BI-MODAL VEHICLES WITH DRIVE MEANS FOR EXTERNAL OR SELF-PROPULSION
First Claim
1. An electro-mechanical transmission comprising differential drive means having an input element and first and second output elements, said input element being drivably connectable to a source of mechanical power, a transmission output member drivably connected with said first differential output element, a first electrical machine operable as a motor and drivably connected with said transmission output member, a second electrical machine capable of operation either as a motor or as a generator, first friction drive establishing means operable in a first transmission operating mode to drivably connect said second electrical machine to said transmission output member, second friction drive establishing means operable in a second transmission operating mode to drivably connect said second differential output element to said second electrical machine for driving said second electrical machine as a generator, and electrical connection means operable in said fIrst operating mode to connect said first and second electrical machines to an external source of electric power for driving said electrical machines as motors, said connection means being operable in said second mode to connect said second electrical machine for operation as a generator and to deliver the generated electrical output of said second electrical machine to said first electrical machine.
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Accused Products
Abstract
A bi-modal vehicle, such as a rail car, is provided in a preferred embodiment with a propulsion turbine and an electromechanical transmission arranged to drive the vehicle either from the turbine or from an external source of electrical power. The electro-mechanical transmission includes a split torque feature whereby, in the self-propelled mode, some of the turbine torque is delivered mechanically to the output shaft while the remainder passes through an electrical path including a motor and generator combination. In the external electric drive mode, both the generator and motor of the transmission are utilized as drive motors directly driving the output shaft. Numerous additional features are included.
29 Citations
8 Claims
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1. An electro-mechanical transmission comprising differential drive means having an input element and first and second output elements, said input element being drivably connectable to a source of mechanical power, a transmission output member drivably connected with said first differential output element, a first electrical machine operable as a motor and drivably connected with said transmission output member, a second electrical machine capable of operation either as a motor or as a generator, first friction drive establishing means operable in a first transmission operating mode to drivably connect said second electrical machine to said transmission output member, second friction drive establishing means operable in a second transmission operating mode to drivably connect said second differential output element to said second electrical machine for driving said second electrical machine as a generator, and electrical connection means operable in said fIrst operating mode to connect said first and second electrical machines to an external source of electric power for driving said electrical machines as motors, said connection means being operable in said second mode to connect said second electrical machine for operation as a generator and to deliver the generated electrical output of said second electrical machine to said first electrical machine.
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2. An electro-mechanical transmission comprising first and second planetary gear sets, each including a sun gear, a ring gear, and planet gears engaging both their respective sun and ring gears and connected to a carrier, said first planetary ring gear being drivably connected with said second planetary sun gear, a transmission input member drivably connected with said first planetary sun gear, a transmission output member drivably connected with said first planetary carrier, first and second electrical machines, said first machine being operable as a motor and drivably connected with said transmission output member, said second machine being operable either as a motor or a generator and being drivably connected with said second planetary ring gear, first friction drive establishing means between said second machine and said transmission output member and engageable to drivably connect them in a first transmission operating mode, second friction drive establishing means between said second planetary carrier and ground and engageable to ground said second carrier in a second transmission operating mode, whereby said second machine is drivably connected through said second and first planetary gear sets with said transmission input member, and electrical connection means operable in said first mode to electrically connect said first and second machines to an external source of electric power for operating said machines as motors and said connection means being operable in said second mode to connect said first machine to receive generated current from said second machine.
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3. Drive means for a bi-modal vehicle operable in a first operating mode from an external electrical source and in a second operating mode as a self-powered vehicle, said drive means comprising a vehicle-mounted prime mover having a mechanical output, differential drive means having an input element drivably connected with said power source output and first and second output elements differentially connected with said input element, a drive output member drivably connected with said first differential output element, a first electrical machine operable as a motor and drivably connected with said drive output member, a second electrical machine capable of operation either as a motor or as a generator, first friction drive establishing means operable in said first operating mode to drivably connect said second electrical machine to said drive output member, second friction drive establishing means operable in said second operating mode to drivably connect said second differential output element to said second electrical machine for driving said second electrical machine as a generator, and electrical connection means connecting with said first and second electrical machines, said connection means being operable in said first operating mode to connect said first and second electrical machines to an external source of electric power for driving said electrical machines, and said connection means being operable in said second operating mode to connect said second electrical machine for operation as a generator and to deliver the generated electrical output of said second electrical machine to said first electrical machine.
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4. The drive means of claim 3 and further comprising an auxiliary alternator drivingly connected to said vehicle mounted prime mover mechanical output to be driven thereby and control means associated with said vehicle-mounted prime mover and operable to maintain during operation a constant speed for said meChanical output.
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5. The drive means of claim 4 wherein said electrical connection means include means to connect the field of said second electrical machine for series excitation by the armature current or for said connection means being arranged to provide for series excitation in said first operating mode and to connect said field with separate exciter means in said second operating mode, said exciter means being controlled by said prime mover control means to vary the power absorbed by said second electrical machine as necessary to maintain said prime mover output speed constant.
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6. The drive means of claim 4 and further comprising an oil pump drivingly connected with said auxiliary alternator and driven thereby, and an overrunning clutch in the driving connection between said auxiliary alternator and said mechanical output and arranged to permit said alternator to be driven electrically when said vehicle mounted prime mover is not in operation, whereby said oil pump may be driven in either operating mode.
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7. In combination with a bi-modal vehicle, drive means operable in a first mode from an external electrical source and self-powered in a second mode, said drive means comprising a vehicle mounted gas turbine including gas-producing means and a power turbine adapted to be driven by gas from said gas-producing means, said power turbine having an output shaft, first and second planetary gear sets each including a sun gear, a ring gear and planet gears engaging both their respective sun and ring gears and connected with a rotatable carrier, said power turbine output shaft being drivably connected to said first planetary sun gear and said first planetary ring gear being drivably connected with said second planetary sun gear, a drive output member drivably connected with said first planetary carrier, first and second electric machines each having a rotatable armature and a stationary field, said first machine having its field connected in series with its respective armature and having its armature drivably connected with said drive output member, said second machine having its armature drivably connected with said second planetary ring gear, a first friction drive establishing means between said second machine armature and said drive output member and engageable to drivably connect them in said first mode, a second friction drive establishing means between said second planetary carrier and ground and engageable to ground said second carrier in said second mode, whereby said second machine armature is drivably connected through said first and second planetary gear sets with said power turbine output shaft, first electrical connection means operable in said first mode to electrically connect said first and second machines to an external source of electric power for driving said machines and to connect the field of said second machine in series with its armature and second electrical connection means operable in said second mode to electrically connect said first machine to receive generated current from said second machine and to connect the field of said second machine to separate excitation means for excitation thereby.
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8. The combination of claim 7 and further comprising an auxiliary alternator drivingly connected with said power turbine output shaft to be driven thereby, speed control means connected with said power turbine output shaft and with said field excitation means, said speed control means being effective during operation in said second mode to maintain turbine output shaft speed constant by varying the excitation of said second machine field to control the torque of said turbine output shaft, an oil pump connected with and driven by said auxiliary alternator, and an overrunning clutch in the driving connection between said auxiliary alternator and said turbine output shaft, said overrunning clutch being arranged to permit said alternator to be electrically driven when said power turbine is Not operating so as to provide for the driving of said pump under all operating conditions.
Specification