Freefall winds with a freefall brake

Abstract

Freefall winds (1), comprising: - a housing (70) and a winch drum (2) rotatably mounted relative to the housing (70) about its axis of rotation (D), - a free-fall brake (100) comprising at least one first brake body (110) and at least one second brake body (120), wherein the at least one first brake body (110) and the at least one second brake body (120) are pressable against each other to achieve a friction-based braking torque, - a gearbox (10) arranged between the winch drum (2) and the free-fall brake (100), which is designed to convert a rotation of the winch drum (2) into a rotation of at least one second brake body (120) relative to the first brake body (110), - a sensor (80) designed to detect a measured value from which the braking torque of the free-fall brake (100) acting between the winch drum (2) and the housing (70) can be determined.

Description

[0001] The invention relates to a free-fall winch with a free-fall brake for decelerating the winch. The brake thus primarily serves as a service brake, but can also serve as a holding brake. The free-fall winch is designed or configured so that the braking torque of the free-fall brake is adjustable.

[0002] The free-fall winch with its integrated free-fall brake plays a crucial role in controlling the free-fall speed and accurately decelerating the load, thus preventing slack in the rope. The winch can be, for example, a motorized free-fall winch or a lifeboat winch.

[0003] From DE 41 34 722 A1, a free-fall winch of this type is known, which has a winch drum that is driven by a motor via a gearbox. The gearbox has a gearbox shaft and a multi-disc brake comprising first and second discs, the second discs being connected to the gearbox shaft in a rotationally fixed manner. The first discs are connected to the housing in a rotationally fixed manner. In free-fall operation, the rotation of the winch drum can be slowed down or a braking torque generated by pressing the first and second discs against each other. The brake can be used to slow down the rotating winch drum or to hold the winch drum rotationally fixed relative to the housing. The proposed service brake thus also serves as a holding brake.

[0004] A general problem with such free-fall winches is that the braking torque applied by the brake depends heavily on the type and wear of the friction lining, the coefficient of friction, the rotational speed, the temperature, the oil viscosity, the hydraulic pressure, and other factors. The braking torque is often controlled by the operator using a brake pedal connected to the hydraulic circuit. Setting the desired braking torque requires considerable experience on the part of the operator. If the brake pedal is pressed too hard, the winch or the brake can be overloaded. If the brake pedal is pressed too lightly, the desired braking effect will not be achieved.

[0005] US patent 2011 / 0303493 A1 discloses a brake torque control system for an elevator braking device. Measuring the braking torque is intended to prevent any bouncing or jolting felt by passengers in the elevator car when the brake is released.

[0006] The invention is based on the objective of providing a free-fall winch and a method which allows the setting of a desired braking torque to be simplified or improved.

[0007] The problem is solved using the characteristics of the independent claims. Advantageous further developments arise from the dependent claims, the description, and the figures.

[0008] The free-fall winch, also referred to herein as a winch, has a measuring device, in particular a sensor, strain gauge, torque sensor, or force sensor, which is designed to detect a measured value from which the actual braking torque (actual value) of the free-fall brake acting between the winch drum and the housing can be determined. For example, the measured value can be a torque, a force, a deformation of a component, an inductance, or an electrical resistance. For example, the deformation of a component located in the path of the force or torque flow from the winch drum to the housing, which passes through the brake, can be measured. For example, the actual value of the braking torque can be determined by measuring the deformation of the component.

[0009] The sensor can be configured for a resistance-based measurement method. This means that the sensor is designed to change its electrical resistance depending on the deformation acting upon it. For example, the sensor can have a strain gauge or a thin-film coating applied to a surface of the component whose deformation is to be determined, particularly by bonding it to the material. A change in the component's shape thus simultaneously causes a change in the shape of the strain gauge or thin-film coating, and consequently, a change in its electrical resistance. The braking torque, deformation, or force can be determined from the change in electrical resistance, and the braking torque can then be determined from the deformation or force.

[0010] Alternatively, the sensor can be designed for a magnetic field-based measurement method. This means that the magnetic field of the sensor changes depending on the deforming component. For example, the sensor can have coils whose changes in position relative to each other cause a change in the magnetic field and thus a change in the inductance of the coils. The braking torque, or a deformation or force, can be determined from the change in inductance, and the braking torque can then be determined from the deformation or force.

[0011] The free-fall brake has at least one first brake element, for example, first brake discs, and at least one second brake element, for example, second brake discs. The first and second brake elements can be pressed together to generate a friction-based braking torque, for example, by means of a pressure piece. The braking torque changes depending on the force with which the first and second brake elements are pressed together. The actual braking torque (actual value) of the brake acting between the winch drum and the housing can be determined using the sensor.

