Claims:I claim;
1. A supercharger (10) for a single cylinder engine, said supercharger (10) comprising at least,
- a housing (12), two central shaft (14) located in said housing (12) extending the length of said housing (12), at least one rotor blade (16) mounted on the central shaft (14) and a gear mounted on said central shaft (14) and a bypass channel 20;
characterized in that
at least one single sided bearing (22) provided in said housing (12), adapted to support said central shaft (14);
an end plate (24) to support rotor blades (16) at the other end of the housing (12) away from the central shaft (14); and
a rotary sleeve valve (26) located in said bypass channel 20 adapted to be operated such as to be opened or closed to bypass air charged by said supercharger (10).
2. The supercharger (10) as claimed in claim 1, wherein said housing (12) comprising at least one cavity adapted to store a lubricant.
3. The supercharger (10) as claimed in claim 1 and 2, wherein said housing (12) comprises at least one bore extending from said cavity at one end of said bore (28) to said at least one single sided bearing (22) at the other end of said bore.
4. The supercharger (10) as claimed in claim 1, wherein said at least one single sided bearing (20) is such that the length of the bearing (20) is such that the load from the driven pulley of the supercharger (10) is exerted on one side of the at least one single sided bearing (20).
5. The supercharger (10) as claimed in claim 1, wherein said end plate (24) is located beyond the rotor blades (16) in a manner such that the clearance between said end plate (24) and said rotor blades (16) is minimal.
6. The supercharger (10) as claimed in claim 1, wherein said rotary sleeve valve (26) is located beyond the first end plate (24) close to inlet (11) of supercharger (10).
7. The supercharger (10) as claimed in claim 1, wherein said rotary sleeve valve (26) is adapted to be rotated from a first operative open position to a second operative closed position.
8. The supercharger (10) as claimed in claim 6, wherein in said first operative open position of said rotary sleeve valve (26) supercharged air is sent to the inlet of said supercharger.
9. The supercharger (10) as claimed in claim 7, wherein in said second operative closed position of said rotary sleeve valve (26) supercharged air is sent to the single cylinder engine inlet.
, Description:Field of the invention
[0001] This disclosure relates to a supercharger for a single cylinder engine.
Background of the invention:
[0002] A supercharger is a device that is well known in the state of the art. Superchargers are driven by the engines to which the supercharger supplies the air. The supercharger has a driven pulley which is connected to the central shaft of the supercharger. The driven pulley is connected to a pulley on the engine through a belt drive. Rotor blades are mounted on the central shaft. The central shaft is supported by bearings and lubricated by oil. The superchargers are provided with at least two bearings, one bearing is provided at the end which is in proximity of the driven pulley while the other bearing is provided beyond the rotor blades. Both the bearings need to be lubricated, for lubricating the bearing which is in proximity of the driven pulley there bores are provided from a cavity near the bearing. For lubricating the bearing which is beyond the rotor blades, additional bores need to be made and a flow connection between an oil sources and the bores need to be provided. Also the bypass valve can be provided only after the bearing which is beyond the rotor blades.
Brief description of the accompanying drawings:
[0003] An embodiment of the disclosure is described with reference to the following accompanying drawings;
[0004] Figure 1 and figure 2 illustrate a supercharger in accordance with this disclosure.
Detailed description of the embodiments:
[0005] Figure 1 illustrates a supercharger in accordance with this disclosure. The supercharger 10 for a single cylinder engine , the supercharger 10 comprises a housing 12, a central shaft 14 located in the housing 12 extending the length of the housing 12, at least one rotor blade 16 mounted on the central shaft 14 and a gear mounted on the central shaft 14. The supercharger also has a bypass channel 20. The supercharger is characterized such that at least one single sided bearing 22 is provided in the housing 12, adapted to support the central shaft 14 and an end plate at the other end of the housing 12 away from the central shaft 14 and a rotary sleeve valve 26 located in said bypass channel 20 adapted to be operated such as to be opened or closed to bypass air charged by said supercharger.
