GB2078017A - Rotor system for a rotating electrical machine - Google Patents

Abstract

Slip-rings 21a, 22a are mounted on a sleeve or pin (17) and the sleeve or pin is inserted into a bore (26) in the end face of the rotor shaft, to mount the slip-rings coaxially with the shaft. Application to commutator mounting is also disclosed. Connection leads 23a, b extend through bores in the rotor shaft (11) and sleeve (17). Ring 22a may be planar-ended (Figure 2, not shown). Sleeve 17 may be replaced by a pin with a longitudinal recess corresponding to bore 26. <IMAGE>

Description

SPECIFICATION Rotor system for a rotating electrical machine The invention relates to a rotor system for a rotating electrical machine.

In conventional rotor systems having a contacting arrangement for the rotor winding, the commutator or the slip-ring arrangement is mounted around the rotor shaft. This results in relatively large diameters of the contacting parts and a high peripheral velocity and thus a considerable amount of wear on the carbon brushes. Furthermore, in rotor systems having a contacting arrangement located outside the associated rotor shaft bearing, the diameter of the bearing must be very large in order that the contacting arrangement may be pushed through the bearing during assembly of the machine.

There is provided by the present invention a rotor system for a rotating electrical machine having a contacting device for the rotor winding, and a carrier for the contacting device, secured to the rotor shaft, wherein the carrier is in the form of a rod and is inserted axially symmetrically into an end of the rotor shaft, so as to mount the contacting device coaxially with the shaft.

In contrast to the conventional arrangements, the arrangement in accordance with the invention has the advantage that the rotor shaft can be shorter, thereby resulting in a saving of material. Further advantage is that the slip-rings or commutators can be chosen to have a small external diameter, thereby increasing the service life of the contacting device and the associated carbon brushes.

It is particularly advantageous that an inexpensive, commercially available mounting sleeve or a commercially available mounting pin can be used as the carrier. Furthermore, it is advantageous that the sleeve or the pin is held in the rotor shaft by its inherent spring force, i.e. by being force fitted.

Moreover, the inherent spring force of the pin or the sleeve holds the contacting device, that is to say, for example, the slip-rings. Finally, the connection leads can lead from the contacting device to the rotor winding in a simple manner within the sleeve or a bore in the pin. The connection leads are thus protected against external influences and damage.

Embodiments ofthe invention are illustrated in the accompanying drawings, in which: Figure 1 shows a contacting device having two annular slip-rings, and Figure 2 shows a contacting arrangement having an annular slip-ring and a planar ended slip-ring.

Referring to Figure 1, a rotor body 12 having a rotor winding 13 is secured two a rotor shaft 11. An end face 14 of the rotor shaft 11 incorporates a central bore 15. The front end 14 of the rotor shaft 11 is journalled in a ball bearing 16. A mounting sleeve 17 is inserted into the bore 15. A contacting device 18 comprising an insulating body 19, has two annular slip-rings 21 a, 22a and is slipped onto the free end of the clamping sleeve 17. Connection leads 23a, 23b lead from the rotor winding 13 through bores 25a, 25b in the rotor shaft 11 and then through the bore 26 of the clamping sleeve 17 to the slip-rings 21 a, 22a that is to say, the connection lead 23a leads through a bore 24 in the clamping sleeve 17 and the connection lead 23b leads through an opening 27 in the insulating body 19.

In the second embodiment illustrated in Figure 2, the same reference numerais are used for the same components. The essential difference between the two embodiments is that the slip-ring 22b is in the form of a planar ended slip-ring and is slipped onto that end 28 of the sleeve 17 which is remote from the rotor shaft 11, with lead 23b making contact with the inner face of the end wall of the slip-ring.

Alternatively, instead of using a sleeve 17, a mounting pin having a longitudinal recess corresponding to the bore 26 can be provided. Both the mounting pin and sleeve are held in the bore 15 of the rotor shaft 11 by their inherent radially directed spring force, i.e. they are force fitted. The insulating body 19 having the slip-rings 21,22 is also likewise retained by the sleeve 17 or the pin as the case may be.

1. A rotor system for a rotating electrical machine having a contacting device for the rotor winding, and a carrier for the contacting device, secured to the rotor shaft, wherein the carrier is in the form of a rod and is inserted axially symmetrically into and end of the rotor shaft, so as to mount the contacting device coaxiallywith the shaft.

2. A rotor system as claimed in claim 1, wherein the carrier has a through hole which extends substantially axially symmetrically in the longitudinal direction of the carrier.

3. A rotor system as claimed in claim 2, wherein connection leads leading to the winding of the rotor are passed through the through hole.

4. A rotor system as claimed in any of the preceding claims, wherein the carrier is in the form of a sleeve.

5. A rotor system as claimed in any of claims 1 to 3, wherein the carrier is a mounting pin.

6. A rotor system as claimed in any of the preceding claims, wherein a bearing for the rotor shaft is provided spaced between the contacting device and the rotor body.

7. A rotor system as claimed in any of the preceding claims, wherein the contacting device is constructed with slip-rings of cap form and is slipped onto the carrier.

