Drive system, in particular for a self-propelled construction machine, in particular a soil compactor

Patent metadata

Field	Value
Publication number	US-10059184-B2
Application number	US-201414574890-A
Country	US
Kind code	B2
Filing date	Dec 18, 2014
Priority date	Dec 20, 2013
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A drive system, in particular for a self-propelled construction machine, in particular a soil compactor, comprising an internal combustion engine comprising a drive unit, at least one hydraulic circuit with a hydraulic pump that can be driven by the drive unit, as well as a hydraulic-drive support unit with a hydraulic pump/motor assembly and at least one pressure fluid reservoir, wherein the hydraulic pump/motor assembly is or can be drivingly coupled with the drive unit or/and at least one hydraulic circuit, wherein the hydraulic pump/motor assembly can be operated in a charging operating mode by the drive unit or/and at least one hydraulic circuit as a pump to charge at least one pressure fluid reservoir and be operated in an drive support operating mode as a motor to provide a drive support torque for the hydraulic pump of at least one hydraulic circuit, characterized in that the hydraulic pump/motor assembly can be operated in a recirculation operating mode as a motor to start the drive unit.

First claim

The invention claimed is:

1. A drive system, comprising:
a drive unit comprising an internal combustion engine,
at least one hydraulic circuit with a hydraulic pump driven by the drive unit,
a hydraulic-drive support unit with a hydraulic pump/motor assembly and at least one high pressure fluid reservoir, wherein the hydraulic pump/motor assembly can be drivingly coupled with the drive unit or/and at least one hydraulic circuit, wherein the hydraulic pump/motor assembly can be operated in a charging operating mode by the drive unit or/and at least one hydraulic circuit as a pump to charge the at least one high pressure fluid reservoir and be operated in a drive support operating mode as a motor to provide a drive support torque for the hydraulic pump of at least one hydraulic circuit,
wherein the hydraulic pump/motor assembly can be operated in a starting operating mode as a motor to start the drive unit,
wherein the hydraulic drive support unit comprises a starting valve unit to selectively release/interrupt a flow connection between the at least one high pressure fluid reservoir and the hydraulic pump/motor assembly at least in the flow direction from the at least one high pressure fluid reservoir to the hydraulic pump/motor assembly,
wherein a flow restriction arrangement is provided in a flow path between the at least one high pressure fluid reservoir and the starting valve unit or/and in a flow path between the starting valve unit and the hydraulic pump/motor assembly.

2. The drive system according to claim 1 , wherein the starting valve unit comprises a proportional valve.

3. The drive system according to claim 1 ,
wherein the hydraulic drive support unit comprises a charge/discharge valve unit to selectively release/interrupt a flow connection between the hydraulic pump/motor assembly, and the at least one high pressure fluid reservoir at least in the flow direction from the at least one high pressure fluid reservoir to the hydraulic pump/motor assembly and an expansion valve unit to selectively release/interrupt a flow connection between the at least one high pressure fluid reservoir and a low pressure fluid reservoir at least in a flow direction from the at least one high pressure fluid reservoir to the low pressure fluid reservoir.

4. The Drive system according to claim 3 ,
wherein the starting valve unit or/and the charge/discharge valve unit is/are pre-tensioned to a basic state interrupting the flow connection, or/and in that the expansion valve unit is pre-tensioned to a basic state releasing the flow connection.

5. The drive system according to claim 1 , wherein the hydraulic drive support unit comprises an open circuit.

6. The drive system according to claim 1 ,
wherein there is no fluid exchange connection between the at least one fluid circuit and the hydraulic drive support unit.

7. A self-propelled construction machine, comprising a drive system according to claim 1 .

8. The drive system according to claim 5 ,
wherein there is no fluid exchange connection between the at least one fluid circuit and the hydraulic drive support unit.

9. A drive system for a self-propelled construction machine comprising:
a drive unit comprising an internal combustion engine,
at least one hydraulic circuit with a hydraulic pump driven by the drive unit,
a hydraulic-drive support unit with a hydraulic pump/motor assembly and at least one high pressure fluid reservoir, wherein the hydraulic pump/motor assembly is or can be drivingly coupled with the drive unit or/and at least one hydraulic circuit, wherein the hydraulic pump/motor assembly can be operated in a charging operating mode by the drive unit or/and at least one hydraulic circuit as a pump to charge the at least one high pressure fluid reservoir and be operated in a drive support operating mode as a motor to provide a drive support torque for the hydraulic pump of at least one hydraulic circuit,
wherein the hydraulic pump/motor assembly can be operated in a starting operating mode as a motor to start the drive unit,
wherein the hydraulic drive support unit comprises a starting valve unit to selectively release/interrupt a flow connection between the at least one high pressure fluid reservoir and the hydraulic pump/motor assembly at least in the flow direction from the at least one high pressure fluid reservoir to the hydraulic pump/motor assembly, and
wherein the hydraulic drive support unit comprises a charge/discharge valve unit to selectively release a flow connection between the hydraulic pump/motor assembly, and the at least one high pressure fluid reservoir in the drive support operating mode of the motor/pump assembly and interrupt the flow connection at least in the flow direction from the at least one high pressure fluid reservoir to the hydraulic pump/motor assembly,
said starting valve unit being arranged in a bypass flow path bypassing said charge/discharge valve unit.

10. The drive system according to claim 9 ,
wherein the hydraulic drive support unit further comprises an expansion valve unit to selectively release/interrupt a flow connection between the at least one high pressure fluid reservoir and a low pressure fluid reservoir at least in a flow direction from the at least one high pressure fluid reservoir to the low pressure fluid reservoir.

Assignees

• Hamm Ag

Inventors

• Röhr Andreas
• Henker Thomas
• Pieske Ronny

Classifications

• F02N2300/102

  Control of the starter motor speed; Control of the engine speed during cranking · CPC title

• F15B2211/88

  Control measures for saving energy · CPC title

• F15B2211/20569

  capable of working as pump and motor · CPC title

• B60K2006/126

  the hydraulic accumulator starts the engine · CPC title

• E02F9/2292

  Systems with two or more pumps · CPC title