Abstract: A transmission control circuit for controlling a system pressure provided by a pressure pump in a transmission. The circuit includes a pressure control valve and an electronic control unit. Load states and operating states of the working machine can be detected by the control unit and transmission input torque limits associated with the load states and state values representing at least one first operating state and state values representing at least one second operating state are stored therein. The first operating state corresponds with the maximum system pressure and the second operating state corresponds with a reduced system pressure compared to the maximum system pressure. The circuit includes a pressure limiting valve activated by the control unit to overrule the pressure control valve in order to variably set the reduced system pressure.

Abstract: The invention relates to an system for supplying a hydraulic circuit with hydraulic fluid. The system includes a working reservoir and an auxiliary reservoir connected to the working reservoir by a hydraulic line. An air pump has an inlet connected to a suction line that opens into a liquid-free portion of the auxiliary reservoir so that a negative pressure can be built up in the auxiliary reservoir relative to the atmospheric ambient pressure. The air pump inlet is also connected to a control line, which comprises a control opening which is covered by the hydraulic fluid in the working reservoir, at least before the air pump is started up.

Abstract: The invention relates to an system for supplying a hydraulic circuit with hydraulic fluid. The system includes a working reservoir and an auxiliary reservoir connected to the working reservoir by a hydraulic line. An air pump has an inlet connected to a suction line that opens into a liquid-free portion of the auxiliary reservoir so that a negative pressure can be built up in the auxiliary reservoir relative to the atmospheric ambient pressure. The air pump inlet is also connected to a control line, which comprises a control opening which is covered by the hydraulic fluid in the working reservoir, at least before the air pump is started up.

Abstract: A transmission control circuit for controlling a system pressure provided by a pressure pump in a transmission. The circuit includes a pressure control valve and an electronic control unit. Load states and operating states of the working machine can be detected by the control unit and transmission input torque limits associated with the load states and state values representing at least one first operating state and state values representing at least one second operating state are stored therein. The first operating state corresponds with the maximum system pressure and the second operating state corresponds with a reduced system pressure compared to the maximum system pressure. The circuit includes a pressure limiting valve activated by the control unit to overrule the pressure control valve in order to variably set the reduced system pressure.

Abstract: The invention relates to an system for supplying a hydraulic circuit with hydraulic fluid. The system includes a working reservoir and an auxiliary reservoir connected to the working reservoir by a hydraulic line. An air pump has an inlet connected to a suction line that opens into a liquid-free portion of the auxiliary reservoir so that a negative pressure can be built up in the auxiliary reservoir relative to the atmospheric ambient pressure. The air pump inlet is also connected to a control line, which comprises a control opening which is covered by the hydraulic fluid in the working reservoir, at least before the air pump is started up.

Abstract: A support for at least one brush element. The support includes at least one carrier, to which the at least one brush element is removably attached on a flat front side of the at least one carrier, and at least one bar, which is removably attached to the at least one carrier on a rear side opposite the front side of the at least one carrier. To the rear side of the at least one carrier at least one elastic locking element is attached, which is lockable with a plurality of parallel flutes of the at least one bar.

Abstract: The invention concerns a system for supplying hydraulic fluid to a hydraulic system, with an operating reservoir that accepts the hydraulic fluid provided for the operation of the hydraulic system and an auxiliary reservoir connected to the operating reservoir over a hydraulic line for intermediate storage of hydraulic fluid withdrawn from the operating reservoir. According to the invention, an air pump is available that is connected on the one hand on its low pressure side to a suction line that ends in a fluid free area of the auxiliary reservoir, so that a negative pressure can be built up in the auxiliary reservoir as against the external atmospheric pressure, and that is connected, on the other hand, to a control line that is provided with a control opening that is covered by the hydraulic fluid in the operating reservoir at least before the air pump is put into operation.

Abstract: A support for at least one brush element. The support includes at least one carrier, to which the at least one brush element is removably attached on a flat front side of the at least one carrier, and at least one bar, which is removably attached to the at least one carrier on a rear side opposite the front side of the at least one carrier. To the rear side of the at least one carrier at least one elastic locking element is attached, which is lockable with a plurality of parallel flutes of the at least one bar.

Abstract: The invention concerns a system for supplying hydraulic fluid to a hydraulic system, with an operating reservoir that accepts the hydraulic fluid provided for the operation of the hydraulic system and an auxiliary reservoir connected to the operating reservoir over a hydraulic line for intermediate storage of hydraulic fluid withdrawn from the operating reservoir. According to the invention, an air pump is available that is connected on the one hand on its low pressure side to a suction line that ends in a fluid free area of the auxiliary reservoir, so that a negative pressure can be built up in the auxiliary reservoir as against the external atmospheric pressure, and that is connected, on the other hand, to a control line that is provided with a control opening that is covered by the hydraulic fluid in the operating reservoir at least before the air pump is put into operation.

