Friction type transmission device and pressing force control method for friction type transmission device
AssigneeNissan Motor Co., Ltd.
InventorTakeshi Yamamoto
Life of this patent
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Abstract
In a friction drive transmission apparatus arranged to transmit power by a frictional transmission force between two roller units pressed against each other, there is provided a pressing force imparting means to increase and decrease a pressing force imparted to a roller pair to vary the frictional transmission force between both roller units smoothly at the time of a shift.
Claims14
A friction drive transmission apparatus comprising:
- a driving roller unit and a driven roller unit which are supported rotatably, the driving and driven roller units being pressed in press contact to each other and arranged to transmit power from one of the driving and driven roller units to the other by a frictional transmission force produced in a contact portion therebetween, the driving and driven roller units comprising a plurality of roller pairs having different roller radii, at least one of the driving and driven roller units being supported rotatably on an eccentric shaft so that an inter-axis distance of each of the plurality of roller pairs is varied by rotation of the eccentric shaft, and the power is transmitted selectively by one of the plurality of roller pairs;
- and
- a pressing force imparting member configured to vary a pressing force imparted to the roller pairs so as to vary the frictional transmission force smoothly at a time of a shift, the pressing force imparting member comprising:
- an actuator that increases the pressing force by adding an additional force to the plurality of roller pairs;
- and
- a controller for the actuator, the controller being configured to:
- control the pressing force with the actuator,
- hold the additional force before a shift operation, and
- increase the additional force transiently at the time of the shift so as to vary the frictional transmission force smoothly at the time of the shift.
A control method of controlling a pressing force of a friction drive transmission apparatus comprising a driving roller unit and a driven roller unit which are supported rotatably, the driving and driven roller units being pressed in press contact to each other and arranged to transmit power from one of the driving and driven roller units to the other by a frictional transmission force produced in a contact portion therebetween, the driving and driven roller units comprising a plurality of roller pairs having different roller radii, at least one of the driving and driven roller units being supported rotatably on an eccentric shaft so that an inter-axis distance of each of the plurality of roller pairs is varied by rotation of the eccentric shaft, and the power is transmitted selectively by one of the plurality of roller pairs, the control method comprising:
- varying the pressing force imparted to the one of the plurality of roller pairs so as to vary the frictional transmission force smoothly at a time of a shift;
- providing an actuator that adds an additional force to the one of the plurality of roller pairs so as to increase the pressing force, and
- providing a controller for the actuator to control the pressing force with the actuator, the controller being configured to:
- hold the additional force of the actuator before a shift operation, and
- increase the additional force transiently at the time of the shift to vary the frictional transmission force smoothly at the time of the shift.
Dependencies are inferred from the claim text.