DE2518613A1 - OFFSHORE CRANE WITH WEIGHT BALANCING - Google Patents

Description

1 BERLIN 33 8 MUNICH 80

Auguste-Viktoria-Strasse 65 p. D I I Or ^ Ul W E J? DADTMCD PienzenauerstraBe 2

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Telephone: 030 / | f ₆ 38 * BERLIN - MÖNCHEN ^Teiefon: ""'98725S

Telegram address: Telegram address:

Quadrature Berlin Quadrature Munich

TELEX: 183786 TELEX: 522767

A 1506

American Hoist & Derrick Company, St. Paul, Minnesota

Offshore crane with counterbalance

The invention relates to base cranes with counterbalance. Such cranes are used for reloading goods or loads from seaworthy Such cranes are special when ships are used on floating platforms or on the seabed Benefit, for example, in offshore oil drilling

It is known per se on a horizontal supporting surface behind a rear part of a rotatable masohine deck to store a counterweight to counterbalance the weight when handling heavy loads.

According to US Pat. No. 3,842,984, the down Directed loading of the machine deck by the counterweight completely avoided by the fact that the counterweight on the machine

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ceiling and is mounted rotatably with this, but is supported by wheels that rest on a relatively flat horizontal surface that carries the crane car body. However, in order to be able to use the weight of the rear part of the machine deck as an additional counterweight when the counterweight is no longer supported by the ground, the relationship between the mast and the counterweight suspension and between the mast and the machine deck bearing must be checked critically _e Only in this way the outermost rear end of the machine deck can serve as a counterweight for the load on the loading boom when the counterweight is lifted from the supporting surface

Neither the horizontal support surface according to US Pat. No. 2,842,984 nor the ring according to US Pat No. 3 485 383 for cranes of the embodiment according to US patent specification Er2,703,180, for example · This is a consequence of the fact that it is not economically feasible to use effective means for a Provide a horizontal support surface for the counterweight without damaging or at least unsettling the base Acting torques.

The invention is based on the object of a counterweight support to handle very heavy loads without placing undue stress on the engine deck and just as little Swivel bearing connections between the masehinsn & eck and the base, if such heavy loads are not unloaded

According to the invention, this object is achieved in that the counterweight on the rear part of the machine end counter-

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set to the loading boom pivotable with respect to the machine documentation is stored that at least one support wheel is provided for the counterweight, which with respect to a lower part of the Counterweight is rotatably mounted about a vertical axis, that a bearing surface for the support wheel of the counterweight is provided under the deck on the base, that means are provided which include the support means for the counterweight, a rotation of the deck about its vertical axis «a Rotation of the counterweight about the same vertical axis causes, and that suspension means are provided that the counterweight connect to an upper part of the mast.

Cooperating bearing means can be provided between the counterweight and a rear end part of the machine deck be that the acting on the counterweight and upward forces on said rear end portion of the Machine doks transferred when the load hanging on the load part causes the »wide suspension means to lift the counterweight from the entire support. The cooperating storage means may include a storage platform that forms part of the counterweight and is perpendicular to the outermost one End part of the masohine deck is arranged · furthermore, between this outermost part of the deck and The storage platform of the counterweight inserts are provided that an upward movement of the counterweight immediately on the rear Transfer the end part of the deck. According to the invention is the pivot bearing for the counterweight between the vertical axis of rotation of the deck with respect to the base and the extreme rear end portion of the deck.

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The invention will now be described in detail »In the accompanying drawings

Figol shows a side view of an offshore crane according to the invention with counterbalance on a base resting on the seabed,

Fig # 2 is a horizontal section through the crane following the line 2-2 in Fig.1 and the

Fig. 3 is a detail from a vertical section through the Crane according to line 3-3 in FIG. 2, with the attachment of the pedestal on a floating barge is shown.

The offshore crane shown in Figol with counterbalance has a cylindrical base 12, which remains continuously sunk into the seabed 14, as well as a machine document 16, which is rotatably attached to the base 12

A loading boom 18 and a mast 22 are pivotably attached to a front part 20 of the machine deck.

