Free fall winch

Abstract

The invention relates to a free fall winch comprising a drum which can be rotated by a winch drive via a multistage planetary transmission, wherein a drive stage of the planetary transmission is connected to the winch drive on the input side and can be braked by a service brake, and an output stage of the planetary transmission is connected to the drum on the output side. A free fall brake is provided in order to brake the drum during a free fall operation and is connected to the planetary transmission by means of a brake rotor. The brake rotor of the free fall brake is rotationally fixed to a transmission element of the output stage or an optionally provided intermediate stage of the planetary transmission. At least the drive stage of the planetary transmission, including the sun gear, the planet carrier, and the ring gear thereof, are stopped during the free fall operation of the service brake.

Description

[0001] Freefall winch

[0002] The present invention relates to a free-fall winch with a drum which can be driven in rotation by a winch drive via a multi-stage planetary gear, wherein a drive stage of the planetary gear is connected on the input side to the winch drive and can be braked by a service brake and an output stage of the planetary gear is connected on the output side to the drum, wherein a free-fall brake is provided for braking the drum in free-fall operation and is connected to the planetary gear by a brake rotor.

[0003] Free-fall winches are used in a variety of applications where the rope wound on the winch drum, or another pulling or lifting device such as a belt, is to be paid out or lowered at high speeds over long distances. The drum rotates more or less without resistance in idle mode or, if necessary, with slight braking by the gear resistance. This type of unwinding is sometimes referred to as "free fall." At least at the end of the free fall, it is necessary to brake the rope drum relatively quickly to prevent further uncontrolled unwinding of the rope and the associated slack in the rope on the winch drum, creating an untidy, tangled rope pattern. Such free-fall winches can be used, for example, in cable excavators when a compacting mass is dropped to the ground in free fall for soil compaction.For example, in planetary gears used on drums, individual planetary gear stages are decoupled so that the compressor load hits the ground with the greatest possible fall energy. However, shortly before impact with the ground, the free-fall brake must be applied to prevent slack rope from forming on the winch drum. This process is repeated cyclically at short intervals, changing the cooling oil of the free-fall brake and the friction coefficients of the brake bodies. Accordingly, the excavator operator must continually adjust the braking of the free-fall winch.

[0004] Similarly, when working with a dragline bucket, it is thrown into a quarry lake by rotating the cable excavator's upper carriage—similar to casting a hook with a fishing rod. When the dragline bucket hits the water surface, the previously released drum must be braked to prevent slack rope.

[0005] With diaphragm wall grabs used to excavate very deep foundations, the grab is lowered at a high, controlled rate of descent. To control the rate of descent, the grab must be applied by applying the free-fall brake during descent. Here, too, heating of the system and changes in the friction coefficient of the brake elements require the braking force of the free-fall brake to be readjusted in order to lower the rope with the attached grab at the desired speed while maintaining a certain level of rope tension.

[0006] It is also desirable for various handling tasks to be able to pull the rope off the free-fall winch easily by hand, for example to attach the rope to various pieces of equipment. Even when the free-fall brake is open, frictional forces inside the winch must be overcome, for example in the area of ​​a gear through which the winch drive drives the drum, and in the area of ​​the free-fall brake itself. Particularly with cold lubricant and a correspondingly high viscosity, this is hardly feasible by hand, so assistance from the winch drive would be desirable, although the required level of drive assistance for manual pulling depends on the temperature of the lubricant. While greater assistance is required with cold lubricant, motor-driven pull-off assistance of the same strength can lead to undesirably rapid unspooling when the lubricant is warm and has a lower viscosity.

[0007] A free-fall winch of the type mentioned above is shown, for example, in EP 0 538 662 B1 or DE 41 34 722 A1. In this case, the winch drive drives the drum via a two-stage planetary gear housed inside the drum. A sun gear of one of the planetary stages can be driven by the winch drive and blocked by a holding brake. A planet carrier of one of the planetary stages extends out of the opposite end of the drum via a shaft, where it can be braked by a free-fall brake supported on the counterbearing plate.

