View Full Version : A hard question for someone really clever!
02-11-2004, 06:05 PM
I've just been reading the latest issue of EVO UK magazine (issue 065) and they have a full behind the scenes article at TVRs Blackpool factory, covering the development of the upcoming Sagaris and Typhon models. They have a whole section about the supercharging of the Speed Six engine for the Typhon with an interview with the guy in charge of the project, Simon Hindle. In one paragraph they (attempt to) describe the mechanicals of the custom designed Rotrax supercharger. Now I consider myself to have a fairly good grasp of technical engine type stuff, and know the basics of forced induction systems, but this went WAY over my head! :confused:
"Inside the Rotrax's casing, the epicyclic drive comprises three steel rollers surrounding the drive spindle. One has an arm connected to the spindle and the faster the crank-driven outer casing turns, the harder the rollers engage."
Can anyone please enlighten me as to what the hell they are on about??!!
03-07-2004, 05:14 PM
belive it or no that was the simplified version...
1) Annulus drive-ring
2) Rollers (planets)
3) High-speed output shaft (sun)
exploded gearbox view:
"Traction drive is performed by the shearing force of an elastohydro-dynamic lubrication oil film between two rotating surfaces. The viscosity of the traction fluid increases momentarily under high contact surface pressure. Thus becoming solid and able to transmit the torque.
Having a solid phase with line contact between three planet-rollers enables a high power-transmission between smooth surfaces, without traditional gear-wheels.
The gear-wheels are replaced by traction-technology!
The traction concept requires a constant slip of 0,2 to 0,8% during operation.
Traction fluids are based on highest grade ATF oils and have superior lubrication characteristics for ball and roller-bearings.
The lubricant also cools the heat generated by the slip.
Self-adjusting geometry applies contact pressure between rolling components.
No external control applied.
The geometry adapts automatically to speed and load.
The ROTREX gearbox is a fixed ratio planetary roller traction gear, which has a built in capability to adjust contact forces applied to the traction surfaces of the transmission in relation to the torque required.
Traction transmissions require relatively large engagement forces between traction surfaces to prevent slippage. The ROTREX automatically adjusts the contact force, to optimize the gear for the current torque required for the situation and application at hand. This means a reduction in frictional losses and wear of the transmission. Where full torque is transmitted, the transmission has the capability to provide sufficient traction force to prevent slippage."