Hydraulic steering unit

Patent metadata

Field	Value
Publication number	US-10717464-B2
Application number	US-201815970344-A
Country	US
Kind code	B2
Filing date	May 3, 2018
Priority date	May 8, 2017
Publication date	Jul 21, 2020
Grant date	Jul 21, 2020

Abstract

A hydraulic steering unit ( 1 ) is described comprising a supply port arrangement having a pressure port ( 8 ) connected to a main flow path ( 6 ) and a tank port (T) connected to a tank flow path ( 7 ), a working port arrangement having a left working port (L) connected to a left working flow path ( 9 ) and a right working port (R) connected to a right working flow path ( 10 ), a bridge arrangement ( 14 ) of variable orifices having a first left orifice (A 2 L) connected to the main flow path ( 6 ) and to the left working flow path ( 9 ), a first right orifice (A 2 R) connected to the main flow path ( 6 ) and to the right working flow path ( 10 ), a second left orifice (A 3 L) connected to the left working flow path ( 9 ) and to the tank flow path ( 7 ), and a second right orifice (A 3 R) connected to the right working flow path ( 10 ) and to the tank flow path ( 7 ). Such a hydraulic steering unit should allow comfortable steering. To this end a measuring motor arrangement is arranged in one of the left working flow path ( 9 ) and the right working flow path ( 10 ), the measuring motor arrangement ( 15 ) having a first measuring motor ( 16 ) and a second measuring motor ( 17 ).

First claim

What is claimed is:

1. A hydraulic steering unit comprising a supply port arrangement having a pressure port connected to a main flow path and a tank port connected to a tank flow path, a working port arrangement having a left working port connected to a left working flow path and a right working port connected to a right working flow path, a bridge arrangement of variable orifices having a first left orifice connected to the main flow path and to the left working flow path, a first right orifice connected to the main flow path and to the right working flow path, a second left orifice connected to the left working flow path and to the tank flow path, and a second right orifice connected to the right working flow path and to the tank flow path, wherein a measuring motor arrangement is arranged in one of the left working flow path and the right working flow path, the measuring motor arrangement having a first measuring motor and a second measuring motor, and wherein a variable main orifice is arranged in the main flow path upstream the variable first left orifice and the variable first right orifice.

2. The hydraulic steering unit according to claim 1 , wherein a valve is arranged between the measuring motors establishing a parallel connection between the measuring motors or interrupting the parallel connection.

3. The hydraulic steering unit according to claim 2 , wherein the valve short-circuits one of the measuring motors when the parallel connection is interrupted.

4. The hydraulic steering unit according to claim 3 , wherein the valve is actuated by a pressure difference between the pressure port and the tank port and the force of a spring.

5. The hydraulic steering unit according to claim 3 , wherein a check valve is arranged between the pressure port and the bridge arrangement, the check valve opening in a direction towards the bridge arrangement.

6. The hydraulic steering unit according to claim 2 , wherein the valve is actuated by a pressure difference between the pressure port and the tank port and the force of a spring.

7. The hydraulic steering unit according to claim 2 , wherein a check valve is arranged between the pressure port and the bridge arrangement, the check valve opening in a direction towards the bridge arrangement.

8. The hydraulic steering unit according to claim 2 , wherein a variable third left orifice is arranged in the left working flow path and a variable third right orifice is arranged in the right working flow path.

9. The hydraulic steering unit according to claim 1 , wherein a check valve is arranged between the pressure port and the bridge arrangement, the check valve opening in a direction towards the bridge arrangement.

10. The hydraulic steering unit according to claim 1 , wherein a tank orifice is arranged in the tank flow path.

11. The hydraulic steering unit according to claim 10 , wherein the tank orifice is a variable orifice.

12. The hydraulic steering unit according to claim 1 , wherein a variable third left orifice is arranged in the left working flow path and a variable third right orifice is arranged in the right working flow path.

13. The hydraulic steering unit according to claim 12 , wherein the variable third left orifice and the variable third right orifice open faster than the variable first left orifice and the variable first right orifice.

14. A hydraulic steering unit comprising a supply port arrangement having a pressure port connected to a main flow path and a tank port connected to a tank flow path, a working port arrangement having a left working port connected to a left working flow path and a right working port connected to a right working flow path, a bridge arrangement of variable orifices having a first left orifice connected to the main flow path and to the left working flow path, a first right orifice connected to the main flow path and to the right working flow path, a second left orifice connected to the left working flow path and to the tank flow path, and a second right orifice connected to the right working flow path and to the tank flow path, wherein a measuring motor arrangement is arranged in one of the left working flow path and the right working flow path, the measuring motor arrangement having a first measuring motor and a second measuring motor, and wherein a check valve is arranged between the pressure port and the bridge arrangement, the check valve opening in a direction towards the bridge arrangement.

15. The hydraulic steering unit according to claim 14 , wherein a valve is arranged between the measuring motors establishing a parallel connection between the measuring motors or interrupting the parallel connection.

16. The hydraulic steering unit according to claim 14 , wherein a tank orifice is arranged in the tank flow path.

17. The hydraulic steering unit according to claim 14 , wherein a variable third left orifice is arranged in the left working flow path and a variable third right orifice is arranged in the right working flow path.

18. A hydraulic steering unit comprising a supply port arrangement having a pressure port connected to a main flow path and a tank port connected to a tank flow path, a working port arrangement having a left working port connected to a left working flow path and a right working port connected to a right working flow path, a bridge arrangement of variable orifices having a first left orifice connected to the main flow path and to the left working flow path, a first right orifice connected to the main flow path and to the right working flow path, a second left orifice connected to the left working flow path and to the tank flow path, and a second right orifice connected to the right working flow path and to the tank flow path, wherein a measuring motor arrangement is arranged in one of the left working flow path and the right working flow path, the measuring motor arrangement having a first measuring motor and a second measuring motor, and wherein a variable third left orifice is arranged in the left working flow path and a variable third right orifice is arranged in the right working flow path.

19. The hydraulic steering unit according to claim 15 , wherein a valve is arranged between the measuring motors establishing a parallel connection between the measuring motors or interrupting the parallel connection.

20. The hydraulic steering unit according to claim 15 , wherein a check valve is arranged between the pressure port and the bridge arrangement, the check valve opening in a direction towards the bridge arrangement.

Assignees

• Danfoss Power Solutions Aps

Inventors

• Arbjerg Niels
• Bates Charles Anthony
• Ennemark Poul
• Frederiksen Mogens
• Olesen Casper Mikael

Classifications

• B62D5/093

  Telemotor driven by steering wheel movement (hydraulic steering gear B62D3/14) · CPC title

• B62D5/06 Primary

  fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle · CPC title

• B62D5/08

  characterised by type of {steering} valve used (valves in general F16K) · CPC title

• B62D5/065 Primary

  characterised by specially adapted means for varying pressurised fluid supply based on need, e.g. on-demand, variable assist · CPC title

• B62D5/14

  Rotary motor · CPC title