[0008] By connecting the free-fall brake to the planetary gear unit, the gear ratio can be used to absorb a larger braking torque on the drum with a smaller braking torque on the free-fall brake, allowing the brake to be used with a comparatively small-sized free-fall brake that can be integrated into the interior of the drum. On the other hand, however, the planetary stages of the planetary gear unit rotating during free-fall operation result in relatively large rotating inertial masses, which slow down the initial acceleration of the drum in free-fall operation and inhibit a rapid start to free fall. At the same time, when braking from free-fall operation, the aforementioned advantage of the inherently smaller braking torque is partially compromised by the fact that the high inertial masses must be braked, which requires a correspondingly high braking power and causes thermal loads.

[0009] Another free-fall winch comprising a planetary gear is shown in document CN 205 151 608 U, whereby here too, in free-fall operation, relatively large rotating, inert masses must be accelerated by the rotating planetary stages of the planetary gear.

[0010] Furthermore, free-fall winches are also known that operate with only one brake and simultaneously use the holding brake as a free-fall brake. DE 3 223 632 C2, for example, shows a free-fall brake whose drum is driven by a hydraulic motor via a two-stage planetary gear. The ring gear common to both planetary stages is connected to a brake shield to which the drum brake, which acts directly on the flanged disk of the cable drum, is attached. When the brake is applied, the torque is transmitted via the brake to the cable drum, thus establishing the connection between the motor and the cable drum. When the brake is applied, the planetary gear is decoupled from the cable drum. However, the cooling problem described still exists with this brake arrangement.In addition, in order to hold the rope drum in place during load operation, for example when holding a heavy lifted load, high braking forces must be applied, which must be transferred to the drum shell via the flanged disc to which the brake acts.

[0011] Other free-fall winches are also known from the documents EP 3 678 975 B1 and WO 2019 / 048 303 A1.

[0012] From the document DE 101 16 342 C2, a Kelly winch is known in which the cable tension or the associated torque on the drum is monitored as the cable is unwound. For this purpose, the winch drive is generally rotatably mounted on the drum, but supported on the frame via a lever-shaped torque arm, with a measuring device recording the load on the torque arm in order to determine the supported torque. The winch drive is controlled depending on the recorded load on the torque arm in such a way that a certain load on the torque arm is not exceeded and thus an associated torque on the drum and correspondingly a residual tensile force on the cable is maintained in order to prevent slack in the cable. Furthermore, the document DE 10 2014 109 918 A1 shows a drilling rig whose drilling tool can be lowered along a mast by a winch.A hydraulic pump driving the winch is controlled depending on a cable pulling force, which is measured by means of a force measuring bolt on a pulley of the cable.

[0013] Based on this, the present invention seeks to create an improved free-fall winch of the type mentioned above that avoids the disadvantages of the prior art and advantageously develops them further. In particular, the aim is to achieve improved dynamic free-fall and braking operation, allowing for smooth, rapid acceleration and deceleration during free-fall operation and requiring a slim-sized free-fall brake without overheating or thermal performance degradation.

[0014] The stated object is achieved by a free-fall winch according to claim 1. Preferred embodiments of the invention are the subject of the dependent claims.

[0015] It is therefore proposed to connect the brake rotor of the free-fall brake to the planetary gear, but not to its first planetary stage or its drive stage. While this would provide favorable conditions in terms of braking torque, the high inertial masses would simultaneously impair the winch dynamics in free-fall operation, as all planetary stages would also rotate in free-fall operation. In order to utilize the gear ratio of the planetary gear for the free-fall brake and achieve a certain reduction in the braking torque on the free-fall brake, while also reducing the inertial masses in free-fall operation, it is proposed to connect the free-fall brake not to the drive stage of the planetary gear, but rather to a downstream planetary stage.

