Low-construction trolley for wire rope hoist

Abstract

A low-construction trolley for a wire rope hoist is arranged to travel along a lower flange of a horizontal rail, on both longitudinal edges thereof. The trolley includes a trolley frame; bearing wheels that are attached to the trolley frame and arranged to travel on an upper surface of the lower flange of the rail; a hoisting mechanism including a rope drum for a hoisting rope, a hoisting member in cooperation with the hoisting rope for hoisting a load, a hoisting motor for driving the rope drum, and a gear to interconnect the hoisting motor and the rope drum; whereby the rope drum is supported to one side of the trolley frame and the hoisting member is arranged to travel under the rail in a vertical plane (A) passing substantially through the middle of the beam. For balancing the trolley without using a counterweight, the hoisting motor is placed under the rail and at least partly on a different side than the rope drum in relation to a vertical plane (B) passing through contact lines of the bearing wheels that touch the lower flange of the rail on the rope drum side.

Claims

1. A low construction trolley for a wire rope hoist, arranged to travel along a lower flange of a horizontal beam or rail, whereby the trolley comprises: a trolley frame; bearing wheels that are attached to the trolley frame and arranged to travel on an upper surface of the lower flange of the beam or rail on both longitudinal edges thereof, and at least some of which are driven wheels to move the trolley; and a hoisting mechanism comprising a rope drum for a hoisting rope, a hoisting member in cooperation with the hoisting rope for hoisting a load, a hoisting motor for driving the rope drum and a gear to interconnect the hoisting motor and the rope drum, whereby the rope drum is supported to one side of the trolley frame and the hoisting member is arranged to travel under the beam or rail in a vertical plane (A) passing substantially through a middle of the beam or rail, wherein the hoisting motor is placed entirely lower than the beam or rail and at least partly on a different side than the rope drum in relation to a vertical plane (B) passing through contact lines of the bearing wheels that touch the lower flange of the beam or rail on the rope drum side, and wherein the hoisting motor is placed so that a longitudinal centre line of the hoisting motor is parallel to the longitudinal direction of the beam or rail.

2. The trolley as claimed in claim 1, wherein the hoisting motor is placed under the beam or rail and at least partly on a different side than the rope drum in relation to the vertical plane (A) passing through the middle of the beam or rail.

3. The trolley as claimed in claim 2, wherein the hoisting motor is placed at essentially a same vertical plane as the beam or rail, whereby the vertical plane (A) passing through the middle of the beam or rail is passing essentially through the longitudinal centre line of the hoisting motor.

4. The trolley as claimed in claim 1, wherein the hoisting motor is placed at essentially a same vertical plane as the beam or rail, whereby the vertical plane (A) passing through the middle of the beam or rail is passing essentially through the longitudinal centre line of the hoisting motor.

5. The trolley as claimed in claim 4, wherein the gear that interconnects the hoisting motor and the rope drum is arranged so that the hoisting motor and the rope drum are on a same side in relation to the gear, whereby the hoisting motor, gear and rope drum are in a C form, as seen from the above.

6. The trolley as claimed in claim 4, wherein the gear interconnecting the hoisting motor and the rope drum is arranged so that the hoisting motor and the rope drum are on different sides in relation to the gear, whereby the hoisting motor, gear and rope drum are in a Z form, as seen from the above.

7. The trolley as claimed in claim 1, wherein the gear that interconnects the hoisting motor and the rope drum is arranged so that the hoisting motor and the rope drum are on a same side in relation to the gear, whereby the hoisting motor, gear and rope drum are in a C form, as seen from the above.

8. The trolley as claimed in claim 1, wherein the gear interconnecting the hoisting motor and the rope drum is arranged so that the hoisting motor and the rope drum are on different sides in relation to the gear, whereby the hoisting motor, gear and rope drum are in a Z form, as seen from the above.

9. The trolley as claimed in claim 1, wherein the hoisting motor is placed so that its longitudinal centre line is perpendicular to the longitudinal direction of the beam or rail.

10. The trolley as claimed in claim 9, wherein the gear is transverse in a same line with the hoisting motor, the hoisting motor, gear and rope drum thus being in an L form as seen from the above.

11. The trolley as claimed in claim 1, wherein the hoisting motor is located between vertical planes passing through the bearing wheels.

Description

LIST OF FIGURES

(1) The invention is now described in closer detail in connection with preferred embodiments, with reference to the accompanying drawings, in which

(2) FIG. 1 is a front view of a first preferred embodiment of a trolley of the invention seen in the direction of a rail supporting it;

(3) FIG. 2 is a side view of the trolley according to FIG. 1;

(4) FIG. 3 is a top view of the trolley according to FIG. 1;

(5) FIG. 4 is a top view of a second preferred embodiment of the trolley according to the invention; and

(6) FIG. 5 is a top view of a third preferred embodiment of the trolley according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(7) With reference to FIGS. 1 to 3, a low construction trolley 1 of a wire rope hoist according to the invention is shown, the trolley being arranged to move along a lower flange 3 of a horizontal beam or, as in here, rail 2. The rail 2 typically forms a main support of a bridge crane, or is included in it as its lower part.

(8) The trolley 1 is shown as a simplified schematic view that only presents what is needed to understand the invention.

(9) The trolley 1 comprises a trolley frame 4, bearing wheels 51 and 52 and a hoisting mechanism 6.

