Drive unit
Patent Information
- Application Number
- EP2023802210
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-11-08
- Filing Date
- 2023-11-07
- Publication Date
- 2025-09-17
AI Technical Summary
Generic drive units consume excessive energy for controlling plunger cycles due to separate inlet and outlet valves, leading to increased energy costs and potential efficiency losses from pressure-dependent friction and leaks.
A drive unit design where the outlet valve controls both the opening of the inlet valve and its closure, eliminating the need for separate valve control, reducing energy consumption and eliminating deformable seals in the high-pressure area to minimize friction and leaks, with a compact arrangement that allows for cost reduction and improved efficiency.
The solution reduces energy consumption for valve control, minimizes pressure-dependent friction, and eliminates leaks, resulting in a more efficient and cost-effective drive unit with improved switching times and reduced size.
Smart Images
Figure 1.1
Abstract
Description
[0001] drive unit
[0002] The present invention relates to a drive unit according to the preamble of claim 1 and the use of such a drive unit.
[0003] In drive units of this type, a crankshaft or similar device is driven by one or more plungers. The plungers, in turn, are driven by the supply of a high-pressure fluid, which is admitted into the working chamber of a plunger assembly. After the plunger has been driven, the fluid, reduced in pressure by the expansion of the working chamber, is forced back from the working chamber via a pressure line by the plunger as the plunger returns to its initial position. These plunger strokes are controlled by a valve arrangement with an inlet and an outlet valve, which are controlled by a valve control system.
[0004] Typically, separate intake and exhaust valves are used for this purpose, each of which is controlled separately via the valve control unit.
[0005] The object of the present invention is to be able to operate a generic drive unit with reduced energy consumption for the control.
[0006] This first object is achieved by a drive unit having the features of claim 1.
[0007] The drive unit according to the invention has a plunger arrangement with a first working chamber and a plunger arranged to be axially movable back and forth in the first working chamber.
[0008] The drive unit further comprises a valve housing with a high-pressure connection and a low-pressure connection. A valve seat ring is arranged in the valve housing, with a second working chamber fluidically connected to the first working chamber, a high-pressure valve seat open to the second working chamber, and a low-pressure valve seat open to the second working chamber.
[0009] An inlet valve is located on the high-pressure valve seat between the high-pressure port and the valve seat ring. An outlet valve is located on the low-pressure valve seat between the low-pressure port and the valve seat ring.
[0010] At least one opening of the intake valve can be controlled via the exhaust valve and one opening and closing of the exhaust valve can be controlled via a valve control unit.
[0011] In a working position, the exhaust valve is closed, and the inlet valve is moved into an open position by the exhaust valve, so that high-pressure fluid supplied via the high-pressure connection can be fed to the first working chamber via the second working chamber. In a non-working position, the exhaust valve is open and the inlet valve is closed, so that low-pressure fluid can be discharged from the first working chamber via the second working chamber and the low-pressure connection after driving the plunger. The at least one plunger can be coupled (in conjunction with a crankshaft) to a consumer.
[0012] With such a drive unit, it is possible to reduce the control energy for the valve arrangement of the inlet and exhaust valves, since only the exhaust valve needs to be controlled, which enables the opening of the inlet valve through a movement.
[0013] Furthermore, the compact arrangement of the intake valve and the exhaust valve makes it possible to make the drive unit smaller overall, which enables a reduction in the cost of the drive unit.
[0014] A further advantage of the drive device is that in this design there are no deformable seals arranged in the high-pressure area, which would lead to pressure-dependent friction and thus negatively influence the switching times of the valves or, if a labyrinth seal is selected, would generate additional leaks and reduce the efficiency.
[0015] Advantageous embodiments of the invention are the subject of the subclaims.
[0016] According to an advantageous embodiment, the outlet valve has a tappet protruding into the second working chamber, said tappet having a first sealing surface that, in the closed position of the tappet, rests against a sealing surface of the low-pressure valve seat. The inlet valve has a closing body with a second sealing surface that, in the closed position, rests against a sealing surface of the high-pressure valve seat. When moving from an open position to the closed position, the tappet pushes the closing body from the closed position to its open position.
[0017] This mechanical coupling of the intake valve with the exhaust valve ensures reliable control of the intake valve via the exhaust valve.
[0018] According to an advantageous further development, in the closed position of the exhaust valve, the first sealing surface of the tappet touches the sealing surface of the low-pressure valve seat and in the closed position of the inlet valve, the closing body touches the sealing surface of the high-pressure valve seat.