[0012] The sensor can be arranged, with reference to the force or torque flow in free-fall operation, for example between the at least one first brake body and the housing, between the winch drum and the at least one second brake body, or between the winch drum and a winch frame to which the housing is attached.

[0013] From the sensor signal, an actual value can be determined as a controlled variable, for example, a torque, a force, a component deformation, an inductance, or an electrical resistance. This controlled variable can then be continuously compared with a setpoint value as a reference variable, such as a torque, a force, a component deformation, an inductance, an electrical resistance, or, in particular, the desired braking torque. Based on the result of this comparison, the force with which the at least one first brake element and the at least one second brake element are pressed against each other can be adjusted, especially to align the controlled variable with the reference variable. This allows the braking torque of the winch to be set with relative precision.

[0014] Accordingly, the winch or a system comprising the winch can have a control loop that enables this functionality. The control loop can be designed, in particular, to determine a controlled variable, for example, the actual value of the braking torque, from the sensor signal and to continuously compare it with a reference variable, which can be, in particular, a desired braking torque. Based on the result of this comparison, the force with which the at least one first brake element and the at least one second brake element are pressed against each other is then influenced in order to adjust the controlled variable to the reference variable.

[0015] An actuating device may be provided, comprising an actuator, such as a hydraulic or pneumatic valve, and a control unit designed to switch the actuator. The valve may, for example, be a proportional valve. The actuating device can be controlled by a control variable of a control unit within the control loop to change the force exerted by the pressure piece on the first and second brake bodies.

[0016] In the corresponding procedure, particularly during free-fall operation or when the at least one second brake element rotates relative to the at least one first brake element, the sensor detects a measured value from which a controlled variable is determined. This controlled variable is continuously compared with a reference variable, which may be, in particular, a desired braking torque. Based on the result of this comparison, the force with which the at least one first brake element and the at least one second brake element are pressed against each other is adjusted to align the controlled variable with the reference variable. If the actual value exceeds the setpoint value, the force with which the at least one first brake element and the at least one second brake element are pressed against each other is reduced.If the actual value falls below the target value, the force with which the at least one first brake body and the at least one second brake body are pressed against each other is increased.

[0017] The winch comprises a housing and a winch drum rotatably mounted relative to the housing. The housing can be a single piece or, preferably, multi-piece, i.e., it can have several housing parts joined together, in particular joined in a torsionally and / or axially fixed manner. The housing can be at least partially enclosed by the winch drum. Alternatively or additionally, the housing can also surround the winch drum or at least a part of the winch drum. In particular, the winch drum can, for example, be rotatably mounted on the housing about an axis of rotation by means of a rolling bearing or a sliding bearing and / or be supported by the housing. The housing can, for example, be part of a winch frame or be designed to be connected to the winch frame. For example, the housing can incorporate a fastening device, such as a clamp.The housing must have a mounting flange designed to attach the winch to the winch frame, in particular to secure it against rotation and axial movement. For example, the mounting device or the mounting flange can be attached to the winch frame by means of several bolts. Alternatively, the housing can be welded to the winch frame.

[0018] The winch drum is designed to accommodate a traction element, in particular a rope, such as a steel or fiber rope, in one or more layers on its outer circumference.

[0019] The winch comprises a gearbox designed to convert, particularly during free-fall operation of the winch, a rotation of the winch drum into a rotation of at least one second brake element relative to the at least one first brake element, specifically such that the at least one second brake element rotates at a higher speed than the winch drum. The gearbox is kinematically arranged between the winch drum and the housing. The path of the force or torque flow from the winch drum to the housing during free-fall operation passes through the gearbox. A multitude of variants of such gearboxes in a winch are known to those skilled in the art. In particular, the gearbox can have at least one planetary stage, which is kinematically arranged between the at least one second brake element and the winch drum. For example, one, two, three, or even more planetary stages can be provided, which can be interconnected.

[0020] For example, a transmission shaft can be provided that is rotationally fixed to or coupled with at least one second brake element. Thus, this transmission shaft and the at least one second brake element can rotate together relative to the at least one first brake element during free-fall operation. For example, the measuring device, in particular a sensor, can be arranged on the transmission shaft, or the transmission shaft can incorporate the measuring device. The measuring device can, for example, be a torque sensor.

[0021] For example, the sensor can be located on a component of the gearbox, such as on a planet carrier of a planetary stage supported on the housing or winch frame, or on a shaft or hollow shaft connected to a sun gear of a planetary stage of the gearbox in a rotationally fixed manner.