(10) The bearing wheels 51 and 52 are fastened to the frame 4 of the trolley and arranged to travel on the upper surface of the lower flange 3 of the rail 2, on both longitudinal edges thereof, and at least some of them are driven wheels to move the trolley 1. An actuator (a moving mechanism of the trolley) for driving the bearing wheels 51 and 52 is not shown.

(11) The hoisting mechanism 6 comprises a rope drum 7 for a hoisting rope 8, a hoisting member co-operating with the hoisting rope 8, in this case a lifting hook 9, to hoist a load, a hoisting motor 10 to drive the rope drum 7 and a gear 11 to interconnect the hoisting motor 10 and the rope drum 7.

(12) The rope drum 7 is fixed as supported by both of its ends to one side of the trolley frame 4, whereby the centre axis of the rope drum 7 is parallel to the rail 2, and the lifting hook 9 is arranged to travel under the rail 2 in a vertical plane A passing through the middle of the rail.

(13) The hoisting rope 8 is led from the rope drum 7 down to a first rope pulley 12 of the lifting hook 9, from there up to a sheave 13 on the other side of the trolley 1, from the sheave 13 down again to a second rope pulley 14 of the lifting hook 9 and, finally, from there up to a fixing point (not shown) on the frame 4 of the trolley 1 on the same side of the trolley 1 as the rope drum 7. The lifting hook 9 moves up and down depending on whether the hoisting rope 8 is reeled on or off the rope drum 7. This conventional control of the hoisting rope 8 is referred to as a four-rope roping system, in which the hoisting rope 8 is constantly in seven folds. The weight caused by the load is here distributed on four ropes. Another type of roping, e.g. a system of two ropes, is naturally also conceivable. However, the roping system is not essential for the present invention, it is being explained only to illustrate the operation of the hoist.

(14) Then again, in order to balance the trolley 1 or to at least improve the balance, it is essential in the invention that the hoisting motor 10 is placed under the rail 2 and at least partly on a different side than the rope drum 7 in relation to a vertical plane B passing through contact lines of the bearing wheels 52 that touch the lower flange 3 of the rail 2 on the rope drum 7 side on this side of the rail 2, preferably at least partly on a different side than the rope drum 7 in relation to a vertical plane A passing through the middle of the rail 2. Contact lines are longitudinal lines running on the lower flange 3 of the rail 2, the bearing wheels 51, 52 travelling along the lines, which are parallel to the rail 2.

(15) In the embodiment of FIGS. 1 to 3 the hoisting motor 10 is placed with its longitudinal centre line parallel to the longitudinal direction of the rail 2 and, to be more specific, so that the hoisting motor 10 is placed at a substantially same vertical plane as the rail, the vertical plane A passing in the middle of the rail 2 thus running substantially through the longitudinal centre line of the hoisting motor 10. The sideward location of the hoisting engine 10 may, however, be changed as needed to achieve the desired balance.

(16) In this example solution the gear 11 connecting the hoisting motor 10 and the rope drum 7 together are arranged so that the hoisting motor 10 and the rope drum 7 are on the same side in relation to the gear 11, so, as seen from the above, the hoisting motor 10, gear 11 and rope drum 7 are in a C form.

(17) FIG. 4 shows an example embodiment in which the gear 11 interconnecting the hoisting motor 10 and the rope drum 7 are arranged so that the hoisting motor 10 and the rope drum 7 are on different sides in relation to the gear 11, so, as seen from the above, the hoisting motor 10, gear 11 and rope drum 7 are in a Z form. In this implementation the trolley has a frame 4 which differs from the frame 4 of the trolley according to FIGS. 1 to 3 in that the location of the rope drum 7 on the frame 4 has been shifted in the longitudinal direction of the rail 2 so that the rope drum 7 is more in line with the lifting hook 9 and the bearing wheels than in the solution according to FIGS. 1 to 3. This is now possible because no space needs to be reserved between the gear 11 and lifting hook 9 for the hoisting motor 10. Here the control of the hoisting rope 8 differs from the one shown in FIGS. 1 to 3 mainly due to the positioning of the rope drum 7 in the longitudinal direction, the rope being driven from the rope drum 7 down to the rope pulley 14 of the lifting hook 9, from there up to a sheave 13 on the other side of the trolley 1, from the sheave 13 again down to a rope pulley 12 of the lifting hook 9 and, finally, from there up to a fixing point X on the frame 4 of the trolley 1, on the same side of the trolley 1 as the rope drum 7. In a way, here the guiding of hoisting rope 8 to the lifting hook 9 takes place in a reverse order compared to the implementation shown in FIGS. 1 to 3, and the fastening of the hoisting rope 8 to the frame 4 takes place in an area between axes passing through two successive bearing wheels 52.

(18) In the embodiment of FIG. 5 the hoisting motor 10 is placed so that its longitudinal centre line is perpendicular to the longitudinal direction of the rail 2. At the same time, the gear 11 has a common transverse line with the hoisting motor 10, the hoisting motor 10, gear 11 and rope drum 11, as seen from the above, thus being in an L form. In this solution, the positioning of the trolley frame 4 and the rope drum 7 is the same as in the implementation according to FIG. 4.

(19) According to an embodiment, it is advantageous to shape and build the structure carrying the trolley 1 so that the beam or rail 2 is connected to a parallel load-bearing casing, which is mostly above the beam or rail 2. In that case the main part of the load may rest on the casing, the beam or rail 2 providing a well-suited fastening bar to the trolley 1.

(20) 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.