[0016] According to the invention, the brake rotor of the free-fall brake is connected in a rotationally fixed manner to a gear element of the output stage or a possibly present intermediate stage of the planetary gear, wherein at least the drive stage of the planetary gear, including its sun gear, planet carrier and ring gear, can be stopped by the service brake in free-fall operation. By stopping at least the entire first planetary stage, i.e. the drive stage of the planetary gear connected to the winch drive, the rotating inertial masses can be significantly reduced in free-fall operation, since the gear elements of the said first planetary stage, i.e. its sun gear, its planet carrier, its planet gears and its ring gear, do not rotate when the drum rotates in free fall and the rotation of the drum is only transmitted to the brake rotor of the free-fall brake via part of the planetary gear.By stopping the otherwise fast-rotating planetary stage during free-fall operation, the inertial masses to be accelerated for free-fall operation can be considerably reduced, since it is precisely the fast-rotating gear elements that have a greater influence on the inertia.

[0017] Since the inertial masses vary quadratically with the gear ratio, namely according to the relationship J2 = Ji xi 2, where i is the transmission ratio and J is the moment of inertia, a considerable reduction in the mass moment of inertia can be achieved, which in turn places less strain on the free-fall brake and results in lower thermal stress. Above all, however, a much more dynamic free-fall operation can be achieved. On the one hand, the drum can accelerate much faster when the free-fall process is initiated, since at least one of the stationary planetary stage does not need to be accelerated. Due to the faster acceleration at the beginning of free-fall operation, for example in applications in the dragline bucket area, the dragline bucket can be ejected further because the inertial masses in the drum are smaller.Likewise, more energy can be used for soil compaction at the same drop height. And with diaphragm wall grabs, which are used to chisel from small drops to loosen hard rock, the grab experiences more energy when hitting the rock at the same drop height. Conversely, at the end of the free-fall process, the drum can be braked very quickly because the free-fall brake only has to brake a reduced inertial mass, meaning that a relatively small free-fall brake is sufficient without suffering thermal overload. In a further development of the invention, the planetary gear can be designed with at least three stages, whereby the brake rotor of the free-fall brake can be connected to an intermediate planetary stage which, with regard to the power flow or torque flow in winch operation, is provided between the drive stage and the output stage of the planetary gear.This allows for a favorable compromise between having as few rotating gear components as possible, resulting in correspondingly reduced inertial masses, on the one hand, and limiting the braking torque required at the free-fall brake, on the other. Connecting the brake rotor of the cable drum directly to the drum, thus braking the drum directly opposite the winch frame, would allow for maximum reduction of inertial masses and thus highly dynamic free-fall operation. On the other hand, such a configuration would require very high braking torques at the free-fall brake, as it would have to apply the drum braking torque without any transmission.

[0018] If the planetary gear system has four or more stages, the brake rotor of the free-fall brake can be connected to the intermediate stage of the planetary gear system or be non-rotatably coupled to the intermediate stage of the planetary gear system, which forms the second planetary stage of the planetary gear system or connects directly to the input stage of the planetary gear system. This still allows a significant reduction in the braking torque occurring at the free-fall brake system, while conversely, an entire planetary stage can still be shut down and its inertial masses eliminated for free-fall operation.

[0019] In an alternative development of the invention, it would also be possible to connect the brake rotor of the free-fall brake to a third planetary stage, i.e., an intermediate stage that is not directly coupled to the first planetary stage or the drive stage of the planetary gear, but is coupled to the aforementioned drive stage via at least one further intermediate stage. This could achieve an even greater reduction in inertial masses, while at the same time allowing a less significant, but still present, reduction in the braking torque.If the free-fall brake is not connected to the second planetary stage, but rather to another intermediate stage, for example, the third planetary stage, the planetary gear can advantageously be designed to be switchable so that, for free-fall operation, not only the drive stage but also the second planetary stage, including its sun gear, planet carrier, and ring gear, can be stopped, in order to achieve an even greater reduction in inertial mass. In this case, the rotation of the drum during free-fall operation is transmitted past the first and second planetary stages only via the output stage and the remaining at least one further intermediate stage to the brake rotor of the free-fall winch.For example, such a switchability can comprise a clutch and / or a brake for engagement with a transmission element of the second and / or third planetary stage in order to be able to stop the second planetary stage - in addition to the drive stage - when the drum rotates in free-fall operation and the third and possibly each further planetary stage transmits the rotation of the drum to the brake rotor.

