FREE FALL WINCH

Abstract

The present invention relates to a free-fall winch comprising a drum which can be rotatorily driven by a winch drive via a transmission and can be retained by a holding brake, wherein in addition to the holding brake a free-fall brake is provided for slowing down the drum in free-fall operation. According to the invention, the free-fall brake is arranged between winch drive and holding brake on the one hand and drum on the other hand such that when the free-fall brake is open, the drum is decoupled from the winch drive and from the holding brake and can be rotated at idle with respect to the winch drive and the holding brake.

Claims

1. A free-fall winch, comprising a drum (2) which can be rotarily driven by a winch drive (8) via a transmission (8) and can be retained by a holding brake (10), wherein in addition to the holding brake (10) a free-fall brake (11) is provided for slowing down the drum (2) in free-fall operation, characterized in that the free-fall brake (11) is arranged between winch drive (8) and holding brake (10) on the one hand and drum (2) on the other hand such that when the free-fall brake (11) is open, the drum (2) is decoupled from the winch drive (8) and from the holding brake (10).

2. The free-fall winch according to claim 1, wherein the free-fall brake (11) is arranged such that always at least a part (11a) of the free-fall brake (11) is configured to rotate along with the drum (2) and/or with the winch drive (8).

3. The free-fall winch according to claim 1, wherein a bearing counter-shield (7), on which the drum (2) is rotatably mounted on a side opposite the winch drive (8) and the holding brake (10), also remains torque-free when the free-fall brake (11) is closed.

4. The free-fall winch according to claim 1, wherein one half of the free-fall brake (11) is non-rotatably connected to the drum (2) drum and the other half of the free-fall brake (11) is connected to a transmission element of the transmission (9) so that when the free-fall brake (11) is open and when the free-fall brake (11) is closed, at least part of the free-fall brake (11) always is arranged to rotate along with the drum (2).

5. The free-fall winch according to claim 1, wherein the free-fall brake (11) is accommodated in the interior of a drum casing (3) of the drum (2) and with a free-fall brake outer part (11a) is non-rotatably attached to the drum casing (3) or to a drum casing attachment rigidly connected thereto.

6. The free-fall winch according to claim 1, wherein the transmission (9) comprises a single-stage or multi-stage planetary transmission which is accommodated in the interior of the drum (2), wherein the free-fall brake (11) is rotatably attached to a planetary transmission element with a free-fall brake inner part (11i).

7. The free-fall winch according to claim 6, wherein the free-fall brake inner part (11i) is non-rotatably attached to a ring gear (12) of the planetary transmission.

8. The free-fall winch according to claim 7, wherein said ring gear (12) forms a common ring gear of two or more planetary stages of the planetary transmission of multi-stage configuration.

9. The free-fall winch according to claim 1, wherein the free-fall brake (11) can be actuated by an actuating device (13) which is arranged on a side of the drum (2) opposite the winch drive (8) and the holding brake (10), wherein the actuating device (13) is rotatably supported on a bearing counter-shield (7) and/or is configured to be rotatable in itself so that at least part of the actuating device (13) is freely rotatable with respect to the bearing counter-shield also when the free-fall brake (11) is applied.

10. The free-fall winch according to claim 9, wherein the actuating device (13) includes a rotatorily stationary and axially adjustable actuating cylinder (13i) for actuating the free-fall brake (11), which is rotatably mounted with respect to at least part of the free-fall brake (11) and/or with respect to the drum (2).

11. The free-fall winch according to claim 1, wherein the free-fall brake (11) is configured as a multidisk brake, wherein a first disk set is non-rotatably attached to the drum (2) and a second disk set is non-rotatably attached to a transmission element of the transmission (9).

12. The free-fall winch according to claim 1, wherein at least one part of the free-fall brake (11) continuously rotating along with the drum (2) is provided with oil conveying and/or circulating contours preferably in the form of flushing grooves.

13. The free-fall winch according to claim 1, wherein the holding brake (10) is provided between the winch drive (8) and the transmission (9) and is configured to retain an output shaft of the winch drive (8) and/or an input shaft of the transmission (9).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The invention will subsequently be explained in detail with reference to an advantageous exemplary embodiment. In the drawing:

[0028] FIG. 1: shows a schematic sectional view of a free-fall winch according to an advantageous embodiment of the invention with a non-stationary free-fall brake.

DETAILED DESCRIPTION

[0029] As shown in FIG. 1, the free-fall winch 1 comprises a drum 2 which has an approximately cylindrical drum casing 3 onto which a cable 4 can be wound. Said drum casing 3 therefor can include cable grooves on its outside in order to wind up the cable 4 on the drum 2 in a controlled way. Said drum casing 3 laterally and at its ends each is enclosed by a flanged wheel 5 which extends transversely to the longitudinal axis of the drum casing 3 and protrudes beyond its outside dimension.

[0030] The drum 2 is rotatably mounted parallel to the longitudinal axis of the cylindrical drum casing 3. For this purpose a pair of bearing shields 6 and 7 can be provided, on which the drum 2 is rotatably mounted. The bearing shields 6 and 7 themselves are mounted on a base structure on which the cable winch is to be used, for example the uppercarriage of a cable excavator.

[0031] The cable winch furthermore comprises a winch drive 8, for example in the form of an electric motor or a hydraulic motor, which can be arranged on one side of the drum 2, for example outside the bearing shield 6 provided there, and can be supported on said bearing shield.

