| 摘要 |
The invention relates to a hydraulic control circuit for a radial piston engine with two speeds. The changeover between the speeds takes place through the alteration of the absorption volume, the delivery side (22, 122, 222) being connected to the discharge side (24, 124, 224, 324) with a bypass connection by means of a valve arrangement 830, 130, 230, 330, 430) for a selected number of engine pistons. The aim of the invention is to provide a particularly space-saving means of ensuring that the changeover between speeds occurs smoothly and in such a manner as to preserve the individual components as far as possible. To this end, at least one intermediate switching position (230-Z; 330-Z2; 330-Z3), in which the delivery side (22, 122, 222) is throttled to the discharge side (24, 124, 224, 324), i.e. connected via a diaphragm-type arrangement (231; A1; A2; 282; 284-A; 284-B; 286-B; 382-2; 384-2), is provided in front of valve arrangement (30, 130, 230, 330, 430) between the two end switching positions. The valve arrangement (30, 130, 230, 330, 430) is preferably driven in such a way that a valve body (270, 370, 470) can be moved through the intermediate switching position at a controlled speed.
|
