EP 0279362 A1 19880824 - Hydraulic system.
Title (en)
Hydraulic system.
Title (de)
Hydraulisches System.
Title (fr)
Système hydraulique.
Publication
Application
Priority
US 1631887 A 19870219
Abstract (en)
A crawler loader or other large industrial earthmoving machine has a hydraulic propulsion system comprising at least two hydraulic motors (26, 28) which are powered from a pump (44) to drive a common load, namely its tracks (24). Each motor (26, 28) of the hydraulic propulsion system is provided with two compensating valve assemblies (30, 32 and 34, 36). Each compensating valve assembly has a compensating spool (48, 50, 52, 54) and a shuttle spool (56, 58, 60, 62) to provide accurate control of the hydraulic motors (26, 28). In each pair of compensating valve assemblies (30, 32 and 34, 36), there is a forward compensating valve assembly (30, 34) and a backward valve assembly (32, 36) respectively controlling forward and backward movement of the associated hydraulic motor (26, 28). Between both forward compensating valve assemblies (30, 34) and the respective hydraulic motors (26, 28), the compensating valve assemblies (30, etc.) are fluidically coupled to one another by a small hydraulic communication line (98) that better equalizes hydraulic fluid flow to the motors (26, 28) and prevents domination of one forward compensating valve assembly over the other. Similarly, the backward compensating valve assemblies (32, 36) are provided with an identical small hydraulic communication line (100) accomplishing the same results.
IPC 1-7
IPC 8 full level
B62D 11/04 (2006.01); E02F 3/32 (2006.01); E02F 9/22 (2006.01); F15B 11/044 (2006.01); F15B 11/16 (2006.01); F15B 11/22 (2006.01); F15B 13/02 (2006.01)
CPC (source: EP)
E02F 9/2253 (2013.01); F15B 11/0445 (2013.01); F15B 11/16 (2013.01); F15B 11/22 (2013.01); F15B 13/022 (2013.01); F15B 2211/30525 (2013.01); F15B 2211/3056 (2013.01); F15B 2211/50545 (2013.01); F15B 2211/6051 (2013.01); F15B 2211/7058 (2013.01); F15B 2211/71 (2013.01); F15B 2211/782 (2013.01)
Citation (search report)
- [X] GB 1131750 A 19681023 - LINDE AG
- [X] GB 1035141 A 19660706 - PRIESTMAN BROTHERS
- [A] US 3960284 A 19760601 - CARPENTER EMERL R
- [A] DE 2336157 A1 19740124 - KUBOTA LTD
- [A] GB 1044851 A 19661005 - AUXITRA SA
- [A] US 2912131 A 19591110 - BERNHARD JUNG, et al
- [A] DE 3525823 A1 19870129 - SCHMITZ SOEHNE GMBH MASCHF [DE]
- [X] MACHINE DESIGN, vol. 40, no. 13, 6th June 1968, pages 166-170, Columbus, Ohio, US; W. MEISEL: "Hydraulic actuators"
Designated contracting state (EPC)
DE FR IT
DOCDB simple family (publication)
EP 0279362 A1 19880824; EP 0279362 B1 19901205; CA 1274748 A 19901002; DE 3861194 D1 19910117; JP 2604399 B2 19970430; JP S63215467 A 19880907
DOCDB simple family (application)
EP 88102046 A 19880212; CA 557948 A 19880202; DE 3861194 T 19880212; JP 3731888 A 19880219