# US 9,435,355 B2 · Hydraulic launch assist system

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- Number: US 9,435,355 B2
- Document ID: US9435355B2
- Status: Granted
- Kind: B2
- Application number: 13/930,924
- Filed: 2013-06-28
- Published: 2014-01-02
- Granted: 2016-09-06
- Earliest claimed: 2012-06-29
- Assignees: Eaton Corporation
- Applicants: Eaton Corporation
- Inventors: Michael William Olson; Brian Lewis Van Batavia
- Web page: https://patentgrep.com/patent/US9435355B2

## CPC

- F15B 1/024: {used as a supplementary power source, e.g. to store energy in idle periods to balance pump load}
- B60K 6/12: by means of a chargeable fluidic accumulator
- B60W 10/04: including control of propulsion units
- B60W 10/06: including control of combustion engines
- B60W 10/30: including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
- B60W 20/10: Controlling the power contribution of each of the prime movers to meet required power demand
- B60W 30/18127: {Regenerative braking}
- B60W 30/1886: {Controlling power supply to auxiliary devices}
- F15B 21/14: Energy-recuperation means
- B60W 2510/09: Other types of propulsion units, e.g. fluid motors, or type not specified
- B60W 2710/09: Other types of propulsion units, e.g. fluid motors, or type not specified
- B60Y 2200/144: Garbage trucks, e.g. refuse trucks
- F15B 2211/20523: Internal combustion engine
- F15B 2211/20538: constant capacity
- F15B 2211/20546: variable capacity
- F15B 2211/20561: reversible
- F15B 2211/20569: capable of working as pump and motor
- F15B 2211/20576: with multiple pumps
- F15B 2211/212: the pressure sources being accumulators
- F15B 2211/214: the pressure sources being hydrotransformers
- Y02T 10/62: Hybrid vehicles
- F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- B60Y: INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A hybrid hydraulic drivetrain is configured to propel a vehicle and regenerate propulsion energy. The drivetrain includes a prime mover, an accumulator, an axle, a first rotating group, a second rotating group, and a hydraulic transformer. The first rotating group is configured to receive shaft energy from the prime mover, receive shaft energy from the drive axle, send shaft energy to the drive axle, receive hydraulic energy from the hydraulic accumulator, and send hydraulic energy to the accumulator. The second rotating group is configured to receive shaft energy from the prime mover. The hydraulic transformer is configured to charge the accumulator with hydraulic energy received from the second rotating group. The hydraulic transformer may be remotely mounted from the second rotating group. The second rotating group may supply hydraulic energy to an auxiliary circuit of the vehicle. The auxiliary circuit may operate with the prime mover shut down.

## Claims

### Claim 1

A hydraulic drivetrain adapted to convert kinetic energy of a vehicle into stored potential energy and thereby decelerate the vehicle and further adapted to release the stored potential energy and thereby accelerate the vehicle, the hydraulic drivetrain comprising:
a prime mover adapted to supply shaft power to the vehicle via an output shaft of the prime mover;
a hydraulic accumulator adapted to receive and supply hydraulic fluid power;
at least one drive wheel adapted to accelerate and decelerate the vehicle, the drive wheel coupled to a wheel drive;
a hydraulic pump-motor including an input-output shaft;
a first hydraulic pump including an input shaft coupled to the output shaft of the prime mover, the first hydraulic pump adapted to supply hydraulic fluid power to an auxiliary hydraulic circuit of the vehicle;
a second hydraulic pump including an input shaft; and
a hydraulic propel circuit that includes the hydraulic pump-motor, wherein hydraulic fluid of the auxiliary hydraulic circuit is isolated from hydraulic fluid of the hydraulic propel circuit;
a first mode wherein the input-output shaft of the hydraulic pump-motor is rotationally coupled to the wheel drive, wherein hydraulic fluid power is transferred from the hydraulic accumulator to the hydraulic pump-motor, and whereby shaft power is transferred from the input-output shaft of the hydraulic pump-motor to the wheel drive;
a second mode wherein the input-output shaft of the hydraulic pump-motor is rotationally coupled to the wheel drive, wherein shaft power is transferred to the input-output shaft of the hydraulic pump-motor from the wheel drive, and whereby hydraulic fluid power is transferred to the hydraulic accumulator from the hydraulic pump-motor;
a third mode wherein the second hydraulic pump transfers hydraulic fluid power to the hydraulic accumulator; and
a fourth mode wherein the output shaft of the prime mover is mechanically rotationally coupled to the wheel drive.

