WO2000010903A1

WO2000010903A1 - Pull winch

Info

Publication number: WO2000010903A1
Application number: PCT/NO1999/000256
Authority: WO
Inventors: Nils Rasmussen
Original assignee: RAPP HYDEMA AS
Current assignee: RAPP HYDEMA AS
Priority date: 1998-08-18
Filing date: 1999-08-17
Publication date: 2000-03-02
Anticipated expiration: 2001-02-18
Also published as: AU5388899A; NO983774L; NO983774D0

Abstract

A pull winch, especially for use on board vessels for pulling a wire out of the sea and on to a storing drum. The pull winch is comprising two drums (7, 8) located side by side with sleeves (3, 4) having grooves for a wire, the drums (7, 8) being rotatable fixed to a base (6) and each drum (7, 8) is driven directly by a motor (1, 2) respectively so that the drums (7, 8), may be driven independently with different power from each motor. To avoid that the wire leaves the groove of one of the drums (7; 8) at an angle in relation to the groove it arrives on to the other drum (8; 7), the axis of rotation (10, 11) of the drums (7, 8) are twisted in relation to each other at an angle α which is adapted to the pitch angle of the grooves of the sleeves (3, 4) on the drums (7, 8). With this twisting angle α twisting of the wire is avoided and makes an essential less wear of the wire. In that the drums are twisted in relation to each other they may be located closer to each other than prior art drums so that the winch can be made smaller and have a lighter weight.

Description

Pull winch

This invention relates to a pull winch, especially for use on board vessels, as stated in the preamble of claim 1.

Such pull winches, also called "yard winches", are used for pulling the wire out of the sea and on to a storing reel. Prior art yard winches have two yards (drums) with parallel rotation axis and grooves for the wire. The yards are mechanically connected to each other via a gearbox. Hydraulic motors are used for rotating the yards. Gear wheels are connecting the motors to the yards to assure equal rotation speed of the yards. The problem with prior art yard winches is that the wire is leaving the groove of one of the yards at an angle in relation to the groove it arrives on to the other yard. To minimise the said angle the distance between the rotation axis of the yards should be as long as possible. This means that the winch must be relatively long. Further, it is known that this angle between the wire and the groove on the other yard makes the wire twist, something which is not desired because this will destroy the wire after sometime. Another problem with this type of winches is that it is heavy due to the structure. The torque on each of the yards is equal, something which is not necessary.

The object of this invention is to provide a pull winch wherein the above said problems are avoided. According to the invention this object is achieved by the characteristic features of the pull winch as disclosed in claim 1. A preferable embodiment is stated in the dependent claim.

The yard winch according to the invention is both smaller and lighter than previously known yard winches. In that the wire is moving straight out of the yard grooves this gives a considerable less wear of the wire and twisting of the wire is avoided. In that it is used easy replaceable sleeves having grooves adapted to the actual wire dimension the yard winch according to the invention may quickly be adapted to other wire dimensions.

Each driving motor is mounted directly at each yard, as the need of torque is different on each yard. With that, the driving of each yard is independent and the driving source for each yard may be optimised, i.e. that it may be used motors having different dimensions at each yard.

A computer may make the control of the operation. The invention will now be described with reference to an embodiment and to the drawings, wherein Fig. 1 is a perspective view of a yard winch according to the invention which also shows the replaceable sleeves, Fig. 2 shows the yard winch seen at a slant angle from above, and Fig. 3 is an end view of the yard winch.

In the drawings the yard winch is shown seen form different angles.

The yard winch is comprising two drums 7, 8 located side by side with mounted sleeves 3, 4 thereon having grooves for a wire. The drums 7, 8 are rotatable fixed to a base 6 and each drum 7, 8 is driven directly by a hydraulic motor 1, 2 respectively and fixed to the base 6. The drums 7,8 are twisted in relation to each other so that their axis of rotation 10, 11 are forming an angle α therebetween, see Fig. 3. The angle α is adapted to the pitch angle of the grooves of the sleeves 3, 4 on the drums 7, 8.

The yard winch is fixed to the deck of a vessel. When a wire (not shown) is pulled out of the sea, it is first guided on to the grooves of the sleeves 3, 4 of the yard winch fixed to the drums 7, 8. After a number of runnings of the wire between the drums 7, 8 of the yard winch driven by the hydraulic motors 1, 2, the wire is guided on to the storing drum (not shown). The tension of the wire on the storing drum is approx. 5 per cent of the pull of the winch. In that the axis of rotation 10, 11 of the drums 7, 8 are twisted in relation to each other at an angle α, which in the present embodiment is 4,5°, the wire will run straight out of the grooves of the sleeves 3, 4 on one of the drums 7, 8 and straight on to the grooves of the sleeves 4, 3 on the other drum 8, 7. This makes an essential less wear of the wire and twisting of the wire is avoided. The sleeves 3, 4 comprise 180° arced elements, see Fig. 1, fixed to the drums 7,8. The sleeves 3, 4 are easy replaceable and having grooves for adaptation to the wire dimension used.

In that the drums 7, 8 are driven independently with different power from each motor 1 , 2, the operation of each yard may be optimised as the requirement of torque is different on each yard.

Therefore, the motors 1, 2 at each yard may be differently dimensioned. The control of the power of each motor 1, 2 may be made by a computer.

1 1 will be appreciated that the pull winch according to the invention also may be used in other fields than on board a vessel.

Claims

C l a i m s

1. A pull winch, especially for use on board vessels, having yards comprising two drums (7, 8) located side by side with mounted sleeves (3, 4) thereon, having grooves for a wire, the drums (7, 8) being rotatable fixed to a base (6), each drum (7, 8) being driven directly by a motor (1, 2) respectively and fixed to the base (6), the drums (7, 8) are driven independently with different power from each motor (1, 2), characterised in that the drums (7, 8) are twisted in relation to each other so that their axis of rotation (10, 1 1), projected onto a vertical plane, are forming an angle α therebetween, the said angle α being adapted to the pitch angle of the grooves of the sleeves (3, 4) on the drums (7, 8) so that the wire will run straight out of the grooves of the sleeves (3;4) on one of the drums (7; 8) and straight on to the grooves of the sleeves (4; 3) on the other drum (8; 7).

2. A pull winch according to claim 1, characterised in that the said sleeves (3, 4) with grooves are comprising 180° arced elements fixed to the drums (7, 8).