Abstract: A hydraulic position control arrangement with a base body which is rotatably supported on a shaft that includes a hydraulic fluid passage for the admission of hydraulic fluid to an operating chamber which is delimited by the base body and an annular piston which is axially movably supported by the base body, includes an annular sealing element disposed in the base body and seated on the shaft and a leakage return path which extends from the area outside the shaft to the operating chamber through the sealing element. The shaft has at least two axial sections with different outside diameters with the sealing element being seated on the axial shaft section of smaller diameter. The sealing element has a seal lip which abuts the outside of the shaft and is axially supported by a support ring which is provided in the base body.

Abstract: A fan wheel with fan blades which are supported in a hub so as to be pivotable about the longitudinal fan blade axes, with the fan wheel including a drive flange which is connected to the hub via a limited free-wheeling structure, is provided with a planetary transmission arranged between the drive flange and the fan blades. A sun gear of the planetary transmission which is connected to the drive flange for rotation therewith and the drive flange are arranged at axially opposite front sides of the fan wheel.

Abstract: A hydraulic position control arrangement with a base body which is rotatably supported on a shaft that includes a hydraulic fluid passage for the admission of hydraulic fluid to an operating chamber which is delimited by the base body and an annular piston which is axially movably supported by the base body, includes an annular sealing element disposed in the base body and seated on the shaft and a leakage return path which extends from the area outside the shaft to the operating chamber through the sealing element. The shaft has at least two axial sections with different outside diameters with the sealing element being seated on the axial shaft section of smaller diameter. The sealing element has a seal lip which abuts the outside of the shaft and is axially supported by a support ring which is provided in the base body.

Abstract: A fan wheel including a fan wheel hub with fan blades supported rotatably on the fan wheel hub so as to extend radially therefrom, and a fan wheel drive accommodated in the fan wheel hub so as to be rotatable relative thereto within a limited angular range and connected to the fan blades for a corresponding rotation of the fan blades about their longitudinal axes, whereby the flow direction of the fan wheel is reversible by an inertia-based rotation of the fan wheel relative to the fan wheel drive.

Abstract: A fan wheel including a fan wheel hub with fan blades supported rotatably on the fan wheel hub so as to extend radially therefrom, and a fan wheel drive accommodated in the fan wheel hub so as to be rotatable relative thereto within a limited angular range and connected to the fan blades for a corresponding rotation of the fan blades about their longitudinal axes, whereby the flow direction of the fan wheel is reversible by an inertia-based rotation of the fan wheel relative to the fan wheel drive.

Abstract: A fan wheel with a hub is centrally supported with respect to a drive and coaxially rotatable with the hub between stops relative to the hub. The fan wheel having fan blades extending radially from the hub are rotatable about their axes in a range delimited by the stops. Overlaying the rotational support between the stops of the hub, a rotational support between the hub and the drive is provided including a planetary drive in operative arrangement with an adjustment control ring of the driven hub. The fan blades are rotatable in the hub about their blade axes, and adjustment of the blade angles of the fan blades via drive connections to the adjustment control ring, which connections operate in a manner superimposed on one another starting from the drive of the fan wheel.

Abstract: A fan wheel to be driven in only one rotational direction comprising a central drive unit. A hub positioned coaxially relative to the drive unit and comprising radial fan blades mounted in the hub. The fan blades engage at the base end of the hub between two drive tracks which are fixed relative to the drive unit and are arranged coaxially opposite one another in the direction of the axis of rotation of the fan wheel. The fan blades can be adjusted in terms of their blade angle, into opposing blowing directions, by being driven by a respective one of the drive tracks about their blade axis via a reversal plane which extends perpendicular to the plane of rotation of the fan wheel.

Abstract: A fan wheel with a hub is centrally supported with respect to a drive and coaxially rotatable with the hub between stops relative to the hub. The fan wheel having fan blades extending radially from the hub are rotatable about their axes in a range delimited by the stops. Overlaying the rotational support between the stops of the hub, a rotational support between the hub and the drive is provided including a planetary drive in operative arrangement with an adjustment control ring of the driven hub. The fan blades are rotatable in the hub about their blade axes, and adjustment of the blade angles of the fan blades via drive connections to the adjustment control ring, which connections operate in a manner superimposed on one another starting from the drive of the fan wheel.

Abstract: A hydraulic rotary feed-through with a neck which is accommodated in a housing via a bearing arrangement and through a pressurized fluid line extends to a pressure space with a seal arrangement provided axially between the pressure space and the bearing arrangement, the bearing arrangement and the seal arrangement are disposed in frames which are accommodated in the housing axially engaged with one another under pressure.

Abstract: A fan wheel including a fan wheel hub with fan blades supported rotatably on the fan wheel hub so as to extend radially therefrom, and a fan wheel drive accommodated in the fan wheel hub so as to be rotatable relative thereto within a limited angular range and connected to the fan blades for a corresponding rotation of the fan blades about their longitudinal axes, whereby the flow direction of the fan wheel is reversible by an inertia-based rotation of the fan wheel relative to the fan wheel drive.

Abstract: A fan wheel to be driven in only one rotational direction comprising a central drive unit. A hub positioned coaxially relative to the drive unit and comprising radial fan blades mounted in the hub. The fan blades engage at the base end of the hub between two drive tracks which are fixed relative to the drive unit and are arranged coaxially opposite one another in the direction of the axis of rotation of the fan wheel. The fan blades can be adjusted in terms of their blade angle, into opposing blowing directions, by being driven by a respective one of the drive tracks about their blade axis via a reversal plane which extends perpendicular to the plane of rotation of the fan wheel.

Abstract: A hydraulic rotary feed-through with a neck which is accommodated in a housing via a bearing arrangement and through a pressurized fluid line extends to a pressure space with a seal arrangement provided axially between the pressure space and the bearing arrangement, the bearing arrangement and the seal arrangement are disposed in frames which are accommodated in the housing axially engaged with one another under pressure.

Abstract: The invention relates to a fan assembly having a rotatingly driven hub (7) and fan blades (10) which can be pivoted relative to the hub body (29). The fan blades (10) are adjusted by means of a linear drive in the form of a spindle drive (13) or a piston drive (52).

Abstract: The invention concerns a hydraulic adjusting device (1, 35) having at least two leakage paths (24, 25) which are connected by a transition channel (27), a sealing arrangement (18) which leads back to a working chamber (10) being provided in one of the leakage paths (24, 25) in delimiting manner relative to the working chamber (10) of the adjusting device (35).

Abstract: The invention relates to a fan assembly having a rotatingly driven hub (7) and fan blades (10) which can be pivoted relative to the hub body (29). The fan blades (10) are adjusted by means of a linear drive in the form of a spindle drive (13) or a piston drive (52).

Abstract: The invention concerns a hydraulic adjusting device (1, 35) having at least two leakage paths (24, 25) which are connected by a transition channel (27), a sealing arrangement (18) which leads back to a working chamber (10) being provided in one of the leakage paths (24, 25) in delimiting manner relative to the working chamber (10) of the adjusting device (35).

Abstract: In an internal combustion engine cooling system, wherein a fan with an adjustable cooling performance is provided with a fan wheel having a hub with radial fan blades pivotally supported on the hub, a control piston is disposed in the hub and connected to the blades for the pivot position adjustment thereof over a range from a suction position to a blowing position including a neutral position in which the blades are oriented in a plane including the axis of rotation of the fan wheel under the control of a control unit causing movement of the piston for pivoting the blades to a position for a cooling performance adjusted to the engine requirements. The system is simple, safe and efficient and permits counter flow operation of the fan for cleaning purposes.