- I -
A winch for marine application, in particular a davit winch, a davit winch provided with a swell-compensator.
The invention relates to a winch for marine applicati in particular a davit winch, and a davit winch provided with a swell-compensator according to the preamble to claim l. Winches for marine applications are known in many 5 diverse forms, see GB-A-2.084.953. The latter winch is provide with two hoisting motors. The first of these motors operates at a relatively low speed with a high torque whilst the other operates at a relatively high speed with a low torque. When a ship at sea now discharge or launch a load lifeboat 0 or is required to hoist these inboard from a sea with a relatively heavy swell running, the low-torque action of the motor pulls the hoisting-cable taut and the high-torque action of the latter hoists the load. Whilst however this system of movements, one superimposed on the other, provide some 5 compensation against the shock-loads imposed on the cables and the winch when hoisting from a rough sea they do not however provide satisfactory solutions to the problems experienced when discharging a load onto a supply-vessel or when launching a lifeboat heavily loaded with people in a rough sea. The two omotors can then only pay-out the cables jointly at high speed but they cannot exercise any swell-compensating function under full load. The result* of which is that either the load or the lifeboat, whichever the case, is threatened which experienc difficulties from the effects of the waves. 5 The object of the invention is to obviate these objections, this object is achieved by the application of the arrangement claimed in the characterising clause of claim 1.
By the application of the invention, the cable drums can be driven in both directions of rotation at an infinitely variable speed without the need engage or disengage clutches and can be shocklessly reserved in their directions or rotation
- 1 bis - and through which peak-loading conditions and shock factors imposed on the cables can be eliminated and through which the winch whole system can be made lighter with an increase in safety. The use of winches according to the invention is possible on the one hand on drilling platforms , ships and the like and on the other hand they are especially suitable for davit winches which include swell-compensating arrangements . The latter can work very effectively for both hoisting-in and paying-out operations .
OM
- 2 - The invention is now to be described further with reference to to accompanying drawings of a number of einbodimen of the invention in which:
Fig. 1 is schematically illustrative of a first embodiment of the winch according to the invention.
Fig. 2 is schematically illustrative of a second embodiment of the invention.
The embodiment shown in fig. 1 comprises a drum 1 for the cables (not shown) which for example may be the operating cables for a pair of davits and/or of one or more lifeboats. The cable drum is affixed to the output shaft 2 of a reduction-drive designated by the reference numeral 3 in its entirety and provided with an input shaft 4.
This reduction drive 3 comprises two 'in-line* planet gearing transmission arrangements 5 and 6.
Through this arrangement, the input shaft 4 is directly connected to the sun-gear 61 the external teeth of which engage with the teeth of at least three alike planet-wheel 62 which in their turn engage with the internal teeth of the crownwheel 63. The planet-wheels 62 are mutually connected by a planet-carrier 64 which, via an intermediate shaft 7, is coupled to the sun-wheel 51 of the planetary-gearing transmission arrangement 5. This sun-wheel 51 also accomodates a number of planet-wheels 52 around its periphery, the latter of which on the one hand engage with the inner teeth of the outer or crownwheel 53 and on the other hand with the aid of a planet-wheel carrier 54 are coupled to the output shaft 2 which, as foregoingly stated herein, drives the said one or more cable drums. The input shaft 4 of the reduction-drive 3 functions as the output shaft of the planetary-differential drive arrangement designated in its entirety by the reference numeral 8 and is driven by the input shaft 9. This input shaft 9 is coupled to the sun-wheel 81 around which a number of at least three planet-wheels 82 are constrained to move and which, in their turn, are movable within the outer or crownwheel 83. The planet-wheels 82 are accomodated on the planet-carrier 84 which is coupled to the output shaft 4.
The outer or crownwheel 83 is affixed to an externally toothed αearwheel 85 which is engaged by a pinion-gear 10
- 3 - is in its turn in engagement with a larger gearwheel 11.
This gearwheel 11 is affixed to the output shaft 12 of a planetary-gearing transmission arrangement which is designated in its entirety by the reference numeral 13 and 5 of which the input shaft 14 carries a centrifugal-brake 15 and a stop-brake 16. The input shaft 14 is connected to the sun- wheel 131 aroubd which at least three planet-wheels (132) rotat and which, in their turn, engage with the internal teeth of the outer or crownwheel 133 which is held stationary. The planet- 0 gear carrier 134 is coupled to the output shaft 12.
The input shaft 9 of the planetary-differential gearin transmission arrangement 8 is affixed to a bevel-gear 17, and another bevel-gear 18 engages the latter perpendicular to the input shaft 9 and is affixed to a driving-shaft 19 from an 5 electric-motor M 20 for example and the other end of the driving-shaft 19 of which carries the stop-brake 21. In the possible event of there being a need to operate the winch manually, a further bevel-gear 22 is arranged in engagement with the bevel-gear 17 perpendicular thereto and which bevel- o gear 22 is connected to a manually-powered driving shaft which, with the aid of a coupling 24, can be driven by a cranked-handl 25. Furthermore the centrifugal-brake 26 acting on the manually poweder driving shaft 23 is arranged on this shaft.
