WO2010071497A1

WO2010071497A1 - Fuel pump arrangement and vehicle comprising a fuel pump arrangement

Info

Publication number: WO2010071497A1
Application number: PCT/SE2008/000734
Authority: WO
Inventors: Rolf Thoresen; Jerry Killey
Original assignee: Volvo Lastvagnar Ab
Priority date: 2008-12-18
Filing date: 2008-12-18
Publication date: 2010-06-24

Abstract

The invention relates to a truck fuel pump arrangement (10) particularly designed for a commercial vehicle fuel pump (30), the arrangement comprising a fuel pump (30) providing a through shaft (22) extending through the fuel pump (30) which through shaft (22) is coupled to a drive source (20) for driving the through shaft (22). The fuel pump (30) comprises a first coupling unit (52) to the drive source (20) for driving the fuel pump (30) and a second coupling unit (54) providing a power-take-off for a second device (60), wherein the second device (60) has a nominal operational power of at least 5 times of the fuel pump (30), preferably of at least 10 times of the fuel pump (30).

Description

D E S C R I P T I O N

Fuel Pump Arrangement and Vehicle Comprising a Fuel Pump Arrangement

TECHNICAL FIELD

The invention relates to a fuel pump arrangement and an engine comprising a fuel pump arrangement according to the preambles of the independent claims.

BACKGROUND OF THE INVENTION

It is known in the art of trucks to have a tandem fuel pump arrangement in which a power steering pump is connected to a fuel pump. The power steering pump is as "biggest" component is mounted closest to the transmission as drive source. The fuel pump as a significant smaller component in power consumption and weight is mounted as a complete unit with a common drive shaft to the steering pump. The comparably long drive shaft can cause quality problems with abnormal hysteresis on the pump displacement which result in a higher wear of pump components.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a fuel pump arrangement which is less vulnerable to wear. It is another object to provide a truck engine with a fuel pump arrangement which has improved properties compared to the prior art fuel pump arrangements.

The objects are achieved by the features of the independent claims. The other claims and the description disclose advantageous embodiments of the invention.

A truck fuel pump arrangement is proposed, the arrangement comprising a fuel pump providing a through shaft extending through the fuel pump which through shaft is coupled to a drive source for driving the through shaft. The fuel pump comprises a first coupling unit connectable to the drive source for driving the fuel pump and a coupling unit providing a power-take-off for a second device, wherein the second device has a nominal operational power of at least 5 times of the fuel pump, preferably of at least 10 times of the fuel pump. Advantageously, the coupling to the drive source can be achieved by the through shaft comprising a spline which engages an according drive gear of the engine transmission. This coupling of the through shaft to e.g. an engine transmission provides a high operational power for a second device while allowing to drive the fuel pump with engine speed at a much lower operational power.

The fuel pump is comparably small and lightweight. Favourably, the fuel pump can carry a second device, e.g. a steering pump for a servo steering system, of significant weight, e.g. 25 kg, and of much higher operational power. Compared to the steering pump the fuel pump has a typical power of e.g. below 1 kW, whereas such a steering pump can typically have a power of 25 kW. The coupling of the fuel pump to the drive source is favourable independent of a coupling between the fuel pump and the second device, i.e. if a fuel pump arrangement is required with only the fuel pump and without a second device, the fuel pump arrangement can be used simply without attaching the second device without negative effect or additional components as placeholder to replace the second device. In the prior art, when a fuel pump arrangement without a steering pump is required, it is necessary to use as placeholders special flanges to couple the fuel pump to the drive source without the steering pump as intermediate device.

According to a favourable embodiment of the invention, the fuel pump can be arranged at an end portion of the arrangement adjacent the drive source.

Particularly, the fuel pump can comprise a standardized flange for attaching the second device on an end portion of the arrangement opposite to the drive source.

According to a favourable embodiment of the invention, the fuel pump can comprise a feedthrough for the through shaft. Preferably, the feedthrough can be used for coupling the through shaft to the second device. The through shaft can also be used to drive the fuel pump, via splines arranged at an outer circumference of the through shaft. Particularly, the through shaft is much stronger than needed for the fuel pump itself, as it is intended for the second device. Advantageously, the fuel pump can comprise the same components as a standard fuel pump with an adapted housing only.

According to a further favourable embodiment of the invention, the through shaft can be accessible at a front side of the fuel pump. Thus it is a simple arrangement in cases in which a second device is not needed in the fuel pump arrangement. On one side, the fuel pump can be coupled to the first coupling unit providing drive torque for the fuel pump, on another side of the fuel pump, particularly on the opposite side, a separate coupling unit for the second device can be provided. This second coupling unit can simply be left free if the second device is not required without complex additional components for replacing the second device.