[0020] Even if the planetary gear set can have four or more planetary stages, it is advantageous to use a three-stage planetary gear set, and in this case, connect the brake rotor of the free-fall brake to the intermediate stage, i.e., the second planetary stage. With a three-stage planetary gear set, a compact design can be achieved with a sufficient gear ratio. By connecting the brake rotor to the intermediate stage, a relatively small overall inertial mass can be achieved during free-fall operation, thus achieving agile, dynamic free-fall behavior.

[0021] In order to be able to stop the first planetary stage, i.e. the drive stage of the planetary gear in free-fall operation in a simple manner with only a few switchable gear elements, it can be provided in an advantageous development of the invention that the drive stage has a gear element which, in addition to the gear element that can be stopped by the service brake, is supported in a stationary manner or can be stopped by a further brake, so that in free-fall operation, on the one hand, a gear element of the drive stage is stopped by the service brake and a further gear element of the drive stage is also stationary due to its support that is fixed against rotation or blocked by a brake.

[0022] For example, if the winch drive is connected to the sun gear of the planetary gear drive stage, the ring gear of the drive stage can be non-rotatably supported on the bearing block of the cable winch or another stationary component in the surrounding installation, so that the ring gear remains stationary even during winch operation. If the sun gear is then braked or stopped by the service brake during free-fall operation, the entire first planetary stage and, in addition, the gear element of the second planetary stage, which is non-rotatably connected to the output element of the drive stage, also remain stationary.In the above-mentioned embodiment with a brakeable sun gear and a ring gear supported in a rotationally fixed manner on the bearing block, the output element of the first planetary stage would be its planet carrier, which would then also be stationary when the sun gear is braked and can, for example, be coupled to the sun gear of the second planetary stage, so that in this case the sun gear of the second planetary stage is also stationary in free-fall operation and contributes to a further reduction of the inertial masses.

[0023] Alternatively, it would also be possible to connect another gear element of the first planetary stage, for example its ring gear or its planet carrier, to the winch drive instead of the sun gear and to mount a second gear element of the drive stage in a stationary or non-rotatable manner, for example the sun gear or the planet carrier, in order to be able to stop the entire first planetary stage again in free-fall operation by applying the service brake.

[0024] In order to achieve an overall compact design and, in particular, to be able to arrange the free-fall brake at least partially inside the drum, an advantageous development of the invention can provide for the output stage of the planetary gear to be arranged, viewed in the axial direction, between the drive stage and an intermediate stage of the planetary gear. In particular, said drive stage and the at least one intermediate stage can be arranged at opposite axial end sections of the planetary gear, while the output stage coupled to the drum is arranged in an axial central section of the planetary gear.

[0025] This allows the winch drive to be connected and / or the service brake to be arranged easily on one axial end face of the planetary gear, while the free-fall brake can be arranged on the opposite axial end face of the planetary gear. In particular, the brake rotor of the free-fall brake can be easily connected to the intermediate stage of the planetary gear located on the end face, for example, to the ring gear of the intermediate stage, which can form the end face of the planetary gear.

[0026] The free-fall brake can advantageously be arranged completely inside the drum, wherein the brake rotor protrudes towards the inside of the drum and can be connected to the gear element, for example the ring gear, which can be connected to the end section of the adjacent planetary gear, while the brake stator of the free-fall brake can be arranged or protrude towards the outside or towards the front of the drum in order to be supported in a rotationally fixed manner, for example, on the bearing block of the cable winch.

[0027] The free-fall brake mentioned can, for example, be designed as a multi-disk brake, wherein plates extending essentially transversely to the axis of rotation of the drum are provided and can engage with one another, wherein the plates can be alternately fastened to the brake rotor and the brake stator. The mentioned brake plates can advantageously be arranged or accommodated entirely inside the drum, wherein, if necessary, a brake actuator for actuating or pressing the plates against one another can also be arranged inside the drum. In the latter case, essentially only a part of the brake stator protrudes from the drum in order to be supported on the bearing block of the cable winch. If necessary, however, the bearing block can also have a support stub protruding into the drum, to which the free-fall brake can be attached.Regardless of the specific design of the free-fall brake as a multi-disk brake or its arrangement inside the drum, the brake rotor of the free-fall brake can be coupled to the planetary gear system in such a way that the brake rotor rotates at a speed that is lower than the speed of the winch drive but higher than the speed of the drum. In particular, the brake rotor can rotate at the speed of the gear element of the intermediate stage of the planetary gear system, to which the aforementioned brake rotor is non-rotatably connected.

