Hoisting arrangement of rope hoist

Abstract

A hoisting arrangement of a rope hoist includes a hoisting rope, a rope drum with one rope groove for the hoisting rope, and a hoisting member for hoisting a load. The hoisting member includes a rope pulley arrangement for the hoisting rope. The hoisting rope is routed from the rope drum via at least the hoisting member's rope pulley arrangement to a fixed attachment point on the rope hoist. The rope drum is tilted in relation to the horizontal plane in a manner where the first end of the rope drum, towards which the hoisting rope is wound in the hoisting member's upper position, is higher than the rope drum's second end, towards which the hoisting rope is unwound in the hoisting member's lower position.

Claims

1. A hoisting arrangement of a rope hoist, comprising: a hoisting rope; a rope drum, with one rope groove for the hoisting rope; and a hoisting member for hoisting a load, the hoisting member having a rope pulley arrangement for the hoisting rope, wherein the hoisting rope is routed from the rope drum at least via the rope pulley arrangement of the hoisting member to a fixed attachment point of the rope hoist, wherein the rope drum is tilted in relation to a horizontal plane in a manner where the first end of the rope drum, towards which the hoisting rope is wound in an upper position of the hoisting member, is higher than a second end of the rope drum, towards which the hoisting rope is unwound in a lower position of the hoisting member, wherein the hoisting rope is in one layer on the rope drum, and wherein a tilting angle of the drum is fixed.

2. The hoisting arrangement as claimed in claim 1, wherein the tilting angle is approximately 1-4 degrees.

3. The hoisting arrangement as claimed in claim 1, wherein the magnitude of the tilting angle depends on a length of the rope drum.

4. The hoisting arrangement as claimed in claim 1, wherein a magnitude of the tilting depends on a length of the rope drum.

5. The hoisting arrangement as claimed in claim 1, wherein the hoisting rope is guided from the rope drum via the rope pulley arrangement of the hoisting member and at least one upper sheave to the fixed attachment point of the rope hoist.

6. The hoisting arrangement as claimed in claim 1, wherein the hoisting rope contains 1 roping, in which case the hoisting rope has n up-down pitches, where n is equal to 2, 3, 4, 5, 6, 7, 8, 9 or 10.

7. The hoisting arrangement as claimed in claim 6, wherein, when the number of roping is odd (n=3, 5, 7 or 9), the attachment point of the hoisting rope is adapted to the hoisting member.

Description

LIST OF FIGURES

(1) The invention will now be explained in more detail with reference to the accompanying drawings, in which

(2) FIG. 1 presents a hoisting arrangement where the rope drum is placed horizontally;

(3) FIG. 2 presents a hoisting arrangement pursuant to FIG. 1, however, the rope drum has been tilted in accordance with the invention;

(4) FIG. 3 presents the effects of the tilting pursuant to the invention on the fleet angle; and

(5) FIGS. 4-7 present different implementations of hoist roping with four hoisting ropes in the order pursuant to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(6) With reference to FIG. 1, it shows a hoisting arrangement of rope hoist (for example, in a bridge crane trolley that is not shown) that comprises the rope drum 1 for the hoisting rope 2 and the hoisting member 3 for hoisting the load (not shown). Hoisting member 3 has pulley arrangement 4 for hoisting rope 2. Correspondingly, a higher part of the rope hoist's fixed section, such as its frame, has sheave 5 for hoisting rope 2. Hoisting rope 2 is routed from rope groove 1a on rope drum 1 to the fixed attachment point X on the rope hoist via rope pulley arrangement 4 for hoisting member 3 and sheave 5. This uses the single hoisting rope 2 to form a four-rope or 14 hoisting rope arrangement pursuant to the Figure that comprises four pitches in the up-down directions. When hoisting member 3 is lowered, hoisting member 3 moves to the side by distance S/i. Rope drum 1 is in the horizontal position. Hoisting rope 2 is on rope drum 1 in one layer.

(7) FIG. 1 shows the following symbols:

(8) S=horizontal transfer of hoisting rope 2 on rope drum 1, when hoisting member 3 has moved from the position shown at the top of the Figure to the position shown at the bottom of the same Figure

(9) S.sub.0=measurement of the horizontal position of hoisting rope 2 when hoisting member 3 is in the top position

(10) e=hoisting height

(11) e.sub.0=measurement of the vertical position of hoisting member 3 when hoisting member 3 is in the top position

(12) i=rope ratio

(13) p=pitch of rope groove 1a

(14) D=(effective) diameter of rope groove 1a

(15) d=diameter of hoisting rope 2

(16) =constant

(17) =fleet angle (variable angle between hoisting rope 2 and rope groove 1a)

(18) =angle of hoisting rope 2 relative to vertical planes V.sub.1 and V.sub.2

(19) V.sub.1 and V.sub.2=vertical planes

(20) =angle corresponding to the pitch of rope groove 1a

(21) In this case,
S=(e*i*p)/(*D)
tan =(S+S.sub.0S/i)/(e+e.sub.0)
tan =p/*D
=

(22) Furthermore, the marking 14 may be used in connection with rope ratio i and roping; this means that 4 pitches in the up-down direction have been created using a single hoisting rope 2. In this case, rope ratio i equals 4.

