GB2202460A

GB2202460A - Installation for flushing out a unit

Info

Publication number: GB2202460A
Application number: GB08806673A
Authority: GB
Inventors: Narido Palazzini; Andrea Becciu
Original assignee: FiatGeotech SpA
Current assignee: FiatGeotech SpA
Priority date: 1987-03-19
Filing date: 1988-03-21
Publication date: 1988-09-28
Also published as: FR2612602A1; IT1207638B; GB8806673D0; IT8703397A0; DE3808288A1; FR2612602B3

Abstract

An installation for flushing out a unit (5), such as a gear box, comprises a duct (62), the ends of which are demountabiy engaged with an inlet and outlet of the unit (5) into which oil has been preliminarily introduced, pumping means (63) to cause the oil to circulate around the duct (62) and the unit (5), filtering means (65) to retain the impurities leaving the unit (5) in the oil, and means (6) for causing movement of the rotatable parts of the unit (5) while it is being flushed. The oil is initially fed from and subsequently returned to a closed reservoir (Fig. 1), having attached thereto a closed, constant flow filtering and heating circuit (1) and a second circuit (2) which feeds the oil to unit 5 when required via one of demountable couplings (61). Various valves are controlled by push-buttons via pneumatic actuators. <IMAGE>

Description

AN INSTALLATION FOR FLUSHING OUT THE INTERIOR OF A UNIT 22-0246un The

present invention relates to an installation for flushing out the interior of a unit, for example for washing out a tractor gear box unit.

At present, the following process is used for flushing out a unit having rotatable parts. First the unit is filled with oil drawn from a storage vessel by means of a pump, after having been filtered. The quantity of oil to be introduced into the unit is left to the operator to determine visually. Subsequently the unit is positioned on a test bed, and rotatable parts are connected to an electric or hydraulic motor in such a way as to perform a functional test. In this test, because of the movement of the rotatable parts, the oil circulates throughout the whole of the unit. Finally, when the test is terminated, the oil is allowed to fall from the unit into an underlying upwardly open vessel and from this the oil is returned to the storage tank. As it leaves the unit under the action of gravity, the oil also carries with it some of the dust particles, working residues and various contaminants which remain in the unit after its assembly.

The above described method for flushing out a unit under test has several disadvantages.

In particular, because the oil leaves the unit under gravity, it does not carry with it all of the particles, in fact it is found that the heavier particles remain on the bottom wall of the unit and this is evidenced by the fact that, for example, in, the case of tractor gear box units, the filter which is q 'l utilised on the tractor assembly line for the protection of hydraulic actuating circuits with which the tractor is provided is replaced after the test because it is clogged. Moreover, the vessel underlying the unit, to be able to collect the oil falling from it, must be of the upwardly open type. Consequently, dust particles tend to fall into this ve-ssel from the external environment which, being in an assembly line, is particularly polluted. Finally, it is to be noted that after having been utilised for a predetermined number of times the oil in the storage vessel, even if there has been oil added to maintain the level constant, exceeds all limits of tolerability and therefore must be completely replaced with new oil at a not inconsiderable cost in that in some installations the volume of the storage container is in the region of 3, 000 litres.

The subject of the present invention is an installation for flushing out the interior of a unit under test which will be free from the cited disadvantages and which will allow a correct flushing of the unit with a distinctly lower cost than at present.

According to the present invention there is provided an installation for flushing out the interior of a unit under test, characterised in that it comprises a duct, the ends of which are engaged in a respective inlet opening and outlet opening of the unit., into which a predetermined quantity of oil has been preliminarily introduced, first pumping means installed in the duct and operable to cause flushing of the unit by the oil, first filtering means installed in the duct and able to retain the impurities carried by the oil leaving the unit, and means for causing movement of the rotatable parts of the unit.

is An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings, of which:

Figures 1 and 2 are two schematic views of respective parts of an installation for flushing out the interior of a unit.

As illustrated in the attached drawings, the installation comprises three hydraulic circuits respectively indicated with the reference numerals 1, 2 and 3. The circuit 1 (Figure 1) allows a unit 5 having rotatable parts to be filled with oil. The circuit.3 (Figure 2) provides for the flow of oil through the interior of the unit 5 whilst this is under test and the rotary parts thereof are in motion driven by a hydraulic motor 6.

