Abstract: In a control cylinder device of a variable displacement compressor, an annular cylinder concentric with a driving rotary shaft is provided in a housing of a compressor body, and an annular control piston is slidably fitted in the cylinder to define a control pressure chamber within the cylinder. The annular control piston is connected to a sleeve, such that the sliding movement of the sleeve can be controlled by the operation of the control piston. Further, inner and outer seal rings are interposed in an axially misaligned relation to each other between inner and outer slide surfaces of the cylinder and control piston. This facilitates an accurate formation of the inner and outer surfaces of the cylinder in the cylinder device on which the control piston slides. Also, this easily insures sealing properties required between the slide surfaces of the cylinder and the piston. In addition, it is possible to effectively prevent the inclination of the control piston within the cylinder.

Abstract: An injection pump for internal combustion engines having a pump piston and a pump piston bushing, to which a suction chamber is connected, the connection of the suction chamber to the work chamber of the pump is overtaken by the pump piston upon supply onset, and in which a diversion of the pump pressure at the end of supply is effected by re-opening the communication with the suction chamber. At least one separate diversion chamber, defined by a pressure maintenance valve and a throttle is connected to the work chamber via a connection that is likewise openable and closable upon the compression stroke; this connection to the work chamber is opened earlier, at the end of pump supply, than a further connection to the suction chamber.