Continuously variable transmission having a continuously slipping clutch
AssigneeVan Doorne's Transmissie B.V.
InventorsEngbert Spijker, Peter Bäuerle
Life of this patent
Estimating the term…
Abstract
A continuously variable transmission (1) is provided with: an endless transmission (14) for transmitting a driving torque; a clamping force (13-1, 13-2) coupled with the endless transmission (14) for applying a clamping force thereon; a controller (15) coupled with the clamping force (13) for influencing the driving torque by controlling the clamping force applied on the endless transmission (14); and a clutch (16) coupled with the controller (15), whereby the controller (15) is arranged to control the clutch such that the clutch (16) is allowed to slip continuously. The net effect of a practical implementation of the transmission in a vehicle is a fuel saving which, if a slip of around 5 rpm is permitted, amounts about 3-4%.
Claims18
A continuously variable transmission (CVT) connecting a driving shaft adapted to be coupled to an engine and a driven shaft adapted to be coupled to a load, the CVT comprising:
- transmission means for transmitting power between the driving and driven shafts;
- clamping force application means for applying a clamping force to said transmission means;
- a clutch having an in-going shaft and an outgoing shaft;
- and
- control means for controlling both said clamping force application means and said clutch to cause said clutch to slip a non-zero amount during continuous operation of the CVT, an amount of the clutch slip being a difference between a rotational speed of said in-going shaft and a rotational speed of said out-going shaft, and to reduce the clamping force when said clutch slips the non-zero amount compared to when said clutch has zero slip.
A continuously variable transmission (CVT) connecting a driving shaft adapted to be coupled to an engine and a driven shaft adapted to be coupled to a load, the CVT comprising:
- transmission means for transmitting power between the driving and driven shafts;
- clamping force application means for applying a clamping force to said transmission means, the clamping force being a force required to transmit the power plus a safety margin;
- a clutch having an in-going shaft and an outgoing shaft;
- and
- control means for controlling said clamping force application means and for controlling said clutch to select a zero slip condition wherein said clutch does not slip and a clutch slip condition wherein said clutch allows a non-zero amount of clutch slip, an amount of the clutch slip being a difference between a rotational speed of said in-going shaft and a rotational speed of said out-going shaft, wherein the safety margin in the clutch slip condition is lower than the safety margin in the zero slip condition.
Dependencies are inferred from the claim text.