GB2029505A

GB2029505A - A cleaning appliance pump assembly

Info

Publication number: GB2029505A
Application number: GB7926160A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-07-26
Filing date: 1979-07-26
Publication date: 1980-03-19
Also published as: DE7920974U1; SE440817B; JPS5559874A; BR7904771A; GB2029505B; FR2433653B3; SE7906241L; DK311179A; DE2929652C2; DE2929652A1; FR2433653A1

Abstract

A cleaning appliance pump assembly (1) comprises a housing (22) of substantially liquid tight construction and containing a pump (10) for pumping a cleaning liquid, an electric motor (9), a shaft (11) drivably connecting a rotor (19) of the motor (9) and the pump (10), an electrically non-conductive cooling liquid, e.g. oil, covering the motor (9) and the pump (10), impeller means to circulate the cooling liquid within the housing 22 and heat exchange means to facilitate heat exchange between the cooling liquid and the cleaning liquid. <IMAGE>

Description

SPECIFICATION A cleaning appliance The present invention relates to a cleaning appliance for use in for example the wet cleaning of building walls and floors, swimming pools, motor cars or the like.

Cleaning appliances in the form of high pressure spray units are known to be used for the most diverse purposes. Stationary appliances may be used in motor vehicle washing installations and movable or drivable constructional units may be used in the wet cleaning of the walls and floors of buildings, for example stables, and also any other desired articles or equipment, such as for example synthetic material surfaces, tarpaulins, swimming pools or the like. In accordance with the intended purpose, water serving as the cleaning or washing liquid may be provided with appropriate additives, for example alkaline or acid cleaning, corrosion protecting, lubricating or washing means. The spraying of the cleaning or washing liquid takes place at least in the case of the movable and smaller appliances by means of manually guided liquid jets, especially spray pistols.Especially in the case of stationary appliances spraying may be effected by means of locally fixed nozzles or the like, which are connected to an outlet duct of a high pressure unit by means of a flexible duct or a hose.

The known cleaning appliances have the serious disadvantage that they are complicated by reason of their constructional concepts and therefore have relatively large dimensions as well as a high overall weight in relation to their performance. Although this disadvantage occurs in locally fixed or stationary cleaning appliances, for example for motor vehicle washing plants, this disadvantage is particularly serious in appliances which in accordance with their intended purpose must be transportable, for example for the house for private use.

The reason for the relatively voluminous and heavy mode of construction of the known cleaning appliances is because three-piston plunger pumps with a serial piston arrangement are as a rule used for the production of the high pressure jet and the drive takes place through a motor separated from the pump, wherein the load transfer between motor and pump as a rule leads to further constructional complexities. This build-up usually also forces both parts of the high pressure unit to be provided with a correspondingly projecting and expensive cladding.

The electrical motors usually employed for this purpose in consequence of their air cool ing require complicated and larger housings and produce loud noises which cause a nuisance in continuous operation. In so far as squirrel-cage motors are used in that case, these have the disadvantage that they can overload the pumps by means of their stalling torque and in consequence require additional pressure protections. The stalling torque of air-cooled squirrel-cage motors can be used for only a short time, but not in continuous operation for the driving power of the pump.

For the stated reasons, the known cleaning appliances of the aforedescribed species have not only a complicated and correspondingly expensive construction, relatively large dimensions and a correspondingly great weight, but are also expensive to buy and keep, so that they are not suitable for private and domestic use.

According to the present invention there is provided a cleaning appliance comprising a housing of substantially liquid-tight construction and containing a pump for pumping a cleaning liquid, an electric motor, a shaft drivably connecting a rotor of the motor and the pump, the motor and the pump in use being substantially submerged in an electrically non-conductive cooling liquid, the housing further containing impeller means to circulate the cooling liquid within the housing and heat exchange means to facilitate heat exchange between the cooling liquid and the cleaning liquid.

The cooling liquid, which is enclosed in the working space as well as flowing around the pump and the motor, makes it possible to load the electrical motor, especially a squirrelcage motor, more highly and in continuous operation than would be permissible with conventional air-cooled electrical motors.This may be assured thereby, that the cooling liquid within the closed working space is subjected to a constant forced circulation by impelling means associated with the rotating part and thereby, that the parts of the pump lying free relative to the cooling liquid within the working space as well as its feed and outlet ducts in consequence of their being acted on inside by cold cleaning or washing liquid flowing through, form heat exchange surfaces of relatively large area, which may be prolonged or enlarged within wide limits without increase of the constructional dimensions or of the constructional effort in so far as this is required.

It has surprisingly been proved that it is possible to build a cleaning appliance of usual performance category with a spray water pressure of 200 or 250 bar so small that it only has the height of a water bottle conventionally used in trade with a liquid content of one litre.