[0019] According to an advantageous further development, the first sealing surface is designed as a conical annular surface which connects a first cylindrical tappet section extending through the second working chamber of the valve seat ring with a second cylindrical tappet section extending in the direction of the low-pressure connection.
[0020] The tappet is preferably guided exclusively in the region of a portion of the tappet extending from the second cylindrical tappet section away from the valve seat ring in a low-pressure section of a housing body of the valve housing or in a guide bush arranged in the housing body and is sealed in this region by an elastically deformable low-pressure seal or a low-pressure seal designed as a labyrinth seal.
[0021] This allows the exclusive arrangement of a deformable seal in the low-pressure area to seal the tappet from the environment or the valve control.
[0022] According to a further advantageous development, the inlet valve has an energy accumulator, in particular in the form of a compression spring, which presses the closing body into its closed position.
[0023] This allows, in particular, the tappet of the exhaust valve to only rest against the closing body of the intake valve without having to move it into its closed position. According to a preferred embodiment, the closing body is designed as a sphere, which has the particular advantage that, when the intake valve is open, the spherical surface reduces turbulence.
[0024] According to an advantageous design variant, the outlet valve can be controlled pneumatically, electrically or hydraulically.
[0025] According to an advantageous embodiment, the valve control unit is coupled to a position sensor which detects the rotational position of the crankshaft and thus the position of the plunger in the first working chamber.
[0026] According to a further preferred embodiment, at least three, preferably five plunger arrangements are provided, each of the plungers being assigned an inlet valve and an outlet valve.
[0027] An inventive use of a drive unit for pressure control in a hydraulic process setup is characterized in that the drive unit is designed as described above, wherein the drive unit is coupled to the process setup in such a way that the plunger is coupled via a crankshaft to a generator for generating electrical energy or via a crankshaft to a mechanism utilizing the rotary movement transmitted to the crankshaft.
[0028] Preferred embodiments are explained in more detail below with reference to the accompanying drawings. They show:
[0029] Figure 1 is a schematic sectional view through an embodiment of a drive unit according to the invention,
[0030] Figure 2 is an enlarged detail of a section of the drive unit marked II, III in Figure 1 to show the inlet valve and the exhaust valve as well as the valve seat ring with the exhaust valve closed and the inlet valve open, and
[0031] Figure 3 is an enlarged detail corresponding to Figure 2 with the exhaust valve open and the inlet valve closed.
[0032] In the following description of the figures, terms such as top, bottom, left, right, front, rear, etc., refer exclusively to the exemplary representation and position of the drive unit, plunger assembly, plunger, valve seat ring, intake valve, exhaust valve, and the like chosen in the respective figures. These terms are not to be understood as limiting; i.e., these references may change due to different operating positions or the mirror-symmetrical design, etc.
[0033] In Figure 1, the reference number 1 designates an embodiment of a drive unit.
[0034] The drive unit 1 essentially consists of a plunger assembly 2 with a plunger 22, which is arranged in a working chamber 22 of a plunger housing surrounding the plunger 22 and is movable back and forth axially (coaxially in the illustrated embodiment) in the direction of its longitudinal axis. The plunger 22 with the plunger housing 23 is accommodated in a plunger frame 10.
[0035] It is also conceivable to design the drive unit 1 with several such plunger arrangements, in which the plungers are preferably arranged in one row or several rows next to one another.
[0036] A crankshaft 12 or the like is preferably connected to one end of the plunger 22, so that the movement of the plunger 22 enables the direct or indirect drive of a consumer. The crankshaft 12 is coupled to the plunger 22 via a connecting rod 13 and a coupling piece 14 attached to the connecting rod 13.
[0037] It is also conceivable to use the drive unit 1 for energy recovery, in which a fluid brought to high pressure in a previous process is fed into the drive unit 1 and, for example, a generator is driven via the plunger driven by the high pressure and the crankshaft connected to the plunger, which generator converts the energy released by the relaxation of the high-pressure fluid into electrical current.
[0038] The first working chamber 21 of the plunger arrangement 2 is followed by a high-pressure line 8 arranged in a connecting frame 9, which in turn opens into a valve housing 3.
[0039] As shown in Figure 1, the valve housing 3 has a housing body 33, to the underside of which a high-pressure connection 31 is connected. The high-pressure connection 31 is accommodated in a further frame 11, which is attached to the housing body 33 of the valve housing 3.
[0040] The housing body 33 of the valve housing 3 itself also has a low-pressure connection 32.
[0041] A valve seat ring 4 is arranged in a cavity of the housing body 33.