[0022] The winch can have a drive shaft to which a drive motor for motorized lifting and / or lowering operation can be connected or is connected, particularly indirectly via other components or directly. The gearbox can be designed such that a rotation of the drive shaft relative to the housing is converted into a rotation of the winch drum relative to the housing. Preferably, the drive shaft is rotatable about the axis of rotation of the winch drum, or the axis of rotation of the drive shaft coincides with the axis of rotation of the winch drum and / or the axis of rotation of at least one second brake element and / or the gearbox shaft. In particular, the gearbox can be designed such that the rotation of the drive shaft is transmitted to the winch drum with a reduction in rotational speed, particularly while maintaining the direction of rotation or reversing the direction of rotation.The winch drum rotates in a first direction for motorized lifting operation and in a second direction, opposite to the first, for motorized lowering operation and free-fall operation. During motorized lifting and / or lowering operation, the free-fall brake is fully engaged (i.e., the first and second brake bodies are secured against rotation by being pressed so tightly together that they are frictionally locked against each other). It can perform the holding brake function alone or additionally with a further brake comprising a third and fourth brake body, wherein the at least one fourth brake body is connected against rotation to the at least one second brake body or is mounted on the same drive shaft as the at least one second brake body. The at least one third brake body is connected against rotation, for example, to the housing.A corresponding arrangement with a service and holding brake mounted on a common transmission shaft is disclosed, for example, in EP 3 028 983 A1, to which explicit reference is hereby made.

[0023] During free-fall operation, the drive shaft to which the motor is connected can be held in a rotationally fixed position relative to the housing, for example. This can be achieved by the motor itself or, preferably, by an additional holding brake designed to prevent the drive shaft, to which the motor is connected or can be connected, from rotating relative to the housing or winch frame.

[0024] For example, the free-fall brake, whose braking torque is to be determined, can be, or form, a slide-in unit together with the housing and optionally with the gearbox, meaning that it is partially or completely enclosed by the winch drum. For example, the free-fall brake can be partially or completely enclosed by the winch drum or located outside the winch drum. The slide-in unit can be inserted into the winch drum via its end face for installation.

[0025] The free-fall brake, which can optionally also function as a holding brake, comprises at least one first brake body, mounted, for example, in a rotationally fixed manner to a brake body support, and at least one second brake body, mounted, for example, in a rotationally fixed manner to a second brake body support. The second brake body is rotatable with the at least one second brake body about an axis of rotation, which corresponds, for example, to the axis of rotation of the winch drum, relative to the first brake body support and the at least one first brake body. The at least one first brake body and the at least one second brake body can be pressed against each other to achieve a friction-based braking effect, in particular by a force acting along the axis of rotation. The force can be applied, for example, by a force-applying device such as a spring, electromechanically, pneumatically, or hydraulically.

[0026] In further developments, the free-fall brake can be a multi-disc brake. This means that several first discs form the at least one first brake body, and several second discs form the at least one second brake body. The at least one first brake body and the at least one second brake body can be pressed against each other to achieve a braking effect based on friction, in particular by means of a pressure piece of the brake. The first and second discs can be arranged alternately along the direction of rotation, so that a second disc is arranged between two first discs and a first disc is arranged between two second discs.

[0027] The second brake body support can, for example, be rotatable about the axis of rotation of the winch drum and / or the gearbox shaft. The second brake body support can be coupled to the gearbox and / or the winch drum in such a way that, during free-fall operation, a rotation of the winch drum about its axis of rotation causes the second brake body support to rotate relative to the first brake body support about its axis of rotation. For example, the axis of rotation of the second brake body support coincides with the axis of rotation of the gearbox shaft and / or the winch drum. The second brake body support can, for example, be coupled or connected to the gearbox shaft by means of a torsionally rigid connection, such as a shaft-hub connection. Alternatively, instead of a shaft-hub connection, the gearbox shaft itself can form the second brake body support.

[0028] In one embodiment, the first brake body support can be flexibly mounted about the axis of rotation of the first and / or second brake body support, i.e., rotatable through a certain or small pivot angle. The first brake body support and the housing can be connected via at least one component that incorporates a sensor. This advantageously ensures that the braking torque, which is generated by closing the brake or by pressing the at least one first brake body and the at least one second brake body together and which acts between the winch drum and the housing or winch frame, is transmitted into the housing or winch frame via the at least one component connecting the first brake body support and the housing. The at least one component is subject to a mechanical load dependent on the braking torque, which causes an elastic deformation of the component that is also dependent on the braking torque.The sensor is designed to determine the deformation of at least one component or to output a signal dependent on the deformation. The at least one component is designed such that it deforms elastically even under the maximum permissible braking torque for the brake.

