JPS5827194B2 - Equalizer for overhead crane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an overhead crane in which a trolley supporting bridge frame carrying a hoisting device and moving laterally is supported at its four corners by trucks on a main inway.

A problem affecting this type of overhead crane is local deformation or subsidence of the thinway or runway supports.

If the crane bridge frame is rigid and the trucks directly support the frame, any misalignment of the trucks will cause large inequalities in the loads transmitted through the individual trucks.

This increases the stress on the thinway, the track and frame on which side the load is increased.

In extreme cases, even a slight deformation of the sinkway can cause one or two tracks to become unloaded.

Various approaches have been tried to address this problem.

One is to make the bridge frame sufficiently flexible to follow the deformation or subsidence of the thinway.

Typical examples include configuring a bridge frame using links or providing flexible links around the frame.

This method does not cause high torsional stresses in the frame, but the bridge frame itself tilts at the links.

The disadvantage of this method is that the tilting of the bridge frame allows for tilting of the trolley runway on the frame supporting the trolley frame, and a design must be considered on the trolley to accommodate such deformations.

Furthermore, in a bridge frame using links, when the bridge frame runs on the main sinway, the deformation in the horizontal plane caused by the links that make up the bridge frame causes the wheels on either the left or right side of the frame to move closer to the wheels on the other side. This tends to cause the vehicle to run more slowly.

Therefore, the tracking performance of such a bridge frame is inferior to that of a frame with high rigidity.

As a result, frame alignment on the runway tends to deteriorate.

If the rigidity of the bridge frame is increased, the alignment of the trolley frame will be easier to maintain and there will be fewer problems with tracking performance.

However, the loads transmitted from the tracks supporting the bridge frame on the Shinway create very high torsional stresses within the frame.

Crane and Shinway designers must therefore consider both the stiffness of the bridge frame and the possible degree of subsidence and deformation to which the Jinway is susceptible.

Of course, predicting the extent of future runway subsidence is often difficult.

Although it would be theoretically possible to design a runway foundation that will not subside, in reality it is difficult to predict how much subsidence will occur.

The present invention is a rectangular bridge frame for an overhead crane;
Four tracks supporting the four corners of the frame on parallel running rails for the frame, and collapsing of the parallel rails that evenly transmits the load from the frame to the four tracks between the frame and the four tracks. two supports that support one side of the bridge frame disposed on two tracks placed on one side; and two supports disposed on one side of the bridge frame that link and connect the upper ends of these two supports to each other. The two supporting parts are configured symmetrically to each other in the longitudinal direction of the running rail and are configured to engage with saddles provided on the two tracks respectively. An outer or inner trunnion is provided on a horizontal axis perpendicular to the trunnion, and an inner or inner trunnion is provided on a saddle provided on the lower surface of one side of the bridge frame, which is horizontally shifted from the trunnion in the longitudinal direction of the running rail and is provided in a parallel shaft shape. This equalizer for an overhead crane is characterized in that it is comprised of an outer trunnion and a lever arm that is integrally fixed to the trunnion and extends upward, the upper end of which is connected to the tie bar.

According to the present invention, the load applied to the remaining two sets of tracks is less affected by the deformation of the main sinway.

Preferably, the pair of support parts are bell cranks having a pair of inner and outer hook trunnions whose centers are shifted in the horizontal direction, and a lever arm extending upward from these trunnions.

and the bridge frame is supported by the inner or outer trunnions of the two supports, the track supports the outer or inner trunnions of the two supports, and the two lever arms are integral with the inner and outer trunnions. It is configured to extend upward, and its upper end is linked with a tie bar.

The links may also incorporate elastic elements, which provide some elasticity to the support of the frame.

In Figure 1, the crane has a highly rigid rectangular frame 2.
The rectangular frame 2 consists of a horizontal member 4 and end members 6 and 8.

Attached to the horizontal member 4 are rails 10 forming a second runway for the trolley 12.

A conceptually illustrated hoisting device 14 is mounted on the trolley 12.

The frame 2 is supported through tracks 18.20 on a main sinway formed by running rails 16.16.

The tracks 20 are attached to the lower sides of both ends of the end member 8 by a known method (not shown).