To produce the stated spraying pressure, it was hitherto required to use an electrical motor for a nominal performance of about 5 kilowatts, where against it is possible to con struct embodiments of the present invention with a substantially smaller electrical motor having a nominal performance of 1.5 kilow atts.

Apart from the comparison of size, the comparison of weight is of appreciable significance. Whilst in conventional cleaning appliances the electrical motor with a nominal performance of 5 kilowatts has a weight of 35 kilograms, an appliance embodying the present invention may have a weight of only 23 kilograms so that it can be an easily manipulatable high performance appliance, particularly transportable by hand.

It has proved preferable to use oil as the cooling liquid, particularly since the cooling liquid in this case can at the same time serve as lubricant for the rotating and moved parts of the pump.

A squirrel-cage motor may be used which is undersized in its nominal output relative to the load requirement of the pump determined by the production of the pressure jet of the cleaning or washing liquid by such an amount that it is in full load operation loaded in the loading range near its stalling torque with corresponding drop in rotational speed. This is the case when an electrical motor with a nominal performance of only 1.5 kilowatts with correspondingly smaller constructional dimensions is utilized instead of a squirrel-cage motor with a nominal performance of 5 kilowatts hitherto required for the same pump performance.

Although the pump needed for the build-up of the required jet pressure can be of different mode of construction, it is particularly expedient to construct this as radial piston pump, since it can be best adapted to the housing cross-section even with higher performance without having too great an axial length.

In order to improve the forced circulation of the cooling liquid in the common working space of electrical motor and pump in the interest of as intensive as possible a heat exchange, it can in many cases suffice to provide the rotating parts, particularly of the electrical motor, with vanes.

The shaft may be provided with an axial induction channel as well as at least one transverse bore connected to this for the forced circulation of the cooling liquid.

The channel may extend continuously over its entire length and, at least at one end e.g.

upper end projecting out above the rotor of the electrical motor, have diametrally opposed transverse bores for the spinning out of the cooling liquid.

The channel may end at the height level of the pump and its upper as well as its lower end is connected to at least two diametrally opposed transverse bores, wherein the transverse bores disposed in the height range of the pump are equipped with spin pipes projecting radially outwards relative to the outside circumference of the shaft in such a manner that the upper transverse bores form induction openings and the openings of the spin pipes form exit openings for the forced circulation of the cooling liquid.

The constant forced circulation, between cold cooling liquid and that heated up in the region of the electrical motor, within the working space is intensified by the stated means additionally thereby, that further liquid-conduction flow channels are provided in the housing wall, in the stator and/or rotor which are expediently so constructed and dimensioned that they in conjunction with the impelling means associated with the rotating parts assure a constant directed circulating motion of the cooling liquid between the regions of the working space disposed above and below the electrical motor.

Although it has proved quite adequate to use only inlet ducts connecting pump cylinders with one another the outlet ducts connecting pump cylinders with one another for the cleaning and cooling liquid as heat exchange surfaces for the heat exchange between the cooling liquid and the cleaning or washing liquid, it can be of advantage artificially to enlarge the cooling surfaces. This can be effected by prolonging or enlarging as well as letting the different ducts into plates, ribs or the like enlarging the cooling surfaces.

For the improvement of the heat exchange the inlet or outlet ducts may be prolonged.

Preferably the inlet duct is prolonged by at least one cooling channel within the housing.

The channel is arranged in the working space filled with the cooling liquid, below the filling level thereof and in the upper region of the electrical motor, and passes directly through the cooling liquid in the working space.

It is possible to increase the prolongation of the cooling duct provided by the cooling channels, possibly thereby, that the cooling channels conducted below the liquid surface in the upper region of the housing through this are constructed to be branched and/or extending in spiral shape or thereby, that they are connected with the pump within the housing wall through several flow channels connected in parallel to them.

Embodiments of the present invention will now be more particularly described by way of example and with reference to the accompanying drawings in which: Figure 1 shows a cleaning appliance in vertical longitudinal section, Figure 2 shows a horizontal cross-section through the cleaning appliance along line ll-ll of Fig. 1, Figure 3 shows a further horizontal crosssection through the cleaning appliance of Fig.

1 along line Ill-Ill, Figure 4 shows a second embodiment of a cleaning appliance in vertical longitudinal section, Figure 5 shows a horizontal cross-section through the cleaning appliance of the Fig. 4 along line V-V, Figure 6 shows a horizontal cross-section through the cleaning appliance of Fig. 4 along the line Vi-Vi, and Figure 7 shows a size comparison of a cleaning appliance embodying the present invention with five different cleaning appliances of the same performance class and electrically operated in conventional manner.

The cleaning appliance 1 shown in the Fig.

1 has a housing 4 comprising of two parts 2 and 3. Both the housing parts 2 and 3 abut against each other along the plane ll-ll, wherein their mutually facing end surfaces can interengage in the manner of a grooveand-key toothing. At least one peripherally continuous seal 5 is however provided.

