This invention relates to pump installations e.g. hydraulic pump installations and in particular to such installations for use within a tractor chassis formed from several castings secured together in an end to end configuration.

It is known to mount hydraulic pumps within such a chassis configuration with the pumps mounted on a transmission housing and extending within an adjacent clutch housing which is bolted to the engine block. This configuration causes problems when the pumps are being mounted in their operation position as the assemblers have to work within the confines of the clutch housing when mounting the pumps and making the hydraulic connections to the pumps prior to securing the clutch housing to the engine sump.

It is an object of the present invention to provide a chassis housing arrangement which allows the installation of the pumps and their connections to be carried out before the chassis housing is connected to the clutch housing thus avoiding the above difficulty.

Thus according to the present invention there is provided a tractor chassis housing having attachment flanges at both ends for attachment to adjacent components of a tractor chassis, one end of the housing having an internal transversely extending support web adjacent said end of the housing for mounting one or more fluid pressure generating pumps thereon, the walls of the housing outboard of the web having one or more apertures through which the pump or pumps are connected with fluid pressure operated components outside the housing.

Such a housing allows the pump or pumps to be connected to the web prior to the housing being connected to the adjacent chassis members and also allows all the connections to the pump or pumps to be made to the wall apertures prior to the attachment of the housing to the remainder of the chassis. Thus after connection of the housing to the remainder of the chassis it only remains to connect the external fluid pressure operated components to the appropriate apertures.

Typically the apertures enable connections to the consumers powered by the respective pumps and connections of pressure sensing lines used to monitor the performance of the pumps.

In a typical installation the tractor chassis housing will be a transmission housing which will be secured to a clutch housing inside which the pumps or pumps at least partially extend. In an alternative arrangement the chassis housing could be a back axle housing and the pump or pumps could extend at least partially into the rear of a transmission housing of the tractor chassis. Other alternatives are possible in which the pump or pumps are mounted on one chassis housing and extend within another housing which also forms part of the chassis of the tractor.

Preferably the support web includes a detachable pump mount on which the pump or pumps are mounted.

Conveniently the web not only mounts the pumps but also supports drive shafts of the transmission.

The pumps are also conveniently driven from the transmission.

The chassis housing may be a transmission housing and the pump or pumps mounted on the support web extend partially inside an adjacent housing mounted on the engine block of the tractor.

The invention also provides a tractor chassis including a chassis housing as described above. Although the primary application of the invention is seen as relating to hydraulic pumps the invention could be used for other pumps such as pneumatic pumps used to power various consumers on the tractor.

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

Figure 1 shows a longitudinal section through a transmission housing in accordance with the present invention bolted to an associated clutch housing;

Figure 2 is a perspective view partly in section of the transmission housing of Figure

1 prior to its connection to the clutch housing;

Figure 3 is a perspective view partly in section of the transmission housing of Figure

2 connected to the clutch housing;

Figure 4 is an end view of the transmission housing of Figure 2 in the direction of the arrow X of Figure 2;

Figure 5 shows the transmission housing and clutch housing of Figure 3 with the pump omitted for clarity, and

Figure 6 shows a section through the top part of the transmission housing shown in Figures 1 to 5 showing an external connection aperture.

Referring to the drawings, a transmission housing 10 forms part of a tractor chassis and is provided with an attachment flange 11 at one end for attachment by bolts to a clutch housing 12 which is itself attached via flanges 13 to an engine block (not shown). The other end 14 of the housing is provided with an attachment flange (not visible in the drawings) for attachment to a back axle housing of the tractor chassis indicated diagrammatically at 15 in Figure 1. The transmission housing has an internal transversely extending support web 16 located adjacent to the flange 11 for mounting one or more hydraulic pumps 17 thereon. The web 16 includes a detachable central mount 20 which is secured to the remainder of web 6 by bolts 21. This mount 20 also includes support apertures 30 for the transmission shafts (not shown). The portion 18 of the walls of the housing to the left of web 16 (i.e. outboard of the web 16) has one or more apertures A, B and C (see Figure 5) through which the pump or pumps are connected with hydraulic components outside the housing. In Figures 1 to 4 only one pump 17 is shown but a second pump can be fitted on mount 20 via mounting surface 22 (see Figure 4).

Pump 17 has an intake pipe 23 provided with an intake filter 24 at its lower end for sucking up hydraulic fluid from the bottom of the clutch housing 12 which acts as a reservoir for the pump. Pump 17 supplies pressurised fluid via a manifold block 17a to an external consumer via pipe 25 which is connected with a further aperture D (see Rgure 6) in the top of the housing wall portion 18 via a connector 25a to supply an external consumer nearer the rear of the tractor. Pump 17 also has a second outlet hose 26 which is connected via a union 27 with the lower aperture B. A further hose 28 is connected via union 29 with the upper aperture B. This hose 28 provides a pressure signal indicative of the load under which the pump is operating and is used in the pump control system. The equivalent pressure signal hose for the other pump is connected to aperture A. Apertures C provide a hydraulic connection for a wheel driven emergency steering pump (not shown) which is mounted on mounting surface 41 (see Figure 4) on the detachable mount 20.

A further aperture E provides a hydraulic connection for a transmission lubricant pump (not shown) which is mounted on a mounting surface 40 (see Figure 4) on the detachable mount 20.

To reduce noise/vibration in the hydraulic circuitry a Helmholtz resonator 31 is fitted on pump 17. Pipe 32 provides an oil return. As can be best seen from Figure 2, prior to attachment of the transmission housing 10 to the clutch housing 2, after the assembly of the transmission within housing 10, the pump mount 20 is attached to the web 16 and the pump 17 (and the other pumps if fitted) and all the associated piping are attached to the mount and connected to the external connections A, B, C, D and E. This assembly as then attached to the clutch housing 12 via flanges 11 with the pump or pumps projecting into the clutch housing 11 as shown in Figures 1 and 3.

With the smaller diameter connections such as A and B flexible hoses such as hose 28 are used. With larger diameter connections such as D rigid pipes such as pipe 25 can be used as any inaccuracy in the shape of the rigid pipe is overcome by the increased size of the connection so the pipe can still be connected to the connection (see difference in the diameter of pipe 25 and aperture D in Figure 6).

The present invention, with its pump support web 16 and apertures A, B, C, D and E in the portion 18 of the housing wall which is outboard of the web 16, allows the pump or pumps and all the associated pipes to be attached to the transmission housing 10 prior to the attachment of the housing 10 to the clutch housing 12 thus considerably simplifying the assembly of the tractor chassis.