Abstract: A drive system, in particular for a self-propelled construction machine, in particular a soil compactor, comprising an internal combustion engine comprising a drive unit, at least one hydraulic circuit with a hydraulic pump that can be driven by the drive unit, as well as a hydraulic-drive support unit with a hydraulic pump/motor assembly and at least one pressure fluid reservoir, wherein the hydraulic pump/motor assembly is or can be drivingly coupled with the drive unit or/and at least one hydraulic circuit, wherein the hydraulic pump/motor assembly can be operated in a charging operating mode by the drive unit or/and at least one hydraulic circuit as a pump to charge at least one pressure fluid reservoir and be operated in an drive support operating mode as a motor to provide a drive support torque for the hydraulic pump of at least one hydraulic circuit, characterized in that the hydraulic pump/motor assembly can be operated in a recirculation operating mode as a motor to start the drive unit.

Abstract: A drive system, in particular for a self-propelled construction machine, in particular a soil compactor, comprises a drive unit, at least one hydraulic circuit with a hydraulic pump driven by the drive unit, a hydraulic drive support unit with a hydraulic pump/motor assembly, and at least one pressure fluid reservoir, wherein the hydraulic pump/motor assembly is, or can be, drivingly coupled with the drive unit and/or at least one hydraulic circuit, wherein the hydraulic pump/motor assembly can be operated in a charging operating mode by the drive unit and/or at least one hydraulic circuit as a pump to charge at least one pressure fluid reservoir, and be driven in a drive support operating mode as a motor to provide a drive support torque for the hydraulic pump of at least one hydraulic circuit, characterized in that the hydraulic pump/motor assembly is operated in a recirculation operating mode as a pump to convey fluid out of a fluid reservoir and into a fluid reservoir.

Abstract: A drive system, in particular for a self-propelled construction machine, especially a soil compactor, comprising a drive unit, at least one hydraulic circuit with a hydraulic pump drivable by the drive unit, as well as a hydraulic drive support unit with a hydraulic pump/motor assembly and at least one compressed fluid reservoir, wherein the hydraulic pump/motor assembly is, or can be, drivingly coupled to the drive unit and/or to at least one hydraulic circuit, wherein the hydraulic pump/motor assembly can be operated in a charging operating mode as a pump by means of the drive unit and/or by means of at least one hydraulic circuit for charging at least one compressed fluid reservoir, and which is drivable in a drive support state as a motor to provide a drive support torque for the hydraulic pump of at least one hydraulic circuit, is characterized in that a maximum drive torque provided by the drive unit is smaller than a maximum request torque to be applied for operating at least one hydraulic circuit.

Abstract: A drive system, in particular for a self-propelled construction machine, especially a soil compactor, comprising a drive unit, at least one hydraulic circuit with a hydraulic pump drivable by the drive unit, as well as a hydraulic drive support unit with a hydraulic pump/motor assembly and at least one compressed fluid reservoir, wherein the hydraulic pump/motor assembly is, or can be, drivingly coupled to the drive unit and/or to at least one hydraulic circuit, wherein the hydraulic pump/motor assembly can be operated in a charging operating mode as a pump by means of the drive unit and/or by means of at least one hydraulic circuit for charging at least one compressed fluid reservoir, and which is drivable in a drive support state as a motor to provide a drive support torque for the hydraulic pump of at least one hydraulic circuit, is characterized in that a maximum drive torque provided by the drive unit is smaller than a maximum request torque to be applied for operating at least one hydraulic circuit.

Abstract: A drive system, in particular for a self-propelled construction machine, in particular a soil compactor, comprising an internal combustion engine comprising a drive unit, at least one hydraulic circuit with a hydraulic pump that can be driven by the drive unit, as well as a hydraulic-drive support unit with a hydraulic pump/motor assembly and at least one pressure fluid reservoir, wherein the hydraulic pump/motor assembly is or can be drivingly coupled with the drive unit or/and at least one hydraulic circuit, wherein the hydraulic pump/motor assembly can be operated in a charging operating mode by the drive unit or/and at least one hydraulic circuit as a pump to charge at least one pressure fluid reservoir and be operated in an drive support operating mode as a motor to provide a drive support torque for the hydraulic pump of at least one hydraulic circuit, characterized in that the hydraulic pump/motor assembly can be operated in a recirculation operating mode as a motor to start the drive unit.