[0028] The connection of the output stage of the planetary gear to the cable drum can basically be accomplished in different ways.

[0029] In order to transmit the greatest possible torque to the drum, an advantageous development of the invention allows the planet carrier of the output stage of the planetary gear to be non-rotatably coupled to the drum. Particularly when the planetary gear is designed such that the carrier shaft is the summing shaft, this allows the greatest torque to be transmitted to the cable drum. The differential shaft, i.e., the inner gear, transfers the reaction torque via the winch frame. This allows the greatest torque to be transmitted directly via the cable drum to the load to be moved.

[0030] In an alternative development of the invention, the output stage of the planetary gear can also be connected to the drum in a rotationally fixed manner via its ring gear, so that the ring gear of the output stage transfers the torque to the drum. In this case, the planet carrier of the output stage can be arranged upright, in particular supported in a rotationally fixed manner on the bearing block of the cable winch, preferably together with the ring gear of the drive stage. This not only achieves a particularly simple and compact connection of the drum to the planetary gear, since the ring gear of the output stage is located directly on or very close to the inner circumference of the drum, but also enables simple assembly of the planetary gear itself. In this case, the firmly supported planet carrier of the output stage transfers the greatest torque to the winch frame, i.e. the greatest torque of the planetary gear is transmitted via the bearing block or the winch frame.a fixed element of the installation environment was removed.

[0031] The invention is explained in more detail below with reference to preferred embodiments and the accompanying drawings. In the drawings:

[0032] Fig. 1: a longitudinal section through a free-fall winch according to an advantageous embodiment of the invention, in which the free-fall brake is connected to an intermediate stage of the planetary gear and the cable drum is mounted on the ring gear of the output stage of the planetary gear in a rotationally fixed manner, and

[0033] Fig. 2: a longitudinal section through a free-fall winch according to a further advantageous embodiment of the invention, in which the free-fall brake is also connected to an intermediate stage of the planetary gear, but in contrast to Figure 1, the cable drum is non-rotatably attached to the planet carrier of the output stage.

[0034] As the figures show, the free-fall winch 1 comprises a drum 2 having an approximately cylindrical drum shell 3 onto which a rope 4 can be wound. For this purpose, the drum shell 3 can include rope grooves on its outer side to enable controlled winding of the rope 4 and can be enclosed at the axial end with flanges 5 (see Figures 1 and 2).

[0035] The drum 2 is rotatably mounted parallel to the longitudinal axis of the cylindrical drum shell 3. For this purpose, a pair of bearing plates 6 and 7 can be provided, on which the drum 2 is rotatably mounted, for example by means of roller and / or plain bearings. The bearing plates 6 and 7 themselves are mounted on a base structure on which the cable winch is to be used, for example on the upper carriage of a cable excavator. The cable winch further 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 plate 6 provided there, and can be fixedly mounted, for example supported on said bearing plate 6.

[0036] The winch drive 8 drives the drum 2 in rotation via a planetary gear 9, wherein the said planetary gear 9 is designed in several stages and can, for example, comprise three planetary stages 9a, 9b and 9c, see Figure 1 and Figure 2.

[0037] The planetary gear 9 can be accommodated inside the drum shell 3, so that the winch drive 8 and the majority of the planetary gear 9 can extend on opposite sides of the bearing plate 6. A gear input shaft 10 or a rotary gear input element, or conversely, the output shaft of the winch drive 8, can extend through the bearing plate 6 in order to transmit the rotary drive movement of the winch drive 8 through the bearing plate 6 to the internal planetary gear 9.

[0038] For example, the winch drive 8 can drive a sun gear 11 of the first planetary stage, i.e. the drive stage of the planetary gear 9, whose planet carrier 12 can be coupled to the sun gear of the next or second planetary stage 9b.