8. A rotor system as claimed in claim 7, wherein one of the slip-rings is a planar ended slip-ring.

9. A rotor system as claimed in claim 3 and any of claims 4 to 8 as dependent thereon, wherein the rotor shaft incorporates at least one radial bore through which the connection leads are guided from the contacting device to the winding.

10. A rotor system substantially as hereinbefore described with reference to Figure 1 or Figure 2 of the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (10)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Rotor system for a rotating electrical machine The invention relates to a rotor system for a rotating electrical machine. In conventional rotor systems having a contacting arrangement for the rotor winding, the commutator or the slip-ring arrangement is mounted around the rotor shaft. This results in relatively large diameters of the contacting parts and a high peripheral velocity and thus a considerable amount of wear on the carbon brushes. Furthermore, in rotor systems having a contacting arrangement located outside the associated rotor shaft bearing, the diameter of the bearing must be very large in order that the contacting arrangement may be pushed through the bearing during assembly of the machine. There is provided by the present invention a rotor system for a rotating electrical machine having a contacting device for the rotor winding, and a carrier for the contacting device, secured to the rotor shaft, wherein the carrier is in the form of a rod and is inserted axially symmetrically into an end of the rotor shaft, so as to mount the contacting device coaxially with the shaft. In contrast to the conventional arrangements, the arrangement in accordance with the invention has the advantage that the rotor shaft can be shorter, thereby resulting in a saving of material. Further advantage is that the slip-rings or commutators can be chosen to have a small external diameter, thereby increasing the service life of the contacting device and the associated carbon brushes. It is particularly advantageous that an inexpensive, commercially available mounting sleeve or a commercially available mounting pin can be used as the carrier. Furthermore, it is advantageous that the sleeve or the pin is held in the rotor shaft by its inherent spring force, i.e. by being force fitted. Moreover, the inherent spring force of the pin or the sleeve holds the contacting device, that is to say, for example, the slip-rings. Finally, the connection leads can lead from the contacting device to the rotor winding in a simple manner within the sleeve or a bore in the pin. The connection leads are thus protected against external influences and damage. Embodiments ofthe invention are illustrated in the accompanying drawings, in which: Figure 1 shows a contacting device having two annular slip-rings, and Figure 2 shows a contacting arrangement having an annular slip-ring and a planar ended slip-ring. Referring to Figure 1, a rotor body 12 having a rotor winding 13 is secured two a rotor shaft 11. An end face 14 of the rotor shaft 11 incorporates a central bore 15. The front end 14 of the rotor shaft 11 is journalled in a ball bearing 16. A mounting sleeve 17 is inserted into the bore 15. A contacting device 18 comprising an insulating body 19, has two annular slip-rings 21 a, 22a and is slipped onto the free end of the clamping sleeve 17. Connection leads 23a, 23b lead from the rotor winding 13 through bores 25a, 25b in the rotor shaft 11 and then through the bore 26 of the clamping sleeve 17 to the slip-rings 21 a, 22a that is to say, the connection lead 23a leads through a bore 24 in the clamping sleeve 17 and the connection lead 23b leads through an opening 27 in the insulating body 19. In the second embodiment illustrated in Figure 2, the same reference numerais are used for the same components. The essential difference between the two embodiments is that the slip-ring 22b is in the form of a planar ended slip-ring and is slipped onto that end 28 of the sleeve 17 which is remote from the rotor shaft 11, with lead 23b making contact with the inner face of the end wall of the slip-ring. Alternatively, instead of using a sleeve 17, a mounting pin having a longitudinal recess corresponding to the bore 26 can be provided. Both the mounting pin and sleeve are held in the bore 15 of the rotor shaft 11 by their inherent radially directed spring force, i.e. they are force fitted. The insulating body 19 having the slip-rings 21,22 is also likewise retained by the sleeve 17 or the pin as the case may be. CLAIMS

1. A rotor system for a rotating electrical machine having a contacting device for the rotor winding, and a carrier for the contacting device, secured to the rotor shaft, wherein the carrier is in the form of a rod and is inserted axially symmetrically into and end of the rotor shaft, so as to mount the contacting device coaxiallywith the shaft.

2. A rotor system as claimed in claim 1, wherein the carrier has a through hole which extends substantially axially symmetrically in the longitudinal direction of the carrier.

3. A rotor system as claimed in claim 2, wherein connection leads leading to the winding of the rotor are passed through the through hole.

4. A rotor system as claimed in any of the preceding claims, wherein the carrier is in the form of a sleeve.

5. A rotor system as claimed in any of claims 1 to 3, wherein the carrier is a mounting pin.

6. A rotor system as claimed in any of the preceding claims, wherein a bearing for the rotor shaft is provided spaced between the contacting device and the rotor body.

7. A rotor system as claimed in any of the preceding claims, wherein the contacting device is constructed with slip-rings of cap form and is slipped onto the carrier.

8. A rotor system as claimed in claim 7, wherein one of the slip-rings is a planar ended slip-ring.

9. A rotor system as claimed in claim 3 and any of claims 4 to 8 as dependent thereon, wherein the rotor shaft incorporates at least one radial bore through which the connection leads are guided from the contacting device to the winding.

10. A rotor system substantially as hereinbefore described with reference to Figure 1 or Figure 2 of the accompanying drawing.