GB2443172A

GB2443172A - Apparatus for assembling a generator to an engine

Info

Publication number: GB2443172A
Application number: GB0618772A
Authority: GB
Inventors: Kerry William Marsh
Original assignee: Newage International Ltd; Cummins Generator Technologies Ltd
Current assignee: Cummins Generator Technologies Ltd
Priority date: 2006-09-22
Filing date: 2006-09-22
Publication date: 2008-04-30
Also published as: GB0618772D0

Abstract

An apparatus 14 for assembling a generator to an engine comprises a first portion 16 for attaching to a generator housing 2, and a second portion 18 mounted to the first portion for attachment to a rotor shaft 8. An actuator 34 causes relative axial movement of the first and second portions so as to effect axial movement of the rotor shaft with respect to generator housing. An outer part 32 of the second portion may be mounted to the first portion by means of a helical track 29 and track follower 28. Thus, a coupling disc 10 at a drive end 4 of an engine may be exposed for easier connection to a flywheel.

Description

APPARATUS FOR ASSEMBLY OF GENERATOR SETS

This invention relates to apparatus for the assembly of generator sets, and in particular to apparatus for facilitating connection of the rotor of a generator to the flywheel of an engine in such sets.

A generator set generally comprises a generator and an engine for driving the generator, both being contained in respective housings. To assemble the generator set, the engine flywheel has to be connected to the generator rotor shaft, and the adjacent ends of the housings are then fixed together. The rotor shaft of the generator extends axially within the housing, and runs in a bearing in a bracket at the end of the housing remote from the engine, known as the non-drive end. At the drive end, the rotor shaft commonly mounts a coupling disc. The coupling disc is provided for connection to the flywheel of the engine, and is located within the generator housing at the drive end.

The assembler of a generator set faces two main difficulties; locating the coupling disc in the correct position with respect to the flywheel, and accessing bolts to fasten the disc to the flywheel, which are commonly spaced around the periphery of the disc.

Traditionally the coupling disc includes a dowel or pin fitted as an assembly aid to locate it in the correct position with respect to the flywheel for connection thereto. In this position, the housings of the generator and the engine are also abutting for fastening together.

Therefore the only way of connecting the disc to the flywheel has been to feed bolts through cooling apertures in the generator housing near the drive end. These cooling apertures are provided adjacent a cooling fan, and therefore the bolts must be manipulated past the blades of the fan towards the flywheel. Often the crankshaft and rotor must then be turned in order to access the next bolt hole. This procedure is difficult and time consuming.

To assist in this process, it has been proposed to withdraw the rotor shaft partly out of the generator housing at the drive end. This would give much better access to the positions of the bolts. However, in practice it is extremely difficult to dislodge the rotor shaft bearing from the non-drive end bracket.

This invention aims to facilitate the withdrawal of the rotor shaft to allow the coupling disc to be accessed in a convenient way.

According to the present invention there is provided apparatus for assembling a generator to an engine, the generator having a housing and an axially extending rotor shaft, the apparatus comprising a first portion arranged to be connectable to the generator housing, and a second portion arranged to be connectable to the rotor shaft for axial movement therewith, the second portion being mounted to the first portion, and an actuator for causing relative reciprocating movement between the first and second portion, so as to effect axial movement of the rotor shaft with respect to the housing.

The apparatus is intended to be assembled to the generator housing and the rotor shaft at the non-drive end of the generator. Operation of the actuator then causes movement of the second portion relative to the first portion to push the rotor shaft towards the drive end. This exposes the coupling disc at the drive end, which may then be connected more easily to the flywheel of the engine. With the rotor shaft now fixed to the engine, the actuation may be reversed to move the generator housing back over the rotor shaft. The generator housing may then be bolted to the flywheel housing to complete the assembly.

The second portion may for example comprise an inner part in the form of a shaft extension fixable to the end of the rotor shaft, and an outer part rotatable relative to the shaft extension. The outer part of the second portion may be mounted to the first portion of the apparatus by means of a track and track follower, such that rotation of the second portion of the apparatus causes axial movement relative to the first portion.

Thus the actuator may comprise a lever for manual rotation of the second portion. The second portion is conveniently tubular in shape, and the first portion is conveniently annular so as to surround the second portion. The track and track follower may be in the form of a peg extending radially inwardly from the first portion to engage in an angled recess in the outer part of the second portion. The peg may be withdrawable to facilitate assembly of the apparatus to the generator.

In order that the invention may be more readily understood, reference will now be made by way of example to the accompanying drawings in which: Figure 1 is a side view of a generator with an apparatus according to one embodiment of the invention attached thereto, and the rotor shaft withdrawn, with the non-withdrawn position of the rotor shown in broken lines; Figure 2 is a cross-sectional side view of the apparatus shown in Figure 1.

