WO2012146886A1

WO2012146886A1 - A winch drum

Info

Publication number: WO2012146886A1
Application number: PCT/GB2012/000201
Authority: WO
Inventors: Thor Strand
Original assignee: National Oilwell Varco Norway As; Parry, Simon James
Priority date: 2011-04-27
Filing date: 2012-02-29
Publication date: 2012-11-01
Also published as: GB201107101D0; GB2490350A

Abstract

A winch drum (11) comprising a cylindrical drum shell (2) having a radially inner surface (10), a radially outer surface (9) and a separate reinforcement layer (4; 5) which can comprise plastic applied to at least one of said surfaces.

Description

A WINCH DRUM

The present invention relates generally to winches. More particularly, the invention relates to a winch drum.

Winches are used in various applications as stand alone machines for lifting and pulling and can also be combined with other machines to form part of lifting cranes or other hoisting devices. A winch usually comprises: a winch drum, also known as a spool, around which a rope is wrapped; and a means for driving rotation of the winch drum. Winch drums usually take the form of a cylindrical drum shell terminated at each end by a flange.

Conventionally, winch drums are manufactured of materials such as steel, iron or aluminium. The winch drum will typically have a welded, bolted or cast construction which is capable of withstanding the forces exerted upon it in use. When a rope is wrapped around the winch drum in tension a compressive force is exerted on the drum shell. If the compressive forces acting on the winch drum as a result of tension in the rope exceed the strength of the drum shell material, the drum shell will be crushed resulting in its deformation or destruction.

Traditionally, winches capable of withstanding greater forces are constructed using an increased thickness of the chosen manufacturing material such as steel, iron or aluminium.

A problem associated with the traditional winch construction described above is that for larger winches designed to withstand heavy loads, for example winches with a pull capacity of 50mT and above, the weight of the winch itself is large. An increased weight of a winch leads to problems during manufacturing and may also affect the stability of a vehicle or vessel carrying the winch.

It is an object of the present invention to provide an improved winch.

According to the present invention, there is provided a winch drum comprising a cylindrical drum shell having a radially inner surface and a radially outer surface; and a separate reinforcement layer applied to at least one of said surfaces.

Preferably, the winch drum further comprises a flange, the flange having a first surface and a second surface at least one of which has a reinforcement layer.

Preferably, the flange is metal. Preferably, the drum shell is metal.

Advantageously, the winch drum may have a said reinforcement layer which comprises a plastic.

Preferably, the winch drum may have a said reinforcement layer which is molded. Preferably, the winch drum, has a said reinforcement layer which comprises a high tensile material.

Conveniently, the winch drum may comprise a said reinforcement layer which is wrapped around the outside surface of the drum shell.

Optionally, the winch drum may have a reinforcement layer applied to said outer surface which includes grooves for the purpose of guiding a rope on to the drum during spooling.

Conveniently, the winch drum may have a said reinforcement layer which comprises an elastic material.

Advantageously, the winch drum has a said reinforcement layer which may be formed by a substantially rigid material.

So that the invention may be more readily understood, and so that further features thereof may be appreciated, embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which.

Figure 1 is a perspective view of a winch drum in accordance with the present invention, provided in combination with a rope wrapped around the winch drum shell;

Figure 2 shows a longitudinal cross section of a winch drum in accordance with the present invention having a reinforcement layer on a radially inner surface of the winch drum shell;

Figure 3 shows a large scale longitudinal cross section view of the portion of the winch drum highlighted by dashed lines in figure 2;

Figure 4 shows a longitudinal cross section of a second embodiment of the winch drum having a reinforcement layer on a radially outer surface of the winch drum shell; Figure 5 shows a large scale longitudinal cross section view of the portion of the winch drum highlighted by dashed lines in figure 4; and

Figure 6 shows a longitudinal cross section of a winch drum having reinforced flanges.

