Hydraulic hybrid swing drive system for excavators

Patent metadata

Field	Value
Publication number	US-9926946-B2
Application number	US-201314370795-A
Country	US
Kind code	B2
Filing date	Jan 4, 2013
Priority date	Jan 4, 2012
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

A swing drive system ( 11 ) for an excavator is provided which utilizes a prime mover ( 20 ) mechanically connected to a first hydraulic pump/motor ( 30 ) and a second hydraulic pump/motor ( 32 ) mechanically connected to a swing mechanism ( 70 ). The system includes a hydraulic circuit ( 31 ) connecting a hydraulic fluid reservoir ( 42 ), a hydraulic accumulator ( 40 ), the first hydraulic pump/motor ( 30 ), and the second hydraulic pump/motor ( 32 ). The system is operable in one mode where the second hydraulic pump/motor acts as a pump to retard movement of the swing mechanism and pressurized hydraulic fluid from the second hydraulic pump/motor is pumped into the hydraulic accumulator. The system is operable in another mode where the pressurized fluid from the hydraulic accumulator is used to assist the prime mover in driving hydraulic consumers ( 62,64,66 ), including the swing mechanism.

First claim

The invention claimed is:

1. A swing drive system of a vehicle comprising:
a prime mover mechanically connected to a first hydraulic pump/motor;
a second hydraulic pump/motor mechanically connected to a swing mechanism;
a hydraulic circuit connecting a hydraulic fluid reservoir, a hydraulic accumulator, the first hydraulic pump/motor, and the second hydraulic pump/motor;
wherein the system is operable in a first mode where the second hydraulic pump/motor acts as a pump to retard movement of the swing mechanism and pressurized hydraulic fluid from the second hydraulic pump/motor is pumped into the hydraulic accumulator; and
wherein the system is operable in a second mode wherein the second hydraulic pump/motor acts as a motor to provide supplementary power to the swing mechanism using pressurized fluid from the hydraulic accumulator;
wherein the prime mover is also mechanically connected to a hydraulic pump which is hydraulically connected to a plurality of hydraulic power consumers; and
the swing drive system further comprising a hydraulic accumulator fluidly connected between the hydraulic pump and the plurality of hydraulic power consumers.

2. A swing drive system of a vehicle comprising:
a prime mover mechanically connected to a first hydraulic pump/motor;
a second hydraulic pump/motor mechanically connected to a swing mechanism;
a hydraulic circuit connecting a hydraulic fluid reservoir, a hydraulic accumulator, the first hydraulic pump/motor, and the second hydraulic pump/motor;
wherein the system is operable in a first mode where the second hydraulic pump/motor acts as a pump to retard movement of the swing mechanism and pressurized hydraulic fluid from the second hydraulic pump/motor is pumped into the hydraulic accumulator; and
wherein the system is operable in a second mode wherein the second hydraulic pump/motor acts as a motor to provide supplementary power to the swing mechanism using pressurized fluid from the hydraulic accumulator; and
the swing drive system further comprising
a transmission gear set,
the transmission gear set mechanically connected between the engine and the first hydraulic pump/motor; and
the transmission gear set mechanically connected between the swing mechanism and the second hydraulic pump/motor.

3. The swing drive system according to claim 2 wherein the transmission gear set includes a reverse gear.

4. A swing drive system of a vehicle comprising:
an excavator swing mechanism;
a prime mover mechanically connected to a first hydraulic pump/motor;
a second hydraulic pump/motor mechanically connected to the excavator swing mechanism;
a hydraulic circuit connecting the first hydraulic pump/motor, the second hydraulic pump/motor, a hydraulic accumulator, and a hydraulic reservoir;
an isolation valve associated with the hydraulic accumulator which selectively disconnects the hydraulic accumulator from the rest of the hydraulic circuit;
wherein the system is operable in a first mode where the second hydraulic pump/motor acts as a pump to retard movement of the excavator swing mechanism, the pressurized hydraulic fluid from the second hydraulic pump/motor is pumped into the hydraulic accumulator when the isolation valve is open; and
wherein the system is operable in a second mode wherein the second hydraulic pump/motor provides a supplementary power to the excavator swing mechanism using pressurized fluid from the hydraulic accumulator when the isolation valve is open; and
wherein the system is operable is a third mode where the second hydraulic pump/motor acts as a pump to retard movement of the excavator swing mechanism, the pressurized hydraulic fluid from the second hydraulic pump/motor rotates the first hydraulic pump/motor as a motor which provides supplemental power to the prime mover when the isolation valve is closed; and
further comprising
a transmission gear set,
the transmission gear set mechanically connected between the engine and the first hydraulic pump/motor;
the transmission gear set mechanically connected between the excavator swing mechanism and the second hydraulic pump/motor.