### Claim 2 (depends on 1)

The hydraulic drivetrain of claim 1, wherein the input shaft of the first hydraulic pump is coupled to the output shaft of the prime mover via a clutch.

### Claim 3 (depends on 1)

The hydraulic drivetrain of claim 1, wherein the second hydraulic pump is included in a hydraulic transformer.

### Claim 4 (depends on 3)

The hydraulic drivetrain of claim 3, wherein the hydraulic transformer includes a motor rotationally coupled to the second hydraulic pump via the input shaft of the second hydraulic pump and wherein the first hydraulic pump transfers hydraulic fluid power to the motor of the hydraulic transformer when the hydraulic drivetrain is in the third mode.

### Claim 5 (depends on 3)

The hydraulic drivetrain of claim 3, wherein the hydraulic transformer is mounted remotely from the first hydraulic pump.

### Claim 6 (depends on 3)

The hydraulic drivetrain of claim 3, wherein the hydraulic transformer is a rotary hydraulic transformer.

### Claim 7 (depends on 3)

The hydraulic drivetrain of claim 3, further comprising a fifth mode wherein the hydraulic accumulator transfers hydraulic fluid power to the hydraulic transformer and the hydraulic transformer transfers hydraulic fluid power to the auxiliary hydraulic circuit.

### Claim 8 (depends on 7)

The hydraulic drivetrain of claim 7, wherein the prime mover is off in the fifth mode.

### Claim 9 (depends on 3)

The hydraulic drivetrain of claim 3, further comprising a valve, wherein the hydraulic transformer includes a motor rotationally coupled to the second hydraulic pump via the input shaft of the second hydraulic pump, wherein the first hydraulic pump transfers hydraulic fluid power to the motor of the hydraulic transformer when the valve is in a first position, and wherein the first hydraulic pump transfers hydraulic fluid power to the auxiliary hydraulic circuit when the valve is in a second position.

### Claim 10 (depends on 9)

The hydraulic drivetrain of claim 9, wherein the valve is a pilot operated valve that automatically switches to the second position when the hydraulic accumulator reaches a predetermined pressure.

### Claim 11

A hydraulic drivetrain adapted to convert kinetic energy of a vehicle into stored potential energy and thereby decelerate the vehicle and further adapted to release the stored potential energy and thereby accelerate the vehicle, the hydraulic drivetrain comprising:
a prime mover including an output shaft;
a hydraulic pump-motor including an input-output shaft;
a hydraulic accumulator adapted to receive and supply hydraulic fluid power from and to the hydraulic pump-motor via an accumulator circuit;
an auxiliary pump adapted to supply hydraulic fluid power to an auxiliary circuit of the vehicle, the auxiliary pump including an input shaft mechanically rotationally coupled to the output shaft of the prime mover;
a drive axle including a wheel drive mechanically rotationally coupled to drive wheels of the vehicle; and
a drive shaft arrangement including a first segment and a second segment, the first segment selectively mechanically rotationally coupled to the output shaft of the prime mover, the first segment selectively mechanically rotationally coupled to the input-output shaft of the hydraulic pump-motor, the first segment selectively mechanically rotationally coupled to the second segment, the second segment selectively mechanically rotationally coupled to the input-output shaft of the hydraulic pump-motor, and the second segment mechanically rotationally coupled to the wheel drive of the drive axle;
wherein the auxiliary circuit is fluidly separated from the accumulator circuit;
wherein the hydraulic drivetrain includes a first configuration that accelerates the vehicle with the hydraulic fluid power from the hydraulic accumulator by mechanically rotationally coupling the hydraulic pump-motor to the second segment of the drive shaft arrangement;
wherein the hydraulic drivetrain includes a second configuration that decelerates the vehicle by mechanically rotationally coupling the hydraulic pump-motor to the second segment of the drive shaft arrangement thereby suppling the hydraulic fluid power to the hydraulic accumulator; and
wherein the hydraulic drivetrain includes a third configuration that accelerates the vehicle with the prime mover by mechanically rotationally coupling the first and the second segments of the drive shaft arrangement.

