Operating material supply device

The invention relates to an operating material supply device for hydrodynamic components, for example, hydrodynamic switching elements for use in starting units, retarder assemblies or gearing assemblies. The material supply device includes an operating material reservoir arranged in the housing of the starting unit, retarder unit, or gearing assembly and comprises an operating material sump with at least one filling line that connects the operating material sump to the hydrodynamic component. The operating material sump may be closed in a pressure-tight manner.

FIELD OF THE INVENTION

The invention relates to an operating material supply device for switchable elements, for example, hydrodynamic components in starting units, retarder units or gearing assemblies.

BACKGROUND INFORMATION

Hydrodynamic components for use in starting units, retarder units or gearing assemblies may be switchable, and these components may be filled and emptied. Rapid chilling may be required. For example, when hydrodynamic constructional units form hydrodynamic retarders, very short filling times may be required for safety to achieve a rapid braking action or a regulated torque profile that, for example, may cause a certain speed profile when starting an engine. According to general designs known in the prior art, the filling occurs with the aid of operating material reservoir devices, which use external auxiliary power from the vehicle or from their own force to accelerate the filling process when hydrodynamic elements are being filled. In this case, piston-type reservoirs, which are actuated by spring force or compressed air from the compressed air system of the vehicle, may be used. The entire housing space may be set under pressure, which causes operating material to exit the oil sump into the corresponding, hydrodynamic component. Corresponding pump devices may also be employed to aid filling.

However, it is believed that the designs according to the prior art disadvantageously consume power with respect to the conversion and presupposing of special equipment.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an operating material supply device for switchable elements of starting units, retarder units, or gearing assemblies that avoids the disadvantages of the prior art described above. For example, an exemplary embodiment of the present invention permits short filling times. If compressed air is used as the pressure medium, the consumption of air is effective and kept as small as possible. Furthermore, an exemplary operating material supply device according to the present invention is not impaired in function, even in the case of repeated, rapidly successive actuations. The structural outlay and cost expenditure is kept low.

Another exemplary operating material supply device according to the present invention for switchable elements, for example, hydrodynamic components in starting units and gearing assemblies, includes an operating material reservoir having an operating material sump arranged in the housing of the corresponding, switchable element or of the overriding starting, retarder or gearing assembly. The operating material sump is connected to the switchable element, for example, the hydrodynamic component, via at least one filling line. According to an exemplary embodiment of the present invention, the operating material sump may be closed in a pressure-tight manner with respect to the remaining part of the operating material reservoir or the housing of the switchable element, for example, the hydrodynamic component or an overriding starting unit, retarder unit or gearing assembly. For this purpose, a corresponding arrangement may provide the pressure-tight closure of the operating material sump with respect to the surroundings or the housing interior. To cause a rapid filling operation, an arrangement may be provided for charging the operating material in the operating material sump with an influencing pressure.

An exemplary embodiment of the present invention advantageously permits simple filling via a pressure medium, and the geometrical shape and dimensions of the operating material sump may be freely configured to adapt to available structural space. Reservoir volumes may be advantageously kept large, and little pressure medium may be consumed, since only the operating material volume of the operating material sump is sealed, while the remaining portions of the operating material reservoir remain vented. Sequential switching operations are not impaired, since oil that flows out of the hydrodynamic elements when switching off occurs is returned directly into the sump. In this case, the operating material sump receives operating material flowing back from switching elements and from hydrodynamic components.

The arrangement to provide the pressure tight seal and the arrangement to charge the operating material sump with an influencing pressure may be configured in a variety of ways. To cause rapid filling, the arrangement to provide the pressure tight seal and the arrangement to charge the operating material sump may be functionally coupled to each other. Furthermore, these arrangements may be structurally coupled to each other, and individual components may be part of both arrangements.

The arrangement to provide the pressure-tight closure of the operating material sump with respect to the surroundings or the housing interior includes at least one control valve having at least one valve element that interacts with a valve seat. The valve seat is formed by the element forming the opening. The arrangement also includes a movable piston element coupled to the valve element. The control valve is coupled to an actuating device for actuating the valve element. The actuating device connects a pressure connection to the pressure chamber. The arrangement for producing an influencing pressure also includes a valve device which, when charged via an actuating device, connects a pressure medium connection or a connection to the atmosphere to the operating material sump. According to an exemplary compact design of the present invention, the control valve of the arrangement for providing the pressure-tight closure and the valve device for coupling the atmosphere or a pressure medium connection to the operating material sump are combined in a combined valve device. Furthermore, the actuating device for the control valve and the valve device is formed by an actuating device jointly assigned to both. The combined valve device comprises at least one pressure space, in which the valve element of the control valve and the valve element of the second valve device of the arrangement for charging with pressure are arranged and displaceably mounted, and a connection to the atmosphere or to a pressure medium source and a further, second connection to the operating material sump. The valve elements of the valve device of the charging arrangement and of the control valve are kept in a prestressed position in an unpressurized state by spring devices. The dimensions of the spring devices and of the charging surfaces of the piston elements forming the valve elements permit the closure of the operating material sump and the filling to be functionally coupled, without additional control measures.