With reference to Figure 1, the circuit 1 comprises two ducts 7 which extend into the container 4 and in each of which is connected a pump 8, for example of the gear type. The pumps 8 are driven by an electric motor 11. The ducts 7 join together in a duct 12 in which is mounted a valve or tap 13 and a manometer 14. The duct 12 divides into two ducts 15 in each of which is fitted a respective filter 16 provided with a valve or tap 17. The ducts 15 then join together into a single duct 18 provided with a valve or tap 20 and a manometer 21, and to which there is connected a heat exchanger 22. The duct 18 then enters into the container 4 within which is fitted a thermostat 23 for controlling a solenoid valve 24 which permits the passage of water through the heat exchanger 22 by means of a suitable hydraulic circuit 25.

The circuit 1 is generally always in operation for constantly filtering the oil present in the container 4 and to maintain this oil at a temperature between 550 and 600C which is the optimum temperature to obtain a correct flow within the unit 5. The two pumps 8 are connected in parallel in the circuit 1 because of the high volume of the container 4 and the large quantity of oil to be filtered. The pumps 8 pump oil around the circuit 1 so that upon passing through the filters 16 it is purified, and upon passing through the heat exchanger 22 it is raised to the abovementioned temperature. The manometers 14 and 21 indicate the pressures of the oil upstream and downstream of the filters 16. The pressure difference which is detected between the manometers 14 and 21 gives an indication of the level of clogging of the filters 16 which must be replaced when this pressure difference exceeds a predetermined value. By means of the taps 13, 17 and 20, it is posssible to draw off oil from various points of the circuit 1 in such a way as to be able to monitor its characteristics by effecting, for example, a chemical analysis.

As illustrated in Figure 1, the circuit 2 includes a duct 31 which extends into the container 4 and in which are connected, in succession, a pump 32 driven by an electric motor 33, an interception valve 34, a flow rate measuring instrument (flow meter) 35 connected to a source of elelctrical energy, and a unidirectional valve 36. Between the pump 32 and the valve 34 of the duct 31 there is a branch duct 37 which re-enters into the container 4 and in which is f itted a maximum f low rate valve 38. The valve 34 is pneumatically controlled by an electric push button 42. The pneumatic control is achieved by means of an air is treatment unit 43 which connects a source of compressed air 44 to the solenoid valve 41. The unit 43 is generally constituted by a filter 43a, a flow rate regulator 43b provided with a manometer 43c, and a lubricator 43d. The unit 43 is of known type and therefore available on the market, for example the Olympian unit produced by the firm Martonair SpA (Italy).

By connecting the duct 31 to an inlet opening of the unit 5 (naturally hermetically closing the other opening of this latter) filling of the unit 5 throughthe circuit 2 is achieved under the control of the measuring instrument 35. This instrument is generally constituted by two sets of apparatus: in one of which the volume of oil to be introduced into the unit 5 is set and the other of which is able to count the number of litres of oil introduced into the unit 5 and then control closure of the duct 31. This latter apparatus is able to control an acoustic and/or illuminable warning device 39 to advise the operator that filling is completed. The volume of oil to be introduced into the unit 5 is predetermined on the basis of the capacity of the unit. The measuring instrument 35 is of known type and is available on the market, for example the measuring instrument produced by the firm Isothermic Swiss (Switzerland-) and constituted by the apparatus called Contoil and by the pulse counter apparatus denominated KM The source of compressed air 44 is further connnected by means of the unit 43 and by way of a solenoid valve 45 to an interception valve 46 installed in a duct 47 which connects the container 4 to a centralised reservoir to which are connected all the containers 4 of several installations arranged along J 01 various assembly lines of the concern. Electrical control of the solenoid valve 45 is obtained by a sensor 48 installed within the container 4 and operable to detect a minimum oil level within the container 4. The sensor 48 is no more than a microswitch of the float type able to allow electrical supply to the solenoid 45 when the oil within the container 4 falls to a minimum level, which allows pneumatic control of the valve 46 to allow replenishment of the oil in the container 4 by means of the duct 47. Figure 1 schematically illustrates an electrical central control unit 51 connected to a source of electrical supply and operable to control the solenoid valve 45. The central control unit 51 is in fact connected to the sensor 48 and three other sensors 52, 53 and 54 of the same type as the sensor 48. The sensor 52 acts to detect the maximum predetermined level of the oil in the container 4 and is therefore operable, by way of the central control unit 51, to de-energise the solenoid valve 45 to close the duct 47 when the oil in the vessel 4 reaches this maximum predetermined level. The sensors 53 and 54 are operable to detect the minimum and maximum saftely leves respectively and are operable, by way of the central control unit 51 to control an acoustic and/or illuminable warning device 55 to alert the operator.