(23) When, following this, rope drum 1, onto which hoisting rope 2 has been wound in a single layer, has been tilted in relation to the horizontal plane pursuant to FIG. 2 and the invention in a manner where the first end of rope drum 1, towards which hoisting rope 2 is wound in the upper position of hoisting member 3, is higher than the other end of rope drum 1, towards which hoisting rope 2 is unwound in the lower position of hoisting member 3 (in this example, it can also be stated that the end of rope drum 1 that is closer to the vertical line of hoisting member 3 is higher than the end that is further away from this vertical line), the reduced fleet angle may be calculated from the formula
=,

(24) where

(25) =is the stated tilting angle for the rope drum.

(26) The benefit of the tilting regarding the fleet angle is especially evident in FIG. 3, which presents the fleet angle as a function of hoisting height e. The upper curve describes a typical change in fleet angle with an non-tilted rope drum 1, while the lower curve describes it for the tilted rope drum 1. The benefit of a tilted rope drum 1 in the reduction of fleet angle is obvious already at relatively low hoisting heights. FIG. 3 presents the lower curve as a graph where it clearly differs from the horizontal axis. In practice, the benefit from the tilting may be so high that the lower curve runs very close to the horizontal axis, but here, it is clearly separated in order to improve readability.

(27) FIG. 4 presents a hoisting arrangement pursuant to the invention that contains a tilted hoisting drum 1; this differs from the hoisting arrangement in FIG. 2 in that hoisting member 3's rope pulley arrangement 4 and sheave 5 are rotated by 90 degrees about the vertical axis.

(28) FIG. 5 presents a hoisting arrangement pursuant to the invention that contains a tilted hoisting drum 1; this differs from the hoisting arrangement in FIG. 2 in that hoisting rope 2 is routed to rope drum 1 on the other side of rope pulley arrangement 4 (the upper side of rope drum 1). Furthermore, attachment point X for hoisting rope 2 is on the other side of sheave 5.

(29) FIG. 6 presents a hoisting arrangement pursuant to the invention that contains a tilted hoisting drum 1; this differs from the hoisting arrangement in FIG. 2 in that the rope pulley arrangement 4 is rotated by 90 degrees about the vertical axis. Furthermore, hoisting rope 2 is guided onto rope drum 1 from the rope pulley that is on the side of the upper end of rope drum 1 and attachment point X for hoisting rope 2 is on the other side of sheave 5.

(30) FIG. 7 presents a hoisting arrangement pursuant to the invention that contains a tilted hoisting drum 1; this differs from the hoisting arrangement in FIG. 2 in that the rope pulley arrangement 4 is rotated by 90 degrees.

(31) FIGS. 4-7 demonstrate that the tilting of rope drum 1 pursuant to the invention may be used with differently arranged sheaves and rope pulley arrangements. Furthermore, the invention is not limited to the four ropes presented here; the number of ropes may be lower or higher depending on the hoisting height and the size of the load.

(32) The tilting of rope drum 1 is implemented by means of at least one riser (not shown in the Figures) in the supports or bearing housings (not shown) of rope drum 1, which offers the possibility of attaching the ends of rope drum 1 at mutually different heights. This allows for utilising similar bearings at both ends of rope drum 1. A riser in a general sense refers to a device that allows for adjusting the height position. Therefore, the lower surface of a horizontal structure may be raised downward between at least one of the bearing housings (or supports) and the horizontal structure. Alternatively, tilting with a side-attached drum mechanism may be implemented with screw holes drilled at different heights on the attachment point or end pieces or by means of similar fastenings. Oval holes drilled at the same height are also suitable for the purpose.

(33) Advantageously, the slanted angle of rope drum 1 is fixed in each hoisting device, but it may vary between different hoisting devices or hoisting device series.

(34) When attachment is made at the top, a longer suspension part may be used at the drum mechanism end that will hang lower. This part may also be adjustable. The attachment point of the suspension part in the trolley or end contains a different height measurement between the ends or must be adjusted to a different height.

(35) The present invention aims to change the basic starting point of the design; earlier, the selection of the hoisting device type involved several more or less interconnected structural parameters that defined a limited window of operation as described in the background for the invention. Expanding the window in a specific direction may have easily resulted in only one hoisting device type being available due to a specific parameter. The invention aims to completely eliminate the effects of one limiting parameter, creating a larger window of operation for each hoisting device type. Correspondingly, in serial manufacturing, the number of different parts and frame sizes may be reduced while offering even wider characteristics for each hoisting device type. For example, the building of hoisting devices with 18 and 110 roping has been limited due to this, but it is made possible by the invention.

(36) The drawings present hoisting arrangements with an even number of ropes. An odd number of ropes (for example, 3, 5, 7 or 9 up-down pitches) is also possible, in which case the attachment point of hoisting rope 2 is adapted to hoisting member 3. This has not been separately presented in the drawings.

(37) Therefore, the above description of the invention is only intended to illustrate the basic idea of the invention. A person skilled in the art may thus vary its details within the scope of the attached claims.