The solution may also be coupled to a closed, pressure-tight circuit assigned to the hydrodynamic component.

There are no restrictions with regard to the sphere of use. Uses both in the vehicle and in stationary systems are possible.

DETAILED DESCRIPTION

FIG. 1illustrates an operating material supply device1according to the present invention for switchable elements in starting, retarder and/or gearing assemblies. The switchable elements may be hydrodynamic components that form hydrodynamic clutches, hydrodynamic brakes or hydrodynamic speed/torque converters. The operating material supply device1includes an operating material reservoir2having an operating material sump3. The operating material sump is coupled to the switchable element, for example, to a working space of a hydrodynamic component, via at least one filling line4. Furthermore, a suction line36of an oil supply pump is provided. The operating material reservoir2is arranged in a housing of the switching element, of the starting unit, retarder unit or of the gearing assembly. The operating material reservoir2includes a housing5, which may be formed by the housing32of the switchable element, of the starting unit or retarder unit or of the gearing unit. In an exemplary compact embodiment of the present invention, the housing5of the operating material reservoir2is formed by the housing of the hydrodynamic component when the operating material supply device1is assigned to a hydrodynamic component. According to an exemplary embodiment of the present invention, the operating material sump3is closeable via an arrangement6for providing the pressure-tight closure of the operating material sump with respect to the surroundings or the housing interior33, in which the operating material reservoir2is situated. The operating material sump3and the operating material reservoir unit2are arranged with respect to the switchable element so that the switchable element is arranged below the operating material level7(e.g., below the oil level in the operating material reservoir2). The operating material sump3is enclosed by a housing wall region8, which lies below the operating material level7usually present in the switchable element or the housing32of the switchable element or its overriding unit. The housing wall region8forms a chamber9, which may be filled with operating material. The chamber9includes at least one opening11in an upper region on the upper boundary wall10in the installed position. The arrangement6to provide the pressure-tight closure of the operating material sump3with respect to the surroundings or the rest of the housing interior of the operating material reservoir2or, when this housing5is formed from the housing of the switchable element or of the gearing assembly or of a starting element, with respect to the housing interior33thereof includes a device12to close the opening11. Device12includes a control valve13, the valve element14of which is formed by a movable piston element15that enters into operative connection with a valve seat16formed by opening11. For this purpose, the valve element14may be charged with a pressure medium, for example, via an actuating element17for actuating the valve element14, for example, in the form of a valve device18, which controls the supply of pressure medium to the valve element14. In the case illustrated, the movable piston element15is guided in a pressure chamber19, which may be charged with pressure medium. To carry out the filling as rapidly as possible, arrangement26is provided to produce an influencing pressure on the operating material situated in the operating material sump3. Arrangement26includes a valve device30for coupling the atmosphere25(or a pressure medium connection in the form of a pressure medium source28) to the operating material in the operating material sump3. This valve device30is also assigned an actuating device34. In the case illustrated, the valve device30includes a further piston element20arranged in the pressure chamber19. The valve device forms a valve element and is prestressed by spring device21. The spring force of the spring device21counters to the pressure force in the pressure chamber19when being charged with pressure. With respect to the exemplary compact embodiment illustrated, arrangement6and the arrangement26are functionally and structurally coupled to one another. Individual components of both systems may be used (e.g., the valve device18may be used as actuating device17and34and also the common pressure space19and the coupling to the atmosphere25). Valve devices30and13may be combined to form a structural unit35.

The movable piston element15may be assigned a spring device22, which counters the movement of the piston element15. In the unpressurized state of the system, as illustrated inFIG. 1, the spring device22is relieved of load. In this state, the device12for the closure of the opening11, i.e., the control valve13, is in the opened state. The valve element14does not interact with the valve seat16. Operating material may overflow from the region of the operating material reservoir2above the operating material sump3, for example, the possibility of leakage oil flowing in, the inflow direction of which is indicated by23a, of operating material flowing back from the hydrodynamic element, the flow direction of which is referred to by23b, and of the overflow of directly returned operating material according to23cfrom that region24of the operating material reservoir2which is situated outside the closeable operating material sump and is also partially filled with operating material. The two pistons (i.e., the piston elements15and20of the valve devices13and30combined to form the structural unit35as combined valve device31) are relieved of load, i.e., in an unpressurized state. In this state, the pressure medium connection28(e.g., an air connection) is decoupled from the pressure chamber19. The control valve13is situated in its first functional position I. In a similar manner, the valve device30is situated in functional position I′. The final functional position II of the valve element14and II′ of the valve element20are illustrated inFIG. 2. The position of valve element20is to be taken up when the opening11is closed. With reference thereto, the function of the closeable operating material sump3during the closing process is depicted schematically. The basic construction of the operating material supply device1corresponds to that described inFIG. 1. As such, the same reference numbers are used for identical elements. The functional position II of the valve element14of the control valve13illustrated inFIG. 2differs with respect to the functional position I inFIG. 1.

