| 摘要 |
Pump combination with flow rate control device for the pressure medium supply of hydraulic systems having different rotational drive speeds, preferably for mobile drives. Conventionally, the oil pump design must be able to cope with the lowest operational rotational speeds. In high rotational-speed ranges, however, unnecessarily high deliveries and losses arise, and moreover, in the case of wide delivery ranges, the functional and operating quality of servo devices, control devices and regulating devices suffers. The main purpose and advantages of the present pump combination are an evening-out of the output or appropriate adjustment of the output while saving drive energy, with a number of advantageous functional features tailored to the use in motor vehicles. The main constructional feature and function consists in a plurality of pumps or one pump (pos. 1) being combined with a plurality of pump stages having hydraulic regulating or control devices (3, 5, 7, 53, 54) into one assembly and being connected in such a way that individual pump stages are connected in with, or disconnected from, the useful delivery stream, controlled as a function of the pressure or (usually) the useful output or externally. In the first case they deliver, at low capacity, into a base having a low pressure level (2, 72). An advantage compared to variable-delivery pumps is the possibility of using the low-pressure and low-loss (switched-off) delivery streams economically for lubricating and cooling purposes. <IMAGE>
|