[0006] The construction details of the supercharger 10 in accordance with this disclosure can be explained as follows. The housing 12 is provided with an axial bore through which the central shaft 14 with the rotor blade 16 extends the length of the housing 12. The rotor blades 16 are mounted on the central shaft or the central shaft 14 with the rotor blades 16 can be one single component. A driven pulley is fitted to one end of the shaft and is external to the housing 12. There is also provided within the housing a gear assembly with two gear wheels, one of the two gear wheels is directly mounted on the central shaft 14 and the second gear wheel is driven by the first gear wheel. The central shaft 14 is supported by at least one single sided bearing 22. The at least one single sided bearing 22 is said to be a single sided bearing because the bearing 22 is provided only one side of the rotor blades 16. The supercharger 10 further comprises a second end plate 23 which is fitted to the end of the housing 12 which is in proximity of the driven pulley of the supercharger 10. The housing 12 comprises at least one recess which forms at least one cavity when the second end plate is fitted to the housing. The at least one cavity is adapted to store lubricant. The lubricant is used to lubricate the bearing 22 and the gear wheels of the gear assembly. The housing 12 comprises at least one bore extending from the at least one cavity at one end of the bore 28 to the at least one bearing 22 at the other end of the bore. The cavity allows to store onetime oil filing.
[0007] The least one single sided bearing 22 is such that the length of the bearing 22 is such that the load from the driven pulley of the supercharger 10 is exerted on one side of the at least one bearing 22. Since the supercharger 10 of this disclosure is used in single cylinder engines the bearing can be designed as journal bearing without the necessity of having any ball bearing. The bearing 22 length is kept high such that the bearing 22 acts as two bearing in a manner such that the load from the driven pulley come on one side of the bearing 22 and the load from pressurizing the air through the rotor blades comes from the other side. This also ensures that the central shaft bending if any is under control, which in turns ensure performance parameters of the supercharger 10.
[0008] The first end plate 24 which is located beyond the rotor blades 16 is a simple end plate which is fitted in manner such that the clearance between the end plate 24 and the rotor blades 16 is minimal. When the second end plate 23 is fitted to the housing to form the cavity, a first sealing ring is provided to ensure that there is not oil leakage to the outside. A second sealing ring which is located towards the rotor blades side ensures that there is no oil leakage from the bearing 22 to the air side where the rotor blades 16 are conveying the air.
[0009] A mentioned earlier the supercharger 10 comprises a bypass channel 20. The at least one single sided bearing 22 allow a simple design of the bypass valve. The rotary sleeve 26 type bypass valve is located in the bypass channel 20 and is actuated in a manner such that air flow through the bypass channel 20 can be such that the air is bypassed back to the inlet of the supercharger. The actuation of the rotary sleeve valve 26 can be controlled through the accelerator pedal or handle controlled which allows the flexibility of the engine being provided pressurized air only when it is required. This is particularly important for single cylinder naturally aspirates engine operating in full load condition where lambda gets critical.
[00010] Since only one single sided bearing 22 is used in the supercharger 10 it is possible to design the supercharger with axial inlet 11, radial outlet 26 and to incorporate the bypass channel 20 beyond the first end plate 24 close to the inlet. This helps reducing the packaging of the supercharger 10. The minimal clearance between the first end plate 24 and the rotor blades 16 increases the efficiency of the supercharger. The single sided bearing also ensures that the bypass valve can be simple design and can occupy less space as there is no second bearing.
[00011] The working principle of the supercharger 10 in accordance with this disclosure is that the rotary sleeve valve 26 is adapted to be operated such as to short circuit the inlet and outlet of the supercharger. The rotary sleeve valve 26 is adapted to be rotated from a first operative open position to a second operative closed position. In the first operative open position of the rotary sleeve valve 26 supercharged air is sent back through the bypass channel 20 to the inlet 11 of the supercharger 10. In the second operative closed position of rotary sleeve valve 26 supercharged air is sent to the single cylinder engine inlet. The possibility of being able to circulate the air from the outlet 26 of supercharger 10 back to the inlet 11 of the supercharger there is no need for any additional external air pipe to the supercharger 10.
[00012] As seen in figure 2, when there is no need to bypass the air and send it back to the inlet of the supercharger 10, the rotary sleeve valve 26 is maintained in a first operative open position. However, when it is required the air should be bypassed the rotary sleeve valve 26 is switched through an actuator to a second operative closed position and air is sent back to the inlet of the supercharger. The actuation of the rotary sleeve valve 26 could be done by an actuator which may be at least one chosen from a group of actuators such as a mechanical actuator or an electronic actuator.
[00013] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention in terms of the type of valves, and the like. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.