Referring to Figure 1, a generator housing 2 has a drive end bracket 4 and a non-drive end bracket 6. A rotor shaft 8 extends axially within the generator housing 2 terminating in a coupling disc 10 at the drive end thereof. The generator housing also includes cooling apertures 12 adjacent the drive end 4 arranged to be adjacent a fan (not shown) on the shaft 8 adjacent the coupling disc 10. The apparatus 14 according to the invention is attached to the non-drive end bracket 6 in a manner described below with reference to Figure 2.

The apparatus 14 comprises a first portion 16 and a second portion 18. The first portion 16 has an annular outer flange 20 for attachment to the non-drive end bracket of the generator housing 2 around a bearing 44 of the rotor shaft 46. The connection is conveniently effected by means of a bolt 22 extending through aligned apertures in flange 20 and the non-drive end bracket 6. The first portion 16 has an inner cylindrical part 24 which has a radially extending aperture 26 for receiving a peg body 30 terminating at the inner end thereof in a peg 28. The peg body 30 is radially moveable in the aperture 26 to withdraw or extend the peg 28.

The second portion 18 of the apparatus has a cylindrical outer part 32 which fits closely within the cylindrical part 24 of the first portion and extends axially outwardly beyond the first portion 16. The outer part 32 mounts a radially extending actuator handle 34 adjacent the distal end thereof. An inner part 36 of the first portion effectively forms a shaft extension for the rotor shaft 8 and is attached to the rotor shaft 8 by a screw threaded member 38 so as to rotate therewith. The shaft extension 36 terminates in a handle 40 for manipulating the inner part 36 to engage the screw threaded member 38. Furthermore the inner part 36 is mounted to the outer part 32 for relative rotation therewith by bearings 42 at each end thereof. The second portion 18 is mounted to the first portion 16 my means of a helical channel 29 in the outer part 32 thereof for receiving the peg 28. This provides a track and track follower arrangement.

Use of the apparatus in assembling the generator to an engine will now be described.

The apparatus 14 is aligned with the rotor shaft bearing 44 such that the inner part 36 of the second portion 18 abuts the end of the rotor shaft 8. The handle 40 is then turned in order to turn the inner part 36 securing the screw threaded member 38 to the rotor shaft 8. The first portion 16 of the apparatus is then bolted to the non-drive end bracket 16 of the generator housing by means of the bolt 22.

The operator grasps the actuation lever 44 and turns it. This turns the outer part of the second portion 32, such that it rotates on the bearings 42 around the inner part 36.

Since the peg 28, which is fixed in relation to the housing bracket, is located in the angled channel 29 in the outer part 32 of the second portion, rotational movement of the second portion 18 causes the second portion 18 to be axially displaced towards the right in Figure 2. The connection between the inner part 36 of the second portion 18 and the rotor shaft 8 means that the rotor shaft is therefore pushed to the right in Figure 2. As can be seen from Figure 1, the rotor shaft, and thus the coupling disc 10, moves from the position shown in broken lines to the position shown in solid lines.

Therefore the coupling disc 10 moves out of the housing 2.

It is then possible for the operator to offer up the generator to the engine, and bolt the coupling disc 10 to the flywheel of the engine unencumbered by the presence of the generator housing 2 around the disc 10. With the disc 10 fixed to the engine flywheel, rotational movement of the second portion 18 by means of the actuation lever 34 in the opposite direction causes the generator housing 2 to be pushed back over the coupling disc (ie. to the left in Figure 1). The drive end bracket 4 of the generator housing 2 may then be connected up to the bracket of the engine. The generator set is then assembled.

Claims

1. Apparatus for assembling a generator to an engine, the generator having a housing and an axially extending rotor shaft, the apparatus comprising a first portion arranged to be connectable to the generator housing, and a second portion arranged to be connectable to the rotor shaft for axial movement therewith, the second portion being mounted to the first portion, and an actuator for causing relative reciprocating movement between the first and second portion, so as to effect axial movement of the rotor shaft with respect to the housing.

2. Apparatus as claimed in claim 1, in which the second portion comprises an inner part in the form of a shaft extension fixable to the end of the rotor shaft, and an outer part rotatable relative to the shaft extension and to the first portion.

3. Apparatus as claimed in claim 2, in which the outer part of the second portion is mounted to the first portiOn of the apparatus by means of a track and track follower, such that rotation of the second portion of the apparatus causes axial movement thereof relative to the first portion.

4. Apparatus as claimed in claim 3 in which the actuator comprises a lever for manual rotation of the second portion.

5. Apparatus as claimed in any preceding claims, in which the second portion is substantially tubular in shape, and the first portion is substantially annular so as to surround the second portion.

6. Apparatus as claimed in claim 5, in which the track and track follower are in the form of a peg extending radially inwardly from the first portion and engaging in an angled recess in the outer part of.the second portion.

7. Apparatus as claimed in claim 6, in which the peg is withdrawable to facilitate assembly of the apparatus to the generator.