[0042] The valve seat ring 4 has a second working chamber 41 fluidically connected to the first working chamber 21, a high-pressure valve seat 42 open to this second working chamber 41 and a low-pressure valve seat 43 open to the second working chamber 41.
[0043] An inlet valve 5 is arranged on the high-pressure valve seat 41 between the high-pressure connection 31 and the valve seat ring 4.
[0044] An outlet valve 6 is arranged on the low-pressure valve seat 43 between the low-pressure connection 32 and the valve seat ring 4.
[0045] The inlet valve 5 opens by the movement of the outlet valve 6.
[0046] The opening and closing of the exhaust valve 6 takes place via a valve control unit 7, shown as an example in Figure 1. A separate valve control for opening or closing the intake valve 5 is not provided.
[0047] In the embodiment shown here according to Figures 2 and 3, both the high-pressure valve seat 42 and the low-pressure valve seat 43 are designed as approximately annular recesses enclosing the second working chamber 41, with respective sealing surfaces 421, 431 which, together with the inlet valve 5 and the outlet valve 6, respectively, block or release the flow of the fluid.
[0048] In the embodiment shown here, the outlet valve 6 has a tappet 61 which projects into the second working chamber 41 and on the outer surface of which a first sealing surface 614 is formed which, in the closed position of the tappet 61, bears directly against the sealing surface 431 of the low-pressure valve seat 43, i.e., to seal the second working chamber 41 from the low-pressure side, the tappet 61 bears directly against the valve seat ring 4 (the sealing surface 431 of the low-pressure valve seat 43 of the valve seat ring 4). In the embodiment shown here, the first sealing surface 614 is designed as a conical annular surface which connects a first cylindrical tappet section 612 extending through the second working chamber 41 of the valve seat ring 4 to a second cylindrical tappet section 613 extending in the direction of the low-pressure connection 32.
[0049] An end face 611 of the tappet 61 is adapted to a contact surface of a closing body 51 of the inlet valve 5.
[0050] A portion of the tappet 61 remote from the first tappet portion 612 and extending from the second cylindrical tappet portion 613 is guided exclusively in a low-pressure portion of the housing body 33 of the valve housing 3 or preferably in a guide bush arranged in the housing body 33 and sealed by an elastically deformable low-pressure seal 15.
[0051] The low-pressure seal can also be designed as a labyrinth seal to reduce the friction component of the valve circuit.
[0052] The low-pressure section of the housing body 33 is understood to be the section of the housing body 33 that is not exposed to high pressure. This low-pressure section extends, as can be seen in Figures 2 and 3, above the low-pressure valve seat 43 in the direction of the low-pressure connection 32 and beyond it into the area of the housing body 33 that guides the tappet 61.
[0053] The closing body 51, which is preferably spherically shaped here, is pressed from the side facing away from the plunger 61 against the contact surface 611 of the plunger 61 by an energy storage holder prestressed by a compression spring or another energy storage device 54.
[0054] The valve control unit 7 is, as shown in Figure 1, preferably designed as a pneumatic control unit, with a compressed air inlet 75 which pushes a plate 71 downward relative to a cover 73 when compressed air is admitted, wherein the plate 71 drives the tappet 61 and thus closes the outlet valve and simultaneously opens the inlet valve.
[0055] If the compressed air is released again to open the outlet valve 6, the plate 71 driving the tappet 61 is pressed back into the starting position against the cover 73 by a compression spring 74 in the embodiment shown here.
[0056] The valve control unit 7 preferably has a housing part 72 with an internal thread, which is screwed onto an external thread of a section 34 of the valve housing 3. A flange connection between the valve control unit 7 and the valve housing 3 is also conceivable, for example.
[0057] As an alternative to the spherical closing body 51, a cylindrical or conical closing body 51 is also conceivable.
[0058] The energy storage device 54, which is designed here as a compression spring, is accommodated in a cylindrical recess of the energy storage holder and is supported on a step of a closing body receptacle 56 in a valve holding body 55.
[0059] In a conceivable embodiment, in which the closing body 51 is directly connected to the tappet 61, an energy storage device 54 is not necessarily required. In this case, the compression spring 74 acting on the plate 71 of the valve control unit 7 can assume this function.
[0060] The closing body receptacle 56 is fluidically connected to the high-pressure connection 31.
[0061] The high-pressure fluid can flow via the closing body receptacle 56 through passage openings 52 provided in the energy storage holder past the closing body 51 into the second working chamber 41 of the valve seat ring, provided that a second sealing surface 511 of the closing body 51 does not rest on the sealing surface 421 of the high-pressure valve seat 42, against which the closing body 51 is pressed by means of the force of the spring holder.
