WO2024100026A1

WO2024100026A1 - Drive unit

Info

Publication number: WO2024100026A1
Application number: PCT/EP2023/080966
Authority: WO
Inventors: Martin Oberscheidt; Fabian STOFFERS
Original assignee: Hammelmann GmbH
Priority date: 2022-11-08
Filing date: 2023-11-07
Publication date: 2024-05-16
Also published as: DE102022129520A1

Abstract

A drive unit (1) has a plunger arrangement (2) with a first working chamber (21) and a plunger (22) arranged to move axially 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) and with a second working chamber (41) fluidically connected to the first working chamber (21), a high-pressure valve seat (42) open with respect to the second working chamber and a low-pressure valve seat (43) open with respect to the second working chamber, an inlet valve (5) arranged on the high-pressure valve seat (41) between the high-pressure connection (31) and the valve seat ring (4), an outlet valve (6) arranged on the low-pressure valve seat (43) between the low-pressure connection (32) and the valve seat ring (4), wherein at least an opening of the inlet valve (5) can be controlled via the outlet valve (6) and an 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 by the outlet valve (6) into an open position such that fluid that is supplied via the high-pressure connection (31) and is under high pressure can be supplied via the second working chamber (41) to the first working chamber (21) and in a non-working position the outlet valve (6) is open and the inlet valve (5) is closed such that fluid under low pressure can be discharged out of the first working chamber (21) via the second working chamber (41) and the low-pressure connection (32) after the plunger (22) is driven, wherein the at least one plunger (22) can be coupled to a consumer.

Description

Drive unit

The present invention relates to a drive unit according to the preamble of claim 1 and the use of such a drive unit.

In drive units of this type, a crankshaft or the like is driven by one or more plungers. The plungers are in turn driven by the supply of a high-pressure fluid which is let into the working chamber of a plunger arrangement. After the plunger has been driven, the fluid, which has been reduced in pressure by the enlargement of the working chamber, is forced back out of the working chamber via a pressure line by the plunger when the plunger returns to its initial position. These plunger cycles are controlled by a valve arrangement with an inlet and an outlet valve, which are controlled by a valve control.

Usually, separate inlet and outlet valves are used, each of which is controlled separately via the valve control unit.

The object of the present invention is to be able to operate a generic drive unit with reduced energy consumption for the control.

This first object is achieved by a drive unit having the features of claim 1.

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.

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 this and a low-pressure valve seat open to this.

An inlet valve is arranged on the high-pressure valve seat between the high-pressure connection and the valve seat ring. An outlet valve is arranged on the low-pressure valve seat between the low-pressure connection and the valve seat ring.

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.

In a working position, the outlet valve is closed and the inlet valve is moved into an open position by the outlet valve, so that high-pressure fluid supplied via the high-pressure connection can be supplied to the first working chamber via the second working chamber, and in a non-working position, the outlet valve is opened 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 the plunger is driven. The at least one plunger can be coupled to a consumer (in connection with a crankshaft).

With such a drive unit, it is possible to reduce the control energy for the valve arrangement of the inlet and outlet valves, since only the outlet valve needs to be controlled, which enables the inlet valve to be opened by means of a movement.

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 cost reduction of the drive unit.

A further advantage of the drive device is that in this design there are no deformable seals 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.

Advantageous embodiments of the invention are the subject of the subclaims.

According to an advantageous embodiment, the outlet valve has a tappet protruding into the second working chamber with a first sealing surface which, 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 which, 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.

This mechanical coupling of the intake valve with the exhaust valve ensures reliable control of the intake valve via the exhaust valve.

According to an advantageous 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.

According to an advantageous development, the first sealing surface is designed as a conical annular surface which connects a first cylindrical tappet section extending through the second working space of the valve seat ring with a second cylindrical tappet section extending in the direction of the low-pressure connection.

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.

This allows the exclusive arrangement of a deformable seal only in the low-pressure area to seal the tappet from the environment or the valve control.