A counterweight 24 has a counterweight tank 26 which is filled with seawater 28, for example. This counterweight is, as shown at 30, on a rear portion 32 of the machine deck 16 by means of a downwardly extending Strut 34 and a generally horizontally extending strut mounted versohwenkbar, which struts with the counterweight at 38 and 40 are connected

A first suspension means 44 connects the top of the mast 22 to the top of the cargo boom 18 »As can be seen,

can be the length of this first suspension with the help of a suitable

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Machine 45 are changed on the machine deck by extending or shortening a control cable 48, wherein the distance between the two roller blocks 46, 46 extended or shortened from each ^ Z · A aweites suspension means connecting an upper portion of the counterweight tank 26 (at $ 4) with the upper end of the mast 22, as shown at 41. At the upper end of the loading boom 18, a load rope 50 is guided around a pulley and at the lower end carries a load handling means, e.g. a hook 52 A machine 54 is set up on the machine end with which the length of the load ropes can be adjusted 45 and 54 can be of any conventional or preferred construction and can be set up in any convenient location provided that the regulation cable 48 extends to the pulley blocks 46 and that the load cable extends around the pulley at the top of the boom.

On the engine deck and on the boom 18 is a shock-absorbing Stop device 56 attached, which prevents movement of the loading boom in a position in which the boom in the direction of the the rear part of the engine deck would fall.

As can best be seen from Pig «3, the masohine deck is 16 rotatably mounted on the base by means of a ring rail and a roller conveyor 58 · Extends on the upper part of the base a center pin 59 upwards, on which a bushing 60 of the ring rail sits, which forms part of the engine deck structure forms as well as the load rollers and the hook roller bearing members 62, 62. The load rollers 64 are on the bearing members 62 rotatably mounted and carry the masohine deck on a lollipop flange 66 of the combination 58At these bearing links 62

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hook rollers 68 are rotatably attached to the underside of the Flange 66 abut and the upward forces one Oppose the resistance provided by the machine deek on the flange be exercised. Other suitable means can also be used to rotatably support the machine deck on the base.

line storage unit 70 according to the invention for the counterweight has a support collar 72 for the counterweight, which is on cylindrical base 12 concentric to the vertical axis of the roller conveyor 58 by means of the horizontally protruding outward Plates or Plansche 74 »74 is attached.

The support 76 for the counterweight has the support rollers 78, which are rotatably mounted on vertical axes, which in turn are supported by horizontally extending roller supports 82 be worn. These roller supports are pivotally mounted at 83 on mounting members 84 which form part of the counterweight tank 26 form and move away from. extend outward from a lower part of the tank

The counterweight tank 26 is also equipped with a storage platform 86 which is perpendicular to a mounting member 88 directly aligned below this, which support member 88 is part of the outermost end of the rearward Part 32 of the machine deck 16 forms. After assembling of the parts, as shown in Figures 1 and 3, are between the platform 86 and the support member 88 one or several metallic insert members 90 inserted to secure * u ^ that an upward movement of the counterweight tank 26 and thus the storage platform 86 to the outermost end of the rear part 32 of the Maschinencüaoks 16 over the

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Retaining member 88 is transferred directly.

Way of working

Take the components of the crane as shown in FIG. 2? Ig * 1 Position, and there is no load hanging on the hook 52, then the one exerted by the wide suspension 42 on the counterweight 24 points and upward force has the lowest value. In this The counterweight 24 on the engine deck is caught entirely by the struts 34 and 36 and by the pivot connections 30 These struts are carried with the underside of the rear part of the machine deck 16 «Because of the freedom of movement on the Pin 30 and without any other connection to the machine deck 16 a considerable force is exerted on the cylindrical by a lower part of the counterweight and via the support wheels 78 Counterweight support collar 72 exercised · Here one becomes the same large and oppositely directed shear force exerted by the bush 60 on the central pin 59 with respect to the base 12

As is usual with such devices, a drive pinion is provided, which extends from the machine deck 16 downwards extends and meshes with the ring gear of the bearing ring 58. To the Rotating the machine deck with respect to the pedestal are power plants provided that rotate the pinion about its axis with the result that the machine deck 16 with respect to the combination 58 is rotated. The funds earmarked for this purpose and devices are not shown as they can consist of any conventional or preferred means.

