Abstract: A gear pump has a gear wheel with teeth on an outer circumference and a second gear ring with teeth on the inside surface. The gear ring is guided in a circular-cylindrical recess of a housing and together with the gear wheel, each rotates about their own axis which are offset from one another. The gear pump is equipped with an intake opening and a crescent-shaped pressure opening in a first side wall of the housing that defines the recess. A countersunk feature is also provided, embodied as a hollow cone, in a second wall of the housing opposite the pressure opening. The hollow cone, which is in fluid communication with the pressure opening, promotes the buildup of a fluid film between the gear ring and the housing, which improves the wear resistance of the gear pump.

Abstract: A piston pump, which is provided as a return feed pump for a slip-regulated motor vehicle brake system. In order to simplify the manufacture, a sleeve in the form of a tubular piece is clamped between a fastening element which is inserted into the cylinder bore using a self-clinching technique, and the cylinder bore, and is thus sealed and fixed in place. In addition to the simple manufacture of the sleeve out of reasonably priced tubular material, the piston pump has the advantage of a sealing of the sleeve in the cylinder bore without a separate sealing element such as a sealing ring.

Abstract: The invention relates to a housing block into which a piston pump is inserted. For sealing off and fixing a cylinder of the piston pump in the housing block, the cylinder is provided with a radially outward-protruding annular shoulder, which when the cylinder is press-fitted in the housing block displaces material of the housing block and deforms the housing block plastically radially inward until material rests sealingly on the cylinder and fixes the cylinder in the housing block. The invention makes it possible to accomplish securing and sealing in one operation in an economical way, without requiring additional securing means and economizing on one high-pressure-proof sealing ring.