The circuit 3 comes into play upon completion of filling of the unit 5 which is provided with an inlet opening and an outlet opening to which the ends of a duct 62 are fixed by means of respective rapid attachment devices 61. In the duct 62 there are connected, in succession, a pump 63 drive by an electric motor 64, a filter 65, and an interception valve 66. In the duct 62, between the pump 63 and the filter 65. there is fitted a valve or tap 67 and a a A manometer 68, and likewise between the filter 65 and the valve 66 there is fitted a second valve or tap 71 and a second manometer 72. As in the circuit 1, the pressure difference measured by the manometers 68 and 72 gives an indication of the clogging of the-filter 65, which, among other things, is provided with a valve or tap 73. By means of the taps 67, 71 and 73 it is possible to draw off oil from the various points in the circuit 3 for analysis. A branch duct 74 extends from the duct 62 between the pump 63 and the filter 65 and has an interception valve 75 fitted therein; the branch duct 74 leands, in a manner not illustrated for simplicity, into the container 4. The valves 66 and 75 are pneumatically controlled by means of the same is solenoid valve 76 which can be actuated by means of an electrical push button 77. Pneumatic control is achieved by means of an air treatment unit 78 which is connected between a source of compressed air 81 and the solenoid valve 76. The unit 78 is similar to the unit 43 in that it comprises a filter 78a, a regulator 78b with a manometer 78c and a lubricator 78d.

When the unit 5 is filled by operation of the circuit 2 and then has been fitted into the circuit 3, the pump 63 and the motor 6 are simultaneously energised. The pump 63 causes the oil within the unit to circulate at a predetermined speed and the motor 6 causes movement of the rotatable parts of the unit 5.

Naturally, in this operating stages, the valve 75 closes the duct 74 and the valve 66 leaves the duct 62 open for the passage of oil. The filter 65 obviously filters the oil and retains the impurities present therein. To obtain a proper flushing and therefore achieve correct cleaning of every cavity within the unit 5 the oil which traverses the unit 5 must be turbulent with a Reynolds number of around 4,000. This 0 X turbulence is obtained by driving the oil to flow at a predetermined speed by means of the pump 63 and raising its temperature, by means of the heat exchanger 22, to between 550 and 600C. During this operating stage it is possible, as already previously indicated, to test the oil upstream and downstream of the filter 65 and therefore it is possible to detect clogging of the filter 65 and also to detect, after a predetermined period, the possible presence of impurities in the oil upstream of the filter 65 to decied if to continue with the flushing of the unit 5. During the functional test of the unit 5, if, for example, this is provided with parts movable by means of external levers such as a tractor gear box, it is preferable to effect such movement several times whilst the unit is being flushed.

The installation allows an effective cleaning of a unit having rotatable parts. This involves a greater functionality of the unit when it is in use and simultaneously less wear of the unit in that, as is known, at any moment the impurities which remain in the unit can be put into circulation and damage components of the unit itself. Moreover, by achieving an effective cleaning of the unit, the filters first fitted in the hydraulic circuit of which the unit itself forms part in operation are preserved from clogging for a longer period. Moreover, the circuit 1 allows a constant filtering of the oil present in the container 4 and therefore a greater service life of this oil, also by the fact that the container 4 is hermetically closed and therefore the oil within it is preserved from contact with impurities present in the environment which, if an industrial environment, is particularly polluted. The installation 1 is almost completely automated in that the operator only intervenes to achieve attachment of the ducts 31 and 62 to the unit 5 and to actuate the solenoid valves 41 and 76 by means of the push bottons 42 and 77. This allows greater utilisation of employed labour and therefore lower cost for this. Beyond this it is apparent that the oil present in the container 4, being constantly filtered, does not have to be replaced but only topped-up, with all the economic advantages which derive therefrom.

is The installation could have several separate circuits 3 and thus provide at the same time for the flushing of several units.

