GB2325212A - Lifting apparatus and a lifting method - Google Patents

Abstract

An apparatus for lifting two separate components, 30,31 whilst maintaining the components in a predetermined relative orientation, the apparatus comprising two sets of hydraulic rams 33,34,37,38 and 35,36,39,40, each set of hydraulic rams comprising at least two rams for each component, the apparatus further comprising at least one source of pressurised hydraulic fluid 41,55, and individual conduits 51-54 interconnecting the source of hydraulic fluid with each ram, each conduit being associated with a control valve 43-46 and a pressure gauge 47-50. At least the rams on one component are mounted on slide ways (9, Fig 1) so that the components can be separated after a joining piece 32 is detached. The slide way may have a locating hole or protrusion (11) and a rule (10) to determine the distance moved laterally. A collar (20, Fig 2) and shims (22-24, Fig 3) may be provided for use with the jacks. Preferably the jacks have a manually actuated non-return valve (4) and a double speed manual pump. The rams are used with engine generator sets joined by a drive shaft or crank to realign or change the normal resilient mounting, when necessary.

Description

DESCRIPTION OF INVENTION "Improvements In Or Relating To A Lifting Apparatus And A Method Of Lifting" THE PRESENT invention relates to a lifting apparatus and also relates to a method of lifting. More particularly the invention relates to a lifting apparatus and a method of lifting suitable for use when lifting two components which, although comprising separate components, needed to be lifted simultaneously.

It is envisaged that the invention may find a particular application when lifting heavy power units comprising two components such as an engine and a generator, the engine and the generator being coupled together, for example by means of a drive shaft or crank shaft.

There are many situations where a relatively heavy engine is mounted in position which is coupled, by means of a drive shaft or crank shaft, to an appropriate generator.

The engine may comprise a diesel engine or a gas turbine, and the generator may comprise an appropriate electric generator unit. Typically both the engine and the generator are mounted on resilient mounts, with the axis of the engine being precisely aligned with the axis of the generator. The engine and the generator are interconnected by a linear drive shaft or crank shaft. Should it become necessary to change the resilient mounting on the engine, or change the resilient mounts on the generator, or should it be necessary to re-align the engine and the generator it is necessary to lift the engine and the generator simultaneously, without imparting any substantial deflection to the crank shaft.

One particular situation where this is necessary is in the lifting of a diesel engine or gas turbine engine as utilised in a ship. In a typical ship it is often necessary to remove an engine approximately once every four years (on average) during the operating life of the ship.

Currently the removal of an engine is effected by means of a mechanical screw system. Effectively a screw jack is provided at each of the four corners of the engine and at each of the four corners of the generator. The mechanical screw jacks are actuated by a team of operatives so that the engine and the generator are raised by successive small increments, so that the crank shaft is not deflected.

Subsequently the engine can be moved sideways to release the crank shaft. Both the engine and the generator must be maintained in a horizontal position throughout the operation. The existing technique requires men to be positioned at each corner of the engine and each corner of the generator during the lifting process, and typically a team of ten men may be occupied for a period of nine days in performing these tasks.

The present invention seeks to provide an improved lifting apparatus and an improved method of lifting.

According to this invention there is provided an apparatus for lifting two separate components, whilst maintaining the components in a predetermined relative orientation, the apparatus comprising two sets of hydraulic rams, each set of hydraulic rams comprising at least two rams for each component, the apparatus further comprising at least one source of pressurised hydraulic fluid, and individual conduits interconnecting the source of hydraulic fluid with each ram, each conduit being associated with a control valve and a pressure gauge.

Preferably each hydraulic ram is provided with a manually operable non-return valve.

Conveniently each ram to be associated with one component is associated with means to facilitate lateral movement of the ram.

Advantageously the means to facilitate lateral movement of the ram comprise a slideway and an associated slide, the ram being supported by the slide.

Preferably the slideway comprises a channel formed in a metallic element, the slide comprising a member formed of plastic material.

Conveniently the slideway is provided with a ruler to enable observation of the movement of the slide.