[0039] The ring gear 13 of the first planetary stage 9a can advantageously be non-rotatably supported on the bearing plate 6 or another stationary support part of the installation environment. Conversely, however, it would also be possible to couple the ring gear 13 to the next planetary stage and support the planet carrier 12 in a stationary manner. The design option shown in the figures, with a rotationally driven planet carrier 12 and a vertically supported ring gear 13, allows for a high torque yield while simultaneously maintaining a simple design and convenient installation. In order to hold the cable winch in place under load during operation, a service brake 14 is provided. This service brake can be designed, for example, as a multi-disk brake and can be locked independently of the service brake by a pretensioning device, for example in the form of a spring device, and can be released by a pressure-medium actuator or an electric actuator.

[0040] Regardless of the specific design, the service brake 14 can act on the winch drive 8 and / or be arranged between the winch drive 8 and the planetary gear 9. Advantageously, the service brake 14 can be arranged on the side of the bearing plate 6 facing away from the planetary gear 9, in particular coaxially with the output shaft of the winch drive 8. For example, the service brake 14 can act on the transmission input shaft 10 and / or the output shaft of the winch drive 8 in order to be able to lower a load with braking, or to hold or block it in order to be able to hold a load at a certain height.

[0041] As the figures show, the output element of the first planetary stage 9a, which can be its planet carrier 12, can drive the sun gear 15 of the second planetary stage 9b or be rotationally coupled thereto. The planet carrier 16 can advantageously function as the output element of the second planetary stage 9b, which in turn can drive the sun gear 18 of the third planetary stage 9b (see Figures 1 and 2). The aforementioned third planetary stage 9c can form the output stage of the planetary gear 9.

[0042] As the figures show, the output stage 9c of the planetary gear 9 is advantageously arranged axially between the drive stage 9a and the intermediate stage 9b. Said drive stage 9a and said intermediate stage 9b can be arranged at the axial end sections of the planetary gear 9, whereby the drive stage 9a can be arranged on the side facing the winch drive 8 or the bearing plate 6 (see Figures 1 and 2), while the intermediate stage 9b can face the other axial end section of the drum 2 or a free-fall brake 21 accommodated therein. As Figures 1 and 2 show, the third planetary or output stage 9c of the planetary gear 9 with its ring gear 20 as output element, see Figure 1, or with its planet carrier 19 as output element, see Figure 2, can be rotationally connected to the drum 2 in order to drive said drum 2 in rotation.The connection of the ring gear 20 to the drum 2 results in a space-saving design with simple assembly, since the ring gear 20 is located close to the inside of the drum shell 3, as shown in Figure 1. The planet carrier 19 of the output stage 9c can be mounted vertically, for example, supported on the bearing plate 6 together with the ring gear 13 of the first planetary stage 9a.

[0043] On the other hand, by using the planet carrier 19 as the output element of the third planetary stage 9c, a maximum torque can be transmitted to the drum 2, wherein, with a rotationally fixed connection of the planet carrier 19 to the drum 2, the ring gear 20 of the output stage 9c can be mounted vertically, for example, can be supported on the bearing plate 6 together with the ring gear 13 of the first planetary stage 9a, see Figure 2.

[0044] Overall, the planetary gear 9 with its multiple planetary stages 9a, 9b and 9c can be accommodated in an overall pot-shaped housing, which can be positioned within the drum shell 2, see Figure 1 and Figure 2.

[0045] The aforementioned free-fall brake 21 is advantageously connected to the intermediate stage 9b of the planetary gear 9. As Figures 1 and 2 show, the brake rotor 22 of the free-fall brake 21 can be coupled, in particular, in a rotationally fixed manner to the ring gear 17 of the second planetary stage 9b, so that the brake rotor 22 rotates at the speed of the aforementioned ring gear 17 of the planetary stage 9 during winch operation.

[0046] The free-fall brake 21 can be designed, for example, as a multi-disk brake, whereby, independently of this, a pretensioning device, for example in the form of a spring device, can be provided for pretensioning the free-fall brake 21 into the braking configuration. A release or release device 24, which can overcome the pretension of the pretensioning device 23 and separate the discs, can, for example, comprise a pressure cylinder or another actuator that counteracts the pretensioning device 23.

