WO1990002879A1

WO1990002879A1 - A pumping device, in particular high-pressure pump

Info

Publication number: WO1990002879A1
Application number: PCT/DK1989/000209
Authority: WO
Inventors: Karl Johan Klitgaard Frandsen
Original assignee: K.F. Industri A/S
Priority date: 1988-09-09
Filing date: 1989-09-08
Publication date: 1990-03-22
Also published as: DK164133B; AU4226289A; DK500188D0; DK164133C; EP0433344A1; DK500188A

Abstract

In a pumping device, in particular a high-pressure pump, comprising a pump body (16) with a number of pumping chambers (38) with corresponding displacement organs between a low-pressure part (10) where the pumped medium, for example water, is supplied, and a high-pressure part (14) with a discharge connection to a utility tool, for example a hand-operated jet pipe, the device preferably comprising a motor unit (4) and possibly a clutch (6), the low-pressure part (10) comprises a cylindrical cavity (22) wherein a rotor with peripheral displacement organs is eccentrically journalled in such a way that the displacement organs may successively cooperate with the pumping chambers (38) which are formed in the pump body (16) along the periphery of the cavity (22), and which are connected to the high-pressure part (14) via one-way valves (42).

Description

A PUMPING DEVICE, IN PARTICULAR HIGH-PRESSURE PUMP

The present invention relates to a pumping device, in parti¬ cular a high-pressure pump, comprising a pump body with a number of pumping chambers with corresponding displacement organs between a low-pressure part where the pumped medium, for example water, is supplied, and a highpressure part with a discharge connection to a utility tool, for example a hand-operated jet pipe, the device preferably comprising a motor unit and possibly a clutch.

Such high-pressure cleaners are known in numerous designs for leisure-time purposes, but in reality it is often a que¬ stion of downward-dimensioned and equipment-wise simplified versions of high-pressure cleaners for professional use, that is to say that known high-pressure cleaners for hobby use are encumbered with largely the same disadvantages as high-pressure cleaners for professional use - including a relatively high price. Of other disadvantages may be empha¬ sized that most high-pressure cleaners of this type include an electric motor which then requires connection facilities for supply of electricity, and which in view of various wa¬ ter connections also requires strongly cost-raising but en¬ tirely necessary security systems. The functioning of those meanwhile additionally depends on that the electric instal¬ lation on site includes approved safety relays which unfor- tunately is not always the case, which means that often the¬ re is a certain risk in using known high-pressure cleaners of the type mentioned.

It is a purpose of the invention to provide a pumping device of the kind mentioned initially, and which encompasses a significant simplification equipment-wise and technically which moreover results in a more simple operation - even at strongly reduced manufacturing costs which in the end means a significant reduction in price. The pumping device according to the invention is distinctive in that the low-pressure part comprises a cylindrical cavity wherein a rotor with peripheral displacement organs is ec¬ centrically journaled in such a way that it may successive- ly cooperate with the pumping chambers which are formed in the pump body along the periphery of the cavity, and which are connected to the high-pressure part via one-way valves. In this way one may in a simple manner obtain a significant simpli ication equipment-wise and technically which moreover results in a more simple operation - even at strongly redu¬ ced manufacturing costs which in the end means a significant reduction in price.

The invention builds on a technique according to which a fast-running rotor by means of an eccentric successively cooperates with generally radial pumping chambers placed a- long the periphery of a cylindrical cavity, which constitu¬ tes the low-pressure part of the pumping device, and which is supplied with the pumped medium, for example water. The pumping chambers are all connected to a common high-pressure part which is formed at a cylindrical outer side of the pump body, and which is enclosed by a jacket part which moreover forms a closure for the low-pressure part, and which is fa¬ stened at the outer side of the pump body in a detachable way, for example by means of a number of bayonet locks.

The mentioned displacement organs are either constituted by inelastic parts of the pumping chambers, for example entran¬ ce parts thereof, and by outer elastic parts of the rotor, or by elastic parts of the pumping chambers, for example entrance parts thereof, and by inelastic parts of the rotor, the pumped medium, for example water at water company pres¬ sure, being supplied to the cylindrical cavity - the low- pressure part which then is entirely filled with water a- round the rotor. When the latter is rotated and rolls along the cylindrical outer wall of the low-pressure part, small portions of water will successively become confined in the pumping chambers and will become compressed therein as the effective volume of the pumping chambers is reduced during the passage of the rotor. By rotating the rotor at high speed, for example 5 - 15.000 rpm, a high pressure will be built up in the high pressure part as long as water is disc¬ harged therefrom. If, conversely, there is not discharged water from the high-pressure part, the rotor will only roll inactively on a water film along the outer wall of the low- pressure part - corresponding to an idling situation.

