Rotor for an Electric Motor, Electric Motor, and Method for Producing a Rotor

Abstract

A rotor for an electric motor includes a shaft having a central portion supporting a laminated core of an electrical sheet material. The central portion is also composed of an electrical sheet material. The ends of the rotor shaft may be formed from a different material than the material of the central portion, and may be connected to the central portion by a force-fitting interference fit and/or a knurled interference fit. An electric motor having such a rotor and a method for producing a such a rotor are provided.

Claims

1-5. (canceled)

6. A rotor for an electric motor, comprising: a shaft; and a laminated core supported on the shaft, wherein the laminated core is formed from a first electrical sheet material, and a central portion of the shaft which supports the laminated core is formed from a second electrical sheet material.

7. The rotor according to claim 6, wherein the first electrical sheet material and the second electrical sheet material are the same material.

8. The rotor according to claim 6, wherein the laminated core is configured to support permanent magnets.

9. The rotor according to claim 6, wherein the laminated core is configured to support a squirrel cage rotor.

10. The rotor according to claim 6, wherein the shaft includes has two end components connected to the central portion of the shaft, the central portion is hollow, the two end components are formed from a material which is different from the central portion material.

11. The rotor according to claim 10, wherein at least one of the two end components is connected to the central portion by a force-fitting interference fit.

12. The rotor according to claim 11, wherein at least one of the two end components is connected to the central portion by a knurled interference fit.

13. The rotor according to claim 10, wherein one of the two end components is connected to the central portion by a force-fitting interference fit and the other of the two end components is connected to the central portion by a knurled interference fit.

14. An electric motor, comprising: a rotor having a shaft and a laminated core supported on the shaft, wherein the laminated core is formed from a first electrical sheet material, and a central portion of the shaft which supports the laminated core is formed from a second electrical sheet material.

15. The electric motor according to claim 14, wherein the first electrical sheet material and the second electrical sheet material are the same material.

16. A method for producing a rotor for an electric motor, comprising the steps of: forming a laminated core at least in part from a first electrical sheet material; forming at least a central portion of a shaft at least in part from a second electrical sheet material; and locating the laminated core on the shaft.

17. The method according to claim 16, wherein the shaft includes the central portion and two end components connected to the central portion, and the two end components are formed from a material which is different from the central portion material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG. 1 shows a sectional isometric illustration of a first variant of a rotor in accordance with the present invention;

[0042] FIG. 2 shows a sectional isometric illustration of a second variant of a rotor in accordance with the present invention; and

[0043] FIG. 3 shows a partially sectional exploded illustration of the shaft of FIG. 2.

DETAILED DESCRIPTION

[0044] FIG. 1 shows a rotor which is part of an electric motor, for example.

[0045] The rotor possesses a shaft 1. The shaft 1, for example when in use, is connected to rotatable components or, for example, a gearbox and transmits a torque to the components or gearbox.

[0046] A laminated core 2 is situated on the central portion 10 of the shaft 1. As is commonplace in the prior art, the laminated core 2 is composed of electrical sheet and functions as a support of a squirrel cage rotor (not illustrated here).

[0047] The shaft 1 here is integrally designed and is at least in part composed of an electrical sheet material. The material of the shaft 1 in one design embodiment here is identical to the material of the laminated core 2. In an alternative design embodiment, two different electrical sheet materials are used for the shaft 1 and the laminated core 2. Depending on the design embodiment, inserts or supporting structures are provided in the shaft 1 in order to generate the required levels of strength.

[0048] FIG. 2 shows an alternative embodiment of the shaft 1 for a rotor. The shaft here is in particular a constructed shaft 1. As opposed to the integral shaft 1 of the design embodiment of FIG. 1, this permits the respective matching materials to be used for different portions.

[0049] The shaft 1 is composed of three component parts: the central portion 10 for the electrical laminated core 2, and two end components 11 for the connection to further components or component parts of a vehicle, for example. The end components 11 thus also form the end sides of the shaft 1. The central portion 10 is composed of an electrical sheet material. The two end components 11 are not composed of electrical sheet material but, for example, of common steel, for example the previously mentioned carbon steels.

[0050] The central portion 10 here is designed as a hollow shaft, and the two end components 11 are plugged into the central portion 10.

[0051] The mechanical connection between the central portion 10 and the two end components 11 here is implemented by way of a type of hybrid connection, having a force-fitting interference fit 15 and, axially adjoining the latter, a knurled interference fit 16. A portion of an end region 11 has been provided with a knurl for the knurled interference fit 16. The knurled interference fit 16 is in each case manufactured so as to run axially in the direction away from the central portion 10 so that the interference fit 10 is in each case axially inside.

[0052] The construction of the shaft 1, here in three parts, is illustrated in FIG. 3. The two end components 11 are fixed in the central portion 10 which is designed as a hollow tube. The axially inner region for the interference fit 15, on the one hand, and the knurled region, which is axially further outward, for the knurled interference fit 16, on the other hand, can be seen here, in particular, in the case of the end component 11 illustrated on the left-hand side.