[0047] As the figures show, the aforementioned free-fall brake 21 can release the gear element of the intermediate stage 9b, which is connected in a rotationally fixed manner to the brake rotor 22, from rotation, or can hold it stationary. For this purpose, the free-fall brake 21 can be fixedly supported with its brake stator 25 on the bearing plate 7, which is provided on the side of the drum 2 opposite the winch drive 8, or can be fixedly mounted on another support part of the installation environment of the free-fall winch 1. For example, the brake stator 25 can form a sleeve- or pot-shaped brake housing, which can be fixedly mounted on the bearing plate 7 and simultaneously serve as a support for the brake rotor 22 and / or the drum 2, which can be rotatably mounted on the housing-like brake stator by means of bearings.

[0048] During normal winch operation, for example, to lift a load, the free-fall brake is engaged, so that the ring gear 17 of the intermediate stage 9b is stationary. Conversely, the service brake 14 is released, allowing the winch drive 8 to drive the drive stage 9a via the sun gear 11, which then drives the drum 2 accordingly via the intermediate stage 9b and the output stage 9c.

[0049] For free-fall operation, a control device 26 actuates the aforementioned service brake 14, while, on the other hand, the free-fall brake 21 is released. This stops the first planetary stage 9a, while the sun gear 15 of the intermediate stage 9b is also stopped due to its rotationally fixed coupling with the planet carrier 12 of the drive stage 9a. The drum 2 can rotate in free fall, with the rotational movement of the drum 2 being introduced via the output stage 9c only into the intermediate stage 9b, more precisely its planet carrier 16 and its ring gear 17, and being transmitted by the ring gear 17 of the intermediate stage 9b to the brake rotor 22. Since the entire first planetary stage 9a and also the sun gear 15 of the second stage 9b do not rotate, the inertial mass is significantly reduced, resulting in very agile free-fall behavior with light-footed acceleration.If the rotation of the drum 2 is to be stopped at the end of the free-fall process, for example, when the dragline bucket of the cable excavator hits the surface, the control device 26 causes the engagement or braking of the drop brake 21, whereby the ring gear 17 of the intermediate stage 9b and thus the entire rotation of the drum 2 is stopped or braked. Due to the reduced inertial masses that moved during the free fall, the required braking energy is reduced, and a rapid braking of the drum can also be achieved.

[0050] As can be seen from the previous description, the free fall winch is characterized by the following advantages:

[0051] • fewer rotating components during free fall operation

[0052] • thereby reducing the inert masses

[0053] • the free-fall brake has to absorb less braking energy

[0054] • therefore faster braking and acceleration in free fall mode

[0055] • smaller dimensioning of the brake without thermal overload

[0056] • the entire system becomes more dynamic

[0057] • less splashing losses due to non-rotating planetary stage in free fall operation

[0058] • therefore additionally reduced heat development.

[0059] The following additional advantages arise especially with the cable excavator:

[0060] • at the same fall height of the mass, more energy is needed to compact the soil

[0061] • In dragline operation, the dragline bucket can be ejected further because the inertial masses in the cable drum are lower.

[0062] When using slotted grippers, the following advantages can be added:

[0063] • the grab experiences more energy when hitting the rock at the same drop height, making chiselling from small drop heights to loosen hard rock particularly efficient.

Claims

Claims 1 . Free-fall winch with a drum (2) which can be driven in rotation by a winch drive (8) via a multi-stage planetary gear (9), wherein a drive stage (9a) of the planetary gear (9) is connected on the input side to the winch drive (8) and can be braked by a service brake (14), and an output stage (9c) of the planetary gear (9) is connected on the output side to the drum (2), wherein a free-fall brake (21) is provided for braking the drum (2) in free-fall operation and is connected to the planetary gear (9) by a brake rotor (22), characterized in that the brake rotor (22) of the free-fall brake (21) is connected in a rotationally fixed manner to a gear element (17) of the output or, if applicable,existing intermediate stage (9b) of the planetary gear (9), wherein at least the drive stage (9a) of the planetary gear (9) including its sun gear (11), planet carrier (12) and ring gear (13) is stopped in free-fall operation by the service brake (14).

