EP0329208A2 - Hydraulically driven high-pressure cleaner - Google Patents

Abstract

The hydraulically driven high pressure cleaner has a minimum of three pistons (2) acted on by hydraulic oil, which act against a second fluid to be displaced. Each piston (2) has a synchronising rod (6) which acts against a rotary device (9-12), whose rotation is caused by the axial movement of the synchronising rods (6). The rotary device (9-12) drives a control gear (22, 51) which controls the hydraulic oil to the pistons (2) acted on by hydraulic oil and away from these, thereby generating their axial movement. <IMAGE>

Description

The invention relates to a hydraulically driven high-pressure cleaner with at least three pistons, on one side of which hydraulic oil is applied, which on the other side act on a second liquid to be displaced in a continuous manner, e.g. for the purpose of high pressure cleaning.

Pressure washers of the entire genus are known. These include a plurality of hydraulic pistons that drive a control in the middle and from there a plurality of water pistons that are connected to the hydraulic pistons. Since the use of external rubber seals to seal the pistons is required, a large installation diameter is required. Since in such cases the control system must be arranged between the piston surface acted on by the oil hydraulics and the water side, the radially required installation space is very large, especially since it increases quadratically with the radius; the longitudinal installation space is also increased as a multiplier of the stroke required as a result of the additional installation space, which leads overall to a large weight and volume of the machine. These problems become particularly clear when the synchronization forces are determined, for example from piston friction, Sealing friction and other friction such as from bearings and hydraulic forces, which are necessary to overcome the compression oil enclosed in the dead center in the cylinder. As a general empirical value, it has been found that the rotating device and its bearings and / or sliding parts have to be designed very large in relation to the piston and seal diameters, a further mechanical reinforcement being required in the event of alternating loads. Overall, no generic devices have yet been produced in series, but only "conventional designs", i.e. Devices with hydraulic motor, hydraulic control elements, couplings, water pump, water-side control devices, mounting frame, cover, etc., because the technical difficulties with previous, generic devices were too great.

The invention aims to design a generic cleaning device in an extremely light, compact and yet reliable manner in order to enable simple use with forklifts, agricultural tractors, construction machinery, trucks with on-board hydraulics, concrete mixers, etc.

This aim is achieved according to the invention in that a synchronizing rod (6) is arranged on each oil side of an axially movable and oil-hydraulically driven piston (2), which is connected to a rotating device (9-12) driving it so that the axial movement of the pistons ( 2) is converted into a rotary movement of the swash ring (12), the rotary device (9-12) driving a controller (22) which controls the hydraulic oil to and from the piston (2) in such a way that their axial movement is generated.

As a result of this arrangement, the rotating device (9-12) and the control (22, 51) can be radially enlarged considerably and housed in a freely available space which is usefully formed by the common circumferential circle of all pistons, including their seals. As a result, in turn, you can the piston-cylinder-seal arrangements are placed next to each other as possible, so that a large rotating device (9-12) and control (22, 51) can be freely designed in such a way that the high synchronization forces are absorbed reliably.

As a further result of the concept of the invention, the axial forces driving the rotating device (9-12) and control (22, 51) occur mainly as pulling forces only in one working direction, so that dangerous alternating forces are avoided and the machine life is thereby considerably increased.

As a further result, the machine can be arranged so compactly with all internal parts so close together that all oil-hydraulic and water-side control elements can be housed so close together in the cylinder block (1) or valve block (50) that external piping, connecting pieces, assembly arrangements etc. can be avoided in favor of a totally integrated design.

The overall result is that the machine according to the invention is so compact, light and yet reliable that simple work with forklifts, agricultural tractors, construction machinery, trucks. With working hydraulics, concrete mixers etc. is possible as a small and handy implement.

• Fig. 1 einen Längsschnitt durch einen erfindungsgemäßen Hoch­druckreiniger;
• Fig. 2 einen Schnitt längs der Linie II-II der Fig. 1;
• Fig. 3 einen Längsschnitt einer alternativen Ausführung des Erfindungsgedankens;
• Fig. 4 einen Gewichts- und Volumenvergleich einer konventionellen Maschine im Vergleich mit einem realisierten, erfindungs­gemäßen, hydraulisch angetriebenen Hochdruckreiniger

The accompanying drawings illustrate the invention and show:

• 1 shows a longitudinal section through a high-pressure cleaner according to the invention.
• Fig. 2 is a section along the line II-II of Fig. 1;
• 3 shows a longitudinal section of an alternative embodiment of the inventive concept;
• Fig. 4 shows a weight and volume comparison of a conventional machine in comparison with a realized, hydraulically driven high-pressure cleaner according to the invention

The high-pressure cleaner according to the invention shown in FIG. 1 consists of a cylinder block (1) in which pistons (2) driven by oil hydraulics are arranged so as to be axially movable. Pressure oil (23) is fed into the inlet opening (24) and via a connecting channel (25) to a controller (22), i.e. Via the circumferential channel (26), a connecting bore (27) to the pressure kidney (28) and from there to a control bore (29) and from there into the cylinder space between the right end of the piston (2) and the left end of the synchronizing rod (6) .