When the engine deck in relation to the combination 58 out the toothed ring and the roller conveyor and thus in relation to the base

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is rotated, so the struts 34 and 36 act that the counterweight 24 rotates with the deck with rollers 78 on the Roll along the outside of the cylindrical support collar 72. The downward component of the counterweight's weight is carried by the machine deck on the pin 30. This pin 30 has a relatively small distance from the Axis of rotation of the deck, so that a much smaller bending moment is generated than would be the case if the support was at the extreme rear end portion of the deck 16 would be provided.

In the unloaded state of the crane, the largest vertical "dead weight" of the counterweight acts on a lever arm, the length of which is equal to the horizontal distance of the pin 30 from the vertical axis of rotation of the machine deck «Since this is the greatest rearward bending stress, which only occurs with low or even If there is no load, the various components of the crane can be designed without difficulty in such a way that such a load can be safely handled _e

This unencumbered condition is also the condition of the greatest normal stress on the counterweight, which is over the Support means 76 on the support collar 72 attached to the base acts. Since the cylindrical wall of the collar 72 is perpendicular runs, no downward force component is transmitted to the base 12 via the support collar 72. The only The force in question acts perpendicular to the axis of the support collar and in a generally horizontal plane. Will the base and the plates 74-, 74 protruding radially outward on the support collar, which support the collar on the base, are sufficient strong and stiff, it can be a well-known largest

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Be supported safely and economically

The greatest load to be supported to determine the required strength of the components after the bending effects have been assessed in a load-free state now the Druok load due to the weight of the crane and the counterweight and the weight of the largest load for the Crane is provided, treated.

If a load is attached to one of the hooks 52, and the machine 54 is used to wind up the load rope 50, so that the crane 10 can lift the load, the boom 18 is erected and maintained in this position by the first suspension and via the connection of this first suspension to the top of the mast 22. The mast, the first suspension, the load hooks and the load (not shown) are held in their adjustment by the second suspension 42 associated with the upper Part of the counterweight 24 and the top of the mast 22 is connected · If the load ropes 50 are increasingly loaded, so are those acting in the second suspension 42 and directed upwards Forces always stronger. Here, the force component acting on the pin 30 and directed downwards is reduced, while the horizontal force component, which acts on the support collar 72 via the counterweight rollers 78, is likewise is reduced

If this load is continued, a point is finally reached at which the cylindrical outside of the shoulder collar 72 won the counterweight rollers 78 no more force exerted will. At this point in time, the counterweight is looking for the Pivot 30 around so that the rollers 78 move away from the

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Remove collar 72 search · This movement put the pads 90 and the support member 88 at the far end of the rear part 32 of the machine deck 16 has a resistance to _o Masohinendeck however, is in itself a flexible and not rigid construction · After once the entire weight When the counterweight is borne by the second suspension 42, there is further weight compensation as a result of the rear part 32 of the machine deck 16 bending when the load on the load ropes 50 increases. Additional loading can be handled until the set limits are reached for the total loading of the flexible deck and the weight of the counterweight.

If, as already stated, the load is picked up for the first time, so seeks the upward force exerted by the load, the boom, the first suspension and the mast on the second suspension 42 and thus let off steam on the counterweight that To reduce the load on the rear part of the machine deck. At the same time, the front part of the deck is facing downwards loaded, as the downward component of the weight hanging on the load rope at the points of the swivel connection of the Mast and boom is transferred to the front part of the engine deck. In the stress-free state there is therefore the greatest tendency for the engine deck to bend backwards. This load on the engine deck towards the rear Part reaches a minimum value when the. Load is absorbed which increases to a maximum value at which the front end of the Machine dok is loaded when the entire weight of the counterweight is picked up from the mast via the second suspension 42,

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and if the rear part of the engine deck bends, as the counterweight continues to be pulled up.