Abstract: A drive system, in particular for a self-propelled construction machine, in particular a soil compactor, comprises a drive unit, at least one hydraulic curcuit with a hydraulic pump driven by the drive unit, a hydraulic drive support unit with a hydraulic pump/motor assembly, and at least one pressure fluid reservoir, wherein the hydraulic pump/motor assembly is, or can be, drivingly coupled with the drive unit and/or at least one hydraulic circuit, wherein the hydraulic pump/motor assembly can be operated in a charging operating mode by the drive unit and/or at least one hydraulic circuit as a pump to charge at least one pressure fluid reservoir, and be driven in a drive support operating mode as a motor to provide a drive support torque for the hydraulic pump of at least one hydraulic circuit, characterized in that the hydraulic pump/motor assembly is operated in a recirculation operating mode as a pump to convey fluid out of a fluid reservoir and into a fluid reservoir.

Abstract: A control valve for a hydraulic adjuster for the camshaft of an internal combustion engine is provided, wherein an actuator acts on a pressure part (12) embedded in a control piston (5). In order to prevent the piston (5) from being blocked in the valve housing by the expansion thereof caused by the pressure part embedment, the pressure part (12) and/or the control piston (5) is/are provided with radial recesses (34) in the embedment area (13) which make it possible to limit joining forces and the resulting radial expansion of the piston (5). Alternatively or in addition, the external surface of the control valve (5) has a reduced cross-section in the embedment area (13).

Abstract: An electromagnetic actuating unit (10) of a hydraulic directional control valve (9) is provided having an armature (18) which is arranged such that it can be axially displaced within an armature space (30), and includes a pole core (29) which is arranged in a receptacle (27a) and delimits the armature space (30) in a movement direction of the armature (18). Constructions are provided in order to avoid deposits on a guide surface of the armature (18), as a result of which the dynamics and the response behavior of the actuating unit (10) are increased and hysteresis effects and the risk of a malfunction of the actuating unit are minimized.

Abstract: A device for changing the control times of an internal combustion engine (camshaft adjuster) having a pressure medium distributor arranged within a camshaft is provided. The pressure medium distributor is provided at its front end with a radially extending shoulder, this shoulder forming part of the camshaft axial mounting.

Abstract: A control valve for a hydraulic adjuster for the camshaft of an internal combustion engine is provided, wherein an actuator acts on a pressure part (12) embedded in a control piston (5). In order to prevent the piston (5) from being blocked in the valve housing by the expansion thereof caused by the pressure part embedment, the pressure part (12) and/or the control piston (5) is/are provided with radial recesses (34) in the embedment area (13) which make it possible to limit joining forces and the resulting radial expansion of the piston (5). Alternatively or in addition, the external surface of the control valve (5) has a reduced cross-section in the embedment area (13).

Abstract: A control valve for a device for changing the control times of an internal combustion engine, having a substantially hollow-cylindrical valve housing, a control piston which is arranged within the valve housing and can be displaced axially, a pressure medium connection, two operating connections, and at least one tank connection. The operating connections, the pressure medium connection and the tank connection are formed as radial connections. It is possible for the operating connections to be connected to the pressure medium connection and the tank connection by axial displacement of the control piston within the valve housing. The operating connections are arranged adjacently.

Abstract: A control valve (18) for a device (1) to modify the timing of an internal combustion engine is provided. Here, a controlled rotation of the camshaft in reference to the crankshaft can be achieved via a hydraulic adjustment drive. A control valve (18) with operative connectors (A, B), a hydraulic connector (P), and at least one reservoir connector (T, T1, T2) controls the inflow of hydraulic fluid into and/or the outflow of hydraulic fluid out of the hydraulic adjustment drive. A filter (46) is arranged between the hydraulic connector (P) and the operative connectors (A, B).