Advantageously the slideway is provided with a recess formed in the base of the channel and the slide is provided with a locating peg.

Preferably a collar is provided for use with each ram, the collar being locatable between an outer casing of the ram and the component lifted by the ram when the ram has lifted the component.

Conveniently a set of shims is provided for use with each ram.

Advantageously two sources of hydraulic fluid are provided, each source of hydraulic fluid being connected to an associated manifold, each manifold being associated with one of the said sets of rams.

Conveniently the or each source of hydraulic fluid comprises a double-speed manually operated hydraulic pump.

According to another aspect of this invention there is provided a method of lifting two components whilst maintaining a predetermined orientation of said components, the method comprising the steps of locating under the components two sets of hydraulic rams, the rams from the first set being located under the first side of the first component and the first side of the second component and the rams from the second set being located under the second side of the first component in the second side of the second component, applying hydraulic fluid to the rams from a hydraulic source through separate conduits, each conduit being provided with a control valve and a pressure gauge, extending the rams, optionally with the provision of shims on the rams, until the rams, or the shims, contact the components to be lifted, adjusting the valves so that the pressure gauges for each set of rams show equivalent pressures, and applying further hydraulic fluid so as to extend the rams of each set by equal increments, thus lifting the components whilst maintaining the original orientation of the components.

The method may comprise the subsequent steps of moving one component laterally relative to the other component.

The method may also comprise said lateral movement is effected by sliding the rams along slideways.

In order that the invention may be more readily understood, and so that further features may be appreciated, the invention will now be described by way of example, with reference to the accompanying drawings in which: Figure 1 is perspective view of a hydraulic ram and an associated control valve mounted on a slide, Figure 2 is a view of a collar for use with the ram of Figure 1, Figure 3 is a view of a set of shims for use with the ram of Figure 1, Figure 4 is a top plan part diagrammatic view of an engine and a generator, the engine being shown mounted on top of four rams and slides as shown in Figure 1 and the generator being shown mounted on four rams as shown in Figure 1, and Figure 5 is a diagrammatic view of the rams of Figure 4 and the associated components.

The lifting apparatus of the invention utilises a plurality of hydraulic rams. A typical hydraulic ram 1 is illustrated in Figure 1. The ram comprises a cylindrical outer housing 2 with a plurality of telescopically nested lifting components 3. The ram is of conventional design.

Associated with the ram is a controllable nonreturn valve 4. The non-return valve is provided with an operating handle 5. The non-return valve is connected to a connector 6 adapted to be connected to a flexible hose.

In the arrangement illustrated in Figure 1 the ram is mounted on a slider plate 7. The slider plate 7 is formed of an oil-impregnated plastic material. The slider plate 7 is mounted for sliding movement along a channel 8 formed in a steel slideway 9. A ruler 10 is provided at one edge of the channel 8 adjacent the slide plate 7. The base of the channel 8 may be provided with a recess 11 which forms a locating hole. Various apertures such as the apertures 12 may be formed in the slideway to enable the slideway to be mounted in position. The slideway may be provided with a locating protrusion (not shown) extending from the undersurface of the slideway as illustrated in Figure 1.

Figure 2 illustrates a collar 20 adapted for use with the hydraulic ram of Figure 1. The collar 20 is in the form of a disk of material having a radially extending channel 21, which is of substantially "U" shape when viewed in plan, the channel having a greater length than the radius of the disk 20. The width of the channel 21 is greater than the width of the narrowest telescopic lifting component 3 forming part of the ram 1.

Figure 3 illustrates a set of three shims or spacers 22, 23, 24 intended for use with the hydraulic ram 1. Each shim is of cylindrical form, the diameter of the shim corresponding with the diameter of the outer housing 2 of the ram. Each shim is of a different thickness. Each shim is provided with a projection 25, 26, 27 on its upper surface, the projection having the same diameter as the telescopic lifting component of least diameter that forms part of the ram 2, and each shim has a corresponding recess formed on its undersurface.

