Trolley of rope crane

A trolley of a rope crane, comprising a trolley body, a transverse load beam of the trolley, a hoisting mechanism and comprises a rope drum, a hoisting motor for driving the rope drum, and a gear for coupling the hoisting motor to the rope drum, whereby the gear has a primary side and a secondary side, and whereby the rope drum is located, in the vertical direction of the trolley, between the hoisting motor and load beam parallel to the load beam. The hoisting mechanism is supported by a three-point support to a main beam, whereby the first support point and second support point are adjacent to the secondary side of a gear, and whereby the third support point is formed by a support of the rope from end facing away from the gear to the load beam at a lateral distance from the first and second support point.

BACKGROUND OF THE INVENTION

The invention relates to a trolley of a rope crane, comprising a body of the trolley, a transverse load beam of the trolley, forming part of the trolley body, a hoisting mechanism which is supported to the trolley body and comprises a rope drum for at least one hoisting rope, a hoisting motor for driving the rope drum, and a gear for coupling the hoisting motor to the rope drum, whereby the gear has a primary side coupled to the hoisting motor, and a secondary side coupled to the rope drum, and whereby the rope drum is located, as seen in the vertical direction of the trolley, between the hoisting motor and load beam parallel to the load beam.

In a trolley of the type described in the above, the hoisting mechanism has conventionally been supported to the trolley body by a three-point support in which one support point is between the hoisting gear and the rope drum, that is, on the secondary side of the hoisting mechanism, the second support point on the primary side of the trolley and hoisting gear (where the output shaft of hoisting motor is located), while the third support point is between the load beam and the “free end” of the rope drum i.e. the end of the rope drum, which is facing away from the gear. The moment resulting from the use of the hoisting mechanism is received by the second support point on the primary side of the hoisting mechanism, whereby the support force decreases as the supporting distance increases. The arrangement of the moment support like this is one of the determining factors for the width of the trolley (body of the trolley) or for the rail gauge of the trolley, which may turn out to be too large for certain uses of the trolley. The distance of the primary side support point from the load beam brings forth a situation where it is natural to locate the support point on end girders at the ends of the load beam, and therefore the location of the support point also determines the rail gauge of the trolley. An alternative way is to make a protrusion on the flank of the load beam, which makes the structure of the load beam complicated, bulky, and heavy.

SUMMARY OF THE INVENTION

It is an object of the invention to improve the support of the hoisting mechanism so that the aforementioned problems may be solved. This object is reached by a trolley according to the invention, which is characterized in that a hoisting mechanism is supported by a three-point support to a main beam, whereby the first support point and second support point are located adjacent to the secondary side of a gear so that the first support point is higher on the main beam and the second support point is lower on the main beam at a distance from the first support point, and whereby the third support point is formed by a support of the rope drum end which is facing away from the gear to the load beam at a lateral distance from the first and second support point.

The first support point receives forces in the radial direction of the support point, which are caused by the masses, resultant of the rope force, and support force of the moment caused by the resultant of the rope force. The mass of the hoisting gear, hoisting motor, and rope drum in turn brings forth compression to the second support point. In addition, the second support point acts as a second support point for the moment caused by the resultant of the rope force.

With the inventive moment support arrangement in which also the second support point i.e. moment support is arranged on the secondary side of the hoisting mechanism, but at an adequate distance from the first support point to the load beam, the required moment support is achieved at the same time as this arrangement makes it possible to separate the width of the trolley or its rail gauge from the support of the hoisting mechanism. This means that the aforementioned restrictions are eliminated, caused by arranging the moment support on the end girders.

A preferred application for the solution according to the invention is a trolley in which an active rope guiding device is used in multi-layer winding and guiding of a rope, whereby one or more hoisting ropes are wound on an effectively short rope drum through a plurality of sheaves. However, usage is not limited exclusively to such a trolley, but the invention may be applied to all trolleys for which it is desired that the width or rail gauge of the trolley is independent of arranging the moment support needed by the hoisting mechanism. Consequently, the solution according to the invention allows, in particular, an increase in the width or rail gauge of the trolley.