Expediently the pump body of the pumping device is in two parts, comprising an outer cylindrical, thin-walled jacket part and an inner housing part, likewise cylindrical, which jacket part at one side is arranged to be introduced around the inner housing part and to be secured thereto in a li- quid-tight manner while at the opposite side the jacket part is provided with a supply connection for the pumped medium, and that the cylindrical housing part at an end is provided with a central shaft guide for a shaft which is connected with an eccentric for the said rotor provided in said cavi- ty, the latter being open towards the opposite side of the housing part, that is towards the jacket part which further¬ more opposite the part thereof which surrounds the inner housing part is provided with the said discharge connection.

In a particularly simple way the pumping device according to the invention can be constituted such that the said one-way valves which connect the pumping chambers with the highpreε- βure part are constituted by radial bores opening into the bottom of the circumferential channel and by an elastic ring-shaped body which is placed at the bottom of the chan- nel, for example a divided metal band with springs or an o- ring.

In the following the invention will be more closely explai¬ ned with reference to the drawing, wherein:- Fig. 1 shows the application of a portable embodiment of a pumping device according to the invention,

Fig. 2 shows a corresponding embodiment of a pumping device according to the invention - provided with a combustion en- gine - and seen from the side.

Fig. 3 shows an end view of the pumping device according to the invention as shown in Fig. 2,

Fig. 4 is an end view - part in section - of an embodiment of a pump part for the pumping device according to the in- vention, while

Fig. 5 is a side view - part in section - of the pump part shown in Fig. 4.

As shown in Fig. 1 - 3 the idea is primarily that the pum¬ ping device according to the invention is manufactured as a rather small portable pumping device which, when provided with a combustion engine, can be used entirely independent from external supplies of energy, that is, a relatively light and compact device which can be used anywhere and for every imaginable purpose including the operation of connec- ted utility tools^" which can be driven by pressurized liquid, and which can be controlled solely by on/off-regulation of the flow of liquid on the high-pressure side of the pumping device. Possibly a clutch 6 is inserted between a pumping u- nit 2 and a motor unit 4, for example a common centrifugal clutch comprising a clutch dome connected to the pumping u- nit 2 and a device of swivel shoes connected with the motor unit 4. The pumping unit 2 has a hose connection 8 for supp¬ ly of a pressure medium, for example water at water company pressure, to a low-pressure part 10, as well as a discharge connection 12 from a high-pressure part 14 (Fig. 5).

The pumping unit 2 which is shown in greater detail in Fig. 4 and 5, comprises a two-part cylindrical pump body 16, which consists of a body part 18 which at one side is inten¬ ded to be mounted to the motor unit 4, possibly via the clutch 6 as mentioned, and which at the opposite side is e- quipped with a cylindrical cavity 22 wherein a rotor 24 is rotatably journaled in such a way on an eccentric 26 that by rotation of a shaft 28 connected to the eccentric '26 the ro¬ tor 24 can be made to roll on the cylindrical inner wall 23 of the cavity 22. The latter, which constitutes the low-- pressure part 10 of the pumping unit, is open outward to¬ wards a jacket part 30 which is introduced around the hou¬ sing part 18 and connected therewith in a liquid-tight man¬ ner at an outer cylindrical face 32 of the housing part 18, the jacket part 30 moreover being fastened to the housing part 18 by means of a number of bayonet locks 34. Between the inner side of the jacket part 30 and the cylindrical fa¬ ce 32, O-ring seals are provided at both sides of a circum¬ ferential channel 36, the channel 36 constituting the said high-pressure part 14. Opposite the low-pressure part 10 the jacket part 30 is as already mentioned - provided with the hose connection 8 for supply of water to the cavity 22 such that the rotor 24 can be entirely surrounded by pressure me¬ dium - water.

In the housing part 18, between the low-pressure part 10 and the high-pressure part 14, pumping chambers 38 are formed, with equal mutual distances, along the cylindrical inner wall 23, the pumping chambers inwardly being adapted to coo¬ perate with the rotor 24 and outwardly being connected with the channel 35, that is, with the highpressure part 14 via radial channels 40 and one-way valves 42 which preferably a- re constituted by openings of the channels 40 and a strong elastic ring body 44 which is provided at the bottom of the ring channel 36 around the housing part 18.