According to a further favourable embodiment of the invention, the through shaft can constitute a drive key arrangement for coupling to the second device. A drive key arrangement is a reliable coupling for even high operational loads.

According to a further favourable embodiment of the invention, the second device can be a steering pump. Favourably, in the fuel pump arrangement according to the invention the small fuel pump can carry the load of a much stronger and heavier steering pump.

According to a further favourable embodiment of the invention, the drive source, the fuel pump and a steering pump can be arranged subsequently in this order in direction of the through shaft. In the arrangement, the fuel pump constitutes an intermediate component between the drive source and the steering pump. In case the steering pump is needed in a first vehicle type, the arrangement can be used with a steering pump coupled to the fuel pump. If the steering pump is not needed in a second vehicle type, the same fuel pump type can be used simply without a steering pump attached. In this case, the feedthrough in the fuel pump through which the drive key at the free end of the through shaft is accessible for a steering pump can simply be closed with a cover. In the prior art, as the steering pump constitutes an intermediate component between the drive source and the fuel pump, omitting the steering pump means to replace the steering pump by a placeholder instead. Otherwise, flanges and attachment devices would be needed for such a fuel pump arrangement used for various vehicle types.

According to a further favourable embodiment of the invention, the fuel pump furnishes a standardized flange for attaching the second device. Favourably, the flange can be a standard SAE flange. An SAE flange (SAE = Society for Automotive Engineers) is a standard component which are available "off the shelf without complex redesign for connecting between components. Particularly, a diameter for a through shaft as well as borings for screws for attaching one component to another are provided at defined sizes and locations on the flange. Of course, other standards than SAE can be used.

According to another aspect of the invention, a truck-engine-based fuel pump is proposed designed for a fuel pump arrangement which comprises a first coupling unit to the drive source for driving the fuel pump and a coupling unit providing a power-take-off for a second device, wherein the second device has a nominal operational power of at least 5 times of the fuel pump, preferably of at least 10 times of the fuel pump, wherein the fuel pump comprises a feedthrough for a through shaft for driving the second device and a standardized flange for attaching the second device.

According to another aspect of the invention, a truck engine is proposed comprising a fuel pump arrangement, wherein the fuel pump comprises a first coupling unit to the drive source for driving the fuel pump and a coupling unit providing a power-take-off for a second device, wherein the second device has a nominal operational power of at least 5 times of the fuel pump, preferably of at least 10 times of the fuel pump. Preferably, the fuel pump is arranged at an end portion of the arrangement adjacent the drive source. The second device, particularly a steering pump, can be arranged at a side of the arrangement opposite to the drive source.

Favourably, the fuel pump can be coupled to the engine and the engine transmission as drive source via the through shaft. The fuel pump can run at engine speed without complex intermediate devices with or without a much stronger and heavier steering pump. Thus, a standardized fuel pump arrangement can be provided for different types of vehicles which may or may not require a steering pump for a servo steering. A very cost efficient fuel pump arrangement is provided which can easily be employed on different truck engine types. .

According to another aspect of the invention, a vehicle is proposed, particularly a heavy duty vehicle, comprising a fuel pump arrangement, wherein the fuel pump comprises a first coupling unit to the drive source for driving the fuel pump and a coupling unit providing a power-take-off for a second device, wherein the second device has a nominal operational power of at least 5 times of the fuel pump, preferably of at least 10 times of the fuel pump, and wherein the fuel pump is arranged adjacent a drive source driving a through shaft through the fuel pump. A steering pump driven by the through shaft may be attached to the through shaft and the fuel pump via a standardized flange.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention together with the above-mentioned and other objects and advantages may best be understood from the following detailed description of the embodiments, but not restricted to the embodiments, wherein is shown schematically:

Fig. 1 a fuel pump arrangement according to the prior art;

Fig. 2a-2c a first embodiment of a fuel pump arrangement according to the invention, wherein only a fuel pump is provided without a second device coupled to a drive source (Fig. 2a), a perspective view on internal parts of the fuel pump arrangement (Fig. 2b) and a cut through a middle part of the fuel pump arrangement (Fig. 2c); and

Fig. 3a-3c a second embodiment of a fuel pump arrangement with a coupling unit for a second device without coupled second device (Fig. 3a), the fuel pump arrangement with the second device coupled (Fig. 3b) and a preferred embodiment of the fuel pump arrangement attached to a truck engine (Fig. 3c). DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In the drawings, equal or similar elements are referred to by equal reference numerals. The drawings are merely schematic representations, not intended to portray specific parameters of the invention. Moreover, the drawings are intended to depict only typical embodiments of the invention and therefore should not be considered as limiting the scope of the invention.

