Abstract: A piston engine or machine with a belt drive which is surrounded by a housing, with the housing substantially sealing off the belt drive from the environment and from the piston engine or machine, is provided. The housing may have Helmholtz resonators facing the belt drive.

Abstract: A coupling comprising a first machine element having a recess, a second machine element which can be inserted into the recess and an elastic, U-shaped bracket, adjacent positioning devices being associated with the first and the second machine elements and the bracket having a direction of movement which extends transverse to the direction of coupling and being able to be brought into engagement with the positioning devices. The first machine element has in the region of its positioning devices in the direction of movement of the bracket at least two detents located one behind the other which are arranged in the direction of movement in front of and behind the recess for the second machine element. The bracket is provided in the direction of movement at least at its front end with a lock device which can be brought into engagement with the detents of the first machine element. The bracket can in retracted condition be brought into engagement with the first detent and is then arranged outside the recess.

Abstract: A belt pulley is described which includes a pulley member and a flanged wheel. The pulley member has a belt-bearing surface and a projection disposed at a position axially adjacent to the belt-bearing surface. The flanged wheel is capable of being assembled separately on the pulley member and includes a spring washer having an inside diameter and an outside diameter. The spring washer is substantially elastically extendable in the area of the inside diameter. The dimensions of the inside diameter are defined such that, upon assembly, the inside diameter elastically extends and touches upon a surface of the projection over at least a portion of the inside diameter such that the flanged wheel is mounted concentrically and non-rotatably in relation to the belt-bearing surface.

Abstract: The plastic impeller of a coolant pump is attached to the bearing shaft with a bearing journal, so that the journal engages to be seated firmly in an axial bore of the shaft. Here, the bearing journal and the impeller are formed in one piece of the same material. The bearing journal is pressed or glued into the bore of the bearing shaft, and the impeller as well as the bearing journal are formed of a phenolic resin which is resistant to the coolant.

Abstract: An intake manifold for an internal combustion engine is disclosed. The intake manifold has an intake manifold body of fixed cross-section with a passage passing through it. The passage area can be altered by an expansible member arranged in the passage. The expansible member is an elastically expandable membrane, as well as a supply pipe used to expand the membrane, as needed, by use of a fluid medium.

Abstract: A cooling water pump for combustion engines has, between a sealing element 6 and a bearing 5, an annular chamber 7 provided with at least two openings 8, 9 penetrating the cover 2 of the bearing on opposing sides of the shaft 4. At least one absorbent disc 10 is provided axially between the ventilating openings 8, 9 and the bearing 5.