As a result of this arrangement, when pressure oil is introduced, the piston (2) moves to the left, generates a pulling force on the rotating device (9-12) via the synchronizing rod (6), causing the swash ring (12) to rotate due to its one-sided inclined surface .

Perforated disc (9) is rotatably supported in the swash ring (12) by means of an inner bearing (11) which is held by circlips (16, 17). Swash ring (12), on the other hand, is rotatably held on the outside by means of an outer bearing (13) between the cylinder block (1) and cover (14), and on the inside by means of a locking ring (15). As soon as the synchronizing rod (9) is under tensile force, the swash ring (12) is set in rotary motion because of its inclined surface inclined to the left relative to the axis of rotation, which is on the drive shaft (19) by means of bolts (20) and from there to the control (22) by means of bolts (21) is transferred.

As soon as pressure oil (23) is fed into the inlet (24) and via the control (22) to the oil side of the piston (2), the piston (2) and synchronizing rod (6) pull on the perforated disc (9), which causes it to wobble and thereby turn swash ring (12). Since this rotary movement is transmitted to the control (22) via the drive shaft (19), the pressure kidney (28) slides over the control bores (29) so that the cylinders are supplied with pressure oil in succession.

Since opposing control bores (29) connect opposing cylinders to the tank kidney (40), the oil is passed through the connecting bore (41), tumble chamber (42) and connecting duct (43) to the outlet (44), from where it is used as tank oil (45) flows to the tank.

Because of the stroke of a plurality of pistons (2), suction water (30) is sucked into the left-hand cylinder chambers via suction check valves (32) as soon as the piston (2) moves to the right. From there, the water is displaced to the outlet (34) via pressure check valves (33) as soon as the piston (2) is pushed to the left in the direction of the pressure and suction valves (32, 33). Since the driving hydraulic oil (23) is continuously fed into the machine, its inner parts also move continuously, whereby the pressurized water is also continuously displaced preferably by a number of three pistons (2) to the outlet (34).

It is obvious that because of the tumbling of the perforated disc (9) during one revolution, the heads of the synchronizing rods (6) must have the shape of partial balls (8) which are held on the synchronizing rods (6) by locking rings (48). These partial balls (8) are in turn held in an articulated manner in spherical caps (7) which slide a little on the perforated disk (9) in order to compensate for a slight radial path due to the wobble angle of the perforated disk (9).

It is also evident that the end faces (46) of the synchronizing rods (6) must not touch the swash ring (12) at high speed in order to avoid braking. Therefore, according to the invention, a thrust washer (10) must be provided, which e.g. is held by the locking ring (18) and tumbles together with the perforated disc (9).

In order to avoid mixing water and oil, a ventilation duct (5) can be provided which releases any leakage into the atmosphere. Of course, a pressure relief and / or unloader valve can be provided.

The pistons (2) and synchronizing rods (6) can also be connected by a radially and angularly movable joint in order to compensate for manufacturing tolerances and deformations.

If the synchronizing rods (6) are designed to absorb radial forces which result from the inclined position of the perforated disc (9), the piston (2) can remain free of lateral forces, so that a "floating" piston arrangement is possible, i.e. the pistons are only guided in the seals (3, 4) and / or relatively narrow guides of the cylinder block (1) and / or guide rings located therein.

Of course, the controller (22) can be replaced by any other controller, e.g. described in: "2nd Fluid Power Symposium, January 1971, Paper E4, BHRA, Cranfield, Bedford, England."

Fig. 3 shows another embodiment of the invention, according to which the control (22) is replaced by a mushroom head (51) which is balanced by a compensating head (52) and is sealed in perforated disc (9) by means of seals (53, 54) and is pressed onto its counter surface by compression spring (55).

The direct contact of end faces (46) of the synchronizing rods (6) with respect to the thrust washer (10) is replaced by flat partial balls (56) which distribute any pressure surges over the thrust washer (10). In this case, the piston (2) is stepped into an oil piston (57) and a water piston (58) in order to increase the water pressure compared to the oil pressure in accordance with the surface conditions. The pressure relief or unloader valve (38) is replaced by a pressure control valve (59).

Figure 3 further shows an oil unloader (61-64) controlled by the water pressure spool system (70-74).

When the pressure is released, the oil pressure from chamber (65) acts on a ball (62) which opens against the force of spring (71), the force being transmitted via the water piston (72) and oil piston (63), so that the oil flow is largely depressurized discharges into channel (67). If the water pressure increases, the resulting force of the water piston (72) is added to the spring force so that the ball (62) is pressed more firmly into its seat in the insert (61) until the ball closes completely at maximum pressure. When the pressurized water (75) is shut off (e.g. by releasing a spray gun), the pressure control valve (59) opens so that high pressure is maintained in the outlet (75) and chamber (76) while chamber 77 is depressurized. As a result, the water piston (72) remains in its left position against the force of the spring (71) and full oil relief occurs because the ball (62) can move freely to the left.