[0062] In its position sealing the second working chamber 41, the closing body 51, like the first sealing surface 614 of the tappet 61, lies directly against the sealing surface 421 of the high-pressure valve seat 42 of the valve seat ring 4.
[0063] This means that no elastic sealing elements are installed within the high-pressure range, which would lead to pressure-dependent friction and thus negatively affect the switching times of the valves. To drive the plunger 22 from its top dead center position, shown in Figure 1, in the first working chamber 21, the inlet valve 5 must be opened.
[0064] To open the inlet valve 5, the tappet 61 is pressed against the closing body 51 and presses the closing body 51 downwards against the force of the energy accumulator 54 away from the sealing surface 421 of the high-pressure valve seat 42.
[0065] The inlet valve 5 opens by the movement of the outlet valve 6.
[0066] The opening and closing of the outlet valve 6 takes place as described above via the valve control unit 7, shown as an example in Figure 1 .
[0067] The mechanical or geometric coupling of the tappet 61 of the outlet valve 6 with the closing body 51 of the inlet valve 5 makes it possible for the outlet valve 6 to be closed and the inlet valve 5 to be moved into an open position by the outlet valve 6, as shown in Figure 2, in a working position in which the plunger 22 drives a crankshaft by means of its movement with the aid of the high-pressure fluid supplied into the first working chamber 21.
[0068] At the bottom dead center of the plunger 2, the outlet valve 6 is relieved. As shown in Figure 3, the outlet valve 6 is opened and the inlet valve 5 is closed, so that low-pressure fluid can be discharged from the first working chamber 21 via the second working chamber 41 and the low-pressure connection 32 after the plunger 22 is driven.
[0069] As a comparison of Figures 2 and 3 shows, when the outlet valve 6 is open, the conical ring-shaped first sealing surface 614 of the tappet 61 is not in contact with the sealing surface 431 of the low-pressure valve seat 43.
[0070] In this respect, the lowering of the tappet 61 in the z-direction (as shown in Figure 2) enables the outlet valve 6 to be closed simultaneously with the inlet valve 5 being opened, in which the closing body 51 is pressed away from the sealing surface 421 of the high-pressure valve seat 42.
[0071] Furthermore, the described design makes it possible that no moving components need to be sealed to the outside within the high-pressure area, so that dynamic sealing elements, in particular in the form of elastic sealing lips or labyrinth seals, can be completely dispensed with within the high-pressure area.
[0072] The outlet valve 6 can preferably be controlled pneumatically, electrically or hydraulically.
[0073] The drive unit 1 described above can be used in a first application for energy recovery in a hydraulic process setup for generating electrical energy. For this purpose, a generator for generating electrical energy is coupled to the at least one plunger 22 via the crankshaft 12.
[0074] In a second use of the drive unit 1, a mechanism that utilizes the rotational movement transmitted to the crankshaft is coupled via the crankshaft 12. The mechanism that utilizes the rotational movement can, for example, be a pump in which the pump's plunger is coupled to the crankshaft 12.
[0075] Other consumers are also conceivable for utilizing the kinetic rotational energy generated by the drive unit 1.
