GB2042075A

GB2042075A - A direct drive engine and pump combination

Info

Publication number: GB2042075A
Application number: GB8003830A
Authority: GB
Original assignee: Aspera SpA
Current assignee: Aspera SpA
Priority date: 1979-02-08
Filing date: 1980-02-05
Publication date: 1980-09-17
Also published as: FR2448649A1; DE3004778C2; IT7967275A0; FR2448649B1; DE3004778A1; IT1164933B; GB2042075B

Abstract

One end of a support element 15 connecting the engine 10 to the pump 12 is fixed to a portion of a casing 18 of the engine. The support element 15 includes a casing 53 and a tubular central member 52 which extends through the casing and includes a bearing 32 for a pump input shaft 28. The casing 53 and member 52 define an annular chamber 54 a substantial part of an outer wall of which acts as a heat exchanger transferring heat from lubricating oil in the engine 10 to fluid being pumped. Walls extending radially from the tubular casing 53 provide, together with a cover 61, a second chamber 56, through which exhaust gases pass and in which the exhaust gases are placed in thermal contact with the first chamber 54 by means of surfaces extending into the second chamber 54 allowing heat transfer. <IMAGE>

Description

SPECIFICATION A direct drive motor and pump combination The present invention relates to a direct motor and pump combination and concerns a combination in which the motor and pump are connected by a support element through which the pump drive shaft extends.

In known combinations of this type, the support element comprises a tubular member each end of which is provided with a flange which is screwed to either the pump casing or the motor casing.

For reasons of space, the screws connecting the tubular member to the motor casing must be of small cross-section. The screws therefore have low moments of inertia and will be subject to high stresses during use.

It is an object of the present invention to provide an improved motor and pump combination in which screws are no longer used to connect the support element to the motor casing, and in which the support element in addition to serving as a connecting element, has at least one other function which helps to improve the operating efficiency of the combination.

Accordingly the present invention provides a direct drive motor and pump combination, in which an end of a support element connecting the motor and pump is unitary with a portion of a casing of the motor and in which the support element comprises tubular casing means through which extends a tubular central member, the casing means and the central member defining a first chamber which acts as a first heat exchanger removing heat from a lubricating oil in the engine to a fluid being pumped by the pump.

Generally the invention finds application in a combination which comprises an internal combustion engine and a centrifugal hydraulic pump.

Preferably the tubular central member includes a bearing for a pump input shaft and water retaining sealing means.

In a preferred embodiment the tubular casing is provided with a separate second chamber which is connected to an exhaust system and acts as an exhaust silencer allowing exhaust gases to pass to atmosphere.

It is desirable that surfaces extend into the second chamber and that the surfaces are in thermal contact with the first chamber providing a second heat exchanger to remove heat from the exhaust gases to the fluid being pumped.

In order that the invention may be readily understood, an embodiment thereof will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 illustrates diagrammatically in cross-section a known motor and pump combination; Figured is a cross-section, similar to that of Fig. 1, through a motor and pump combination according to an embodiment of the present invention; and Figure 3 is a cross-section through the combination of Fig. 2 taken along the line Ill-Ill of Fig. 2.

Referring now to the drawings, the known motor and pump combination shown in Fig. 1 comprises a single-cylinder air-cooled internal combustion engine 10, a centrifugal hydraulic pump 12, and a support element 14 for connecting a casing 16 of the pump 12 to an end cover 18 of a crankcase 20 of the engine 10.

The pump 12, which is of a known type, has a rotor 22 which in operation takes in fluid from a supply duct 24 in the casing 1 6 and pumps fluid into a delivery duct 26. The rotor 22 is coupled for direct drive to an engine output shaft connected to a crankshaft 30 of the engine. The output shaft is rotatably mounted by means of a rolling bearing 32 in the cover and extends coaxially through a tubular central member 30' of support element 1 4.