As seen from Figs. 1 and 2, the fixed connection of both the housing parts 2 and 3 takes place through nuts and bolts 6 spaced about 90 relative to each other, which at the mutually facing end section of the housing parts 2 and 3 pass through radial flanges 7 provided in the region of the plane Il-Il. The housing part 2 has a largely round crosssection, while the cross-section of the housing part 3 is substantially square.

Both the housing parts 2 and 3 enclose a working space 8, which receives an electrical motor 9 constructed as squirrel-cage motor in the upper region and a radial piston pump 10 in the lower region.

The working space 8 is passed through in longitudinal direction by a shaft 11 drilled through axially. The shaft 11 is rotably jour nalled in a radial bearing in a hub 14 projecting inwardly from the upper end wall 13 of the motor housing part 2 and in a combined axial-radial bearing 15 in a hub 17 projecting inwardly from the bottom 16 of the pump housing part 3.

The rotor 19 of the electrical motor 9 is fastened on a length section 18 reduced in diameter, while the stator 20 is located at a step 21 of the wall 22 of the motor housing part 2. The rotor 19 is passed through by longitudinal channels 24, which are arranged in the shaft 11 parallel to the axial bore 23 and which connect the region of the working space 8 above the electrical motor 9 with the region below the electrical motor 9.

The connections for the electrical motor 9 are not illustrated for clarity of the drawing.

Fig. 1 shows that the axial bore 23 in the shaft 11 is closed off in the region of the radial bearing 12 by a plug 25, while it opens out into the working space 8 in the region of the combined axial-radial bearing 15. Transverse bores 26, which connect the axial bore 23 with the working space 8, extend into the shaft 11 above the rotor 19 of the electrical motor 9, but below the radial bearing 12.

A rolling bearing 28, which through its outer ring acts on four pistons 29, displaced through 90 relative to each other, of the radial piston pump 10, is placed on an eccentric section 27 of the shaft 11 disposed at the height range of the pump housing part 3. The pistons 29 are each sealingly guided in a pump cylinder 30. A sealing ring is designated by 31. The pistons 29 stand under the restoring force of helical compression springs 32, which bear against the pump cylinders 30 and against washers 33 influenced by the eccentric bearing 28.

Provided in each of the pump cylinders 30 is a respective induction valve 34 and a pressure valve 35, which through channels 36 and 37 (see also Figs. 2 and 3) communicate with the feed and outlet ducts Z and A, respectively, for the cleaning liquid conveyed by the pump 10. While the pressure channels 37 of the pump 10 form a component of pipe ducts 38 disposed in the bottom region of the pump housing part 3 (Fig. 3), the induction channels 36 are provided in a plate 40 fastened by screws 39 on the pump cylinders 30. An adjustable pressure-limiting valve 41 is connected to the channels 36 and 37 respectively, in the region of the feed and outlet ducts Z and A of the cleaning liquid.

The pressure-limiting valve 41 is disposed in a housing 42 flanged to the pump housing part 3.

The working space 8 is filled up to about the level N above the electrical motor 9 by a cooling liquid preferably formed by oil. This cooling liquid consequently at the same time forms the lubricant for the rotating or moved parts of the pump 10.

Those parts of the pump 10, which are free relative to the cooling liquid in the working space and which are flowed through by the cold cleaning liquid, as well as its feed and outlet channels 36 and 37 form a heat exchanger for the continuous recooling of cooling liquid. The axial bore 23 in the shaft 11 in this connection forms an induction channel for the cooling liquid, while the transverse bores 26 disposed at the upper end of the shaft 11 serve for the forced circulation of the cooling liquid within the working space 8.

The embodiment of the cleaning appliance 1' shown in Figs. 4 to 6 generally corresponds to the embodiment shown in Figs. 1 to 3. The feed of the cleaning liquid to the pump 10 however takes place in the region of the upper end wall 13 of the motor housing part 2. As Figs. 4 and 5 show the cleaning liquid flows through a connecting stub 43 (the connecting stub 43 is shown in Fig. 4 displaced through 1 35' by comparison with Fig.

5) into a tubular cooling channel 44, which at first extends along the wall 22 of the motor housing part 2 through an angle of about 315 in the plane of the connecting stub 43 and adjoining thereto is embedded in a vertical groove 45 of the housing wall 22 peripherally of the stator 20. The cooling channel 44 is in the region of the connecting location of the pump housing part 3 with the motor housing part 2 connected through a flexible connecting part 46 with the channels 36 in the heat exchange plate 40.

A further difference between the embodiment shown in Figs. 4 to 6 from that shown in Figs. 1 to 3 is that vertical channels 47 are provided in periphery of the stator 20 (for this see also Figs. 5 and 6) into the wall 22 of the motor housing part 2 and consequently connect the region of the working space 8 below the electrical motor 9 with the region above the electrical motor 9.

