| 摘要 |
1380549 Bucket wheel excavators O & K ORENSTEIN & KOPPEL AG 15 June 1973 [16 June 1972] 28603/73 Heading E1F A hydraulic operating system, for a mobile bucket excavator having a hydraulic motor 20 for driving a bucket wheel (7), Fig. 1 (not shown) carried by a jib (8) which may be swivelled about a vertical axis by a hydraulic motor 40, comprises respective digging and swivelling control means 23 and 44 for controlling the supply of pressure fluid from a first source, such as twin pumps 21, 22 and a second source, such as pump 42, to the motors 20 and 40, and first and second control means responsive to the resistance encountered by the buckets for automatically reducing the rate of fluid supply to the motors 20 and 40 respectively. The output of the twin pumps 21, 22 is limited by control devices 32, 33 in response to the fluid pressure in the supply lines to the motor 20. The pump 42 is controlled by a device 43 responsive to the pressure difference between lines 48a, 48b supplied from a source 54 through line 45 and swivel control means 44; the pressure in the line 45 is limited by control means 48, again responsive to the pressure in line 29c feeding the motor 20. The twin pumps 21, 22 include respective pumps 21a, 22a feeding the motor 20 directly and pumps 21b, 22b feeding it through slide valves 28a, 28b which may be set to divert fluid to hydraulic motors 30a, 30b to propel the excavator. The lines 48a, 48b may be vented by valves 53a, 53b controlled by limit switches operated by a cam disc on the jib (8) to prevent the jib colliding with discharge conveyor arm (14). |
