GAS TURBINE ENGINE BRAKING METHOD
First Claim
1. In a vehicle comprising a gas turbine engine and a transmission, the gas turbine engine comprising at least one turbo-compressor spool assembly, wherein the at least one turbo-compressor spool assembly comprises a compressor in mechanical communication with a turbine, the turbine outputting a gas, and a free power turbine in fluid communication with the turbine, the free power turbine being driven by the outputted gas, a system comprising:
- a braking device in mechanical communication with the free power turbine and the transmission to at least one of dissipate energy of the free power turbine and provide a braking force to the vehicle, wherein at least one of the following is true;
(a) the braking device comprises a compressor selectively mechanically engaged and disengaged from the free power turbine and/or the transmission of the vehicle by a clutch assembly;
(b) the braking device comprises a continuously variable transmission;
(c) the braking device comprises an electrical generator configured to generate a selected amount of electrical energy;
(d) the braking device comprises at least one of an eddy current clutch and an eddy current brake; and
(e) the braking device comprises a fluid pump circuit.
2 Assignments
0 Petitions
Accused Products
Abstract
The present disclosure discloses an engine braking system, especially for vehicles powered by a gas turbine. The engine braking system allows for control of engine braking force; control of over-speed of the power turbine and further includes means of recovering some or all of the braking energy of the engine braking system. Dissipative engine braking devices include an auxiliary compressor, or electrical generator, or an eddy current clutch or an eddy current brake, or fluid pump. Several methods of controlling the engine braking force of a dissipative braking device are disclosed and include (1) a continuously variable transmission (“CVT”); (2) an electrical generator and an optional thermal storage device; (3) an eddy current clutch; and (4) a fluid pump system. The various control devices may be operated automatically by appropriate algorithms. One of these control methods utilizes an eddy current clutch assembly. An innovative configuration of eddy current clutch assembly based on a brushless alternator is disclosed. Additional innovations include vehicle braking systems that utilize some or all the braking features to recoup a portion of braking energy available with either or both of a hybrid transmission and a dissipative braking device such as a compressor, an electrical generator or a fluid pump system.
36 Citations
55 Claims
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1. In a vehicle comprising a gas turbine engine and a transmission, the gas turbine engine comprising at least one turbo-compressor spool assembly, wherein the at least one turbo-compressor spool assembly comprises a compressor in mechanical communication with a turbine, the turbine outputting a gas, and a free power turbine in fluid communication with the turbine, the free power turbine being driven by the outputted gas, a system comprising:
a braking device in mechanical communication with the free power turbine and the transmission to at least one of dissipate energy of the free power turbine and provide a braking force to the vehicle, wherein at least one of the following is true; (a) the braking device comprises a compressor selectively mechanically engaged and disengaged from the free power turbine and/or the transmission of the vehicle by a clutch assembly; (b) the braking device comprises a continuously variable transmission; (c) the braking device comprises an electrical generator configured to generate a selected amount of electrical energy; (d) the braking device comprises at least one of an eddy current clutch and an eddy current brake; and (e) the braking device comprises a fluid pump circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. In a vehicle comprising a gas turbine engine and a transmission comprising at least one turbo-compressor spool assembly, the at least one turbo-compressor spool assembly comprising a compressor in mechanical communication with a turbine, the turbine outputting a gas, a free power turbine in fluid communication with the turbine, the free power turbine being driven by the outputted gas, and a braking device in mechanical communication with the free power turbine and the transmission, a method comprising:
performing at least one of the following steps; (a) in response to a sensed revolutions-per-minute of the free power turbine, selectively engaging and disengaging a braking device from mechanical communication with the free power turbine, the braking device retarding rotation of the free power turbine; (b) in response to a sensed braking request of the vehicle, selectively engaging and disengaging a braking device from mechanical communication with the free power turbine, the braking device providing a braking force to the vehicle; (c) varying, by an continuously variable transmission, a gear ratio continuously between first and second gear ratios, the gear ratio being for a mechanical linkage between a braking device and the clutch assembly; (d) generating, by an electrical generator, a selected amount of electrical energy to provide at least one of a selected amount of retardation force against rotation of the free power turbine and a selected amount braking force to the vehicle; (e) applying torque by at least one of an eddy current brake and eddy current clutch to provide at least one of a selected amount of retardation force against rotation of the free power turbine and a selected amount braking force to the vehicle; and (f) intermittently operating a fluid pump in mechanical communication with the free power turbine to provide at least one of a selected amount of retardation force against rotation of the free power turbine and a selected amount braking force to the vehicle. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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36. A vehicle, comprising:
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(a) an engine; (b) a transmission; (c) a braking device to maintain or reduce the ground velocity of the vehicle; and
at least one of the following braking device control devices;(C1) a continuously variable transmission positioned mechanically with respect to the braking device, the transmission and the engine; (C2) an electrical generator configured to generate a selected amount of electrical energy to provide a selected amount of retardation force against rotation of a shaft of the engine; (C3) at least one of an eddy current clutch and eddy current brake positioned mechanically with respect to the braking device, the transmission and the engine; and (C4) a pump and restrictor valve in fluid communication with the braking device. - View Dependent Claims (37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53)
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54. A tangible or non-transient computer readable medium comprising microprocessor-executable instructions operable to perform at least the following steps:
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a) sensing at least one of a revolutions per minute (“
rpms”
) of a free power turbine, at least one of an on and off state of a braking device clutch, at least one of an on and off state of a transmission clutch, and a braking device control setting;b) based on the sensed at least one of a revolutions per minute (“
rpms”
) of a free power turbine, at least one of an on and off state of a braking device clutch, at least one of an on and off state of a transmission clutch, and a braking device control setting, determining that the free power turbine requires over-speed control;c) in response to step (b), disengaging the transmission clutch and engaging the braking device clutch; d) reducing the rpms of the free power turbine by controlling an amount of energy dissipation of the braking device; e) during step (d), sensing rpms of the free power turbine and reducing the rpms of the free power turbine until the rpms of the free power turbine are reduced to less than or equal to a selected value; and f) when the rpms of the free power turbine are less than the selected value, disengaging the braking device clutch.
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55. A tangible or non-transient computer readable medium comprising microprocessor-executable instructions operable to perform at least the following steps:
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a) sensing at least one of an on and off state of braking device clutch, at least one of an on and off state of a transmission clutch, a vehicle ground velocity, a transmission gear setting, and a braking device control setting; b) based on the sensed at least one of a vehicle ground velocity, at least one of an on and off state of a braking device clutch, at least one of an on and off state of a transmission clutch, and a braking device control setting, determining that engine braking is required; c) in response to step (b), engaging the braking device clutch and engaging the transmission clutch for engine braking; d) increasing a vehicle braking force opposing a direction of motion of the vehicle by controlling an amount of energy dissipation of the braking device; e) during step (d), sensing a vehicle ground velocity and applying the engine braking force until the vehicle ground velocity is less than or equal to a selected value; and f) when the vehicle ground velocity is less than or equal to the selected value, disengaging the braking device clutch.
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Specification