Furthermore, Fig. 4 shows that the bore 23 passing axially through the shaft 11 is blocked off at about the height region of the pump 10. The shaft 11 in about the plane of the plate 40 has transverse bores 51, which are equipped with spin pipes 48 projecting radially relative to the outside circumference of the shaft 11. In this case, the upper transverse bores 26 and the shaft 11 consequently form the induction openings and the openings 49 of the spin pipes 48 the exit openings for the cooling liquid for the purpose of forced circulation within the working space 8.

A further difference from the embodiment shown in Fig. 1 is that vanes 50, which enhance the forced circulation of the cooling liquid are in the embodiment shown in Fig. 4 disposed peripherally distributed on each end side of the rotor 19 of the electrical motor 9.

Fig. 7 shows schematically a size comparison of a cleaning appliance 1 and 1' with five cleaning appliances, operated electrically in conventional manner, of various manufacture F, to F5. The size of each product F1 to F5 is illustrated in different lines. Weight and volume changes are to be inserted at the third power of the linear change.

Also conventional manners of construction of cleaning appliances in part contain appreciable hollow spaces, whilst a compact mode of construction with an optimum utilization of the required space is concerned in the case of the cleaning appliance 1 and 1' embodying the present invention.

Fig. 7 shows that the complete cleaning appliance 1 and 1' embodying the present invention requires far less space and has a substantially lower weight than is allowed solely for the electrical motor without any accessories in the case of conventionally constructed and driven cleaning appliance.

A threaded bore in the end wall 13 for the detachable mounting of a carrier handle 53 (Fig. 7) is designated by 52 in the Figs. 1 and 4.

Claims

1. A cleaning appliance comprising a housing of substantially liquid tight construction and containing a pump for pumping a cleaning liquid, an electric motor, a shaft drivably connecting a rotor of the motor and the pump, the motor and the pump in use being substantially submerged in an electrically non-conductive cooling liquid, the housing further containing impeller means to circulate the cooling liquid within the housing and heat exchange means to facilitate heat exchange between the cooling liquid and the cleaning liquid.

2. An appliance as claimed in claim 1, further comprising a container for the cleaning liquid and means connecting the container to the pump.

3. An appliance as claimed in either claim 1 or claim 2, comprising valve means for controlling the pressure of cleaning liquid issuing from the appliance.

4. An appliance as claimed in any one of the preceding claims, wherein the cooling liquid comprises lubricating oil in contact with moving parts of the pump.

5. An appliance as claimed in any one of the preceding claims, wherein the motor is a squirrel-cage motor.

6. An appliance as claimed in claim 5, wherein the motor has a nominal rating such that on full pump load the motor runs near its stalling torque and at a speed lower than the nominal speed thereof.

7. An appliance as claimed in any one of the preceding claims, wherein the pump comprises a radial pump.

8. An appliance as claimed in any one of the preceding claims, wherein the housing comprises a first part containing the motor and a second part connected to the first part and containing the pump, the shaft having a first axial and portion which carries the rotor of the motor and which is journalled in an axial and radial bearing.

9. An appliance as claimed in any one of the preceding claims, wherein for the circulation of the cooling liquid the shaft is provided with an axially extending duct and at least one transversely extending duct connecting the axially extending duct with the interior of the housing.

10. An appliance as claimed in claim 9, wherein the axially extending duct extends along the entire length of the shaft and the shaft is provided with diametrically opposite transverse ducts disposed between the first axial end part and the rotor of the motor.

11. An appliance as claimed in claim 9, wherein the axially extending duct is connected at the region of the pump to radially extending ducts, the appliance being so arranged that in use the cooling liquid passes from the at least one transversely extending ducts through the axially extending duct and then out of the radially extending ducts.

12. An appliance as claimed in any one of the preceding claims, wherein the pump com prises cylinders interconnected by duct means for the passage of the cleaning liquid, the duct means being provided with convoluted surface portions for promoting the heat ex change between the cooling liquid and the cleaning liquid.

13. An appliance as claimed in any one of claims 1 to 11, comprising duct means provided with an inlet portion, an outlet portion and a further portion between the outlet and inlet portions, the further portion extending within the housing from the region of the motor to the region of the pump.

14. An appliance as claimed in any one of the preceding claims wherein at least one of the housing, the stator of the motor and the rotor of the motor is provided with channel means for the passage of the cooling liquid between mutually opposite ends of the motor.

15. A cleaning appliance substantially as hereinbefore described with reference to Figs.

1 to 3 of the accompanying drawings.

16. A cleaning appliance substantially as hereinbefore described with reference to Figs.

4 to 6 of the accompanying drawings.

17. A cleaning appliance substantially as hereinbefore described with reference to Fig.

7 of the accompanying drawings.