Check out this new engine design.
The REVETEC Engine design consists of two counter-rotating trilobate (three lobed) cams geared together, so both cams contribute to forward motion. Two bearings run along the profile of both cams (four bearings in all) and stay in contact with the cams at all times. The bearings are mounted on the underside of the two inter-connected pistons, which maintain the desired clearance throughout the stroke. The two cams rotate and raise the piston with a scissor-like action to the bearings. Once at the top of the stroke the air/fuel mixture is fired. The expanded gas then forces the bearings down the ramps of the cams spreading them apart ending the stroke. The point of maximum mechanical advantage or transfer is around 10deg ATDC (the piston moving approximately 5% of its travel) making the most of the high cylinder pressure.
This compares to a conventional engine that reaches maximum mechanical advantage around 60deg ATDC. (after the piston has moved through 40% of its travel, losing valuable cylinder pressure). The effective cranking distance is determined by the length from the point of bearing contact to the centre of the output shaft (NOT the stroke). A conventional engine's turning distance is half of the piston stroke. The piston acceleration throughout the stroke is controlled by the cam grind which can be altered to give acceleration to suit a certain fuel and/or torque application. This also allows different port timing on opposite strokes, increasing efficiency on 2-Stroke engines.
The piston assembly slides rigidly through the block eliminating piston to cylinder-bore contact. This reduces wear and lubrication requirements. This also reduces piston shock to a negligible amount making ceramic technology suitable. One module which comprises of a minimum of five moving components, produces six power strokes per revolution. Increasing the number of lobes on each cam to five produces ten power strokes without increasing the number of components. The CCE integrates well with existing power plants and can utilise almost all existing engine technology with increased efficiency.
Summaries of CCE advantages are as follows:
Videos:
http://www.revetec.com/?q=system/files&file=CCE3-002.wmv
http://www.revetec.com/?q=system/files&file=CCE3-008.wmv
http://www.revetec.com/?q=system/files&file=RLE5-002.wmv
The REVETEC Engine design consists of two counter-rotating trilobate (three lobed) cams geared together, so both cams contribute to forward motion. Two bearings run along the profile of both cams (four bearings in all) and stay in contact with the cams at all times. The bearings are mounted on the underside of the two inter-connected pistons, which maintain the desired clearance throughout the stroke. The two cams rotate and raise the piston with a scissor-like action to the bearings. Once at the top of the stroke the air/fuel mixture is fired. The expanded gas then forces the bearings down the ramps of the cams spreading them apart ending the stroke. The point of maximum mechanical advantage or transfer is around 10deg ATDC (the piston moving approximately 5% of its travel) making the most of the high cylinder pressure.
This compares to a conventional engine that reaches maximum mechanical advantage around 60deg ATDC. (after the piston has moved through 40% of its travel, losing valuable cylinder pressure). The effective cranking distance is determined by the length from the point of bearing contact to the centre of the output shaft (NOT the stroke). A conventional engine's turning distance is half of the piston stroke. The piston acceleration throughout the stroke is controlled by the cam grind which can be altered to give acceleration to suit a certain fuel and/or torque application. This also allows different port timing on opposite strokes, increasing efficiency on 2-Stroke engines.
The piston assembly slides rigidly through the block eliminating piston to cylinder-bore contact. This reduces wear and lubrication requirements. This also reduces piston shock to a negligible amount making ceramic technology suitable. One module which comprises of a minimum of five moving components, produces six power strokes per revolution. Increasing the number of lobes on each cam to five produces ten power strokes without increasing the number of components. The CCE integrates well with existing power plants and can utilise almost all existing engine technology with increased efficiency.
Summaries of CCE advantages are as follows:
- approximately one quarter the size and weight of a conventional engine (for similar applications) combined with improved output substantially increases power/weight and torque/weight ratio.
- fewer moving and total components. As a result of fewer components, more easily manufactured than conventional engines.
- identical cylinder head assembly (top end) to conventional engines. Most existing head technology can be either adapted or utilised.
- Flexible design - can be four-stroke, two-stroke, petrol, diesel or gas, natural of forced aspiration.
- Eliminated irregularly reciprocating components such as connecting rods.
- Output shaft can be run in either direction if multilobed cams with symmetrical lobes are employed.
- All rotational forces are counteracted via the counter rotating cam eliminates the need for a heavy flywheel.
- Torque and power output can be varied using a fixed capacity and piston stroke.
- The CCE can be designed to operate at greatly reduced operating speeds while delivering high torque output.
- Substantial reduction in stroke reduces heat loss through cylinder wall.
- Extended piston dwell is possible because engine design allows a lower than normal compression ratio to be used reducing power loss from compression cycle.
- Maximum mechanical advantage can be applied to output shaft at only 10 degrees ATDC utilising high cylinder pressure early in the stroke, compared to around 60 degrees ATDC for conventional engines.
- Lower emissions can be achieved due to increased control over combustion.
- Extremely low idle speed due to increase in mechanical efficiency at the top of the stroke.
- Little or no bore contact/piston side thrust, which reduces wear on cylinder bore.
- Can have different port timing on compression stroke than power stroke allowing better control two-stroke).
- Lower centre of gravity.
- Due to controlled piston acceleration rates the CCE reduces engine vibration.
- A hollow output shaft can be utilised for specialty applications, such as peristaltic pumps.
Videos:
http://www.revetec.com/?q=system/files&file=CCE3-002.wmv
http://www.revetec.com/?q=system/files&file=CCE3-008.wmv
http://www.revetec.com/?q=system/files&file=RLE5-002.wmv