Abstract: The invention relates to a cylinder crankcase (4) comprising at least one cylinder liner (2) which is integrally cast in the cylinder crankcase (4). The cylinder liner (2) runs in the cylinder crankcase (4) from a cylinder-head side (6) to an oil-chamber side (8) and has an inner side (10) and an outer side (14). The invention is characterized in that the cylinder liner (2), at least at one end, is longer along the inner side (10) in the axial direction (20) than on the outer side (14). The transition from the inner side (10) to the outer side (14) is affected in the form of encircling, concentric steps (22).

Abstract: The invention relates to a cylinder crankcase (4) comprising at least one cylinder liner (2) which is integrally cast in the cylinder crankcase (4). The cylinder liner (2) runs in the cylinder crankcase (4) from a cylinder-head side (6) to an oil-chamber side (8) and has an inner side (10) and an outer side (14). The invention is characterized in that the cylinder liner (2), at least at one end, is longer along the inner side (10) in the axial direction (20) than on the outer side (14). The transition from the inner side (10) to the outer side (14) is effected in the form of encircling, concentric steps (22).

Abstract: A cylinder liner (2) for a cylinder block has a contouring (6) at one end. The contouring (6) serves to support the liner (2) on a sleeve (4) inside a die-casting tool. When the liner (2) is cast in, recesses (10) of the liner (2) are filled by the material of the cylinder crankcase whereby preventing the liner (2) from seating toward an oil chamber (14). The invention also relates to a method for producing a cylinder liner of the aforementioned type.

Abstract: The invention relates to a process for precision-machining a cylindrical inner surface, in particular a cylinder bearing surface, which has material of different hardnesses in the axial direction. The cylindrical inner surface is subjected to a precision-turning step, a preliminary honing step and a precision-honing step. The process is distinguished by the fact that the preliminary honing step produces a cone (11) in the cylindrical inner surface, in such a way that the cone (11) widens out from a harder region (4) toward a softer region (6). In the subsequent precision-honing step, the cone (11) is compensated for again in the harder region (4) to produce a cylindrical inner surface, whereas the cone (11) is retained in the softer region (6). This prevents the fine abrasive particles on the precision-honing stone from becoming clogged as a result of contact with the softer region.

Abstract: The invention relates to an uncovering compound for uncovering surfaces of materials with pronounced Si crystals, in particular of cylinder bearing surfaces made from aluminum materials with pronounced Si primary crystals. The uncovering compound according to the invention preferably includes very fine uncovering material, particularly preferably comprising silicon carbide grains with a grain size in the range from 4 ?m to 0.1 ?m and/or ceramic fibers comprising Al2O3, which is embedded in a visco-elastic plastic carrier compound. The invention also describes a process and a corresponding apparatus in which the uncovering compound according to the invention is used.

Abstract: The invention relates to a method for fine machining a cylindrical inner surface which has materials of different hardnesses in the axial direction, and comprises the following steps: pre-turning of the surface, with at least one softer area of the surface being pre-turned to a greater diameter than a harder area, honing of at least the harder area down to the diameter level of the softer area.

Abstract: The invention relates to a cylinder liner (2) for a cylinder block. Said cylinder liner has a contouring (6) at one end. The contouring (6) serves to support the liner (2) on a sleeve (4) inside a die-casting tool. When the liner (2) is cast in, recesses (10) of the liner (2) are filled by the material of the cylinder crankcase whereby preventing the liner (2) from seating toward an oil chamber (14). The invention also relates to a method for producing a cylinder liner of the aforementioned type.

Abstract: A casting die for the production of a cylinder block/crankcase of an internal combustion engine includes at least one sleeve, which may be moved relative to its axis and is fitted in each case with a cylinder liner, the sleeve keeping open the cylinder bore of the cylinder block/crankcase and extending from a wall on the cylinder-head side of the die to a wall on the crankshaft side of the casting die. The cylinder liner ends at least 3 mm before the wall on the cylinder-head side of the casting die, and the cylinder liner is held at a distance from the wall on the cylinder-head side of the casting die by a spacer.

Abstract: The invention relates to a method and a device for producing coated holes, in which, after the hole is formed, the hole wall is plasma-sprayed with a coating material. In order to enable, in a relatively simple manner, the coating of the hole wall to be sufficiently durable with respect to mechanical loads, it is proposed that the hole wall be subjected to flow-turning machining.

Abstract: In a process for casting a metallic semi-finished product into a casting, the semi-finished product is roughened on a surface which faces the casting, then being placed in a defined position in a casting mold and surrounded with casting metal, after which a firm bond is formed between the semi-finished product and the solidified casting metal at the roughened surface. The surface of the semi-finished product is roughened by high-pressure water blasting.

Abstract: In a permanent casting die with an at least local ceramic lining, the ceramic lining at least partially forms surface contours of a die cavity. The ceramic lining is applied in a form-fitting manner to a metallic core and the ceramic lining with the core is anchored firmly or movably in the die cavity.