[0029] The braking torque generated by the brake or the deformation itself, particularly quantitatively, can be determined by measuring the deformation (elastic deformation) of at least one component, for example, using an electrical circuit that includes the sensor. A control loop can be provided, which is configured to derive a controlled variable from the force sensor signal and continuously compare it with a reference variable, which can be, in particular, the desired braking torque. The control loop can further be configured to influence, based on the result, the force with which the at least one first brake element and the at least one second brake element are pressed against each other, in order to adjust the braking torque to the reference variable.

[0030] Because the first brake element is flexibly mounted about the axis of rotation of the second brake element relative to the housing, the braking torque generated by the brake is essentially transmitted via the at least one component that incorporates the sensor. This allows the actual braking torque to be determined relatively accurately by measuring the deformation of the at least one component. Therefore, it is preferred that the first brake element support be mounted with as little friction as possible around the axis of rotation on or in relation to the housing, so that the largest possible proportion of the braking torque is transmitted into the housing via the at least one component.

[0031] For example, the first brake body carrier can be mounted on the housing so as to be movable or rotatable about the axis of rotation, in particular by means of plain bearings or rolling elements. In this context, a rotatable or movable mounting of the first brake body carrier is understood to mean a mounting that allows a small movement of the first brake body carrier about the axis of rotation, wherein the small movement is within the limits of what is permitted by the elastic deformation of the at least one component, which depends on the braking torque.

[0032] For example, the first brake body support can be supported on the housing, in particular on an inner circumference of the housing, with its circumference, in particular its outer circumference, movable around the axis of rotation, for example by means of at least one plain or roller bearing.

[0033] For example, the first brake body support can be axially supported on the housing in a manner that allows movement around the axis of rotation, either movably or flexibly, such that the brake body support is fixed against displacement along the axis of rotation. For example, the housing can comprise a first housing part and a second housing part, and optionally even more housing parts, such as a third housing part. The first brake body support can be enclosed between the first housing part and the housing part that is axially and rotationally fixed to the first housing part, such that the first brake body support is axially fixed against displacement with respect to the housing. In particular, the first brake body support can be axially supported on the first housing part and axially on the second housing part, in a manner that allows movement around the axis of rotation, especially by means of at least one plain bearing or one or more rolling elements or at least one rolling bearing.

[0034] In further developments, the measuring device can be a force-measuring bolt, or a force-measuring bolt can incorporate the measuring device. The first brake body carrier can be connected to the housing via the force-measuring bolt. The first brake body carrier can be supported on the force-measuring bolt in the direction of rotation about the axis of rotation, with the force-measuring bolt bearing against the housing. A force-measuring bolt is a connecting bolt between force-transmitting machine elements, in this case the first brake body carrier and the housing, which, in addition to its function as a bolt (force transmission), enables the simultaneous measurement of the transverse forces occurring within it. This measurement can be performed, for example, using strain gauges or magnetic coils of the force-measuring bolt. Force-measuring bolts as such are known to those skilled in the art.

[0035] For example, one component, consisting of the housing and the first brake body support, can form two bearing points for the force-measuring bolt. The force-measuring bolt can rest on these two bearing points with its outer circumference. The other component, also consisting of the housing and the first brake body support, forms a bearing point located between the two bearing points, against which the force-measuring bolt can rest with its outer circumference.

[0036] Preferably, the longitudinal axis of the force-measuring bolt is offset, in particular parallel, to the axis of rotation of the first and / or second brake body support. Due to the distance to the axis of rotation and the braking torque, a transverse force is exerted on the force-measuring bolt, which causes an elastic deformation of the force-measuring bolt that can be measured accordingly.

[0037] For example, the at least one force measuring bolt can be a single force measuring bolt or comprise several, in particular two, three, four or five or more force measuring bolts, which can be distributed around the circumference and / or around the axis of rotation of the first and / or second brake body carrier, in particular evenly distributed.

[0038] Optionally, several components may be provided by which the first brake body carrier and the housing are connected, at least one or only one of which has a measuring sensor, in particular a force measuring bolt.

[0039] In further developments, the at least one component that incorporates the sensor can be a spring, supported at one end by the housing and at the other end by the first brake body support. This causes the spring to be tensioned and deformed depending on the braking torque. By appropriately selecting the spring constant (spring stiffness), a greater rotation of the first brake body support relative to the second can be achieved compared to force-measuring bolts. This results in greater elongation or deformation of the component, thereby increasing the measurement accuracy for determining the braking torque. The spring can be a torsion spring, which winds at least partially or preferably completely around the axis of rotation and can optionally surround the first brake body support, or a compression spring.