Fig. 1 depicts schematically a fuel pump arrangement 10 according to the prior art. A drive shaft 22 is coupled to a drive source 20, indicated by a coupling disk, such as a transmission of an engine (not shown). The drive shaft 22 which drives a steering pump 62 is embodied as a through shaft through the steering pump 62 and provides a coupling unit 66 for a fuel pump 30. The fuel pump 30 is pigtailed to the steering pump 62 which is much bigger in operational power and weight than the fuel pump 30. The steering pump 62 as "biggest" component is mounted closest to the engine transmission adjacent the drive source 20 and the fuel pump 30 is mounted pigtailed onto this as a complete unit with the common drive shaft 22 at an opposite end portion remote from the drive source 20.

If in an installation on another engine type the steering pump 62 is not needed in the fuel pump arrangement 10, it has to be replaced by special flanges (not shown) in order to avoid a costly redesign of the fuel pump arrangement 10 for different vehicle variants. Preferably, the fuel pump 30 as a lightweight component of the fuel pump arrangement 30 may be used for many variants whereas the steering pump 62 may be adapted in size for actual vehicle variants.

Fig. 2a-2c illustrate different views of a first and a second embodiment of a fuel pump arrangement 10 according to the invention, wherein in Fig. 2a the arrangement 10 comprises a fuel pump 30 coupled to a drive source 20 (Fig. 1) without a second device 60 whereas Fig. 2b and Fig. 2c depict a cut through and a perspective view of inner parts of a second embodiment including a second device 60 coupled to the fuel pump 30.

The fuel pump arrangement 10 is particularly designed for a heavy duty vehicle fuel pump 30. The fuel pump arrangement 10 has a first end portion 16 adjacent a drive source 20 (not shown) and a second end portion 18 remote from the drive source 20.

The fuel pump arrangement 10 comprises the fuel pump 30 arranged at the end portion 16 adjacent a drive source 20 (not shown) and provides a through shaft 22 extending through the fuel pump 30 which drive shaft 22 is coupled to the drive source 20 (not shown) for driving the through shaft 22. The drive source 20 may be an engine transmission of the engine 110 (Fig. 3c). The engine 110 is supplied with fuel by the fuel pump 30 by suction and feed pipes attached to fuel ports 46, 48. Typically, the fuel pump 30 runs with engine speed.

The fuel pump 30 comprises a first coupling unit 52, e.g. a coupling gear engaging a spline portion of the through shaft 22, for driving the fuel pump 30 and a second coupling unit 54 providing a power-take-off for a second device 60, e.g. a key drive 26 provided at a front end of the through shaft 22 which may be accessible through an opening in the fuel pump housing. The fuel pump 30 provides a standardized flange 50, for instance a SAE flange, for attaching the second device 60, which may be a steering pump. A standardized flange like e.g. the SAE conversion disk provides predetermined locations for attachment devices, particularly screws, and a predetermined diameter for a shaft, e.g. for the through shaft 22. Through shaft 22 provides a power take-off for e.g. a toothed gear 52 which drives the fuel pump 30. The fuel pump 30 is e.g. screwed to the engine 110 (Fig. 3c) with a holder 32.

In the first embodiment illustrated in Fig. 2a the fuel pump arrangement 10 consists of the fuel pump 30 adjacent the drive source 20 (not shown) and the holder 32. The through shaft 22 extends through a feedthrough 38 through the fuel pump 30. If no second device 60 (Fig. 3a-3c) is attached to the fuel pump 30, the feedthrough 38 can be closed by a cover 28. Fig. 2a displays a preferred embodiment of a truck-engine-based fuel pump 30 designed for a fuel pump arrangement 10 without a steering pump for a servo steering.

Fig. 2b and Fig. 2c illustrate a second embodiment of the fuel pump arrangement 10 where a second device 60, e.g. a steering pump 62, is attached to the fuel pump 30. The fuel pump 30 is arranged between the drive source 20 (not shown) and much bigger the steering pump 62. Fig. 2b depicts a perspective view on internal parts of the fuel pump arrangement 10 in Fig. 2b and a cut through a middle part of the fuel pump arrangement 10 in Fig. 2c illustrating the first coupling unit 52 for driving the fuel pump 30 with the through shaft 22 and the second coupling unit 54 for driving the second device 60 (steering pump 62) with e.g. a key drive 26 at the free end of the through shaft 22.