Figure 1 shows a winch drum 1 1 in accordance with the present invention, having a cylindrical drum shell 2, and a flange 1 located at each end of the cylindrical drum shell 2. A rope 6 is shown spooled around the drum shell 2 about the longitudinal axis 13 of the drum shell. The term rope is used herein to refer to any elongate flexible component or member capable of being coiled or spooled onto a winch and supporting the weight of a load in tension and can include, for example: a chain, a wire, a cable and a cord.

The drum flanges 1 each lie in a plane which is substantially perpendicular to the longitudinal axis 13 of the drum shell. Each flange 1 has a first surface 7 and a second surface 8. At least one surface 7, 8 of the flange lies in a plane which is substantially perpendicular to the longitudinal axis 13 of the drum shell 2.

It can be seen from figure 1 that the diameter of the flanges is greater than that of the drum shell such that the radially outermost parts of the flanges 1 extend from the ends of the cylindrical drum shell to define a rope receiving portion of the drum shell 2 between the two flanges around which the rope 6 can be wound in a generally conventional manner.

The drum shell 2 also includes optional guidance grooves 14 which act to guide the rope 6 onto the drum shell 2 during spooling.

Referring to figures 2 and 3, there is shown a first embodiment of the winch drum 11 . The winch drum has a hollow cylindrical drum shell 2 which has a radially outer surface 9 and a radially inner surface 10 spaced from one another by the radial thickness of the drum shell. The inner and outer surfaces of the drum shell are both cylindrical surfaces. The radially outer surface 9 may be smooth as shown or may include corrugations which form the guidance grooves 14 shown in figure 1 .

In the particular arrangement illustrated both flange surfaces 7, 8 are oriented so as to lie in a plane which is substantially perpendicular to the longitudinal axis 13 of the drum shed 2. The first surface 7 is outwardly facing away from the drum shell and the second surface 8 is inwardly facing towards the drum shell. A reinforcement layer 4 is applied to the inner cylindrical surface 10 of the drum shell. The reinforcement layer includes a high tensile material which, when applied to the inner surface 10, acts as a. radially reinforcing support for the drum shell 2. The reinforcement layer 4 could be a grouting compound. In the embodiment of figure 1 , the reinforcement layer 4 has a cylindrical shape and extends along the inner surface 10 of the drum shell 2 from one flange 1 to the other flange 1. The reinforcement layer 4 optionally includes a plastic.

The reinforcement layer 4 may be molded, and it could be molded directly to the inner surface 10 or could be molded using a separate mold and then inserted inside of the drum shell and affixed to or against the inner surface 10. The reinforcement layer 4 may be attached to the inner surface to hold it in place, for example using an adhesive.

An optional cylindrical support frame 3 is shown located inside of the drum shell 2. It is spaced in relation to the inner surface 10 of the drum shell and thus defines an annular gap for the receipt of the grouting 4. The frame 3, grouting 4 and drum shell 2 are oriented in a concentric arrangement about the longitudinal axis 13. The thickness of the grouting compound 4 is defined by the size of the gap between the frame 3 and the drum shell 2.

Figures 4 and 5 show a second embodiment of the present invention. The second embodiment is a modification of the first embodiment of figures 2 and 3, the modification being that the reinforcement layer 5 is applied to the radially outer surface 9 of the drum shell 2 rather than to the radially inner surface 10.

The reinforcement layer preferably includes a high tensile material which, when applied to the outer surface 9 acts as radially reinforcing armouring for the drum shell 2. The reinforcement layer shown in Figure 4 is cylindrical in shape and extends along the outer surface 9 of the drum shell 2 from one flange 1 to the other flange 1. In the arrangement of the second embodiment shown in figures 4 and 5, the reinforcement layer 5 is formed from a reinforcing material wrapped around the outer surface 9 of the drum shell 2. In the particular arrangement shown, the wrapped reinforcement material is repeatedly wrapped around the drum shell 2 to form multiple sub layers of reinforcement material which make up the reinforcement layer 5. The reinforcement layer 5 may also be applied by other means, for example it could be molded. It could be molded directly around the outside of the drum shell 2 or could be molded separately and then affixed to or against the outer surface 9. The reinforcement layer 5 may be attached to the outer surface 9 of the drum shell for example using an adhesive.

