Method for controlling a hydrostatic drive

Patent metadata

Field	Value
Publication number	US-12416358-B2
Application number	US-202218563789-A
Country	US
Kind code	B2
Filing date	May 20, 2022
Priority date	May 25, 2021
Publication date	Sep 16, 2025
Grant date	Sep 16, 2025

Abstract

A method for controlling a drive, which has a first hydraulic machine coupled to a drive machine and a second hydraulic machine coupled to an output to change one of the hydraulic machines from a pump operation to a motor operation and the other of the hydraulic machines from a motor operation to a pump operation includes controlling the pivoting angle of the other hydraulic machine so that the pivoting angle goes from a positive start pivoting angle to a negative target pivoting angle or from a negative start pivoting angle to a positive target pivoting angle. The control of the pivoting angle of the other hydraulic machine between the start pivoting angle and the target pivoting angle is limited such that the pivoting speed of the pivoting angle of the second hydraulic machine does not exceed a predefined value.

First claim

The invention claimed is:

1. A method for controlling a drive to firstly change one of a first hydraulic machine and a second hydraulic machine from pump operation to motor operation and to secondly change the other of the first hydraulic machine and the second hydraulic machine from motor operation to pump operation, wherein
the first hydraulic machine is configured to couple to a drive machine,
the second hydraulic machine is configured to couple to an output,
the first and second hydraulic machines are fluidically connected to one another via a working line and connected to a pressure medium sink,
each of the first and second hydraulic machines is configured to provide a respective displacement volume that is adjustable to zero and to values above and below zero, and
each of the first and the second hydraulic machines is operably connected to a respective electrohydraulic adjustment unit that is connectable to the working line and to the pressure medium sink, the method comprising:
controlling the one of the first and second hydraulic machines so that a pivoting angle moves from a start pivoting angle toward a target pivoting angle,
wherein (i) the start pivoting angle is positive and the target pivoting angle is negative, or (ii) the start pivoting angle is negative and the target pivoting angle is positive, and
wherein the one of the first and second hydraulic machines is controlled throughout an angular interval, a travel interval, or a time interval, before and after passing through the respective zero displacement volume of the one of the first and second hydraulic machines as the pivoting angle moves from the start pivoting angle toward the target pivoting angle, such that a pivoting speed of the pivoting angle of the one of the first and second hydraulic machines does not exceed a predefined value.

2. The method according to claim 1 , wherein the control of the pivoting speed of the pivoting angle of the one of the first and second hydraulic machines is performed between the start pivoting angle and the target pivoting angle by limiting a torque specification of the one of the first and second hydraulic machines.

3. The method according to claim 2 , wherein a control unit controls the pivoting angle between the start pivoting angle and the target pivoting angle such that the torque specification follows a predefined curve.

4. The method according to claim 2 , wherein the torque specification is limited such that a torque specification gradient is limited.

5. The method according to claim 1 , further comprising:
selecting the target pivoting angle as a function of travel speed.

6. The method according to claim 1 , further comprising:
prior to the controlling of the other hydraulic machine, predicting and/or sensing a change of the other hydraulic machine from motor operation to pump operation.

7. The method according to claim 1 , further comprising:
during the controlling of the pivoting angle, controlling, with a control unit, the respective electrohydraulic adjustment unit of at least one of the first and second hydraulic machines such that a working pressure of the working line is increased within the angular interval, the travel interval, or the time interval, relative to the working pressure outside of the time interval.

8. The method according to claim 7 , wherein the respective electrohydraulic adjustment unit of the at least one of the first and second hydraulic machines is controlled via the control unit, such that the respective displacement volume is limited to a limit within the angular interval, the travel interval, or the time interval.

9. The method according to claim 1 , wherein the drive is a traction drive.

Assignees

• Bosch Gmbh Robert

Inventors

• Wang Ximing
• Tetik Salih
• Linder Lukas

Classifications

• F16H61/4148

  Open loop circuits · CPC title

• F16H61/431

  Pump capacity control by electro-hydraulic control means, e.g. using solenoid valves · CPC title

• F16H61/4183

  Preventing or reducing vibrations or noise, e.g. avoiding cavitations · CPC title

• F16H61/421 Primary

  Motor capacity control by electro-hydraulic control means, e.g. using solenoid valves · CPC title