5. The swing drive system of claim 4 further comprising a directional valve positioned within the hydraulic circuit selectively reversing the flow of fluid through the hydraulic circuit and providing a fluid path to the hydraulic accumulator.

6. A swing drive system of a vehicle comprising:
an excavator swing mechanism;
a prime mover mechanically connected to a first hydraulic pump/motor;
a second hydraulic pump/motor mechanically connected to the excavator swing mechanism;
a hydraulic circuit connecting the first hydraulic pump/motor, the second hydraulic pump/motor, a hydraulic accumulator, and a hydraulic reservoir;
an isolation valve associated with the hydraulic accumulator which selectively disconnects the hydraulic accumulator from the rest of the hydraulic circuit;
wherein the system is operable in a first mode where the second hydraulic pump/motor acts as a pump to retard movement of the excavator swing mechanism, the pressurized hydraulic fluid from the second hydraulic pump/motor is pumped into the hydraulic accumulator when the isolation valve is open; and
wherein the system is operable in a second mode wherein the second hydraulic pump/motor provides a supplementary power to the excavator swing mechanism using pressurized fluid from the hydraulic accumulator when the isolation valve is open; and
wherein the system is operable is a third mode where the second hydraulic pump/motor acts as a pump to retard movement of the excavator swing mechanism, the pressurized hydraulic fluid from the second hydraulic pump/motor rotates the first hydraulic pump/motor as a motor which provides supplemental power to the prime mover when the isolation valve is closed; and
further comprising
a transmission gear set,
the transmission gear set mechanically connected between the engine and the first hydraulic pump/motor;
the transmission gear set mechanically connected between the excavator swing mechanism and the second hydraulic pump/motor; and
wherein the transmission gear set includes a reverse gear.

7. A swing drive system of a vehicle comprising:
a prime mover mechanically connected to a first hydraulic pump/motor through a mechanical gearset;
a second hydraulic pump/motor mechanically connected to a swing mechanism through the mechanical gear set;
wherein the mechanical gear set includes a reverse gear;
a hydraulic circuit connecting the first hydraulic pump/motor, the second hydraulic pump/motor, a hydraulic accumulator, and a hydraulic reservoir;
an isolation valve associated with the hydraulic accumulator which selectively disconnects the hydraulic accumulator from the rest of the hydraulic circuit;
wherein the system is operable in a first mode where the second hydraulic pump/motor acts as a pump to retard movement of the swing mechanism, the pressurized hydraulic fluid from the second hydraulic pump/motor is pumped into the hydraulic accumulator when the isolation valve is open; and
wherein the system is operable in a second mode wherein the second hydraulic pump/motor provides a supplementary power to the swing mechanism using pressurized fluid from the hydraulic accumulator when the isolation valve is open; and
wherein the system is operable is a third mode where the second hydraulic pump/motor acts as a pump to retard movement of the swing mechanism, the pressurized hydraulic fluid from the second hydraulic pump/motor rotates the first hydraulic pump/motor as a motor which provides supplemental power to the prime mover when the isolation valve is closed.

8. The swing drive system of claim 7 wherein the mechanical gear set is operable to selectively connect the pr

Assignees

• Parker Hannifin Corp

Inventors

• Cullman Jeff
• Zhang Hao
• Kimpel Richard D
• Jiang Zhesheng
• Collett Raymond
• Kozul Bogdan

Classifications

• F15B7/003

  with multiple outputs · CPC title

• E02F9/2217

  with energy recovery arrangements, e.g. using accumulators, flywheels · CPC title

• F15B1/024 Primary

  used as a supplementary power source, e.g. to store energy in idle periods to balance pump load · CPC title

• E02F9/202

  Mechanical transmission, e.g. clutches, gears (clutches per se F16D, gears per se F16H) · CPC title

• E02F9/128 Primary

  Braking systems · CPC title