GB2132033A

GB2132033A - A method of coupling an electric machine to another machine

Info

Publication number: GB2132033A
Application number: GB08328814A
Authority: GB
Inventors: Ante Olivari
Original assignee: ANSALDO MOTORI SpA
Current assignee: ANSALDO MOTORI SpA
Priority date: 1982-10-29
Filing date: 1983-10-28
Publication date: 1984-06-27
Also published as: IT8285630A0; GB2132033B; FR2535541A1; IT1159341B; FR2535541B1; GB8328814D0

Abstract

A threaded eyebolt (1) is arranged at one end of a first electric machine and engages both the stator cover (2) and the rotor shaft (3) of the machine such that relative movement between the rotor and stator of the machine is prevented. A second machine is arranged vertically and the first machine is suspended over and aligned with the second machine by way of the eyebolt (1). The eyebolt (1) is then partially unscrewed to release the rotor of the first machine such that its flange (4) can be coupled to a flanged flywheel of the second machine. The stator of the first machine could be raised by way of the eyebolt (1) to permit the coupling of the rotor to be achieved easily. Thereafter, the stator is lowered and its flange is coupled to a corresponding flange of the second machine. The coupled machines can then be rotated to extend horizontally. <IMAGE>

Description

SPECIFICATION A method of coupling an electric machine to another machine The present invention relates to a method of coupling an electric machine to another machine.

It is frequently necessary to couple electric singlebearing machines to other machines, for example, to couple alternators to diesel engines in order to assemble generator set or to couple motors to compressors. Generally, the machines are coupled whilst their axes extend horizontally. This requires that a number of special constructional features be provided and also that particular steps be included in the coupling process such that it is time-consuming and expensive to perform the coupling. Thus, as the rotor of the electric machine is supported only at one end, it is generally necessary to insert cardboard or lamina shims in the air-gap area in order to avoid damaging the laminations or the stator and rotor windings.

Before the coupling process (for example, of an alternator and engine), it is necessary to free the rotor from any support shims fitted into the air-gap or from any brackets which had been inserted onto the rotor flange at its drive end. Such brackets are used to prevent, as much as possible, movement of the rotor.

Furthermore, in orderto couple the rotorflange and the flywheel of the engine by screw or bolts, it is necessary either to pass the screws or bolts through openings provided in the frame or end shield, or to withdraw rotor as much as possible whilst ensuring that the bearing does not fall out of its housing, to enable the parts to be coupled by the coupling bolts.

All of the above described steps have had to be done whilst the rotor shaft is suspended in a perfectly horizontal position. For example, the rotor shaft could be held by a hoist during the assembly.

However, it is disadvantageous to have to hold the rotor in the horizontal position during the coupling process as it causes restricts and otherwise inconveniences the operator's action.

The present invention seeks to provide a coupling method in which the disadvantages and inconveniences described above are reduced.

According to the present invention there is provided a method of coupling a first electric machine to a second machine wherein a threaded member is arranged at one end of said first electric machine to block relative movement between the rotor and the stator of said first machine, comprising the steps of supporting a second machine in a vertical position, suspending the first machine by way of said threaded member in a vertical position above said second machine such that said first and second machines are appropriately aligned, unscrewing said threaded memberto release the rotor, coupling said rotor to said second machine, and thereafter coupling said stator to said second machine.

In an embodiment of the invention the rotor of the electrical machine is prevented by a threaded eyebolt from movement relative to the stator. Thus, during transportation and handling ofthe machine in the coupling process, there is no danger of collision between the rotor and the stator. During coupling the machine is placed vertically and lowered onto the flanged flywheel of an engine which is also in an upright position. Preferably the engine has been rotated through 90" into the upright position by means of a tipping device. At this point it becomes possible to release the rotor by unscrewing the eyebolt from the rotor shaft.However, the eyebolt is kept in place on the cover of the stator such that it can be used to lift the stator as much as necessary such that the bolts holding the rotor's disc or hub fan to the flywheel of the engine can be screwed in easily. Thereafter, the stator may be lowered by way of the eyebolt, and its flange fixed to the engine's flywheel cover flange by means of bolts.

