Apparatus for compensating viscous characteristics of hydraulic fluid in a hydraulic pressure line

• US 7,258,640 B2
• Filed: 04/29/2004
• Issued: 08/21/2007
• Est. Priority Date: 05/09/2003
• Status: Expired due to Fees

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Schiele, Peter, Schmidt, Thilo, Gierer, Georg
• Primary Examiner(s): Pang; Roger
• Application Number:
  US10/834,535
• Publication Number:
  US 20040222319A1
• Time in Patent Office: 1,209 Days
• Field of Search: 475/127, 475/130, 477/127, 477/130, 138/42, 138/116.3, 138/85, 138/625.2, 138/115.08, 138/115.09, 138/115.11, 138/87.03, 138/87.04
• US Class Current: 475/127
• CPC Class Codes: F15B 21/045 Compensating for variations in viscosity or temperature

Abstract

An apparatus for compensating the viscous characteristics of a hydraulic medium in a pressure line (10) in which apparatus a pressure nozzle (12) with constant geometry and constant through-flow cross-section is located in the pressure line (10). It is provided according to the invention that in the pressure Line (10) upstream or downstream of the pressure nozzle (12) at least one channel-shaped area (11, 28) is made or situated which, compared to the pressure nozzle (12), has a smaller through-flow cross-section and a larger axial extension and that the control pressure (P_SekV) abutting between the channel-shaped area (11, 28) and the pressure nozzle (12) can be supplied via a control pressure line (13) to a shift valve (14).

Claims

1. An apparatus for compensating the viscous characteristics of a hydraulic medium in a pressure line (10), the apparatus comprising:

a first pressure nozzle (12) and at least one channel-shaped area (11, 28) connected in series in the pressure line (10), and the at least one channel shaped area (11, 28) being located one of upstream and downstream of the first pressure nozzle (12);

the first pressure nozzle (12) being of constant geometry and a constant through-flow crass-section;

the at least one channel-shaped area (11, 28) having a smaller through-flow cross-section and a larger axial extension than the first pressure nozzle (12);

a control pressure line (13), connected between the channel-shaped area (11, 28) and the first pressure nozzle (12), to provide a control pressure (P_SekV) to a shift valve (14); and

said channel-shaped area (11) being at least one spiral duct (28) on the outer periphery of a pressure nozzle (27).

2. An apparatus for compensating the viscous characteristics of a hydraulic medium in a pressure line (10), the apparatus comprising:

a first pressure nozzle (12) and at least one channel-shaped area (11, 28) connected in series in the pressure line (10), and the at least one channel shaped area (11, 28) being located one of upstream and downstream of the first pressure nozzle (12);

the first pressure nozzle (12) being of constant geometry and a constant through-flow cross-section;

the at least one channel-shaped area (11, 28) having a smaller through-flow cross-section and a larger axial extension than the first pressure nozzle (12);

a control pressure line (13) connected from between the channel-shaped area (11, 28) and the first pressure nozzle (12) to provide a control pressure (P_SekV) to a shift valve (14);

the channel-shaped area (11) is a control line member;

said pressure nozzle (27) is cylindrically designed; and

said cylindrical pressure nozzle (27) is situated in a housing (20) with an upstream inlet aperture (21) and a downstream outlet aperture (22), a through-flow cross-section of the inlet and outlet apertures (21;

22) being smaller than an inner diameter of the housing interior (29).

3. The apparatus according to claim 2, wherein

said pressure nozzle housing (20) has one hollow cylindrical section (23) and one cap (24) shutting said section (23).

4. The apparatus according to claim 3, wherein one cylindrical pressure nozzle (27) is inserted into a pressure nozzle housing (20), on two front side ends of the cylindrical-pressure nozzle (27) one respective pivot (25;

26) is made whose front side surfaces (30;

31) rest on an inner side of the cap (24) and of the housing bottom.