The solution according to the invention additionally facilitates the installation of the hoisting mechanism and does not add to internal forces within the gear.

Preferred embodiments of the invention are disclosed in the dependent claims.

DETAILED DESCRIPTION OF THE INVENTION

With reference the to figures in the drawings, they show an essential part of the trolley1, associated with the present invention. It comprises a trolley to body, of which a load beam2, only, in the transverse direction of the trolley1is shown. Other body parts related to the load beam2and not shown do not bear an essential meaning from the viewpoint of the invention.

The trolley1shown in the drawings further comprises a hoisting mechanism3which is supported to the trolley body2and comprises a rope drum4for at least one hoisting rope (not shown), a hoisting motor5for driving the rope drum, and a gear6for coupling the hoisting motor5to the rope drum4.

The gear6has a primary side coupled to the hoisting motor5and a secondary side coupled to the rope drum4, whereby the rope drum4is located, as seen in the vertical direction of the trolley1, between the hoisting motor5and the load beam2parallel to the load beam2.

The essential matter in the present invention is that the hoisting mechanism3is supported by a three-point support A, B, C to the main beam2, whereby the first support point A and second support point B are located adjacent to the secondary side of a gear6so that the first support point A is higher on the main beam2and the second support point B is lower on the main beam2at a distance from the first support point A, and whereby the third support point C is formed by a support of the rope drum4end facing away from the gear6to the load beam2at a lateral distance from the first and second support point A, B.

At the first support point A, the movement of an installation flange7of the gear6in the vertical, longitudinal, and transverse directions is prevented, but rotation is allowed, i.e. in the XYZ coordinate system, shown in the drawings, movements in the X, Y, and Z directions are prevented whereas rotation in these direction is free. At the second support point B, the movement of the gear6in the direction towards the load beam2is prevented, but movement in the longitudinal and vertical direction of the load beam2as well as rotation allowed, i.e. movement in said coordinate systems in the Y direction is prevented, but allowed in X and Z directions, rotation in all the directions being free. The support point B forms a moment support of the gear, whereby depending on this support, the distance of the resultant of the rope force causes compression or traction towards the load beam2. At the third support point C, the movement of the rope drum4end facing away from the gear6in the vertical direction and towards the load beam2is prevented, but movement in the longitudinal direction of the load beam2and rotation are allowed, i.e. movements in the Y and Z directions, only, are prevented, but free in the X direction are free, rotation in all the directions being free. The gravitational force Fgand on the line SL between the support points the resultant of the support moments Mm=Fg×SLFgand Mf=Fr×SLFrcaused by gravity and rope force defines the magnitude and direction (compression or tractive force) of the force directed to the support point B.

The hoisting mechanism3advantageously comprises a vertical installation flange7fastened to the flank of the gear6, whereby the first support point A comprises a first lug8on the vertical side2aof the load beam2, in its top part, to which lug the top part of the installation flange7is supported by means of a pin and ball joint10in the longitudinal direction of the load beam2, which are installed through openings9in the top part of the installation flange7and the first lug8. The second support point B comprises a second lug11on the vertical side2aof the load beam2, in its bottom part, which has a vertical opening12to which a support protrusion13formed in the bottom part of the installation flange7extends. Obviously, the aforementioned installation flange7may also be part of the casing of the gear6. The third support point C comprises a third lug14on the vertical side2aof the load beam2, at the rope drum4end facing away from the gear7, to which the end Xs of the shaft X of the rope drum4is supported.

With reference toFIG.3a, there is arranged in the second lug11a horizontal pretension, towards the vertical side2aof the load beam2, With this, traction is converted into compression at the support point B. In addition, between the vertical side2aof the load beam2and the second lug11there is arranged a slide surface14which may be arranged between the second lug11and the vertical side2aof the load beam2. In the pretension, a flexible element15between a tensioning surface of the lug11and the support protrusion13, the flexible element inFIG.3abeing shown in a compressed state. An uncompressed state of the flexible element15is shown inFIG.3b.

Alternatively, the aforementioned installation flange7may be part of the casing of the gear6.

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 the details of the invention within the scope of the attached claims.