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US 6,605,016 B2Granted
Toroidal type continuously variable transmission and continuously variable transmission apparatus
AssigneeNsk Ltd.
InventorsShinji Miyata, Daping Liu
Life of this patent
Estimating the term…
Abstract
A hydraulic type pressing device secures the contact pressure between the peripheral surfaces of respective power rollers and the inner surfaces of respective input side disks and respective output side disks. When a torque to be transmitted changes abruptly, the pressing force of the pressing device is set to a value corresponding to the maximum torque to be transmitted by a toroidal type continuously variable transmission. According to this configuration, the variation of the transmission ratio based on the variation of the elastic deformation values at the respective portions is suppressed to prevent the uncomfortable feeling of a driver.
Claims8
A toroidal continuously variable transmission comprising:
- first and second disks each having a concave-shaped inner surface with an arc shape in section, the first and second disks being supported concentrically to be rotatable independently in a state that the inner surfaces thereof are opposed to each other;
- a plurality of trunnions each swingably rotating around pivot shafts which are disposed at twisted positions with respect to a center shaft of the first and second disks;
- displacement shafts each being supported by an intermediate portion of corresponding one of the trunnions in a state of protruding from an inner surface of the corresponding one of the trunnions;
- power rollers each having a spherical convex-shaped periphery and disposed on an inner surface side of corresponding one of the trunnions, each of the power rollers being supported around a periphery of corresponding one of the displacement shafts to be rotatable in a state of being sandwiched between the first and second disks;
- a pressing device which presses the first disk toward the second disk, the pressing device generating a first pressing force corresponding to a magnitude of a torque transmitted between the first and second disks and a second pressing force independent from the torque;
- and
- a controller controlling the pressing device to generate the second pressing force in accordance with a signal, wherein, when a magnitude of a torque transmitted between the first and second disks varies, the controller controls the pressing device to continuously generate a predetermined pressing force equal to or more than a pressing force necessary for transmitting a larger torque before and after the variation during the variation.
4 more elements
A continuously variable transmission apparatus comprising:
- an input shaft coupled to a driving source and driven and rotated by the driving source;
- an output shaft for taking out a power based on the rotation of the input shaft;
- a toroidal continuously variable transmission;
- a planetary gear mechanism;
- a first power transmission path for transmitting a power inputted into the input shaft through the toroidal continuously variable transmission;
- a second power transmission path for transmitting the power inputted into the input shaft without passing through the toroidal continuously variable transmission;
- and
- a mode switching device for switching a state where the power inputted into the input shaft is transmitted to the planetary gear mechanism through the first power transmission path and the second power transmission path,
- wherein the toroidal continuously variable transmission includes:
- first and second disks each having a concave-shaped inner surface with an arc shape in section, the first and second disks being supported concentrically to be rotatable independently in a state that the inner surfaces thereof are opposed to each other;
- a plurality of trunnions each swingably rotating around pivot shafts which are disposed at twisted positions with respect to a center shaft of the first and second disks;
- displacement shafts each being supported by an intermediate portion of corresponding one of the trunnions in a state of protruding from an inner surface of the corresponding one of the trunnions;
- power rollers each having a spherical convex-shaped periphery and disposed on an inner surface side of corresponding one of the trunnions, each of the power rollers being supported around a periphery of corresponding one of the displacement shafts to be rotatable in a state of being sandwiched between the first and second disks;
- a pressing device which presses the first disk toward the second disk, the pressing device generating a first pressing force corresponding to a magnitude of a torque transmitted between the first and second disks and a second pressing force independent from the torque;
- and
- a controller controlling the pressing device to generate the second pressing force in accordance with a signal, wherein, when a magnitude of a torque transmitted between the first and second disks varies, the controller controls the pressing device to continuously generate a predetermined pressing force equal to or more than a pressing force necessary for transmitting a larger torque before and after the variation during the variation,
- wherein the planetary gear mechanism includes:
- a sun gear;
- a ring gear disposed at periphery of the sun gear;
- a planetary gear provided between the sun gear and the ring gear;
- and
- a carrier for rotatably supporting the planetary gear,
- wherein a power transmitted through the first power transmission path and a power transmitted through the second power transmission path is freely transmitted to two of the sun gear, the ring gear and the carrier, and remaining one of the sun gear, the ring gear and the carrier is coupled to the output shaft,
- wherein the mode switching device switches at least between a first mode for transmitting power only through the first power transmission path and a second mode for transmitting power through both the first power transmission path and the second power transmission path, and
- wherein the controller of the toroidal continuously variable transmission controls the pressing device, during the switching of the mode switching device between the first mode and the second mode, to continuously generate a predetermined pressing force equal to or more than a pressing force necessary for transmitting a larger torque before and after the switching.
22 more elements
A continuously variable transmission apparatus comprising:
- an input shaft coupled to a driving source and driven and rotated by the driving source;
- an output shaft for taking out a power based on the rotation of the input shaft;
- a toroidal continuously variable transmission;
- a planetary gear mechanism;
- a first power transmission path for transmitting a power inputted into the input shaft through the toroidal continuously variable transmission;
- a second power transmission path for transmitting the power inputted into the input shaft without passing through the toroidal continuously variable transmission;
- and
- a mode switching device for switching a state where the power inputted into the input shaft is transmitted to the planetary gear mechanism through the first power transmission path and the second power transmission path,
- wherein the toroidal continuously variable transmission includes:
- first and second disks each having a concave-shaped inner surface with an arc shape in section, the first and second disks being supported concentrically to be rotatable independently in a state that the inner surfaces thereof are opposed to each other;
- a plurality of trunnions each swingably rotating around pivot shafts which are disposed at twisted positions with respect to a center shaft of the first and second disks;
- displacement shafts each being supported by an intermediate portion of corresponding one of the trunnions in a state of protruding from an inner surface of the corresponding one of the trunnions;
- power rollers each having a spherical convex-shaped periphery and disposed on an inner surface side of corresponding one of the trunnions, each of the power rollers being supported around a periphery of corresponding one of the displacement shafts to be rotatable in a state of being sandwiched between the first and second disks;
- a pressing device which presses the first disk toward the second disk, the pressing device generating a first pressing force corresponding to a magnitude of a torque transmitted between the first and second disks and a second pressing force independent from the torque;
- and
- a controller controlling the pressing device to generate the second pressing force in accordance with a signal, wherein, when a magnitude of a torque transmitted between the first and second disks varies, the controller controls the pressing device to continuously generate a predetermined pressing force equal to or more than a pressing force necessary for transmitting a larger torque before and after the variation during the variation,
- wherein the planetary gear mechanism includes:
- a sun gear;
- a ring gear disposed at periphery of the sun gear;
- a planetary gear provided between the sun gear and the ring gear;
- and
- a carrier for rotatably supporting the planetary gear,
- wherein a power transmitted through the first power transmission path and a power transmitted through the second power transmission path is freely transmitted to two of the sun gear, the ring gear and the carrier,
- wherein the mode switching device switches between a mode for transmitting power at a low speed and a mode for transmitting power at a high speed, and
- wherein the controller of the toroidal continuously variable transmission controls the pressing device, during the switching of the mode switching device between the mode for transmitting power at a low speed and the mode for transmitting power at a high speed, to continuously generate a predetermined pressing force equal to or more than a pressing force necessary for transmitting a larger torque before and after the switching.
22 more elements
Dependencies are inferred from the claim text.