On the other hand, the track 18 is attached to the lower side of both ends of the end member 60 via a trunnion portion forming a part of the support portion 22.

These trunnions are best shown in FIG.

Each consists of two sets of inner and outer trunnions 24,26 whose center lines are offset horizontally, and the lever arm 2
There is one set on each side of the base of number 8.

The inner trunnion 24 supports a saddle 30 on the lower side of the end member 6.

On the other hand, one outside saddle 726 is mounted on the saddle 32 on the upper side of both shoes 18.

Therefore, due to the load applied from the end member 6 to both tracks 18 through the trunnion part, the axis of the trunnion shaft, that is,
Due to the misalignment of the trunnion track support and frame support, forces are created in the two lever arms 28 that act in opposite directions.

The two lever arms 28 move away from each other.

Such movement causes the two upper trunnions 24 and 26 to
It is restrained by a tie bar 34 connecting clevises 36 attached to the upper ends of the two lever arms 28.

Since the rotational moment generated on both lever arms 28 by the tie bar 34 is equal and opposite in direction, the load applied to the tongue 18 via the shaft 726 (t or 24) will be reduced if the rotational displacement of the support part is small. If so, they are equal and opposite in direction.

This means that as a result, the loads applied to both tracks 18 tend to be equal; in other words, changes in load due to deformation of the running rail occur on both tracks 20 on the opposite side. It means difficult.

In other words, when the crane shown in Fig. 2 moves to the right and the wheels of the right truck 18 come to a place where the traveling rail 16 has sunk and deformed, the right truck 18 will descend somewhat and the saddle on the right truck 18 will fall. The load of the rectangular frame 2 transmitted from the end member 6 to the end member 32 via the trunnion 26 decreases rapidly, and as a result, the load on the end member 6 side of the rectangular frame 2 is concentrated on the left track 18 in FIG. 2.

This concentrated load was coupled onto the left track 18.

A counterclockwise rotational force is applied to the support part 22 around the trunnion 24, and the support part 22 on the right side of the right tongue 18, which is linked via the tie bar 34, also rotates counterclockwise. (The trunnion 26 of the IJII support portion 22 rotates downward around the trunnion 24, and is pressed against the surface of the saddle 32 of the right track 18, so that the loads S on the left and right tracks 18, 18 are restored to be equal.

The above-mentioned load equalization effect on the end member 6 side of the rectangular frame 2 is equivalent to substantially supporting the rectangular frame 2 at one point on the end member 6 side, and the load equalization effect is applied to a certain point near the center of the end member 6 as shown in FIG. It can be imagined that there are two supporting points for the left and right tracks 18.

Since the rectangular frame 2 maintains balance at three points: this virtual fulcrum and the two tracks 20.20 on the opposite side, the running rail 1 also exists between the two tracks 20.20 on the opposite side.
This means that load imbalance due to the deformation of 6 is less likely to occur.

Slight movements of the support system are caught by telescopic elements 37 incorporated between the tie bars 34 to maintain the tightness within the support system.

A spring is normally used as this member and is installed between the bars 34 so as to be compressible.

[Brief explanation of drawings]

Fig. 1 shows an embodiment of the present invention; Fig. 2 is a perspective view showing one side and one end thereof; Fig. 2 is a partially cutaway end front view; Fig. 3 is a detailed view of the lever system. 2 shows the state of connection between the bridge frame and the track in FIG.

Claims (1)

[Claims] 1. A rectangular bridge frame for an overhead crane, four tracks supporting the four corners of the frame on parallel running rails for the frame, and loads from the frame to the four tracks between the frame and the four tracks. two supports that support one side of the bridge frame disposed on two tracks placed on either one of the parallel rails and the upper ends of these two supports are linked together. and a tie bar arranged on one side of the bridge frame, and the two supporting parts are configured symmetrically with respect to each other in the longitudinal direction of the traveling rail and are respectively provided on the two trunks. an outer or inner trunnion provided on a horizontal axis perpendicular to the running rail so as to engage with a saddle mounted on the rail; and a lever arm that is integrally fixed to both of the trunnions and extends upward, the upper end of which is connected to the tie bar. Equalizer for cranes.