The operation of the embodiment of the winch according 5 to the invention and as illustrated in fig. 1 is as follows: The motor M20 effects a driving function in one direction of rotation or another via the shaft 19 on the right-angled transmission gearing arrangement 17, 18 and the input shaft 9 of the planetary-gearing transmission arrangement 8. Through ° this arrangement, the output shaft 4 drives the cable drum 1 via the double planetary-gearing reduction arrangement 5 and 6 of the drive 3. In one direction of rotation of the motor 20 for example, the drum 1 is enabled to haul-in the cables (not shown) whilst in the other direction of rotation the drum is 5 enabled to pay the cables out.
By means of the pinion-gear 10 and the reduction-gearing 11, 12, 13 and 14 slipping and stopping actions can be applied with the aid of the brakes 15 and 16 respectively. This means that the pinion 10 can be held fast or permitted to perform
- 4 _ revolutions slowly in one direction or the other and through which variations in the number of revolutions of the output s 4 of the planetary-gearing differential drive 8 can be effect continuously. With this type of mechanical construction in which the gears are continuously in mesh, there is no need fo de-clutching facilities to be provided whilst very large braking forces can be taken up by the stop-brakes 16 and 21. Impact-loading on the transmission system can also rise to a very high degree without any damage occurring to the system. The manually-powedered facilities 22, 23, 24 and 25 are exclusively destined to be applied for example in cases where the electric-power supply on the mother-vessel falls-ou and through which the electric motor M2 is unable to work. By this arrangement the winch is enabled to carry out all its functions but at a very much reduced speed naturally.
The embodiment illustrated in fig. 2 corresponds to an important degree to that which has been illustrated in fig. 1 and in which however the most important difference is constituted by a swell-compensation arrangement which is connected to the winch.
This swell-compens tion arrangement makes it possible for a lifeboat to be hauled out of the sea or another water at the most suitable instant of time therefor.
That part of the winch lying to the right of the vertical chain-dotted line in fig. 2 and designated B-B is constructively similar to that part shown in fig. 1 to the right of the chain-dotted line A-A so that this will not be discussed further.
The shaft 14 carries a stop-brake 26 and is driven by the main motor 27 coupled to a hydraulic pump P30 via shaft 28 and a freewheel-clutch 29. This hydraulic pump P30 is coupled to the hydraulic lines 31 and 32 to the hydraulic- regulating apparatus C33 which is in turn coupled on one side by the hydraulic lines 33 and 34 respectively to the swell- comoensation motor 1-35. This motor is affixed to the driving- shaft 9 of the planetary-gearing differential drive 8, and which shaft 8 carries the stop-brake 36 with the freewheel- clutch 37 and a centrifugal-brake 38 with a freewheel-clutch 39. The hydraulic-regulating apparatus 33 is connected to the - - -
- 5 - lines 40 and 41 respectively.
The operation of this winch together with the swell- compensation arrangement is as follows: Via the shaft 14, the main motor 27 drives the planetary-gearing reduction arrangemen 13, the shaft 12 with the gearing-transmission arrangement 11, 10 and 85, the crownwheel 84 and the planet-wheels 82, the planet-carrier 84, the shaft 4, the reduction-drive 3, the shaft 2 and the drum 1. With the exception of the hoisting functions derived from the maon motor 27, an auxiliary hoisting function is also provided and operative in swell-compensating conditions and which function is superimposed on the main hoisting function. This auxiliary hoisting function is also derived from the main motor 27 which drives the hydraulic pump P via the freewheel-clutch 29. The hydraulic pump P supplies the hydraulic motor 35 via the hydraulic regulator C, this hydraulic motor drives the shaft 9 to which the sun-wheel 81 of the planetary-gearing differential drive 8 is coupled. With the aid of this slower-running hydraulic motor 35 for example, the hoisting-cables (not shown) connected to a lifeboa can be pulled taut with the use of only a little power when the lifeboat is lifted by the swell causing the cables to becom slack. If a lifeboat is suspended from the cables and is lifted by the swell, then the tension in the hoisting-cables will be reduced. If now these cables were not paid out by the operation of the swell-compensation motor 35 then the cables would be subjected to very high peak tensional-loads when the swell fell again. These peak-loads, capable of producing shock factors from 3 to 4 and which are very dangerous for both the suspension-eyes on the lifeboat and the hoisting-cables of the winch themselves, are completely prevented from occurring by the swell-compensation arrangement according to the invention. If as the result of movement of the swell in the opposite direction the motor 25 assumes a driven functions, then it works as a pump by which means the regulator 33 can, via the lines 40 and 41, apply the brakes 36 and 39 as required In hauling a lifeboat out of the water, the most favourable time to initiate the hoisting operation, at which time the stop-brake 36 is applied, is determined by the reversa of the direction of rotation of the shaft 9. The chanσe in the
- 6 - speed of rotation of the shaft 9 is then gradual with the result that no peak-loads or shock factors manifest themselves in the system.
The scope of the invention is not limited to the illustrated and/or describes embodiments and extends to all variations thereof.
OMP