### Claim 12 (depends on 11)

The hydraulic drivetrain of claim 11, further comprising an accumulator charge pump adapted to charge the hydraulic accumulator, the accumulator charge pump including an input shaft mechanically rotationally coupled to the output shaft of the prime mover.

### Claim 13 (depends on 12)

The hydraulic drivetrain of claim 12, wherein the input shaft of the accumulator charge pump is selectively mechanically rotationally coupled to the output shaft of the prime mover.

### Claim 14 (depends on 11)

The hydraulic drivetrain of claim 11, further comprising an accumulator charge pump adapted to charge the hydraulic accumulator, the accumulator charge pump including an input shaft mechanically rotationally coupled to the input shaft of the auxiliary pump and the output shaft of the prime mover.

### Claim 15

A hydraulic drivetrain adapted to convert kinetic energy of a vehicle into stored potential energy and thereby decelerate the vehicle and further adapted to release the stored potential energy and thereby accelerate the vehicle, the hydraulic drivetrain comprising:
a prime mover including an output shaft;
a hydraulic pump-motor including an input-output shaft;
a hydraulic accumulator adapted to receive and supply hydraulic fluid power from and to the hydraulic pump-motor via an accumulator circuit;
a hydraulic transformer adapted to charge the hydraulic accumulator, the hydraulic transformer including an input shaft mechanically rotationally coupled to the output shaft of the prime mover, and the hydraulic transformer adapted to supply hydraulic fluid power to an auxiliary circuit of the vehicle;
a drive axle including a wheel drive mechanically rotationally coupled to drive wheels of the vehicle; and
a drive shaft arrangement including a first segment and a second segment, the first segment selectively mechanically rotationally coupled to the output shaft of the prime mover, the first segment selectively mechanically rotationally coupled to the input-output shaft of the hydraulic pump-motor, the first segment selectively mechanically rotationally coupled to the second segment, the second segment selectively mechanically rotationally coupled to the input-output shaft of the hydraulic pump-motor, and the second segment mechanically rotationally coupled to the wheel drive of the drive axle;
wherein the hydraulic drivetrain includes a first configuration that accelerates the vehicle with the hydraulic fluid power from the hydraulic accumulator by mechanically rotationally coupling the hydraulic pump-motor to the second segment of the drive shaft arrangement;
wherein the hydraulic drivetrain includes a second configuration that decelerates the vehicle by mechanically rotationally coupling the hydraulic pump-motor to the second segment of the drive shaft arrangement thereby suppling the hydraulic fluid power to the hydraulic accumulator; and
wherein the hydraulic drivetrain includes a third configuration that accelerates the vehicle with the prime mover by mechanically rotationally coupling the first and the second segments of the drive shaft arrangement.

### Claim 16 (depends on 15)

The hydraulic drivetrain of claim 15, wherein the hydraulic transformer is further adapted to discharge the hydraulic accumulator and thereby supply the hydraulic fluid power to the auxiliary circuit of the vehicle.

### Claim 17 (depends on 11)

The hydraulic drivetrain of claim 11, further comprising a transmission selectively mechanically rotationally coupled to the output shaft of the prime mover thereby selectively mechanically rotationally coupling the output shaft of the prime mover to the first segment of the drive shaft arrangement.