2. Free-fall winch according to the preceding claim, wherein the planetary gear (9) is designed in at least three stages and the brake rotor (22) of the free-fall brake (21) is connected to an intermediate stage (9b) of the planetary gear (9).

3. Free-fall winch according to the preceding claim, wherein the brake rotor (22) is connected to the intermediate stage or second planetary stage (9b) directly adjoining the drive stage (9a) of the planetary gear (9).

4. Free-fall winch according to one of the two preceding claims, wherein the brake rotor (22) is connected in a rotationally fixed manner to the ring gear (17) of the intermediate stage (9b).

5. Free-fall winch according to one of the preceding claims, wherein the output stage (9c) of the planetary gear (9) is arranged between the drive stage (9a) and an intermediate stage (9b) of the planetary gear when viewed in the axial direction of the drum (2) and / or the drive stage (9a) and the intermediate stage (9b) are arranged at opposite axial end sections of the planetary gear (9).

6. Free-fall winch according to one of the preceding claims, wherein the connection of the winch drive (8) to the planetary gear (9) and the free-fall brake (21) are arranged on opposite sides of the planetary gear.

7. Free-fall winch according to one of the preceding claims, wherein the drive stage (9a) of the planetary gear (9) has a gear element (13) which, in addition to the gear element (11) which can be stopped by the service brake (14), is supported in a rotationally fixed manner or can be stopped by a further brake.

8. Free fall winch according to one of the preceding claims, wherein the sun gear (11) of the drive stage (9a) of the planetary gear (9) is connected to the winch drive (8) and the ring gear (13) of the drive stage (9a) is rotatably is fixedly and non-rotatably supported on a bearing plate (6) of the free-fall winch (1) or a stationary support element of the installation environment, while the planet carrier (12) of the drive stage (9a) is connected to the intermediate stage (9b) of the planetary gear (9).

9. Free-fall winch according to the preceding claim, wherein the planet carrier (12) of the drive stage (9a) is rotationally fixedly coupled to the sun gear (15) of the intermediate stage (9b), wherein the ring gear (17) of said intermediate stage (9b) is rotationally fixedly coupled to the brake rotor (22) of the free-fall brake (21).

10. Free-fall winch according to one of the preceding claims, wherein the output stage (9c) of the planetary gear (9) with its ring gear (20) as output element is connected in a rotationally fixed manner to the drum (2) and is supported with its planet carrier in a stationary and rotationally fixed manner on the bearing plate (6) of the free-fall winch (1) or a stationary support element of the installation environment.

11. Free-fall winch according to one of claims 1 to 9, wherein the output stage (9c) of the planetary gear (9) with its planet carrier (19) as an output element is connected in a rotationally fixed manner to the drum (2), wherein the ring gear (20) of the output stage (9c) is supported in a stationary and rotationally fixed manner on the bearing plate (6) of the free-fall winch (1) or a stationary support element of the installation environment.

12. Free-fall winch according to one of the preceding claims, wherein the planetary gear (9) and / or the free-fall brake (21) are substantially completely accommodated inside the drum (2).

13. Free-fall winch according to one of the preceding claims, wherein the free-fall brake (21) with its brake stator (25) is supported in a rotationally fixed manner on the bearing plate (7) of the free-fall winch (1) or a stationary support element of the installation environment and the gear element of the planetary gear coupled to the brake rotor (22), in particular the ring gear (17) of the intermediate stage (9b), is blocked in the braked state relative to the bearing plate (7) or the stationary support element of the installation environment.

14. Free-fall winch according to one of the preceding claims, wherein the service brake (14) for braking the drive stage (9a) of the planetary gear (9) is arranged between the winch drive (8) and the planetary gear (9), preferably on an outer side of the bearing plate (6) of the free-fall winch (1).

15. Free-fall winch according to one of the preceding claims, wherein the service brake (14) acts on the transmission input shaft (10) of the planetary gear (9) or an output shaft of the winch drive (8), in particular having a brake rotor coupled thereto.

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