Abstract: A traction mechanism drive, in particular for an internal combustion engine, including a vibration damper (1) having a base part (2) and a rotary part (3) that can be rotated to a limited extent relative to the base part against the effect of an energy store (6). Between the base part (2) and the rotary part (3), a friction unit (8) having a friction ring (9) formed of a support element (15) and a sliding element (16) arranged radially outside of the support element (15) for forming a friction contact in relation to a friction surface (10) is effective. The friction ring (9) is produced in one piece from the support element (15) and the sliding element (16), and the support element (15) and the sliding element (16) are cast on top of each other. A positive fit (17) is effective between said support element and sliding element in the circumferential direction.

Abstract: A spring element that is designed for a flexible drive of an internal combustion engine. The spring element has a cylinder, in which a piston is guided in a linearly displaceable manner, a force being applied to the piston by spring means. Corresponding fixing eyes are respectively allocated to the cylinder and the piston for fixing the spring element. A transverse pin is associated with the piston to limit the travel of the spring element. The pin engages in a positive fit with backlash in a longitudinal guiding element of the cylinder.

Abstract: The invention provides a plastic-sheathed roller, typically a tension roller of plastic for a belt drive. The roller comprises a wheel comprising an inner ring and an outer ring that are connected through radially oriented ribs arranged spaced apart on a periphery and through a central web. The wheel is mounted for rotating through a rolling bearing on a carrier element, while being supported through a running surface on a belt of the belt drive, and injection gates for injection molding are arranged distributed on a lateral surface while being spaced apart angularly non-uniformly from one another.

Abstract: A traction mechanism that includes at least one guide (1, 1?-1???) for tensioning or guiding a continuous traction drive element, especially a chain of the control drive of an internal combustion engine is provided. The guide (1, 1?-1???) is made of plastic and metal inserts and has a double T cross-section having an upper member (3) and a lower member (4) that are connected by a central web (5) and ribs (6) arranged endwise on both ends of the web (5). The invention provides a rigid, compact and inexpensive guide. For this purpose, the guide (1, 1?-1???) includes two lateral plates (2, 2?-2???, 18, 19), preferably made from steel, that are inserted into recesses (7) in the side faces (29) of the ribs (6) in a play-free manner and are held in position by form fitting fastening elements.

Abstract: The invention provides a plastic-sheathed roller, typically a tension roller of plastic for a belt drive. The roller comprises a wheel comprising an inner ring and an outer ring that are connected through radially oriented ribs arranged spaced apart on a periphery and through a central web. The wheel is mounted for rotating through a rolling bearing on a carrier element, while being supported through a running surface on a belt of the belt drive, and injection gates for injection molding are arranged distributed on a lateral surface while being spaced apart angularly non-uniformly from one another.

Abstract: A hydraulic system for a motor vehicle has at least one pressure restricting valve with a housing that has two or more connections. At least one conduit cross-section in the housing can be closed by means of a closing body that is movable axially against the action of an energy accumulator. At least a part of the axial travel of the closing body is damped by means of a damping device.

Abstract: The cylinder of a cylinder and piston unit in the friction clutch engaging/disengaging apparatus of a power train for use in a motor vehicle is assembled of two separately produced coaxial tubular walls. The outer wall is made of a plastic material and is of one piece with an extension serving to supply pressurized hydraulic fluid from a pump or another source to the plenum chamber for the reciprocable annular piston between the two walls. The inner wall is made of sheet metal and one of its end portions is separably coupled to one end portion of the outer wall by snap action. Such one end portion of the outer wall is separably secured to a support, usually the transmission case in the power train of the motor vehicle.

Abstract: A hydraulic master cylinder for a clutch or brake of a motor vehicle is simultaneously optimized for cost-effective mass production and for functional properties.

Abstract: A hydraulic system for a motor vehicle has at least one pressure restricting valve with a housing that has two or more connections. At least one conduit cross-section in the housing can be closed by means of a closing body that is movable axially against the action of an energy accumulator. At least a part of the axial travel of the closing body is damped by means of a damping device.

Abstract: A hydraulically operated central release unit for a motor vehicle clutch is designed as a slave cylinder that is arranged inside a clutch housing. The central release unit includes a housing in which a ring piston is movably guided. The ring piston has a groove ring seal with lips sealingly contacting the sealing tracks. To reduce the wear on the sealing lips and to avoid squeaking noises of the groove ring seal, the surfaces of the sealing tracks are provided with micro cavities.

Abstract: A master cylinder for a hydraulic friction clutch, said master cylinder being connected to a physically actuatable pedal by a piston rod (17) which is articulated in semi-shells (14) enclosed in a piston skirt bushing (10), an end of said piston skirt bushing (10) remote from the piston rod (17) being connected to a piston (7) which is longitudinally displaceable in a guide sleeve (96) of the master cylinder (1), an end face of said piston (7) delimiting a pressure chamber (8) wherein the semi-shells (14) fill an inner space of the piston skirt bushing (10) without play and comprise a cup-shaped recess (15) in which a ball head (16) of the piston rod (17) is retained by positive locking, the piston skirt bushing (10) forming a structural unit with the radially stepped piston (7).

Abstract: A master cylinder for use in a hydraulically actuated clutch or brake system of a motor vehicle, includes a casing formed with a bore, and a piston unit axially displaceable within the bore. The piston unit includes a piston-shaft sleeve received in the bore and having one end formed with a bottom to define an interior, at least two retainer shells received in the interior of the sleeve free of play, and a piston rod having a spherical head swingably mounted to the retainer shells and provided to respond to a manual actuation of a pedal. The retainer shells are each formed at a pedal-proximate end of the piston-shaft sleeve with a spherical recess to define a ball socket in which the spherical head snaps in and is received in form-fitting manner.