US 7,416,045 B2Granted

Dual hydraulic machine transmission

AssigneeTorvec, Inc.

InventorsKeith E. Gleasman, Matthew R. Wrona

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Abstract

The modular transmission uses only a pair of small and light hydraulic machines of remarkably improved volumetric efficiency with pistons having body portions substantially as long as the axial length of the respective cylinders in which they reciprocate. The two hydraulic machines operate in a closed loop, one being used as a pump driven by the vehicle's engine, and the other used as a motor. Each machine has a fully articulatable swash plate. By computer control, the angles of the swash plates of the two machines are infinitely varied to provide an appropriate optimum ratio of engine/wheel speed for all conditions from start-up, city driving, hill climbing varied according to load and steepness, and over-drive for highway. This complete vehicle operation is attained while the vehicle's engine continues to operate at relatively constant speeds and relatively low RPM.

Claims10

Dependent claims

A modular transmission adaptable for use in a vehicle having an engine, an accelerator for indicating desired variations in vehicle velocity, a brake for indicating desired reductions in vehicle velocity, and an output drive for driving the wheels of the vehicle, said transmission comprising:

a plurality of hydraulic machines, each having a rotating shaft, elongated pistons that reciprocate within cylinders formed in a stationary cylinder block, and an angularly adjustable swash plate, said pistons having a stroke that is variable up to a predetermined maximum by angular adjustment of said swash plate;
said hydraulic machines, respectively, being (a) operable as a hydraulic pump with said respective hydraulic pump shaft being rotatable by the engine of said vehicle, (b) operable as a hydraulic motor with said respective hydraulic motor shaft being operatively connected to rotate said output drive of the vehicle, and (c) interconnected in a hydraulic closed loop;
a controller for determining the relative speed of said output drive of the vehicle, said controller being operable following the initiation of operation of said vehicle engine and being responsive to:
the speed of said hydraulic pump shaft;
the speed of said hydraulic motor shaft;
and
desired variations in vehicle velocity as indicated by operation of said accelerator and said brake;
and
said controller determining:
said angular adjustment of the swash plate of said hydraulic pump;
said angular adjustment of the swash plate of said hydraulic motor;
and
the speed of said engine;
said controller modifying the operation of said vehicle in accordance with said desired variations in vehicle velocity as indicated by operation of said accelerator and said brake while compensating for changes in vehicle load and variations in the terrain being traversed by the vehicle and automatically adjusting the speed of said engine to maximize predetermined parameters related to fuel economy.

11 more elements

A hydraulic transmission for an automobile having an engine, an engine drive shaft driven by the engine, and a wheel drive shaft for driving a plurality of wheels to move the automobile, the transmission comprising:

a hydraulic pump and a hydraulic motor connected in a hydraulic closed loop, said pump and motor each comprising:
a non-rotating cylinder block having a plurality of cylinders formed therein, said cylinders being positioned circumferentially at a first radial distance about the rotational axis of a drive element;
a plurality of respective long pistons reciprocally mounted in said cylinders, each long piston comprising a piston body and a spherical head connected to the piston body and each respective cylinder having an open head portion beyond which the piston head extends at all times;
a split swash plate driven by said drive element and comprising:
a variably-inclined rotor that rotates and nutates;
and
a wobbler having a flat face that only nutates;
wherein the stroke of each said piston varies in accordance with the inclination of said swash plate up to a predetermined maximum;
and
said drive element of said hydraulic pump being driven by said engine drive shaft;
and
said drive element of said hydraulic motor transmitting torque and power to said wheel drive shaft;
wherein, when said engine is operating at a relatively constant speed and relatively low RPM, said hydraulic pump and said hydraulic motor provide sufficient torque and hydraulic motor provide sufficient torque and power to said wheel drive shaft to move the automobile from a stationary stop to highway speeds in a continuously accelerating motion without alteration of any intermediate gearing of any kind.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/153,111Filed 15 Jun 2005 · continuation in part
Priority: 28 Aug 2002
Published: US 2005/0247504 A110 Nov 2005
Granted: 26 Aug 2008
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

B60K 17/105
Of fluid gearing: units comprising at least a part of the gearing and a torque-transmitting axle, e.g. transaxles
B60W 10/06
Including control of propulsion units: including control of combustion engines
B60W 30/1882
Controlling power parameters of the driveline, e.g. determining the required power: characterised by the working point of the engine, e.g. by…
F04B 1/126
Pistons: piston shoe retaining means

Family

Application10/229,407Parent of this continuation-in-part · filed 28 Aug 2002
Application10/647,557Parent of this continuation-in-part · filed 25 Aug 2003
Application10/789,739Parent of this continuation-in-part · filed 27 Feb 2004
US 2005/0247504 A1Pre-grant publication · published 10 Nov 2005
US 6,983,680 B2Parent of this continuation-in-part
US 2004/0042906 A1Published application
US 2004/0042910 A1Published application
US 2004/0168567 A1Published application
US 7,416,045 B2This patent

From the US filing history. Foreign family members aren’t listed.