The support element 14 (Fig. 1) is of substantially H-shaped cross-section in axial crosssection and has, on either side of the tubular portion 30', annular connecting flange 34 and 36 adjacent the engine 10 and the pump 1 2 respectively. The flanges 34 and 36 include centering means (not shown) and are apertured. Each aperture 38 of the flange 34 is associated with a screw 40 to secure the flange to the cover 1 8 of the base 20 and similarly each aperture 42 of flange 36 is associated with a screw 44 to secure the flange to the pump casing 16. A water tight seal between the pump 10 and the cover 1 8 is achieved by means of sealing elements 46 interposed coaxially between shafts 28 and the tubular part 30' of support element 14.A second watertight seal between the inside of the base 20 and the support element 14 is achieved by similar sealing means 48 interposed between shaft 28 and cover 1 8.

A drainage aperture 50 is provided in the base of the tubular member 30 to allow any fuel which seeps through the sealing means 46 to drain away.

In contrast to the combination illustrated in Fig. 1, the support element of the motor and pump combination embodying the invention and shown in Fig. 2 is in the form of a dishshaped element 1 5 which is fused to and integral with a portion of the cover 1 8 of crankcase 20 of engine 1 0. The other end of the support element 1 5 is secured, in a similar manner to that described in relation to Fig.

1, to the pump casing 1 6 by screws 44.

The support element 1 5 comprises a tubular central member 52 in which are mounted the bearing 32 and the water retaining seals 46, 48. The element 1 5 includes a drainage aperture (not shown) similar to the drainage aperture 50 of Fig. 1.

A tubular outer casing 53 encioses the tubular member 52. The walls of the casing 53 and member 52 bound an annular chamber 54 which extends between the cover 1 8 and pump 12. The chamber 54 is in communication with the supply duct 24 of the pump 12 allowing fluid pumped by pump 1 2 to enter the chamber.

A large portion of the surface area of the chamber 54 adjacent the base 20 is in thermal contact with the lubricating oil of the engine and thus an effective heat exchanger is formed by which means the fluid removes heat from and thus cools the lubricating oil.

Walls extending radially from but integral with a portion 52' of the tubular casing 53 form together with a cover lid 61, a second chamber 56 adjacent but separate from the chamber 54. The second chamber 56, which communicates by means of passages 57, 59 with the engine exhaust pipe and the atmosphere respectively, is preferably produced by pressure moulding and acts as an exhaust silencer.

Surfaces 63 formed integrally with the cover 61 and the surface of the chamber 56 extend into the chamber 56 and are in thermal contact, with the fluid in chamber 54. A second heat exchanger is thus provided and heat will therefore be removed from the exhaust gases passing through the chamber 56 to the fluid in chamber 54 causing the exhaust gases to cool and thereby reducing the volume of the exhaust gases.

The support element in the region of cover 1 8 may be provided with seats for bearing to support the engine shaft and/or a possible shaft for a controller or for an oil vibrator (not shown).

The above descibed embodiment of the invention thus provides a motor and pump combination which, in addition to being more rugged than the known combination of Fig. 1, operates more efficiently than the known motor and pump combination.

Claims

1. A direct drive motor and pump combination, in which an end of a support element connecting the motor and pump is unitary with a portion of a casing of the motor and in which the support element comprises tubular casing means through which extends a tubular central member, the casing means and the central member defining a first chamber which acts as a first heat exchanger removing heat from a lubricating oil in the engine to a fluid being pumped by the pump.

2. A combination according to claim 1, wherein the tubular central member includes a bearing for a pump input shaft and water retaining sealing means.

3. A combination according to claim 1 or 2, wherein the tubular casing is provided with a separate second chamber.

4. A combination according to claim 3, wherein the second chamber is connected to an exhaust system and acts as an exhaust silencer allowing exhaust gases to pass to atmosphere.

5. A combination according to claim 4, wherein surfaces extend into the second chamber and are in thermal contact with the first chamber providing a second heat exchanger to remove heat from the exhaust gases to the fluid being pumped.

6. A combination according to any preceding claim, wherein the motor is an internal combustion engine and the pump is a centrifugal hydraulic pump.

7. A combination according to any preceding claim, wherein the other end of the support element is connected to a casing of the pump by screws.

8. A direct drive motor and pump combination substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

9. Any novel feature or combination of novel features described herein.