[0032] The winch drive 8 can rotatorily drive the drum 2 via a transmission 9, wherein said transmission 9 advantageously can comprise a planetary transmission which can be of single-stage or multi-stage configuration.

[0033] As shown in FIG. 1, said transmission 9 can be accommodated in the interior of the drum casing 3 so that the winch drive 8 and most of the transmission 9 extend on opposite sides of the bearing shield 6.

[0034] For example, the winch drive 8 can drive a sun gear of a planetary stage arranged in the interior of the drum casing 3, whose planet carrier can be coupled with the sun gear of another planetary stage. As is illustrated in FIG. 1, the planetary transmission 2 or 3 also can include more planetary stages in order to achieve the desired gear ratio.

[0035] To be able to retain or fix the cable winch under load a holding brake 10 is provided, which can engage the winch drive 8 and/or an element of the transmission 9. Advantageously, the holding brake 10 can be arranged between the winch drive 8 and said transmission 9, in particular coaxially to the output shaft of the winch drive 8 between its motor and the transmission 9. For example, the holding brake 10 can act on the input shaft of the transmission 9, which can be connected to the sun gear of the aforementioned planetary stage.

[0036] Said holding brake 10 for example can be a multidisk brake which can be applied by a pretensioning means for example in the form of a spring device and can be released by pressure means. Said holding brake 10 can be arranged outside the bearing shield 6.

[0037] As shown in FIG. 1, the free-fall winch 1 furthermore comprises a free-fall brake 11 which couples said transmission 9 with the drum 2 and/or is arranged in the flux of force between winch drive 8 and drum 2.

[0038] In particular, said free-fall brake 11 can connect a transmission element of the transmission 9 to the drum 2 so that when the free-fall brake 11 is closed, said transmission element can drive the drum 2, and when the free-fall brake 11 is open, the drum 2 can be rotated at idle in a manner decoupled from the transmission 9.

[0039] Advantageously, the free-fall brake 11 can couple a ring gear 12 of the planetary transmission with the drum casing 3 so thatwith the free-fall brake 11 openone part of the free-fall brake 11 rotates along with the drum casing 3 and the other part of the free-fall brake 11 rotates along with the ring gear 12, in case said ring gear 12 rotates. As shown in FIG. 1, said ring gear 12 can include a cylindrical extension 12a which can act as a brake carrier and can be rotatably supported on the drum casing 3. A free-fall brake inner part 11i can be non-rotatably attached to said ring gear cylinder 12a, while a free-fall brake outer part 11a can be non-rotatably attached to the casing inner side of the drum casing 3 or to an intermediate part rigidly connected thereto.

[0040] As shown in FIG. 1, the free-fall brake 11 advantageously can be configured as a multidisk brake whose two interlocking disk sets are arranged transversely to the axis of rotation of the drum 2. A first disk set can be non-rotatably attached to the inside of the drum casing 3, while a second disk set is non-rotatably coupled with the ring gear 12 or another transmission element.

[0041] The free-fall brake 11 can completely be accommodated in the interior of the drum casing 3.

[0042] The free-fall brake 11 can be actuated, i.e. released and/or applied, by an actuating device 13 which advantageously likewise can extend in the interior of the drum casing 3 at least for the most part. Said actuating device 13 can comprise a pretensioning device 14 which applies the free-fall brake 11 under pretension. Said pretensioning device 14 for example can comprise a spring device which can axially pretension the disks of the free-fall brake 11.

[0043] A pressure-medium device for releasing the pretension can comprise a piston-cylinder unit 15 which on the one hand is coupled with the free-fall brake inner part 11i and on the other hand is coupled with the free-fall brake outer part 11a in order to tension the two brake parts against each other or release the same from each other, wherein the direction of action of the piston-cylinder unit 15 for example can extend axially, i.e. substantially parallel to the axis of rotation of the drum 2.

[0044] Said piston-cylinder unit 15 likewise can at least partly be accommodated in the interior of the drum 2. Independent thereof, the piston-cylinder unit 15 can be rotatably mounted with respect to the drum 2 and/or be axially supported thereon so that braking forces are supported directly on the drum 2. In particular, the bearing counter-shield 7 remains freely rotatable regardless of whether the free-fall brake 11 is applied or released. The bearing counter-shield 7 need not absorb any reaction moments, even if the free-fall brake is slowed down.

[0045] In normal hoisting operation, said free-fall brake 11 remains closed so that the winch drive 8 can drive the transmission 9 configured as a planetary transmission, wherein the rotary movement of the ring gear 12 is transferred to the drum 2 via the free-fall brake 11 so that the drum 2 is driven at the rotational speed of the ring gear 12.

[0046] Hence, in a normal hoisting or winch operation the free-fall brake 11 rotates at the rotational speed of the drum 2 so that the disks of the free-fall brake 11 circulate in the oil bath which can be provided in the interior of the drum 2 in order to lubricate the transmission 9. To increase the circulating effect, the inner and outer parts of the free-fall brake 11 can be provided with a spline through which the oil or the cooling fluid can flush the free-fall brake more easily.

[0047] In free-fall operation, the free-fall brake 11 is released. At the same time, the winch drive 8 and/or the holding brake 10 is slowed down so that the input shaft of the transmission 9 is stationary. Said input shaft of the transmission 9 can be connected to said sun gear 16 so that said sun gear 16 is standing still. The drum 2 can rotate nevertheless, as the ring gear 12, which can form a common ring gear for a plurality of planetary stages, is decoupled from the drum casing 3 by the released free-fall brake 11.