The key drive 26 is accessible through an opening in the housing of the fuel pump 30 as depicted in Fig. 3a. As the through shaft 22 is designed to drive the second device 60 (steering pump 62) the through shaft 22 can be designed to be oversized for driving the fuel pump 30. The embodiment displayed in Fig. 3a shows a truck-engine-based fuel pump 30 designed for a fuel pump arrangement 10 with a second device 60 (steering pump 62) attached to the fuel pump 30. The fuel pump 30 is arranged at the end portion 16 of the fuel pump arrangement 10 adjacent to the drive source 20 (Fig. 3c) while the second device 60 (steering pump 62) is arranged at the opposite side 18 of the fuel pump arrangement 10 away from the drive source 20 (Fig. 3c).

The second device 60 is preferably a steering pump 62 which has a nominal operational power of at least 5 times of the fuel pump 30, preferably of at least 10 times of the fuel pump 30. A typical relation of the fuel pump 30 to the steering pump 62 is e.g. an operational power of the fuel pump 30 of less than 1 kW and by way of example 25 kW for the steering pump 62.

Referring now to Fig. 3b, the fuel pump arrangement 10 is displayed with the second device 60 (steering pump 62) attached to the fuel pump 30 on its main face providing the standardized flange 50. The through shaft 22 is accessible for the second device 60 (steering pump 62) at a front side 36 of the fuel pump 30. The second device 60 (steering pump 62) and the fuel pump 30 are coupled by an interface 40 at the flange 50 where the second device 60 (steering pump 62) engages the drive key 26 (Fig. 3a) for taking off drive torque from the through shaft 22.

The drive source 20, the fuel pump 30 and the second device 60 (steering pump 62) are arranged subsequently in direction 12 of the through shaft 22 with the fuel pump 30 is closer to the drive source 20 than the second device 60 (steering pump 62).

Fig. 3c depicts the fuel pump arrangement 10 in a state mounted to a preferred truck engine 110 of a preferred vehicle 100. The fuel pump arrangement 10 with a fuel pump 30 designed as a power-take-off for a second device 60 such as a steering pump 62, the fuel pump arrangement 10 comprising a feedthrough 38 for a through shaft 22 for coupling a drive source 20 to the fuel pump 30 and to the second device 60 (steering pump 62). The second device 60 (steering pump 62) is attached to the standardized flange 50 of the fuel pump 30. The vehicle 100 is displayed only as partial view of the fuel pump arrangement 10 and adjacent components of the vehicle 100 which are generally well known to skilled persons.

Claims

C L A I M S

1. A truck fuel pump arrangement (10) particularly designed for a commercial vehicle fuel pump (30), the arrangement comprising a fuel pump (30) providing a through shaft (22) extending through the fuel pump (30) which through shaft (22) is coupled to a drive source (20) for driving the through shaft (22), wherein the fuel pump (30) comprises a first coupling unit (52) to the drive source (20) for driving the fuel pump (30) and a second coupling unit (54) providing a power-take-off for a second device (60), wherein the second device (60) has a nominal operational power of at least 5 times of the fuel pump (30), preferably of at least 10 times of the fuel pump (30).

2. The truck fuel pump arrangement according to claim 1, characterized in that the fuel pump (30) is arranged at an end portion (16) of the arrangement (10) adjacent the drive source (20).

3. The truck fuel pump arrangement according to claim 1 or 2, characterized in that a second device (60) is attached to a standardized flange (50) of the fuel pump (30) arranged on an end portion (18) opposite to the drive source (20).

4. The truck fuel pump arrangement according to any preceding claim, characterized in that the through shaft (22) comprises a spline for driving the fuel pump (30).

5. The truck fuel pump arrangement according to any preceding claim, characterized in that the through shaft (22) is accessible at a front side (36) of the fuel pump (30).

6. The truck fuel pump arrangement according to any preceding claim, characterized in that the through shaft (22) constitutes a drive key arrangement (26) for driving the second device (60).

7. The truck fuel pump arrangement according to one of the preceding claims, characterized in that the second device (60) is a steering pump (62).

8. A truck-engine-based truck fuel pump (30) designed for a fuel pump arrangement (10) according to any preceding claim, comprising a feedthrough (38) for a through shaft (22) for driving the second device (60) and a standardized flange (50) for attaching the second device (60).

9. A truck engine (110) comprising a fuel pump arrangement (10) according to anyone of the claims 1 to 7.

10. The truck engine according to claim 9, characterized in that a fuel pump (30) is arranged at an end portion (16) of the fuel pump arrangement (10) adjacent a drive source (20) for driving the fuel pump (30).

11. The truck engine according to claim 9 or 10, characterized in that a steering pump (62) is attached to a standardized flange (50) of the fuel pump (30) arranged on an end portion (18) of the fuel pump arrangement (10) opposite to the drive source (20).

12. A vehicle (100), particularly a heavy duty vehicle, comprising a truck fuel pump arrangement (10) according to anyone of the claims 1 to 7.