Lasted edited by Andrew Munsey, updated on June 15, 2016 at 12:54 am.
The Revetec cam-drive engine uses a pair of counter-rotating scissor cams instead of a crankshaft. The result is three times more torque than a conventional engine, and an overall engine efficiency up to 50% more.
REVETEC Limited is a design engine company and developer of the "Controlled Combustion Engine" (CCE). The CCE is an internal combustion engine that is lighter, cleaner and more powerful than equivalent conventional engines, and cheaper to manufacture, due to fewer components.
The Revetec X4v2 engine was independently tested at Orbital Australia. During testing, the engine achieved a best BSFC figure of 207g/(kW-h) or 39.5% engine efficiency on petrol. The efficiency level rivals most diesel engines. (April 27, 2008)
Revetec has just completed their first Independently Certified Test Report carried out by Orbital Australia, achieving a repeatable BSFC figure of 212g/kW-h (38.6% efficiency) with a best tested figure of 207g/kW-h (39.5% efficiency) Visit the announcement on the Revetec website Latest News-- Brad Howell-Smith: Revetec (April 2, 2008) Revetec Latest News
: 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 40deg 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).
: The dual bearings contact the two cams in the opposite side which cancels the side forces out. The piston assembly does not experience any side force which will reduce wear and lubrication requirements at the cylinder contact. 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.
Revetec has just completed their first Independently Certified Test Report carried out by Orbital Australia, achieving a repeatable BSFC figure of 212g/kW-h (38.6% efficiency) with a best tested figure of 207g/kW-h (39.5% 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.
Revolution Engine Technologies Pty Limited (a wholly owned subsidiary of Revetec Limited) holds patents or has made patent applications for the CCE design in 28 countries, including the United States of America, Europe, Australia, China, the United Kingdom and Japan. The beneficial ownership of the patents and patent applications was assigned to Revetec on 14 September 2005.
U.S. Patent http://patft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.htm&r=1&f=G&l=50&d=PTXT&p=1&p=1&S1=%22Revolution+Engine+Technologies%22&OS= 5,992,356 "Opposed piston combustion engine " November 30, 1999 Howell-Smith Bradely David (Worongary, AU).
Abstract : An engine comprises two counter rotating multilobate cams which are acted upon by a pair of diametrically opposed pistons which are rigidly interlinked by connecting rods. Differential gearing is provided to time the counter rotation of the cams. The following is an examiner's statement of reasons for allowance: The prior art fails to teach or fairly suggest the invention as a whole including a shaft having a first multilobate cam axially fixed to said shaft and an adjacent second multilobate cam differentially geared to said first multilobate cam for axial counter rotation about said shaft, at least one pair of cylinders, the cylinders of each pair being diametrically opposed with respect to said shaft with said multilobate cams interposed therebetween, and a piston in each said cylinder, said pistons of a pair of cylinders being rigidly interconnected.
from revetec website
The advantages of Revetec’s engine technology can be applied to most internal and external combustion engines for use in motor vehicles, trucks, buses, motorcycles, pumps and generators, light aircraft engines, diesel and marine engines.
The CCE integrates well with existing power plants and can utilise almost all existing engine technology with increased efficiency.
The CCE engine is extremely well suited for high torque applications such as generators, machinery and light aircraft.
Revetec has completed its design on its prototype, which could now be adapted by our customers to meet their specific requirements. (Ref)
Motorists to Benefit From Revetec’s new Engine Design (Australian Investor subscription required) [copy on company site]
Fuel-saving breakthrough - (Sydney Sunday Telegraph October, 2 2005)
REVETEC Holdings Limited
ACN: 115 621 317
PO Box 8203
Gold Coast Mail Centre
Gold Coast QLD
Phone International: +61 7 5531 6059
Fax International: +61 7 5531 6997
Email [mailto:email@example.com?subjec=Revetec_featured_at_PESWiki.com firstname.lastname@example.org]