The reinforcement layer 5 may include grooves 14 as shown in figure 1 which allow rope to be guided when it is spooled around the drum shell 2. Preferably, the pattern of grooves in the reinforcement layer 5 is designed to control and therefore to improve the spooling of multiple layers of rope. An example of a pattern of grooves which controls the spooling of a rope on to a winch drum so that the rope can be safely spooled into multiple layers is the Lebus System.

Figure 6 shows a third embodiment of the present invention which is another modification of the first embodiment. In addition to the features described in relation to the first embodiment of figures 2 and 3, the arrangement of figure 6 includes a reinforcement layer 12 applied to each of the outwardly directed first surfaces 7 of the flanges 1. The reinforcement layer 12 may be attached to the flange, for example, using adhesive or bolts. In the arrangement shown in figure 6, each reinforcement layer 12 covers substantially all of the first surface 7 of the flange 1.

The drum shell and flange of the present invention are preferably metal. The drum shell and flange may be manufactured separately and subsequently attached to one another, for example by bolts, adhesive or by welding. Alternatively, they may be manufactured together as one piece using a single cast or mold. The reinforcement layer 4, 5 applied to the drum shell reinforces the winch to improve its capability of withstanding the compressive forces exerted on the winch drum by a rope during its use.

Preferably, the reinforcement layer applied to the drum shell or the flange comprises a different material to that of which the drum shell and any flanges are constructed. The use of a combination of different materials in the construction of the winch drum allows the characteristic properties of each of the various materials to be utilised in order to achieve an optimal combination of weight, wear and strength.

The reinforcement layer may have a tensile strength greater than the tensile strength of the material of the cylindrical drum shell. Alternatively, the reinforcement layer may have a tensile strength which is less than or equal to the tensile strength of the drum shell. If the tensile strength of the reinforcement layer is less than the tensile strength of the drum shell material, the weight of the reinforcing material should preferably be lighter than the weight of the drum shell material in order to achieve a reduction in the total weight of the winch drum. By combining traditional winch materials such as steel or aluminium with a reinforcement layer applied to the drum shell, a winch drum construction can be achieved which has a lighter weight whilst still being able to withstand the compressive forces which act on the drum shell of the winch drum as a result of tension in the rope.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or integers.

The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

While the invention has been described in conjunction with the exemplary

embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

Claims

1. A winch drum comprising: a cylindrical drum shell having a radially inner surface and a radially outer surface; and a separate reinforcement layer applied to at least one of said surfaces.

2. The winch drum of claim 1 , wherein the winch drum further comprises a flange, the flange having a first surface and a second surface; at least one of which has a reinforcement layer.

3. The winch drum of claim 2, wherein the flange is metal.

4. The winch drum of any preceding claim, wherein the drum shell is metal.

5. The winch drum of any preceding claim, having a said reinforcement layer which comprises a plastic.

6. The winch drum of any preceding claim, having a said reinforcement layer which is molded.

7. The winch drum of any preceding claim, having a said reinforcement layer which comprises a high tensile material.

8. The winch drum of any preceding claim, comprising a said reinforcement layer which is wrapped around the outside surface of the drum shell.

9. The winch drum of any preceding claim having a reinforcement layer applied to said outer surface which includes grooves for the purpose of guiding a rope on to the drum during spooling.

10. The winch drum of any preceding claim, having a said reinforcement layer which comprises an elastic material.

1 1. The winch drum of any one of claims 1 to 9, having a said reinforcement layer formed of a substantially rigid material.

12. A winch drum substantially as hereinbefore described with reference to and as shown in the accompanying drawings.