Continuously variable transmissions using magnetorheological fluid or oil shear and methods of and systems for using the same in a vehicle, in-wheel application
First Claim
1. A continuously variable speed ratio transmission for providing input torque to an output shaft, the transmission comprising:
- an internal drive element movable about an axis, the internal drive elements further comprising one or more planets, said internal drive element being in communication with a device for providing said input torque;
an external drive element movable about an axis, said external drive element being in communication with the output shaft to provide torque to said output shaft, wherein said internal drive element and said external drive element are structured and arranged to provide a gap therebetween and, further, so that their axes are substantially parallel;
magnetorheological fluid that is disposed in said gap between said internal drive element and said external drive element; and
a magnetic flux producing device, wherein said magnetic flux producing device is moveable with respect to said axes.
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Accused Products
Abstract
Continuously variable speed ratio transmissions (CVT) for an in-wheel application use one or more magnetorheological (MR) or oil-shear clutch assemblies, each of which can have a unique speed ratio, to transmit torque between an input shaft and an output shaft. The clutch assemblies comprise an input drive element, input idler assemblies, a number of clutch assemblies output idler assemblies, and an output shaft assembly. Preferably, the CVT can be structured and arranged to occupy a volume between about 10- and 11-inches in diameter and between about 4 and 5 inches in axial length. The MR clutch assembly includes a rotateable input cylinder and a rotateable output cylinder that are coaxial about a stationary shaft. The input cylinder and output cylinder are separated by a gap that is filled with an MR fluid. A multitude of coil windings are disposed on the stator of each of the MR clutch assemblies. When current flows through the coil windings, a magnetic flux field is produced in the MR fluid. The MR fluid densifies, transferring input cylinder torque to the output cylinder by shear. A control unit can control current to the coil windings so that only clutch assemblies having the desired speed ratio are actuated. Alternatively, a CVT comprises a number of oil-shear clutch assemblies, each of which can have unique speed ratios, to transmit torque between a rotateable clutch cylinder and a rotateable drive cup and hub assembly through shear in the oil and/or through direct contact between the two cups. A control unit can control an external pressure that can be added to one or more of the oil-shear clutches to increase of decrease the separation distance between the two cups to provide the desired speed ratio. A CVT with a moveable magnetic flux producing device to produce a localized magnetic flux field in MR fluid that is disposed in the gap between a rotatable internal drive element and a rotateable external drive element. The speed ratios associated with various positions device differ, providing an infinite variable speed ratio transmission.
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Citations
44 Claims
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1. A continuously variable speed ratio transmission for providing input torque to an output shaft, the transmission comprising:
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an internal drive element movable about an axis, the internal drive elements further comprising one or more planets, said internal drive element being in communication with a device for providing said input torque;
an external drive element movable about an axis, said external drive element being in communication with the output shaft to provide torque to said output shaft, wherein said internal drive element and said external drive element are structured and arranged to provide a gap therebetween and, further, so that their axes are substantially parallel;
magnetorheological fluid that is disposed in said gap between said internal drive element and said external drive element; and
a magnetic flux producing device, wherein said magnetic flux producing device is moveable with respect to said axes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system for providing continuous variable transmission for an in-wheel motor vehicle, wherein the system comprises:
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an in-wheel motor that provides an input speed and an input torque;
a continuous variable speed ratio transmission comprising a magnetorheological fluid and a moveable magnetic flux producing device, wherein said continuous variable speed ratio transmission transfers the input torque from the in-wheel motor through said magnetorheological fluid to an output shaft to drive a motor vehicle wheel by shear; and
a continuous variable transmission control unit that provides a control current to position the moveable magnetic flux producing device at a desired location, wherein said moveable magnetic flux producing device provides a magnetic flux field in the magnetorheological fluid at the desired location that provides a shear region in said magnetorheological fluid at said desired location through which the input torque is transferred. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. A continuously variable speed ratio transmission for providing input torque to an output shaft, the transmission comprising:
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an input drive element further comprising an input shaft, said input drive element being in communication with a device for providing said input torque;