In Fig. 4 four pumping chambers 38 are indicated along the periphery of the cylindrical cavity 22, and the rotor 24, which in the embodiment shown consists of elastic material, for example rubber, is correspondingly shaped with three projections 46, the circumference of the rotor 24 being 3/4 of the circumference of the cylindrical inner wall 23, which is to say that the pumping chambers 38 are mutually shifted by 90° along the inner wall 23 while the projections 46 on the rotor 24 ar mutually shifted by 120° along the circumfe¬ rence of the latter. It is thus assumed that no slippage of any significance occurs between the rotor 24 and the inner wall 23 of the low-pressur part 10 or cavity 22; but natu¬ rally there is nothing to prevent the provision of active steering organs, for example in the nature of a toothed rim and gear wheel, between the rotor 24 an the inner wall 23.

Eventually such a steering gear-rim could be combined with a fixed stator ring which is adapted to be fastened along the cylindrical inner wall 23 and which adjacent to the pumping chambers 38 is provided with special elastic entrance parts which would become deformed by the passage of a rotor part of inelastic material, with a view to an effective reducti- on of the pumping chamber volume and corresponding compres¬ sion of the pressure medium confined within the pumping chamber.

It should be emphasized that in the pumping device according to the invention one operates with a very small effective volume of the individual pumping chambers, in the order of magnitude of about 0,3 - 0,6 cm-2. On the other hand one works with a relatively high speed of revolution of the ro¬ tor 24 in the order of magnitude of about 5 - 15.000 rpm and preferably without any transmission between the pumping unit and the motor unit.

Moreover it is expected that corresponding utility tools, including hand-operated jet pipes, do not need to include pressure reduction valves but can be operated by means of a simple on/off-regulation via a direct hose connection from the mentioned discharge connection.

Claims

C A I S :

1. A pumping device, in particular high-pressure pump, com¬ prising a pump body with a number of pumping chambers with corresponding displacement organs between a low-pressure part where the pumped medium, for example water, is suppli¬ ed, and a high-pressure part with a discharge connection to a utility tool, for example a hand-operated jet pipe, the device preferably comprising a motor unit and possibly a clutch, c h a r a c t e r i z e d in that the low-pressure part comprises a cylindrical cavity wherein a rotor with peripheral displacement organs is eccentrically journaled in such a way that the displacement organs may successively cooperate with the pumping chambers which are formed in the pump body along the periphery of the cavity, and which are connected to the high-pressure part via one-way valves.

2. A pumping device according to claim 1, c h a r a c t e ¬ r i z e d in that the number of displacement organs is smal¬ ler than the number of pumping chambers.

3. A pumping device according to claim 1, c h a r a c t e - r i z e d in that the displacement organs are constituted by inelastic parts of the pumping chambers and by outer elaε.tic parts of the rotor .

4. A pumping device according to claim 1, c h a r a c t e ¬ r i z e d in that the displacement organs are constituted by elastic parts of the pumping chambers and by inelastic parts of the rotor.

5. A pumping device according to claim 1, c h a r a c t e ¬ r i z e d in that the pump body is in two parts, comprising an outer cylindrical, thin-walled jacket part and an inner housing part, likewise cylindrical, which jacket part at one side is arranged to be introduced around the inner housing part and to be secured thereto in a liquid-tight manner whi- le at the opposite side the jacket part is provided with a supply connection for the pumped medium, and that the cylin¬ drical housing part at an end is provided with a central shaft guide for a shaft which is connected with an eccen*ric for the said rotor provided in said cavity, the latter being open towards the opposite side of the housing part, that is towards the jacket part which furthermore opposite the part thereof which surrounds the inner housing part is provided with the said discharge connection.

6. A pumping device according to claims 1 and 5, c h a ¬ r a c t e r i z e d in that at its exterior the inner hous¬ ing part is provided with a circumferential channel which constitutes the mentioned high-pressure part, the circumfe¬ rential channel being enclosed in a liquidtight manner by the said jacket part wherein the discharge connection is found.

7. A pumping device according to claims 1 and 5, c h a - r a c t e r i z e d in that the said one-way valves which connect the pumping chambers with the high-pressure part are constituted by radial bores opening into the bottom of the circumferential channel and by an elastic ring-shaped body which is placed at the bottom of the channel, for example a divided metal band with springs or an o-ring.