According to a further advantageous development, the inlet valve has an energy storage device, in particular in the form of a compression spring, which presses the closing body into its closed position.

In particular, this makes it possible for the tappet of the exhaust valve to only rest on 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 ball, which has the particular advantage that when the inlet valve is open, little turbulence occurs due to the spherical surface.

According to an advantageous design variant, the outlet valve can be controlled pneumatically, electrically or hydraulically.

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.

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.

An inventive use of a drive unit for pressure control in a hydraulic process structure is characterized in that the drive unit is designed as described above, wherein the drive unit is coupled to the process structure 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 that uses the rotary motion transmitted to the crankshaft.

Preferred embodiments are explained in more detail below with reference to the accompanying drawings. They show:

Figure 1 is a schematic sectional view through an embodiment of a drive unit according to the invention,

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 outlet valve as well as the valve seat ring with the outlet valve closed and the inlet valve open and

Figure 3 is an enlarged detail corresponding to Figure 2 with the exhaust valve open and the inlet valve closed.

In the following description of the figures, terms such as top, bottom, left, right, front, back, etc. refer exclusively to the figures in the respective Figures show selected exemplary representations and positions of the drive unit, plunger arrangement, plunger, valve seat ring, inlet valve, outlet valve and the like. These terms are not to be understood as limiting, ie these references can change due to different working positions or the mirror-symmetrical design or the like.

In Figure 1, the reference numeral 1 designates an embodiment variant of a drive unit.

The drive unit 1 essentially consists of a plunger arrangement 2 with a plunger 22, which is arranged in a working space 22 of a plunger housing surrounding the plunger 22 so as to be movable back and forth axially in the direction of its longitudinal axis, coaxially in the embodiment shown. The plunger 22 with the plunger housing 23 is accommodated in a plunger frame 10.

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.

A crankshaft 12 or the like is preferably connected in the area of one end of the plunger 22, so that the direct or indirect drive of a consumer is made possible by the movement of the plunger 22. The crankshaft 12 is coupled to the plunger 22 via a connecting rod 13 and a coupling piece 14 fastened to the connecting rod 13.

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 converts the energy released by the relaxation of the high-pressure fluid into electrical current.

The first working chamber 21 of the plunger arrangement 2 is connected to a high-pressure line 8 arranged in a connecting frame 9, which in turn opens into a valve housing 3.

The valve housing 3 has, as shown in Figure 1, 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 fastened to the housing body 33 of the valve housing 3.

The housing body 33 of the valve housing 3 itself also has a low-pressure connection 32.

A valve seat ring 4 is arranged in a cavity of the housing body 33.

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.

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.

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.

The inlet valve 5 is opened by the movement of the outlet valve 6.

The opening and closing of the outlet 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 inlet valve 5 is not provided.

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, block or release the flow of the fluid.

In the embodiment shown here, the outlet valve 6 has a tappet 61 protruding into the second working chamber 41, on the outer surface of which a first sealing surface 614 is formed, which in the closed position of the tappet 61 lies directly on the sealing surface 431 of the low-pressure valve seat 43, ie to seal the second working chamber 41 to the low-pressure side, the tappet 61 lies directly on 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 with a second cylindrical tappet section 613 extending in the direction of the low-pressure connection 32.

An end face 611 of the tappet 61 is adapted to a contact surface of a closing body 51 of the inlet valve 5.

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 is sealed by an elastically deformable low-pressure seal 15.

The low-pressure seal can also be designed as a labyrinth seal to reduce the friction component of the valve circuit.

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. As can be seen in Figures 2 and 3, this low-pressure section extends above the low-pressure valve seat 43 in the direction of the low-pressure connection 32 and beyond this into the area of the housing body 33 that guides the tappet 61.

The closing body 51, which is preferably spherical in shape here, is pressed against the contact surface 611 of the plunger 61 from the side facing away from the plunger 61 by an energy storage holder prestressed by a compression spring or another energy storage device 54.