[0040] In further developments, the brake can have at least one pre-tensioned spring, and in particular several pre-tensioned springs, which, via a pressure piece, press the at least one first brake body and the at least one second brake body against each other to brake or to generate a braking torque. The pressure piece can be electrically, hydraulically, or pneumatically movable against the force of the pre-tensioned spring to release the brake or to reduce the braking torque. This has the advantage that, in the event of a system failure, the at least one pre-tensioned spring presses the first and second brake bodies against each other, thereby effecting braking with maximum braking torque. For example, an adjusting element can be provided that is displaceable in the direction of movement of the pressure piece. Preferably, the direction of movement of the pressure piece is parallel to, or at least along, the axis of rotation of the second brake body carrier.The displacement of the pressure piece can be effected electrically, hydraulically, or pneumatically. The pressure piece is displaceable, in particular, relative to the housing or the first brake body carrier.

[0041] The adjusting element can be axially supported by the pressure piece. Thus, movement of the adjusting element causes movement of the pressure piece. The pressure piece is movable about the axis of rotation of the first or second brake body carrier relative to the adjusting element. In particular, the pressure piece is mounted to the first brake body carrier in a rotationally fixed manner about the axis of rotation of the first brake body carrier, while the adjusting element is mounted to the housing in a rotationally fixed manner about the axis of rotation of the first or second brake body carrier. This results in a slight movement between the pressure piece and the adjusting element due to the deformation of the at least one component between the housing and the first brake body.To minimize the influence of friction between the pressure piece and the adjusting element, particularly with regard to the control of the braking torque, a low-friction connection can be formed between the pressure piece and the adjusting element, for example by means of an axial roller bearing or a plain bearing. In particular, a ring, for example made of bronze, brass, or plastic such as polytetrafluoroethylene, or another element made of a suitable bearing material, can be arranged between the pressure piece and the adjusting element to reduce friction between them.

[0042] A preferred embodiment of the invention is described below with reference to the figures. The features disclosed therein advantageously further develop the invention, both individually and in any combination thereof. The figures show: Fig. 1 a section of a cross-sectional view through a winch according to the invention and Fig. 2 a schematic diagram of a winch in which the invention can be applied.

[0043] The in Fig. The winch 1 shown in Figure 1 comprises a housing 70 and a winch drum 2 rotatably mounted relative to the housing 70. The winch drum 2 is rotatably mounted on the housing 70 about the axis of rotation D by means of a rolling bearing 75. A seal is also provided, which seals the radial gap between the winch drum 2 and the housing 70. The housing 70 has a flange 74, which is connected to a winch frame 3 about the axis of rotation D in a rotationally and axially fixed manner by means of several bolts distributed around its circumference. The flange 74 and the bearing seat for the rolling bearing 75 are formed by a cup-shaped section of the housing 70. In the example shown, the cup-shaped section is formed by a first housing part 71, which accordingly has the flange 74 and the bearing seat 75.The housing 70 also has a second housing part 72, which in the example shown is formed as a housing cover and closes off the space surrounding the first housing part 71 at the front.

[0044] The winch drum 2 shows, as in Fig. Figure 1 shows a partial area, with an optional groove on its outer circumference to simplify rope guidance. A traction element, in particular a rope, is wound and unwound on the outer circumference of the winch drum 2.

[0045] The winch drum 2 is supported on the winch frame 3 via the housing 70, in particular via the first housing part 71. The housing 70, in particular the first housing part 71, extends from the winch frame 3 into the winch drum 2 at its end face and is thus partially located within the winch drum 2. Optionally, the housing 70 and / or the brake 100 can be located outside, in particular completely or partially outside, the winch drum 2. In the example shown, the brake 100 is located partially inside and partially outside the winch drum 2. Optionally, the brake 100 can be located completely inside the winch drum 2.

[0046] The winds 1 include, as best described, Fig. As can be seen in Figure 2, a gearbox 10 comprises a gearbox shaft 12 and a drive shaft 17. The gearbox 10 includes several planetary stages 22, 42. This is only an example, as other gearbox configurations are also possible. Functionally, the gearbox 10 is designed such that a rotation of the winch drum 2 in free-fall operation is converted into a second direction of rotation via the gearbox 10, resulting in a rotation of the gearbox shaft 12 and the second brake body carrier 121. The rotation of the winch drum 2 in free-fall operation is caused by the load suspended from the cable.