An embodiment of the present invention will hereinafter be described by way of example, with reference to the accompanying drawings, in which Figure 1 shows a section of an alternator in which relative movement between the stator and the rotor is blocked, Figure 2 shows the same alternator with the rotor separated from the stator whilst the rotor is coupled to the flywheel of a second electrical machine.

Figure 3 shows the alternator and the second machine during coupling, and Figure 4 shows the alternator and the machine after coupling.

Figure 1 shows an alternator in which a threaded eyebolt 1 is fixed to the rotor shaft 3. The threaded end of the eyebolt 1 is sufficiently long to enable it to engage the stator's cover as well as the rotor's shaft 3. It will be seen from Figure 1 that the eyebolt 1 blocks relative movement between the rotor and the stator. Thus, the rotor will remain centered with respect to the stator such that the proper air-gap for the machine will be maintained between the rotor and the stator. Thus, whilst blocked by the eyebolt, the machine can be stored, transported or coupled to a second machine without the possibility of contact or collision which could damage either the electrical or the mechanical parts of the machine.

Figure 2 illustrates the first step in the coupling of the alternator to a second machine, for example, an endothermic-engine. The alternator is kept in the vertical position and the axis of a flange 4 of the rotor of the alternator is aligned with the axis of a flanged flywheel 5 of the engine. When the axes are aligned the eyebolt 1 is unscrewed to release it from the rotor shaft 3 but not to release it from the stator cover to which it remains attached, as shown in Figure 2, to enable easy access to the operator coupling the flange 4 and the flywheel 5.

Figure 3 shows the operation described above, with the alternator suspended on a lifting-hook 6 by way of eyebolt 1 and showing the rotor 7 already coupled to the engine 8. Figure 3 also shows a platform 9 which is rotatable through 90"to enable the engine 8 to be positioned for vertical coupling and subsequently repositioned such that the coupled shafts extend horizontally.

When the flange 4 of the alternator and the flange-wheel 5 of the engine have been coupled as shown in Figure 2, the stator 10 of the alternator is lowered to enable the final coupling of a flange 11 of the stator of the alternator to an exterior flange 12 of the engine 8.

The two electric machines are thus coupled together as shown in Figure 4, and the eyebolt 1 can be removed. Preferably the eyebolt 1 is replaced by a bolt 13 which is screwed into the hole provided in the stator cover 2.

Claims

1. A method of coupling a first electric machine to a second machine wherein a threaded member is arranged at one end of said first electric machine to block relative movement between the rotor and the stator of said first machine, comprising the steps of supporting a second machine in a vertical position, suspending the first machine by way of said threaded member in a vertical position above said second machine such that said first and second machines are appropriately aligned, unscrewing said threaded member to release the rotor, coupling said rotor to said second machine, and thereafter coupling said statorto said second machine.

2. A method as claimed in Claim 1, further comprising the step of lifting the stator of the first machine by way of the threaded member when the rotor has been released to enable easy coupling of the rotor to said second machine.

3. A method as claimed in Claim 1 or Claim 2, wherein the threaded member is a threaded eyebolt arranged to extend through the stator cover and to engage within the rotor shaft of the first machine, partial unscrewing of the eyebolt releasing the eyebolt from the rotor shaft and thus releasing the rotor.

4. A method as claimed in any of Claims 1 to 3, wherein the rotor of the first machine has a flange which is coupled to a flanged flywheel of the second machine, and wherein an exterior flange of the stator of the first machine is subsequently coupled to a corresponding flange of the second machine.

5. An electric machine arranged to be coupled to a second machine by a method as claimed in any preceding claim, said machine having a threaded member engaged in the end of the rotor shaft opposite the drive end and extending coaxiallyto said shaft, said threaded member also being screwed into the stator cover of the machine and having a head in the form of a ring whereby relative movement between the rotor and the stator is prevented.

6. An electric machine as claimed in Claim 5, wherein said threaded member is a threaded eyebolt, and said machine is a single-bearing machine.

7. A method of coupling a first electric machine to a second machine substantially as hereinbefore described with reference to the accompanying drawings.

8. An electric machine substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.