shoulder in the shaft prior to sliding the first end plate and the at least one rotor plate onto the shaft.
12. 12. A motor, comprising: A stator; A rotor shaft supported for rotation relative to the stator, and A plurality of rotor plates, each rotor plate having a permanent magnet, the plurality of rotor plates being secured to the rotor shaft and being axially compressed between a first end plate and a second end plate, wherein The first end plate has a first key that engages a first circumferential keyway in the rotor shaft.
13. 13. The motor of claim 12, wherein: The rotor shaft defining a shoulder, and The second end plate abuts the shoulder.
14. 14. The motor of claim 12, wherein: The rotor shaft defining a second circumferential keyway; the second end plate having a second key engaging the second circumferential keyway, and The rotor shaft defines an axial keyway extending from a first step in the shaft, through the first circumferential keyway, and at least to the second circumferential keyway.
15. 15. The motor of claim 12, wherein: The rotor shaft defining a second circumferential keyway; the second end plate has a second key that engages the second circumferential keyway; the rotor shaft defines a first axial keyway extending from a first step in the shaft at least to the first circumferential keyway, and The rotor shaft defines a second axial keyway extending from a second step in the shaft at least to the second circumferential keyway.

Description

Rotor with self-fixing end plate Technical Field The present disclosure relates to electric motors. More specifically, the present disclosure relates to a permanent magnet motor having at least one end plate secured by a circumferential keyway. Background Many motorized vehicles utilize a permanent magnet synchronous traction motor. A permanent magnet synchronous traction motor includes a rotor having a plurality of rotor plates secured to a rotor shaft. The rotor plate is made of magnetically permeable material and has pockets in which permanent magnets are mounted to establish a pattern of alternating north and south magnetic fields around a circumference. These magnetic fields interact with the magnetic fields generated by the currents in the motor stator to produce torque on the rotor shaft. The rotor may also include end plates, which are not necessarily made of magnetically permeable material. The end plates may be axially positioned by a combination of snap rings and bolts extending through the rotor plate. Disclosure of Invention A rotor includes a shaft, a first end plate, and at least one rotor plate. The shaft defines a first circumferential keyway and a first axial keyway. The first axial keyway extends from a first step in the shaft to at least the first circumferential keyway. The first circumferential keyway may extend only partially around the shaft. The first circumferential keyway may define a recess in the shaft facing the first step. The first end plate has a first inner key located in the first circumferential keyway to prevent axial movement of the first end plate. The first internal key may be located in the recess. The rotor plate is rotationally fixed to the shaft on a side of the first end plate opposite the step in the shaft. Each of the rotor plates may have a third inner key located in the first axial keyway. A second end plate having a second inner key may be located in the second circumferential keyway. The first end plate and the second end plate may be on opposite sides of the rotor plate. The first axial keyway may extend from a first step in the shaft to at least the second circumferential keyway. Alternatively, the shaft may define a second axial keyway extending from a second step in the shaft to at least a second circumferential keyway. In yet another alternative, the second end plate may abut a shoulder in the shaft. The end plates may be made of a different material than the rotor plates. A method of assembling a rotor includes sliding a rotor plate and a first end plate onto a shaft. The shaft has a first axial keyway and a first circumferential keyway. The first end plate has a first key that slides within the first axial keyway. After sliding the first end plate onto the shaft, the first end plate is rotated such that the first key engages the first circumferential keyway. The rotor plate may also have a key that engages the first axial keyway. The method may further include sliding a second end plate onto the shaft. The second end plate may have a second key that slides within the first axial keyway. After sliding the second end plate onto the shaft, the second end plate is rotated such that the second key engages a second circumferential keyway in the shaft. The first end plate, the second end plate, and the rotor plate are all slidable onto the shaft from a first end of the shaft. Alternatively, the first end plate and the second end plate may be slid onto the shaft from opposite ends of the shaft. Alternatively, the second key may slide within a second axial keyway in the shaft. In yet another alternative, the second end plate may abut a shoulder in the shaft. A motor includes a stator, a rotor shaft, a plurality of rotor plates, a first end plate, and a second end plate. The rotor shaft is supported for rotation relative to the stator. Each of the rotor plates has a permanent magnet. The rotor plate is fixed to the rotor shaft and axially compressed between the first end plate and the second end plate. The first end plate has a first key that engages a first circumferential keyway in the rotor shaft. The second end plate may abut a shoulder in the rotor shaft. The rotor shaft may define a second circumferential keyway. The second end plate may have a second key that engages the second axial keyway. The rotor shaft may define an axial keyway extending from a first step in the shaft, through the first circumferential keyway, and at least to the second circumferential keyway. Alternatively, the rotor shaft may define a first axial keyway extending from a first step in the shaft to at least a first circumferential keyway, and a second axial keyway extending from a second step in the shaft to at least a second circumferential keyway. Drawings Fig. 1 is a block diagram of an electric vehicle. Fig. 2 is a schematic cross-sectional view of an electric motor. Fig. 3 is a perspective view of the rotor of the permanent magnet electric motor. Fig. 4 is a perspective view