Rotor of a current-activated electric machine having an improved slot filling

Abstract

A rotor of a current-activated electric machine has a plurality of windings which are arranged on the rotor, slots being formed between the windings. A textile has a plurality of fibers connected to one another in flat contact. The textile is arranged in at least one slot, and the textile is impregnated with a filling material which in the normal operational state of the rotor is in a solid state.

Claims

1. A rotor of a current-excited electrical machine, comprising: a plurality of rotor teeth, each rotor tooth having a winding arranged around the respective rotor tooth, wherein a plurality of slots are formed each respectively between the respective winding of successive rotor teeth; and a textile which has a plurality of fibers, wherein the textile is arranged in at least one of the slots, and the textile is impregnated with a filling material which, in a normal operating state of the rotor, is in a solid state.

2. The rotor as claimed in claim 1, wherein the fibers are aramid and/or an aromatic polyaramid.

3. The rotor as claimed in claim 2, wherein the textile is a woven fabric or a nonwoven.

4. The rotor as claimed in claim 3, wherein the textile is arranged in all of the slots of the rotor.

5. The rotor as claimed in claim 1, wherein the textile is a woven fabric or a nonwoven.

6. The rotor as claimed in claim 1, wherein a textile is arranged, respectively, in a plurality of slots of the rotor.

7. The rotor as claimed in claim 1, wherein the filling material is: a resin, and/or an impregnating resin.

8. The rotor as claimed in claim 7, wherein the textile is: an aramid nonwoven, or an aramid woven fabric.

9. The rotor as claimed in claim 1, wherein the textile is: an aramid nonwoven, or an aramid woven fabric.

10. A current-excited electrical machine having a rotor as claimed in claim 1.

11. A method for producing a rotor of a current-excited electrical machine, the rotor including: a plurality of teeth, each rotor tooth having a winding arranged around the respective rotor tooth, wherein a plurality of slots are formed each respectively between the respective winding of successive rotor teeth, the method comprising the acts of: filling at least one of the slots between two windings of respective rotor teeth of the rotor with a textile having a plurality of fibers; and impregnating the textile with a filler, which during impregnation is in the liquid state and during normal operation of the rotor is in solid state.

12. The method as claimed in claim 11, wherein the filler is one of: a resin, or an impregnating resin.

13. The method as claimed in claim 12, wherein the textile exhibits one of: a nonwoven, or a woven fabric.

14. The method as claimed in claim 13, wherein the fibers are aramid fibers.

15. The method as claimed in claim 11, wherein the textile exhibits one of: a nonwoven, or a woven fabric.

16. The method as claimed in claim 11, wherein the fibers are aramid fibers.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) FIG. 1 illustrates a section through a rotor according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWING

(2) FIG. 1 shows a partial section through a rotor 1. The rotor 1 has a plurality of laminate stacks 6 which are arranged rigidly on a spindle 2.

(3) Each laminate stack 6 has a pole or a tooth 4. Arranged on each tooth 4 is a winding 10, wherein a copper wire 8 is wound around the tooth 4. It is possible for all windings 10 of the rotor 1 to be wound by use of a single wire 8.

(4) According to the invention, a nonwoven 12, made for example of aramid fibers, is introduced into the slot 16. The nonwoven 12 can, as in FIG. 1, be arranged in the slot 16 in several layers wound one over another. However, it is also possible to roll up the nonwoven to a greater or lesser extent and then introduce it into the slot 6.

(5) Once the nonwoven 12 has been arranged in the slot 16, the slot 16 is encapsulated, immersed or poured into with a resin 14. As a result, the nonwoven 12 is impregnated. The temperature of the resin 14 during impregnation is approximately in the region of room temperature or at temperatures of up to 200 C. The resin 14 solidifies at room temperature or at temperatures of up to 200 C. and below.

(6) The solidified resin 14 and the nonwoven 12 form a slot closure of the slot 16, thereby ensuring that the centrifugal force cannot move the wires 8 in a winding out of their predetermined position. Consequently, the rotor 1 can be operated at a much higher rotational speed than is the case in rotors without a slot closure or in rotors which have only a resin as a slot closure.

(7) The rotor according to the invention can be arranged in an electrical machine which drives a vehicle. Since the rotor has a higher rotational speed range, the electrical machine can be operated more efficiently and it may be possible to dispense with a manual transmission. Furthermore, the motor can be built in a smaller and lighter manner with the same performance as a result of the increase in rotational speed.

(8) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.