[0047] The gearbox 10 is further configured such that a rotation of the drive shaft 17 relative to the housing 70 is converted, in particular for motorized lifting operation, into a rotation of the winch drum 2 relative to the housing 70 in a first direction of rotation, and, in particular for motorized lowering operation, into a rotation of the winch drum 2 relative to the housing 70 in a second direction of rotation, in particular with a reduction in speed and while maintaining or reversing the direction of rotation of the drive shaft 17. Thus, the speed of the winch drum 2 is preferably lower than the speed of the drive shaft 17.

[0048] For example, in Fig. As can be seen in Figure 2, a brake 6, in particular a holding brake, can be provided between the winch frame 3 and the drive shaft 17, which can block and release rotation of the drive shaft 17 relative to the winch frame 3. In particular, the brake 6 is closed in free-fall operation, thereby blocking the drive shaft 17, i.e., preventing it from rotating relative to the winch frame 3. Alternatively or additionally, the drive shaft 17 can be held in free-fall operation in a rotationally fixed position relative to the winch frame 3 by means of the motor 15. In motorized lifting and lowering operation, the brake 6 is open, i.e., the drive shaft 17 can be rotated relative to the winch frame 3, whereby the transmission shaft 12 is blocked or prevented from rotating relative to the winch frame 3, in particular by the fact that the brake 100 and / or another brake 200, for example shown in EP 3 028 983 A1, is closed.

[0049] In the Fig. In the example shown in Figure 2, the transmission 10 comprises an output planetary stage 22, the sun gear 23 of which is driveable, the planet carrier 24 or the ring gear 28 of which is non-rotatably connected to the winch frame 3, and the remaining free element (ring gear 28 or planet carrier 24) of which is non-rotatably connected to the winch drum 2. Furthermore, the transmission 10 comprises an input planetary stage 42, the sun gear 43 of which is driveable by a motor 15, which is attached to, or can be attached to, the winch 1, in particular by its motor shaft non-rotatably connected to the input shaft 17. The sun gear 23 of the output planetary stage 22 is driveable by the planet carrier 44 of the input planetary stage 42, wherein the transmission shaft 12 is driveable by the ring gear of the input planetary stage 42.Alternatively, the sun gear 23 of the output planetary stage 22 can be driven by a ring gear of the input planetary stage 22, wherein the gear shaft 12 can be driven by a planet carrier 44 of the input planetary stage 42.

[0050] As from Fig.As can be seen in Figure 1, a free-fall brake 100 is provided, comprising at least one first brake body 110 in the form of several brake discs, which is mounted non-rotatably about the axis of rotation D on a first brake body carrier 111, and at least one second brake body 120 in the form of several second brake discs, which is mounted non-rotatably on a second brake body carrier 121. The first and second brake bodies 110, 120 can be pressed against each other by means of a pressure piece 140 acting on the brake discs to achieve a braking effect based on friction. In the example shown, the pressure piece 140 is pressed towards the first and second brake bodies 110, 120 by several springs 141, thus allowing them to be pressed against each other. The at least one spring 141 is supported at one end by the pressure piece 140 and at its other end by the brake body carrier 111.The brake body carrier 111 is composed of several parts that are connected to each other in a rotationally and axially fixed manner. A first brake body carrier part 112 is annular and surrounds the at least one first brake body 110 and is engaged with the at least one first brake body 110 in a rotationally fixed manner about the axis of rotation D. The brake body carrier 111 has a support surface against which the brake disc assembly, consisting of first and second brake discs, is axially supported. The support is formed in particular by a second brake body carrier part 113, which is attached to the first brake body carrier part 112. The at least one spring 141 is supported by a third brake body carrier part 114, which is connected or joined to the first brake body carrier part 112 in a rotationally and axially fixed manner. The pressure piece 140 is arranged in a rotationally fixed manner about the axis of rotation D with respect to the first brake body carrier 111.

[0051] The at least one spring 141 is pre-tensioned so that it presses the brake bodies 110, 120 together, unless a counterforce opposing the spring force is applied.

[0052] The winch 1 further comprises an adjusting element, in particular an adjusting body 142, which in the example shown is designed as a piston. The adjusting body 142 is displaceably arranged along the axis of rotation D on the housing 70, in particular the housing part 72. The housing 70, in particular the housing part 72, and the adjusting body 142 form a chamber 143, which can be pressurized and depressurized with a fluid, in particular a pneumatic or hydraulic fluid. The adjusting body 142 acts axially on the pressure piece 140, such that a displacement of the adjusting body 142 in a first direction causes the at least one spring 141 to be tensioned and the pressure piece 140 to take pressure force off the brake bodies 110, 120, wherein a movement of the adjusting body 142 in the opposite second direction causes the at least one spring 141 to be relaxed and the pressure piece 140 to increase the pressure force.The chamber 143 is arranged such that, when pressurized, the pressure fluid exerts a force on the adjusting element 142 that counteracts the force of the at least one spring 141. When the pressure in the chamber 143 is released, the force of the at least one spring 141 acts on the adjusting element 142 and displaces it in the second direction.