Referring now to Figure 4, it is to be observed that an engine 30 is illustrated connected to a generator 31 by means of a drive or crank shaft 32. The illustration is, of course, schematic.

Located under lifting points provided at the four corners of the engine 30 are respective rams and associated slideways, as illustrated in Figure 1, identified by the reference numerals 33, 34, 35, 36. The slideways are all parallel with each other. Located under lifting points provided at the four corners of the generator 31 are four rams, corresponding to the rams illustrated in Figure 1 but not associated with slideways, identified by the reference numerals 37, 38, 39, 40.

A hydraulic pump 41 is provided, which may comprise a manually operable two-speed hydraulic pump, the pump being connected to a manifold 42. The manifold is connected to four adjustable valves 43, 44, 45, 46. The output side of each valve is connected to a respective pressure gauge 48, 49, 50 and by means of a flexible conduit 51, 52, 53, 54 to respective one of the rams 33, 34, 37, 38. Thus the output of the pump 41 is connected by means of the manifold 42 and the associated valves, pressure gauges and flexible conduits to the four rams which are located on the left-hand side of the arrangement in the orientation illustrated in Figure 4.

It can be observed that an equivalent arrangement is provided on the right-hand side of Figure 4, with a second pump 55 being associated with a manifold 56 having four outputs connected to the four rams 35, 36, 39, 40.

Figure 5 is a diagrammatic side view of the pump, manifold, distribution valves, pressure gauges, conduits and rams of Figure 4.

When it is intended to lift the engine 30 and the generator 31 and subsequently separate the engine 30 from the generator 31 the rams are located as illustrated in Figure 4. Appropriate shims, selected from the supply of shims illustrated in Figure 3, may be mounted on top of each ram so that the upper surface of the ram or the upper surface of the shim is adjacent the appropriate lifting point provided on the engine or generator. If a shim is provided the lifting component of least diameter will be received in the recess in the base of the shim, and if two or more shims are used, the projection on the upper surface of the lower shim will be received in the recess formed in the base of the upper shim.

Hydraulic pressure is then applied to the manifolds 42 and 46 by operating the pumps 41, 55. The pumps may operate in a relatively fast flow mode, the valves 43, 44, 45, 46 will all be open, and the corresponding valves on the right-hand side of Figure 4 will equally be open. The pumping will continue until each ram, or the shim or shims mounted on each ram, has engaged the appropriate lifting point. A pressure will then be indicated by each of the pressure gauges.

The valves are then adjusted so that the pressure shown on each gauge is precisely the same as the pressure shown on each other gauge.

Subsequently, the pumping procedure is continued, but the pump, during this phase of operation, may operate at the lower pumping rate. Because the valves have been adjusted so that the pressure shown by each gauge is constant, as the pumping operation continues, the pressure shown by the various gauges should remain equal, across all of the gauges, during the pumping procedure, at least as far as the gauges associated with each of the two manifolds are concerned. Should the pressure shown by one gauge vary in an undesirable manner, the associated valve may be adjusted.

As the pumping procedure continues, the four rams on each side of the arrangement illustrated in Figure 4 extend by equal increments, meaning that both the engine and the generator are lifted by equal amounts. If there is any discrepancy, the discrepancy will be between the amount of lift provided on the left-hand side of the arrangement as shown in Figure 4 and the amount of lift provided on the right-hand side of the arrangement. This will not, however, cause any distortion of the drive or crank shaft 32.

When the rams have been extended by a sufficient amount, the collars 20 as illustrated in Figure 2, may be mounted in position, the collars being slid into place with the lifting component of least diameter of the ram received in the channel 21. If desired the rams may then be lowered slightly so that the collars assume part of the load. This is achieved by manually releasing the non-return valve 4 associated with each ram 2, and then operating the pump 41 on a central valve associated with the pump so that the hydraulic fluid flows "in reverse" so that fluid is gradually drained away from the rams. It is to be understood that the non-return valves 4 are provided to prevent the rams from releasing the load should, unexpectedly, a flexible conduit be damaged, but may be released manually.