[0076] List of reference symbols
[0077] 1 drive unit
[0078] 2 Plunger arrangement
[0079] 21 first workroom
[0080] 22 plungers
[0081] 23 Plunger housing
[0082] 3 valve housings
[0083] 31 High pressure connection
[0084] 32 Low pressure connection
[0085] 33 Housing body
[0086] 34 flange
[0087] 4 valve seat ring
[0088] 41 second workroom
[0089] 42 High pressure valve seat
[0090] 421 Sealing surface
[0091] 43 Low pressure valve seat
[0092] 431 Sealing surface
[0093] 44 ring bodies
[0094] 45 cross hole
[0095] 5 Inlet valve
[0096] 51 locking body
[0097] 511 second sealing surface
[0098] 52 Passage opening
[0099] 53 pen holders
[0100] 54 energy storage
[0101] 55 valve retaining body
[0102] 56 Locking body holder
[0103] 6 exhaust valve
[0104] 61 plungers
[0105] 611 frontal surface
[0106] 612 first tappet section
[0107] 613 second tappet section
[0108] 614 first sealing surface 7 valve control unit
[0109] 71 plates
[0110] 72 Flange 73 Cover
[0111] 74 compression spring
[0112] 75 Compressed air inlet
[0113] 8 High-pressure line 9 Connecting frame
[0114] 10 plunger frames
[0115] 11 frames
[0116] 12 Crankshaft
[0117] 13 Connecting rod 14 Coupling piece
[0118] 15 Low pressure seal
Claims
Claims Drive unit (1 ), comprising - a plunger arrangement (2) with a first working chamber (21) and a plunger (22) arranged to be axially movable back and forth in the first working chamber (21), - a valve housing (3) with a high-pressure connection (31) and a low-pressure connection (32), - a valve seat ring (4) arranged in the valve housing (3) with a second working chamber (41) fluidically connected to the first working chamber (21), a high-pressure valve seat (42) open to the latter and a low-pressure valve seat (43) open to the latter, - an inlet valve (5) arranged between the high-pressure connection (31) and the valve seat ring (4) on the high-pressure valve seat (41), - an outlet valve (6) arranged between the low-pressure connection (32) and the valve seat ring (4) on the low-pressure valve seat (43), characterized in that - at least one opening of the inlet valve (5) can be controlled via the outlet valve (6) and one opening and closing of the outlet valve (6) can be controlled via a valve control unit (7), - wherein in a working position, the outlet valve (6) is closed and the inlet valve (5) is moved into an open position by the outlet valve (6), so that high-pressure fluid supplied via the high-pressure connection (31) can be supplied to the first working chamber (21) via the second working chamber (41), and in a non-working position, the outlet valve (6) is opened and the inlet valve (5) is closed, so that low-pressure fluid can be discharged from the first working chamber (21) via the second working chamber (41) and the low-pressure connection (32) after driving the plunger (22), - wherein the at least one plunger (22) is connectable to a consumer. Drive unit (1) according to claim 1, characterized in that the outlet valve (6) has a tappet (61) projecting into the second working chamber (41) with a first sealing surface (614) which, in the closed position of the tappet (61), bears against a sealing surface (431) of the low-pressure valve seat (43), and the inlet valve (5) has a closing body (51) with a second sealing surface (511) which, in the closed position of the closing body (51), bears against a sealing surface (421) of the high-pressure valve seat. (42), wherein the plunger (61) pushes the closing body (51) from the closed position into its open position when moving from an open position into the closed position.
3. Drive unit (1) according to claim 2, characterized in that in the closed position of the outlet valve (6) the first sealing surface (614) of the tappet (61) touches the sealing surface (431) of the low-pressure valve seat (43) and in the closed position of the inlet valve (5) the closing body (51) touches the sealing surface (421) of the high-pressure valve seat (42).
4. Drive unit (1) according to claim 3, characterized in that the first sealing surface (614) is designed as a conical annular surface which connects a first cylindrical tappet section (612) extending through the second working space (41) of the valve seat ring (4) with a second cylindrical tappet section (613) extending in the direction of the low-pressure connection (32).
5. Drive unit (1) according to claim 4, characterized in that the tappet (61) is guided exclusively in the region of a section of the tappet (61) extending from the second cylindrical tappet section (613) away from the valve seat ring (4) in a low-pressure section of a housing body (33) of the valve housing (3) or in a guide bush arranged in the housing body (33) and is sealed in this region by an elastically deformable low-pressure seal (15) or designed as a labyrinth seal.
6. Drive unit (1) according to one of claims 2 to 5, characterized in that the inlet valve (5) has an energy accumulator (54) which presses the closing body (51) into its closed position, in particular in the form of a compression spring.
7. Drive unit (1) according to one of claims 2 to 6, characterized in that the closing body (51) is designed as spherical, conical or cylindrical.
8. Drive unit (1) according to one of the preceding claims, characterized in that the outlet valve (6) can be controlled pneumatically, electrically or hydraulically. Drive unit (1) according to one of the preceding claims, characterized in that the valve control unit (7) is coupled to a position sensor that provides the position of the rotational position of a drive shaft coupled to the plunger (22) or of the plunger (22) in the first working chamber (21). Drive unit (1) according to one of the preceding claims, characterized in that at least three, preferably five plunger arrangements (2) are provided, each with a plunger (22), wherein each of the plungers is assigned an inlet valve (5) and an outlet valve (6).Use of a drive unit (1) for energy recovery in a hydraulic process setup, characterized in that the drive unit (1) is designed according to one of the preceding claims, wherein the drive unit (1) is coupled to the process setup in such a way that the plunger (22) is coupled via a crankshaft (12) to a generator for generating electrical energy or via a crankshaft (12) to a mechanism utilizing the rotary movement transmitted to the crankshaft.