[0053] The second brake body support 121 is kinematically coupled to the gearbox 10 and / or the winch drum 2 such that a rotation of the gearbox shaft 12 causes a rotation of the second brake body support 121 relative to the first brake body support 111. In the example shown, the brake body support 121 is designed so that it can be connected to a rotating part of the gearbox 10, in particular by means of a shaft-hub connection, whereby a load acting tangentially on the winch drum 2, e.g., a load suspended from the cable, causes a moment to be exerted on the brake body support 121.

[0054] In conventional solutions, the first brake body carrier 111 is rotationally fixed about the axis of rotation D, i.e. immovably connected to the housing 70, or the brake discs 110 are mounted directly on the housing 70 in a rotationally fixed manner about the axis of rotation D.

[0055] According to one embodiment of the invention, the first brake body carrier 111 is flexibly mounted about the axis of rotation D of the second brake body carrier 121 with respect to the housing 70. This means that the first brake body carrier 111 can perform slight rotational movements relative to the housing 70 about the axis of rotation D, depending on an elastic deformation of at least one component 81, via which the first brake body carrier 111 and the housing 70 are connected. In the example shown, the component 81, designed as a force-measuring bolt, has a sensor 80. In principle, other components are also possible instead of a force-measuring bolt, such as one or more springs. The braking torque generated by the brake 100 can be determined by the sensor 80 based on the deformation of the component 81.The actual value of the braking torque determined by the sensor 80 can be processed in a control system which actuates a valve that supplies the chamber 143 with pressure fluid accordingly in order to adjust the braking torque to a desired value.

[0056] For example, the brake body carrier 111 can only be supported rotationally around the axis of rotation D via the at least one component 81 on the housing 70, which increases the measurement accuracy of the braking torque.

[0057] The housing 70, in particular the housing part 72 and optionally a section 73 integrally formed with the housing part 72, forms two support points for the force-measuring bolt. The force-measuring bolt is supported with its circumference against two support points of the housing 70 in the transverse direction. The first brake body support 111, in particular the brake body support part 114, is supported between the two support points on the circumference of the force-measuring bolt. This allows the transverse force exerted on the force-measuring bolt by the braking torque, or the resulting deformation of the force-measuring bolt, to be determined by means of the force-measuring bolt.

[0058] The force measuring bolt has a longitudinal axis that is arranged parallel and offset to the axis of rotation D, so that the braking torque of the brake 100 causes a transverse force on the force measuring bolt.

[0059] The housing 70, in particular the housing part 72, has an opening through which the brake body carrier 111, in particular part 114, engages. The gap formed between part 114 or the brake body carrier 111 and the housing 70, in particular the second housing part 72, is sealed by means of a seal.

[0060] The brake body carrier 111 is mounted by means of rolling elements 130 with its outer circumference on the inner circumference of the cup-shaped housing section for the lowest possible frictional rotation about the axis of rotation D. The first brake body carrier 111 is enclosed between the first housing part 71 and the second housing part 72, which is axially and rotationally fixed to the first housing part 71, such that the first brake body carrier 111 is axially displaceable (with respect to the axis of rotation D) relative to the housing.