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.

If the compressed air is released again to open the outlet valve 6, the plate 71 driving the tappet 61 in the design variant shown here pressed back into its original position against the cover 73 by a compression spring 74.

The valve control unit 7 preferably has a housing part 72 with an internal thread that 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.

As an alternative to the spherical closing body 51, a cylindrical or conical closing body 51 is also conceivable.

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 holder 56 in a valve holding body 55.

In a conceivable embodiment variant in which the closing body 51 is connected directly to the tappet 61, an energy storage device 54 is not necessarily required. Here, the compression spring 74 acting on the plate 71 of the valve control unit 7 can take over this function.

The closing body receptacle 56 is fluidically connected to the high-pressure connection 31.

The fluid under high pressure 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 against 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.

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.

This means that within the high-pressure area, no elastic sealing elements are installed, which would lead to pressure-dependent friction and thus negatively influence the switching times of the valves. In order to drive the plunger 22 from its top dead center, shown in Figure 1, in the first working chamber 21, the inlet valve 5 must be opened.

To open the inlet valve 5, the tappet 61 is pressed against the closing body 51 and presses the closing body 51 against the force of the energy accumulator 54 downwards away from the sealing surface 421 of the high-pressure valve seat 42.

The inlet valve 5 is opened by the movement of the outlet valve 6.

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 .

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 its movement with the aid of the high-pressure fluid supplied to the first working chamber 21.

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 fluid under low pressure 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 has been driven.

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.

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, whereby the closing body 51 is pressed away from the sealing surface 421 of the high-pressure valve seat 42.

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, particularly in the form of elastic sealing lips or labyrinth seals, can be completely dispensed with.

The outlet valve 6 can preferably be controlled pneumatically, electrically or hydraulically.

The drive unit 1 described above can be used in a first application for energy recovery in a hydraulic process structure 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.

In a second use of the drive unit 1, a mechanism that uses the rotary motion transmitted to the crankshaft is coupled via the crankshaft 12. The mechanism that uses the rotary motion can be, for example, a pump in which the plunger of the pump is coupled to the crankshaft 12.

Other consumers for using the kinetic rotational energy generated by the drive unit 1 are also conceivable.

List of reference symbols

1 drive unit

2 Plunger arrangement

21 first workroom

22 Plungers

23 Plunger housing

3 Valve housing

31 High pressure connection

32 Low pressure connection

33 Housing body

34 Flange

4 Valve seat ring

41 second workroom

42 High pressure valve seat

421 Sealing surface

43 Low pressure valve seat

431 Sealing surface

44 ring bodies

45 Cross hole

5 Inlet valve

51 Locking body

511 second sealing surface

52 Passage opening

53 pen holders

54 Energy storage

55 Valve retaining body

56 Locking body holder

6 Exhaust valve

61 Tappet

611 Front face

612 first tappet section

613 second tappet section

614 first sealing surface 7 Valve control unit

71 plates

72 Flange 73 Cover

74 compression spring

75 Compressed air inlet

8 High pressure line 9 Connecting frame

10 plunger frames

11 frames

12 Crankshaft

13 Connecting rod 14 Coupling piece

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 this and a low-pressure valve seat (43) open to this,

- 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) can be coupled to a consumer. Drive unit (1) according to claim 1, characterized in that the outlet valve (6) has a tappet (61) protruding into the second working chamber (41) with a first sealing surface (614) which, in the closed position of the tappet (61), rests 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), rests 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 portion 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 a low-pressure seal (15) which is elastically deformable 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 storage device (54), in particular in the form of a compression spring, which presses the closing body (51) into its closed position.

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 which 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), each of the plungers being assigned an inlet valve (5) and an outlet valve (6). Use of a drive unit (1) for energy recovery in a hydraulic process structure, 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 structure 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 using the rotary movement transmitted to the crankshaft.