Abstract: An internal-combustion engine with a device for adjusting the rotational angle (camshaft adjuster (1)) of a camshaft (2) relative to a crankshaft is provided. The device comprises a driving wheel (3) connected in a rotationally locked way to the crankshaft, a driven part (6) connected in a rotationally locked way to the camshaft (2), and an adjusting mechanism, with which the phase position between the crankshaft and camshaft (2) can be set and maintained in a certain range of angles. A reduction of the required axial structural space of the camshaft adjuster (1) and the number of individual parts is achieved in that the driven part (6) is fixed to the camshaft (2) with a frictional, positive-fit, or interference-fit connection.

Abstract: An electromagnetic actuating unit (10) of a hydraulic directional control valve (9) is provided having an armature (18) which is arranged such that it can be axially displaced within an armature space (30), and includes a pole core (29) which is arranged in a receptacle (27a) and delimits the armature space (30) in a movement direction of the armature (18). Constructions are provided in order to avoid deposits on a guide surface of the armature (18), as a result of which the dynamics and the response behavior of the actuating unit (10) are increased and hysteresis effects and the risk of a malfunction of the actuating unit are minimized.

Abstract: A device for changing the control times of an internal combustion engine (camshaft adjuster) having a pressure medium distributor arranged within a camshaft is provided. The pressure medium distributor is provided at its front end with a radially extending shoulder, this shoulder forming part of the camshaft axial mounting.

Abstract: A device for changing the control times of an internal combustion engine (camshaft adjuster (1)) having a pressure medium distributor (21) arranged within a camshaft (11) is provided. The pressure medium distributor (21) is provided at its front end with a radially extending shoulder (42), this shoulder (42) forming part of the camshaft axial mounting.

Abstract: The invention relates to a control valve for influencing the action of a pressure medium on a camshaft adjuster of an internal combustion engine. A control valve of said type comprises a valve housing (72), in which a displaceable control piston (71) is arranged in a blind bore. According to the invention, the valve housing (72) is produced with a through bore (73) instead of a blind bore, into which through bore (73) a housing insert (79) is clipped into a groove (80). The housing insert can serve to support a pressure spring (76), and can also additionally have recesses, in the region of which the housing insert (79) serves to form a port, for example to a tank T.

Abstract: An internal-combustion engine with a device for adjusting the rotational angle (camshaft adjuster (1)) of a camshaft (2) relative to a crankshaft is provided. The device comprises a driving wheel (3) connected in a rotationally locked way to the crankshaft, a driven part (6) connected in a rotationally locked way to the camshaft (2), and an adjusting mechanism, with which the phase position between the crankshaft and camshaft (2) can be set and maintained in a certain range of angles. A reduction of the required axial structural space of the camshaft adjuster (1) and the number of individual parts is achieved in that the driven part (6) is fixed to the camshaft (2) with a frictional, positive-fit, or interference-fit connection.

Abstract: A control valve (18) for a device (1) to modify the timing of an internal combustion engine is provided. Here, a controlled rotation of the camshaft in reference to the crankshaft can be achieved via a hydraulic adjustment drive. A control valve (18) with operative connectors (A, B), a hydraulic connector (P), and at least one reservoir connector (T, T1, T2) controls the inflow of hydraulic fluid into and/or the outflow of hydraulic fluid out of the hydraulic adjustment drive. A filter (46) is arranged between the hydraulic connector (P) and the operative connectors (A, B).

Abstract: A device for changing the control times of an internal combustion engine (camshaft adjuster (1)) having a pressure medium distributor (21) arranged within a camshaft (11) is provided. The pressure medium distributor (21) is provided at its front end with a radially extending shoulder (42), this shoulder (42) forming part of the camshaft axial mounting.