To close the operating material sump3, the control valve13(e.g., the movable piston element15) is charged with pressure. This pressure is supplied via the valve device18in the pressure chamber19. In this case, compressed air supplied to the pressure space19via the valve device18when leaving the pressurized state displaces the piston element15to close the control valve13by interaction with the valve seat16. During closure of the opening11, leakage losses during operation are blocked, the return movements of the individual elements, either the return movements directly of the switching elements. Furthermore, to fill the switching elements, the switching elements should be supplied with operating material from the operating material sump3. This occurs via the filling line4, and arrangement26is provided for producing an influencing pressure on the operating material in the operating material sump3, so that the filling operation may occur as rapidly as possible. After closure of the opening11, the operating material sump3is pressure-tight with respect to the remaining region24of the operating material reservoir2or of the corresponding housing, which forms the housing5of the operating material reservoir. The arrangement26includes a pressure line27extending into the operating material sump3. The arrangement26may be coupled to a pressure medium source28, for example, the atmosphere. In the case illustrated, the arrangement26for producing an influencing pressure and the pressure-tight closure of the operating material sump3may be formed as a unit. The valve device18, which acts as an actuating device17, actuates the valve device30to charge the pressure chamber19and cause a movement of the piston element15. The valve device may actuate the second piston element20of the valve device30. The second piston element20permits or blocks a coupling between the pressure medium connection and the operating material sump to couple a pressure medium source28or the atmosphere to the operating material sump3.

InFIG. 2, the piston element20has a functional position II′. In this position, the pressure medium connection28leads into the pressure chamber19and the transfer of the pressure medium from the pressure chamber19into the operating material sump3is blocked. The combined valve device31is used not only to close the operating material sump3, but also to control the influencing pressure on the operating material sump3. This exemplary embodiment of the present invention permits a particularly compact design having few elements. This function may, for example, be separated. However, this may require additional elements and additional outlay.

FIG. 3illustrates the third functional state III of the valve element14.FIG. 3also illustrates functional state III′ of the second piston element for releasing the connection between the pressure medium connection28and the atmosphere25and operating material sump3. Since the operating material sump3is arranged below the conventionally arising operating material level, for example, the functioning material level7in the operating material reservoir2, the operating material sump3remains filled with operating material. In this case, pressure medium flowing in, for example air flowing in via the pressure medium connection28, immediately increases the operating material pressure in the operating material sump3, without the dead volume in the operating material sump having to be sealed. The operating material pressure thus produced results in the operating material being transported out of the operating material sump3via the filling line4to the switching element. The remaining part of the operating material reservoir2, for example, the region24partially filled with operating material, is outside the spatial dimensions of the operating material sump. After the filling operation is finished, the pressure medium connection28, for example, the supply of air, is switched off, and the compressed air in the operating material sump3may escape via the nonreturn valve device29by way of the coupling to the rest of the interior, for example, into the vented part of the housing (e.g., region24). The compressed air may then flow to the atmosphere, and the individual piston elements (i.e., the piston element20and piston element15) may be displaced again into position I or I′ for the unpressurized state. The operating material sump and the remaining region24of the operating material reservoir may be connected again. The leakage oil or operating material collected in the vented region24of the operating material reservoir may flow back into the operating material sump via the opening11, which has been released. Another variant embodiment of the present invention directs the flowing back operating material into the operating material sump3via nonreturn valves.

An exemplary embodiment according to the present invention permits rapid filling of switching elements in gearing assemblies, starting units, retarder units or the like. In this case, the operating material required for the filling operation from an operating material sump of an operating material reservoir2is used, with the latter being placed under pressure for filling purposes. However, this presupposes that the operating material sump3may be closed in a pressure-tight manner with respect to the atmosphere or the rest of the interior of the operating material reservoir2. Furthermore, a corresponding arrangement is required for supplying or producing an influencing pressure on the operating material sump, which has been closed in a pressure-tight manner. In this case, the two functions (i.e., pressure-tight closure of the operating material sump3and production or provision of an influencing pressure and charging of the operating material sump3with the latter) are performed by different devices. In another exemplary embodiment according to the present invention, a control valve device having corresponding line connections is used. This function is enabled, for example, the setting of the corresponding valve position, by the corresponding dimensioning of the forces acting on the valve piston elements20and15via the spring devices and by the pistons and the dimensioning thereof.