Spherical piston for positive-displacement machines

摘要

The invention relates to a spherical piston for positive-displacement machines, especially for slow-running radial-piston machines in eccentric construction. The object of the invention is to provide a positive-displacement machine for high operating pressures with low wear and a good sealing effect which, utilising the advantages of the spherical piston, increases the service life and the efficiency of the machine. This object is achieved by there being arranged, between the cylinder bore and the surface of the spherical piston facing the cylinder chamber, a moulded sealing ring which is guided in the cylinder bore and whose geometric shape matches the shape of the space forming between the cylinder bore and the surface of the sphere, and by the moulded sealing ring being pressed onto the surface of the sphere via a resilient retaining device.