I

Claims

CLAIMS:

is 1. An installation for flushing out the interior of a unit characterised in that it comprises a duct, the ends of which are engaged with a respective inlet opening and outlet opening of the unit, into which a predetermined quantity of oil has been preliminarily introduced, first pumping means installed in the duct and operable to cause flushing of the unit with the oil, first filtering means installed in the duct and able to retain the impurities carried by the oil leaving the unit, and means for causing movement of the rotatable parts of the unit.
2. An installation according to Claim 1, characterised in that, in the duct, there is connected a first interception valve, which is pneumatically controlled by means of a first solenoid valve and which can be actuated with an electrical push button.
3. An installation according to Claim 2, characterised in that ' between the first pumping means and the first filtering means, a branch duct extends from the duct, in which branch duct is connected a second interception valve which is pneumatically controlled by means of the first solenoid valve; the branch duct being able to discharge the oil from the unit once flushing of this latter is terminated.
4. An installation according to claim 3, characterised in that the pneumatic control of the first valve and second valve is achieved by means of a first air treatment unit which is connected between a first compressed air source and the first solenoid valve; the first air treatment unit comprising a 1 - 1 1 - filter, a flow regulator, and a lubricator.
5. An installation according to any preceding Claim, characterised in that respective first manometers are connected in the duct upstream and downstream of the first filtering means.
6. An installation according to any preceding Claim, characterised in that upstream, downstream and in correspondence with the first filtering means there are connected respective first taps by means of which it is possible to draw off oil for analysis.
7. An installation according to any preceding Claim, characterised in that it includes an hermetically sealed storage container, a first hydraulic circuit around which the oil present in the container is constantly circulated, and a second hydraulic circuit through which, in use, the oil is introduced into the unit.
8. An installation according to Claim 7, characterised in that in the first circuit there are installed second pumping means, operable to draw off the oil from the container, second filtering means, operable to filter the pumped oil, and a heat exchanger operable to raise the pumped oil to a predetermined temperature.
9. An installation according to Claim 8, characterised in that in the first circuit there is installed respective second manometers upstream and downstream of the second filtering means.
10. An installation according to Claims a or 9, characterised in that upstream, downstream and in correspondence with the second filtering means there is installed respective second taps through which it is possible in use to draw off the oil for analysis.

is
11. An installation according to at least one of Claims 8 to 10. characterised in that within the container there is installed a thermostat operable to detect the temperature of the oil and to control a second solenoid valve installed in an hydraulic circuit passing through the heat exchanger.
12. An installation according to at least one of Claims 7 to 11, characterised in that in the second circuit there are installed third pumping means, operable to draw off a predetermined quantity of the oil and to deliver this quantity to the unit, a third interception valve pneumatically controlled by means of a third solenoid valve, and a flow rate measuring instrument comprising a first electronic apparatus in which the quantity of the oil to be introduced into the unit is set and a second apparatus operable to detect this quantity and to obstruct the passage of the oil once the predetermined quantity has.been reached.
13. An installation according to Claim 12, characterised in the pneumatic control of the third solenoid valve is achieved by means of a second air treatment unit which is connected between a second source of compressed air and the third solenoid valve; the second air treatment unit comprising a filter, a flow rate regulator and a lubricator.
14. An installation according to claim 13, characterised in that it includes a fourth interception valve which is installed in a duct which connects a reservoir'and the container for replenishing of the oil i f' within the container; the fourth valve being pneumatically controlled by means of a fourth solenoid valve which is connected, by means of the second air treatment unit, to the second source of compressed air.
15. An installation according to Claim 14, characterised in that within the container there are installed two first sensors operable to detect, respectively, the ninimum,and maximum level of the oil within the container and to control the fourth solenoid valve by way of a central electronic processor to effect or stop replenishment of the oil.
16. An installation for flushing out the interior of a unit substantially as herein described with reference to and as shown in the accompanying drawings.

Published 1988 at The Patent =as, State House, 66171 MgbL Holborn, London WC1R 4TP. Further copies may be obtained from The Patent Oface, Sales Branc13, St Mary Oray, Orpington, Kent BRS 3RD. Printed by Multiplex tecbniques ltd, St Mary Cray, Xent. Con. 1187.