GB2400410A

GB2400410A - I.c. engine supercharger driven from the engine flywheel

Info

Publication number: GB2400410A
Application number: GB0307936A
Authority: GB
Inventors: Mark Wayne Brett Nevitt
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-04-07
Filing date: 2003-04-07
Publication date: 2004-10-13
Also published as: GB0307936D0

Abstract

An air induction system is provided for an internal combustion engine (10), e.g. a petrol engine. The system incorporates a supercharging unit (23) drivingly connected by transmission means (25, 29, 27, 28, 30) to a flywheel (21) of the engine (10), and a support bracket (22) attaching the supercharging unit (23) to the engine (10) adjacent the flywheel (21). A pulley (25) is attached to a shaft (26) of the supercharging unit (23) and engaged by the short supercharger drive V-belt (29). An intermediate double track pulley (27, 28) is mounted on the support with the supercharger drive belt (29) passing around one track (27) and a second short V-belt (30) passing around the other track (28) and the flywheel (21). The flywheel (21) is driven by the engine's gearbox (19) and has a pulley track drivingly engaged by the second belt (30). In the case that the engine (10) is mounted transversely of a motor vehicle, the supercharging unit (23) may be mounted to the front of the engine (10).

Description

1 24004 O

AIR INDUCTION SYSTEM

This invention relates to an air induction system for an internal combustion engine. In particular, the invention relates to a system of supercharging an internal combustion engine.

With a normally aspirated internal combustion engine, whether fed an airfuel mixture via a carburettor or fuel injected, the cylinders are filled with air at normal atmospheric pressure. It has been known for many years to improve the power output of an internal combustion engine by means of forced induction of air to the cylinders at a greater pressure, together with a corresponding increase in the supply of fuel. By this means, some 20% to 30% more power may be generated by the engine than with nommal aspiration. The forced induction of air may be achieved by fitting a turbocharger to the engine. Fitting a turbocharger to an existing unturbocharged engine involves a considerable amount of modification to the engine and requires specialist skills. In addition, means must be provided for dealing with the very high temperatures generated by the turbocharged system. In addition, a turbocharged system tends to suffer from lag in power output at lower rpm. As an alternative to turbocharging, and to avoid the disadvantages associated with such a system, a supercharger may be fitted to the engine. With known supercharging systems, the supercharger is driven from the crankshaft pulley by the belt that drives the fan, water pump and alternator. This belt is of necessity under considerable load, is relatively long and is in consequence subject to a limiting speed in the region of 7500 rpm. This limits the boost pressure able to be provided by the supercharger, and hence the power enhancement achievable. In addition, in the case of the transversely mounted engines that are fitted to many motor vehicles, the supercharger is located at the rear of the engine and accessibility to it for maintenance and adjustment purposes is usually severely compromised and difficult.

It is an object of the present invention to provide air induction system for an internal combustion engine that avoids, or reduces to a significant extent, the disadvantages described above that are attendant with the known systems.

The invention provides an air induction system for an internal combustion engine, the system comprising a supercharging unit, transmission means operable to drivingly connect the supercharging unit to a flywheel of the engine, and a support adapted to attach the supercharging unit to the engine adjacent the flywheel.

The transmission means may comprise a supercharger drive belt, and may comprise a V-belt.

The belt may be a multi-V-belt. The transmission means may comprise a pulley attached to a shaft of the supercharging unit and engaged by the belt. The transmission means may also comprise an intemmediate pulley mounted on the support. The intemmediate pulley may be a double track pulley, and the supercharger drive belt may pass around one track and a second belt may pass around the other track and a flywheel of the engine. The one track and the other track may be of the same diameter or the diameter of the one track may be larger than that of the other track. The second belt may be a V-belt and may be a multi-V-belt.

The invention also provides in combination an internal combustion engine, a gearbox and a flywheel connected therewith and air induction system for the engine, the air induction system comprising a supercharging unit, transmission means operable drivingly connecting the supercharging unit to the flywheel, and a support attaching the supercharging unit to the engine adjacent the flywheel.

In this case, the flywheel may comprise a gear ring adapted to be driven by the gearbox and a pulley track drivingly engaged by the transmission means.

The engine may be mounted in a motor vehicle, and may be mounted transversely of the vehicle. In this case, the supercharging unit may be mounted to the front of the engine. The engine may be a petrol engine.

The invention will now be described with reference to the accompanying drawings in which Fig. 1 is a front view of a supercharged engine, and Fig. 2 is a view on A-A of the engine of Fig. 1.