As can be seen from the above description, the horizontal force components as a result of the weight of the Counterweight in the unloaded state of the counterweight. weight load-bearing unit 70 absorbed Da the entire weight of the counterweight is supported, and since the storage platform on the counterweight together with the outermost rear At the end of the deck prevents the counterweight from moving further upwards, the horizontal force components disappear.

In the unencumbered state, the downward one becomes The effect of the counterweight on the rotating machine deck is reduced as there is no connection between the counterweight and the furthest aft end of the deck up to the point where the entire weight of the counterweight is counterbalanced works.

At this time, the counterweight comes into contact with the extreme rear end portion of the machine deck below it, the total weight of this part of the machine deck and the flexible strength of the rear part of the deck Increasing the counterbalancing effect of the counterweight is always valid, regardless of whether the counterweight is supported Unit consists of a cylindrical collar which is attached to a base concentric to the axis of rotation of the platform, as shown, or whether the unit supporting the counterweight consists of a horizontally arranged ring or a hanging rail as disclosed in U.S. Patent No. 3,485,383.

Claims

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Claims (1)

~ 12 - Claims Crane with an upright base, with a machine endo rotatably attached to the base around a vertical axis, with an upright mast and an upright loading boom, which two components on a front ! Parts of the machine deck are mounted pivotably in a vertical plane running through the vertical axis, with a first suspension between an upper part of the mast and an upper part of the cargo boom, with an over the top of the boom running load rope, with means for rotating the machine deck, with means for operating the load rope and with a counterweight to compensate for the load of the crane when it is lifting heavy loads by means (30) for pivotably supporting the counterweight (24) on a rear part of the machine deck (16), so that the counterweight can be freely pivoted downward with respect to the machine deck, by at least a counterweight support wheel (7B) * the one with respect to fine lower Part of the counterweight is rotatably mounted about a vertical axis, by means (72) on the base (12) below of the machine deck, which is a bearing surface for the counterweight support wheel has, by means of means supporting the counterweight, means for rotating the counterweight effect with the engine deck, and through a second suspension (4-2) between the counterweight and an upper one Part of the mast (22) 509846/0408 Crane after. Claim 1, characterized in that the Counterweight (24) to the rear part of the machine deck (16) at an intermediate between the extreme rear end portion of the masohinendeeks and said vertical axis of rotation of the Becks located point is pivotably connected " 3 · Crane according to claim 1 or 2, characterized in that said means for pivotably supporting the counterweight on a rear part of the machine deck of upper (36) and lower (34-) struts, which with upper and lower parts of the counterweight are connected by pins, extending up to the axis of said point (30) of the pivotable Support of the counterweight in relation to the rear part of the deck and surround it 4 «Crane according to claim 1, 2 or 3» characterized by at least two wheel carriers (82) and at least two groups of pairs of wheels (78) »of which each group is on opposite sides Ends of the carrier is mounted rotatably at a distance from one another about vertical axes, and characterized in that Intermediate parts of the wheel carriers are pivotably mounted with respect to spaced apart lower parts of the counterweight (24). 5 · Crane according to one of claims 1-4, characterized that the means having said bearing surface consists of a cylindrical collar (72) which is attached to the base (12) is attached concentrically to the axis of rotation of the machine deck (16). 509846/0408 6 · Crane according to one of claims 1-5 »characterized in that that the counterweight (24) is provided with a storage platform (86) at a point where it connects to the rear • Part of the machine deck comes into contact when the counterweight is raised by the second suspension (42) in the transfer of a load o 7 · Crane according to Claim 6, characterized in that the Storage platform (86) forms part of the counterweight (24) and is perpendicular under an outermost rear end portion of the Machine decks (16) is arranged » 8p crane according to claim 7 »characterized by. Insoles (90) between the storage platform (86) of the counterweight (24) and the outermost rear end part of the machine deck (16), which inserts (90) transmit power to the storage platform (86) and the outermost rear end part of the machine deck (16) and ensure that any attempted upward movement of the counterweight (24) with respect to the Machine deck (16) is immediately and completely transferred to the rear part of the machine deck (16) 509846/0408