Engine Alignment Tool

This invention relates a tool for aligning a fan with a recess; for example the radiator cowl of an engine.

When assembling a machine including an engine, for example a generator set, the components are usually mounted on a bed frame. The engine generally includes a cooling fan which protrudes from one side of the engine, and which has to be aligned in a circular recess or cowl in a radiator housing. Ideally, the fan blades fit closely within the recess to maximise the cooling effect.

The radiator is a large and heavy component, and for assembly it is normally placed on a large jig which is brought towards the engine and adjusted in position until the fan is aligned with the cowl and able to fit within it. The radiator is then fixed in relation to the engine or the bed frame to maintain their relative positions. There is normally a small clearance between the edges of the fan blades and the inner surface of the cowl, such that this aligning operation is difficult and time consuming. Furthermore, as a result of the difficulty with alignment, the fan may not be aligned exactly in the centre of the cowl, which is not ideal.

There is therefore a need for a simple and effective way of aligning the fan within the radiator housing recess.

According to the present invention, there is provided an engine alignment tool for aligning a fan in a recess of a radiator housing with a predetermined clearance

comprising: a spacer for abutting the recess and the fan to provide the predetermined clearance space, and a positioner for maintaining the spacer in the abutment position in the recess.

Thus with the tool inserted abutting the recess, the radiator housing may be placed around the fan and the fan may be brought into abutment with the tool. The radiator housing and fan are thus correctly positioned and may be secured together in the usual manner before removing the tool.

The recess is usually circular, and thus the spacer is preferably an elongate member, such as a plate, being curved along its length into a substantially part circular form, and having an outer surface for abutting the inner surface of the recess, and having a radial thickness arranged substantially to correspond to the predetermined clearance. The outer and inner surfaces may alternatively be discontinuous. The tool preferably has a length arranged to be sufficient to abut the outer edges of a sufficient number of fan blades to define the position of the fan; for example at least two, and more preferably at least three blades of a fan. For example it may be curved over the angle of at least 45°, and more preferably about 120?

The positioner may be provided by an abutment member extending outwardly of the outer surface of the plate for abutting the outer surface at the edge of the recess, to prevent further travel of the tool into the recess. A grip portion may be provided for gripping the tool when inserted into the recess. This facilitates removal of the tool following assembly of the engine to the radiator. This grip portion may simply be the edge of the elongate plate on one side of the abutment member.

Thus, preferably, the abutment member is a flange extending along the length of the plate adjacent one edge thereof. Conveniently, the flange is attached to the plate at a position spaced from the one edge, such that the part of the plate between the abutment member and the one edge forms the grip portion. Thus the tool is simple in construction. The tool may be made of a hard, wear-resistant material such as steel, and the flange may be attached by welding to avoid distortion of the tool.

The invention also provides a method of aligning a fan in a generally circular recess of a radiator housing so as to provide a predetermined clearance between the fan and the recess, the method comprising placing an alignment tool against at least a part of the inner surface of the recess, the tool having a radial width arranged to be substantially equal to the predetermined clearance, placing the fan against an inner surface of the tool, fixing the relative positions of the fan and the recess, and removing the tool.

Preferably the tool is placed at or adjacent the top of the recess, such that the radiator housing may rest on the tool.

The invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 is a schematic side view of an engine and radiator assembly for use with the tool of Figure 1.

Figure 2 is a perspective view of an alignment tool according to one embodiment of the invention;

Figure 3 is a side view of the tool of Figure 1;

Figure 4 is a plan view of the tool of Figure 1 ; and

Figure 5 is a cross-sectional view of the tool of Figure 1 taken along lines IV-IV.

Referring to Figure 1 , a machine such as a generator 2 incorporating an engine 4 with a projecting cooling fan 6. The engine in such a machine is generally mounted on a bracket 8. A radiator housing 10 is mounted via an anti-vibrating mount 12 to a tray 14, and provided with a radiator recess 16 for receiving the fan 6. In order to assemble the machine 2, the radiator recess 16 needs to be carefully aligned with the fan 6, before the tray 14 is assembled onto the engine bracket 8 using bolts 18 to secure the relative positioning of the fan 6 and radiator housing 10.

In order to do this, an alignment tool 20 is provided (see Figures 2 to 5). The tool comprises a spacer in the form of an elongate plate 22 curved along its length to a substantially part-circular shape, and having first and second longitudinally extending edges 21, 23. Thus, the outer surface 27 of the tool corresponds in shape with the circular or cylindrical inner surface 24 of a radiator fan recess 16.

The plate has a radial thickness 25 equivalent to the clearance required between the fan blades 6 and the inner surface 24 of the recess, which as an example may be in the region of about 5 mm, for a plate around 30 mm in length..

The first longitudinally extending edge 21 of the plate is arranged to be inserted into the recess. Adjacent the second longitudinally extending edge 23, the tool 20 has a positioner comprising a radially projecting flange 26 to serve as an abutment member for abutting the outer surface 28 of the radiator housing 10 at the edge of the recess 16. The part of the plate 30 between the second edge 23 and the flange 26 forms a grip portion, with which the tool 20 may be manipulated. This positions the tool by preventing the plate 22 from travelling too far into the recess 16, beyond the edge of the fan.

The tool has a length sufficient to define the position of the fan by extending over an angle to cover at least three blades of a conventional seven or eight blade fan; e.g. about 120°.

In use, the tool 20 is placed with the outer surface 22 against the inner surface 24 of the radiator recess 16, and inserted until the flange 26 abuts the outer edge 28, preferably at the top of the recess. With the tool 20 in position, the radiator 10 may be advanced towards the engine 4 (in the direction of the arrow in Figure 1), until the fan 6 is received within the recess 16. The radiator housing 10 may simply be allowed to rest such that the outer edges of the blades of the fan 6 abut the tool, under the influence of gravity.

The radiator tray 14 may then be attached to the bracket 8, and the bracket 8 can then be fixed onto the engine with bolts 18 in the correct position. The relative positions of the radiator and the engine are thus fixed. The tool 20 may be gripped using the grip portion 30 to remove it from the recess, leaving the required clearance between the fan and the radiator.