Referring now to the figures, there is shown an internal combustion engine 10. The engine 10 has fitted thereto the spark plugs 11 with electrical leads 12 leading from a distributor 13. At the front of the engine 10 is mounted a crankshaft pulley 14 around which passes a fan belt that drives a fan 16, a water pump (not shown) and an alternator 17. A carburettor 18 provides an air/fuel mixture to the engine 10. Mounted at the rear of the engine 10 is a gearbox 19, in which are gears 20 driven by the engine 10 and a gear driven flywheel 21. In these respects, the engine 10 and the devices 11 to 21 are conventional.

Mounted adjacent the gearbox 19 is a bracket 22 on which is mounted a supercharger unit 23.

A conduit 24 connects the supercharger unit 23 with the carburettor 18. A supercharger pulley 25 with a Vgroove around its periphery is fitted to a drive shaft 26 of the supercharger unit 23. The nominally rough-cast flywheel 21 has a V-groove machined around its periphery, or has secured concentrically to it a pulley with such a peripheral groove. Also mounted on the bracket 22 is an intermediate double V-grooved pulley 27, 28. A supercharger drive V-belt 29 passes around the supercharger pulley 25 and the first intermediate pulley 27, and a second drive V-belt 30 passes around the flywheel 21 and the second intemmediate pulley 28.

First intermediate pulley 27 is of larger diameter than second intermediate pulley 28 in order to increase the speed of the supercharger unit 23, but pulleys 27, 28 could be of the same diameter if desired. As an altemative, the supercharger pulley 25, the flywheel 21 and the intermediate pulleys 27, 28 could be toothed, with belts 29, 30 being toothed timing belts.

The rotation of the flywheel 21 when driven by the engine 10 causes the supercharger unit 23 to be driven through the transmission system SO, 28, 27, 29, 25. This provides air at above atmospheric pressure to be supplied through conduit 24 to the carburettor 18 in order that the desired air/fuel mixture can be supplied to the engine 10. The belts 29, 30 are short and are therefore not subject to the same operational speed as the fan belt 15. The speed of the supercharger unit 23 can be readily changed by changing the relative diameters of intermediate pulleys 27, 28. The resulting increase in speed of the supercharger unit 23 provides more boost pressure than was available with known arrangements. In addition, the shorter belts 29, 30 ensure that the present system is more reliable than the known systems, with fewer belt problems. Furthemmore, in the case of engines 10 mounted transversely in a motor vehicle, the supercharger unit 23 of the present invention is located at the front of the engine 10. This arrangement makes accessibility for maintenance purposes much easier than was the case with known supercharger units driven by the fan belt 15.

Claims

1. An air induction system for an internal combustion engine, the system comprising a supercharging unit, transmission means operable to drivingly connect the supercharging unit to a flywheel of the engine, and a support adapted to attach the supercharging unit to the engine adjacent the flywheel.

2. An air induction system according to claim 1, wherein the transmission means comprises a supercharger drive belt.

3. An air induction system according to claim 2, wherein the supercharger drive belt is a V-belt.

4. An air induction system according to claim 3, wherein the supercharger drive belt is a multi-V-belt.

5. An air induction system according to any one of claims 2 to 4, wherein the transmission means comprises a pulley attached to a shaft of the supercharging unit and engaged by the supercharger drive belt.

6. An air induction system according to claim 6, wherein the transmission means also comprises an intermediate pulley mounted on the support.

7. An air induction system according to claim 6, wherein the intermediate pulley is a double track pulley.

8. An air induction system according to claim 7, wherein the supercharger drive belt passes around one track and a second belt passes around the other track and a flywheel of the engine.

9. An air induction system according to claim 8, wherein the one track and the other track are of the same diameter.

10. An air induction system according to claim 8, wherein the diameter of the one track is larger than that of the other track.

11. An air induction system according to claim 8 or claim 9, wherein the second belt is a V- belt.

12. An air induction system according to claim 11, wherein the second belt is a multi-V- belt.

13. In combination an internal combustion engine, a gearbox and a flywheel connected therewith and air induction system for the engine, the air induction system comprising a supercharging unit, transmission means operable drivingly connecting the supercharging unit to the flywheel, and a support attaching the supercharging unit to the engine adjacent the flywheel.

14. A combination according to claim 13, wherein the flywheel comprises a gear ring adapted to be driven by the gearbox and a pulley track drivingly engaged by the transmission means.

15. A combination according to claim 13 or claim 14, wherein the engine is mounted in a motor vehicle.

16. An air induction system according to claim 15, wherein the engine is mounted transversely of the vehicle.

17. An air induction system according to claim 16, wherein the supercharging unit is mounted to the front of the engine.

18. An air induction system according to any one of claims 13 to 17, wherein the engine is a petrol engine.

19. An air induction system for an internal combustion engine substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.