At this stage in the procedure, the engine 30 may be slid, towards the left as shown in Figure 4, by applying appropriate pressure to the engine. The crank shaft 32 may need to be uncoupled before this can be accomplished. The engine will slide towards the left with each slide plate 7 sliding along the channel 8 in the associated slideway.

The degree of movement may be measure by considering the ruler 10, and each slider plate 7 may be provided with a locking pin or the like adapted to be received in the locating recess 11 when the movement has terminated.

It will be readily appreciated that the apparatus, as described, may subsequently be used to replace the engine (or a substitute engine) and the generator in the original position simply by reversing the described sequence.

Whilst, the described embodiment, two manifolds and two pumps have been illustrated, it is conceivable that in alternative embodiments of the invention a single pump may supply two manifolds or a single pump may supply a single manifold, with all of the valve outlets extending from single manifold. Whilst the invention has been described with reference to an embodiment in which four rams are used to lift each of the two components, in an alternative embodiment of the invention a greater number of rams could be utilised, for example six rams for each component.

Claims (17)

1. An apparatus for lifting two separate components, whilst maintaining the components in a predetermined relative orientation, the apparatus comprising two sets of hydraulic rams, each set of hydraulic rams comprising at least two rams for each component, the apparatus further comprising at least one source of pressurised hydraulic fluid, and individual conduits interconnecting the source of hydraulic fluid with each ram, each conduit being associated with a control valve and a pressure gauge.

2. An apparatus according to Claim 1 wherein each hydraulic ram is provided with a manually operable nonreturn valve.

3. An arrangement according to Claim 1 or Claim 2 wherein each ram to be associated with one component is associated with means to facilitate lateral movement of the ram.

4. An apparatus according Claim 3 wherein the means to facilitate lateral movement of the ram comprise a slideway and an associated slide, the ram being supported by the slide.

5. An apparatus according to Claim 4 wherein the slideway comprises a channel formed in a metallic element, the slide comprising a member formed of plastic material.

6. An apparatus according to Claim 4 or 5 wherein the slideway is provided with a ruler to enable observation of the movement of the slide.

7. An apparatus according to Claim 4, 5 or 6 wherein the slideway is provided with a recess formed in the base of the channel and the slide is provided with a locating peg.

8. An apparatus according to any one of the preceding claims wherein a collar is provided for use with each ram, the collar being locatable between an outer casing of the ram and the component lifted by the ram when the ram has lifted the component.

9. An apparatus according to any one of the preceding claims wherein a set of shims is provided for use with each ram.

10. An apparatus according to any one of the preceding claims wherein two sources of hydraulic fluid are provided, each source of hydraulic fluid being connected to an associated manifold, each manifold being associated with one of the said sets of rams.

11. An apparatus according to any one of the preceding claims wherein the or each source of hydraulic fluid comprises a double-speed manually operated hydraulic pump.

12. A method of lifting two components whilst maintaining a predetermined orientation of said components, the method comprising the steps of locating under the components two sets of hydraulic rams, the rams from the first set being located under the first side of the first component and the first side of the second component and the rams from the second set being located under the second side of the first component in the second side of the second component, applying hydraulic fluid to the rams from a hydraulic source through separate conduits, each conduit being provided with a control valve and a pressure gauge, extending the rams, optionally with the provision of shims on the rams, until the rams, or the shims, contact the components to be lifted, adjusting the valves so that the pressure gauges for each set of rams show equivalent pressures, and applying further hydraulic fluid so as to extend the rams of each set by equal increments, thus lifting the components whilst maintaining the original orientation of the components.

13. A method according Claim 12 comprising the subsequent steps of moving one component laterally relative to the other component.

14. A method according to Claim 13 wherein said lateral movement is effected by sliding the rams along slideways.

15. An apparatus for lifting components substantially as herein described with reference to and as shown in the accompanying drawings.

16. A method of lifting substantially as herein described with reference to the accompanying drawings.

17. Any novel feature or combination of features disclosed herein.