Claims

[1] Free-fall winds (1), comprising: - a housing (70) and a winch drum (2) rotatably mounted relative to the housing (70) about its axis of rotation (D), - a free-fall brake (100) comprising at least one first brake body (110) and at least one second brake body (120), wherein the at least one first brake body (110) and the at least one second brake body (120) are pressable against each other to achieve a friction-based braking torque, - a gearbox (10) arranged between the winch drum (2) and the free-fall brake (100), which is designed to convert a rotation of the winch drum (2) into a rotation of at least one second brake body (120) relative to the first brake body (110), - a sensor (80) designed to detect a measured value from which the braking torque of the free-fall brake (100) acting between the winch drum (2) and the housing (70) can be determined. [2] Free-fall winds (1) according to claim 1, characterized by , that the sensor (80) is arranged: - between the at least one second brake body (120) and the winch drum (2) or - between the at least one first brake body (110) and the housing (70) or - between the winch drum (2) and a winch frame (3). [3] Free-fall winds (1) according to any of the preceding claims, characterized by , that the gearbox (10) has a drive shaft (17) to which a motor (15) is connected or can be connected, wherein the gearbox (10) is designed such that a rotation of the drive shaft (17) relative to the housing (70) is converted into a rotation of the winch drum (2) relative to the housing (70). [4] Free-fall winds (1) according to any one of the preceding claims, characterized by, that the free-fall brake (100) has a first brake body support (111) which supports the at least one first brake body (110) in a rotationally fixed manner, and a second brake body support (121) which supports the at least one second brake body (120) in a rotationally fixed manner. [5] Free-fall winds (1) according to the preceding claim, characterized by , that the first brake body carrier (111) is flexibly mounted about the axis of rotation (D) of the second brake body carrier (121) and the first brake body carrier (111) and the housing (70) are connected via at least one component (81) which has the measuring transducer (80), in particular a force sensor. [6] Free-fall winds (1) according to claim 4 or 5, characterized by , that the first brake body carrier (111) is mounted on the housing (70) so as to be movable about the axis of rotation (D), in particular by means of plain bearings or by means of rolling elements (130). [7] Free-fall winds (1) according to any one of claims 4 to 6, characterized by, that the first brake body carrier (111) is supported on the housing (70) with its circumference movable about the axis of rotation (D). [8] Free-fall winds (1) according to any one of claims 4 to 7, characterized by , that the housing (70) has a first housing part (71) and a second housing part (72, 73), wherein the first brake body support (111) is enclosed between the first housing part (71) and the second housing part (72, 73) which is axially and rotationally fixed to the first housing part (71) such that the first brake body support (111) is axially displaceable with respect to the housing (70). [9] Free-fall winds (1) according to any one of the preceding claims, characterized by , that - the sensor (80) is designed for a resistance-based measuring method, in particular having a strain gauge or a thin-film coating, or - the measuring sensor (80) is designed for a magnetic field-based measuring method, in particular has magnetic coils. [10] Free-fall winds (1) according to any one of claims 4 to 8, characterized by , that the measuring sensor (80) is a force measuring bolt on which the first brake body carrier (111) is supported in the direction of rotation about the axis of rotation (D), the force measuring bolt being supported on the housing (70). [11] Free-fall winds (1) according to the preceding claim, characterized by , that one of the housing (70) and first brake body carrier (111) forms two support points for the force measuring bolt and the other of the housing (70) and first brake body carrier (111) forms a support point arranged between the two support points. [12] Free-fall winds (1) according to any one of the preceding claims, characterized by, that the free-fall brake (100) has at least one pre-tensioned spring (141) which, via a pressure piece (140), presses the at least one first brake body (110) and the at least one second brake body (120) against each other for braking, wherein the pressure piece (140) is electrically, hydraulically or pneumatically movable to release the free-fall brake (100) or to reduce the braking torque against the force of the pre-tensioned spring (141). [13] Free-fall winds (1) according to the preceding claim, characterized by an adjusting element (142) which is displaceable in the displacement direction of the pressure piece (140), in particular electrically, hydraulically or pneumatically displaceable, wherein the adjusting element (142) is axially supported on the pressure piece (140) and the pressure piece (140) is movable about the axis of rotation (D) relative to the adjusting element (142). [14] System comprising a free-fall winch (1) according to any one of the preceding claims, characterized bythat a control loop is provided which is designed to - to determine a controlled variable from the signal of the measuring sensor (80) and to continuously compare it with a reference variable, which may in particular be a desired braking torque, and - to influence the force with which the at least one first brake body (110) and the at least one second brake body (120) are pressed together based on the result of the comparison. [15] Method for controlling a braking torque of a free-fall winch (1), wherein the free-fall winch (1) comprises: - a housing (70) and a winch drum (2) rotatably mounted relative to the housing (70) about its axis of rotation, - a free-fall brake (100) comprising at least one first brake body (110) and at least one second brake body (120), wherein the at least one first brake body (110) and the at least one second brake body (120) are pressable against each other to achieve a friction-based braking torque, - a gearbox (10) kinematically arranged between the winch drum (2) and the free-fall brake (100) and a sensor (80), wherein the gearbox (10) converts a rotation of the winch drum (2) into a rotation of the second brake body (120) relative to the first brake body (110) during free-fall operation of the free-fall winch (1), and the sensor (80) records a measured value from which a controlled variable is determined, and wherein the controlled variable is continuously compared with a reference variable, which may in particular be a desired braking torque, and based on the result of the comparison, the force with which the at least one first brake body (110) and the at least one second brake body (120) are pressed against each other is influenced in order to align the controlled variable with the reference variable.

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