a first plurality of idler assemblies that are in communication with the input shaft of the input drive element, whereby input torque provided by said input shaft is transmitted to each of said first plurality of idler assemblies;
one or more magnetorheological clutch assemblies, each of the one or more magnetorheological clutch assemblies having a speed ration and further comprising;
an input cylinder that is rotatable about a stationary shaft;
a clutch input gear, an outer periphery of which is in communication with an outer periphery of one of the first plurality of idler assemblies and the input cylinder so that the clutch input gear, one of the first plurality of idler assemblies and said input cylinder can rotate synchronously; and
a output cylinder which is in communication with an output gear so that the output cylinder and output gear can rotate synchronously, wherein the output cylinder is coaxial with the input cylinder and separated therefrom by a fluid filled-gap;
a second plurality of idler assemblies, wherein each of said second plurality of idler assemblies is in communication with a discrete output gear of the output cylinder of one of the one or more magnetorheological clutch assemblies, whereby torque transmitted to the output gear of said one or more magnetorheological clutch assemblies is further transmitted to each of said second plurality of idler assemblies; and
an output shaft assembly further comprising;
an output shaft;
an output gear, an outer periphery of which is in communication with each of the second plurality of idler assemblies and the output shaft, whereby any torque transmitted to said second plurality of idler assemblies is further transmitted to said output shaft assembly output gear and then to the output shaft of the output shaft assembly. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A method of providing a continuously variable speed ratio in a transmission, the transmission, the method comprises the steps of:
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providing an outer ring gear;
providing at least one inner rotating gear that is disposed inside the outer ring gear;
structuring and arranging the at least one inner rotating gear and the outer ring gear so they are aligned in parallel axes and to provide a space or gap therebetween;
introducing a magentorheological fluid into said space or gap between said at least one inner rotating gear and said outer ring gear;
providing a moveable magnetic flux producing device to induce a magnetic flux field at a desired location within said space or gap in order to activate the magnetorheological fluid at the desired location; and
transferring torque from the at least one inner rotating gear to the outer ring gear as shear stress in the magnetorheological fluid in the desired location to provide a desired speed ratio. - View Dependent Claims (31, 32, 33, 34)
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35. A continuously variable speed ratio transmission for providing input torque to an output shaft, the transmission comprising:
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an input drive element further comprising an input shaft, said input drive element being in communication with a device for providing said input torque;
a first plurality of idler assemblies that are in communication with the input shaft of the input drive element, whereby input torque provided by said input shaft is transmitted to each of said first plurality of idler assemblies;
one or more clutch assemblies, each of said one or more clutch assemblies having a speed ratio, wherein each of said one or more clutch assemblies comprises;
an input clutch gear of the same diameter, and an output clutch gear having a diameter that affects the speed ratio, whereby any torque transmitted to the input clutch gear of each of said one or more clutch assemblies by said first plurality of idler assemblies is further transmitted to the output clutch gear of each of said one or more clutch assemblies;
a second plurality of idler assemblies, wherein each of said second plurality of idler assemblies is in communication with the output clutch gear of said one or more clutch assemblies, whereby any torque transmitted to each output gear of said one or more clutch assemblies by said first plurality of idler assemblies is further transmitted to each of said second plurality of idler assemblies; and
an output shaft assembly further comprising;
an output gear that is in communication with each of said second plurality of idler assemblies, and an output shaft that is in communication with said output shaft assembly output gear, whereby any torque transmitted to the second plurality of idler assemblies is further transmitted to said output shaft assembly output gear and then to the output shaft of the output shaft assembly. - View Dependent Claims (36, 37, 38, 39, 40, 41, 42, 43)
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44. A system for providing continuous variable transmission for an in-wheel motor vehicle, wherein the system comprises:
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an in-wheel motor that provides an input speed and an input torque;
a continuous variable speed ratio transmission comprising one or more oil shear-type clutch assemblies, wherein each of the one or more oil shear-type clutch assemblies has a speed ratio; and
a continuous variable transmission control unit that provides external pressure to actuate one or more of the one or more oil shear-type clutch assemblies to provide a desired speed ratio, whereby actuation can be effected by applying said external pressure to one or more of said one or more oil shear-type clutch assemblies that have the desired speed ratio.
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Specification