It must be explicitly stated that ball (62) can also be made to work in the opposite direction, i.e. by moving the ball seat to the other side of the ball. Of course, other directional control valves with piston tappets instead of balls can also be used.

4 finally shows a comparison of conventional machines with regard to size or construction volume and weight W2 compared to the device according to the invention.

It is obvious that conventional machines of known design cannot be used in general on the aforementioned vehicles, e.g. Forklifts, construction machinery, trucks, etc.

Furthermore, it is obvious that the piston axes of the machine according to the invention do not have to be parallel, but can also be arranged on a conical pitch circle (cone jacket).

It goes without saying that the water-side piston part and the oil-side piston part can be completely separate, but can also be made of one piece and coated. The water-side piston part can be sealed by two soft seals, the space between which is connected to the suction side. This can also be done on the oil side.

Of course, all known hydraulic elements such as pressure relief valves, flow regulators, oil unloaders, check valves, seals etc. can be used together with the high-pressure cleaner according to the invention or in this itself. The same applies to the water-side controls.

A wide variety of other modifications and improvements to the invention are also possible and obvious in light of and incorporating the above description. In this respect, the above description is not intended to limit the inventive concept, but merely to explain it by way of example using two exemplary embodiments.

Claims (18)

1. Hydraulically driven high-pressure cleaner with at least three pistons, on one side of which hydraulic oil is applied, which on the other side act on a second liquid to be displaced in a continuous manner,
characterized by
that on each oil side of a hydraulically driven piston (2) a synchronizing rod (6) is arranged, which is drivingly connected to a rotating device (9-12) so that the axial movement of the pistons (2) into a rotary movement of the swash ring (12) is implemented, the rotating device (9-12) driving a control (22 or 51) which controls the hydraulic oil to the pistons (2) and away from them again so that their axial movement is generated. 2. High-pressure cleaner according to claim 1, dg that a joint between the hydraulic oil-loaded piston (2) and its synchronizing rod (6) is arranged so that a small radial and angular movement between the piston (2) and synchronizing rod (6) is possible . 3. High-pressure cleaner according to claim 2, d.g. that an inner locking ring in an oil-side hole of the piston (2) is arranged so that it holds the joint parts and the synchronizing rod (6) with a positive fit. 4. High-pressure cleaner according to claims 2 or 3, d.g. that between the piston (2) and synchronizing rod (6) an elastic part is arranged so that the joint and the synchronizing rod (6) is pressed against the locking ring within the piston bore. 5. High-pressure cleaner according to one of claims 1 to 4, dg that the piston (2) has different diameters depending on its water-side and its oil-side end. 6. High-pressure cleaner according to one of claims 1 to 5 d.g. that the piston (2) through its seals (3, 4) and / or their support rings. 7. High pressure cleaner according to one of claims 1 to 6, d.g. that at least a first liquid side of a piston (2) is sealed by at least two seals, the at least one intermediate space of which is connected to the low-pressure region of the first liquid. 8. High-pressure cleaner according to one of claims 1 to 7, d.g. that a controller (22, 51) is moved by a wobble ring (12). 9. High-pressure cleaner according to one of claims 1 to 8, d.g. that a control (51) through a perforated disc (9) is moved to wobble. 10. High-pressure cleaner according to one of claims 1 to 9, d.g. that the center lines of the pistons (2) lie on a cone jacket. 11. High-pressure cleaner according to one of claims 1 to l0, d.g. that a water-controlled water control piston (72) is arranged in the water-side valve block so that it actuates a hydraulic valve (61 - 64) arranged in the cylinder block (1). 12. High-pressure cleaner according to claim 11, d.g. that the hydraulic valve (61-64) leaves the hydraulic oil at least largely depressurized, as long as high pressure water is only present at the outlet 75. 13. High-pressure cleaner according to one of claims 1 to 11, d.g. that all hydraulic and / or all water-side valve elements are arranged within the housing of the high-pressure cleaner. 14. High-pressure cleaner according to one of claims 1 to 13, dg that the free ends of the synchronizing rods (6) each contain a partial ball (56). 15. High-pressure cleaner according to one of claims 1 to 14, i.e. the wobble ring (12) contains an axis of rotation parallel to the outer diameter and an axis of rotation inclined thereto. 16. High-pressure cleaner according to one of claims 1 to 15, d.g. that the swash ring (12) touches at least one outer and at least one inner bearing. 17. High-pressure cleaner according to one of claims 1 to 16, d.g. that between the free end of the synchronizing rods (6) and the inner bearing (11) of the swash ring (12), a thrust washer (10) is arranged. 18. High-pressure cleaner according to one of claims 1 to 17, d.g. that the hydraulic valve (61 - 64) closes at high pressure acting only in the water outlet (75).

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