Conveyor machine with a braking device

Abstract

Conveyor machine (1) with a braking device, comprising - at least one braking surface (5), - a plurality of brake calipers (14), each with a pair of brake force generators and a brake release device (14.2) arranged on each brake force generator (14.1) and actuated with hydraulic fluid, wherein each brake force generator (14.1) generates a braking force acting axially in the direction of the braking surface (5) on a brake pad (24) and each brake release device (14.2) generates a force opposite to the braking force for releasing the brake pad (24), characterized in that - each brake calliper (14) is assigned its own pressure generator (12) for the hydraulic fluid, wherein the two brake ventilation devices (14.2) of the brake calliper (14) are fluidically connected to the pressure generator (12), - the braking device has a separate electrical control and regulation unit (13) for the braking force for each brake calliper (14), - wherein all pressure generators (12) and all control and regulation units (13) are arranged directly on the conveyor machine (1).

Description

[0001] The invention relates to a hoisting machine, in particular for an above-ground shaft hoisting system, with a braking device comprising a braking surface and a plurality of brake calipers, each with a pair of braking force generators and a brake release device arranged on each braking force generator and actuated by hydraulic fluid, wherein each braking force generator generates a braking force acting axially in the direction of the braking surface on a brake pad and each brake release device generates a force opposite to the braking force for releasing the brake pad.

[0002] According to TAS / December 2005, Sheet 3 / 15a, Section 3.9.1.1, hoisting machines must be equipped with at least two braking devices. One brake must act as a safety brake directly on the cable carrier. The brakes must be shoe brakes, acting radially as drum brakes or axially as disc brakes on the braking surface, which can be designed as a brake rim or brake disc. Linkage-free braking devices consist of braking force generators, actuation and control devices, and brake shoes with linings as well as braking surfaces. Linkage-free braking devices must have at least two pairs of braking force generators. Each braking force generator generates a braking force on the brake pad, acting axially in the direction of the braking surface. The braking force is generated primarily by springs or spring assemblies.In addition, each brake force generator is equipped with a hydraulic fluid-operated brake release device, which generates a force opposing the braking force to release the brake pad. The brake release device is operated by a hydraulic system, which must be capable of being vented.

[0003] State-of-the-art hoisting machines are predominantly stopped electrically during operation. The braking system primarily functions as a holding or safety brake in the event of a power failure, overspeed, or malfunctions in the shaft area. According to TAS 3.9.5.7, on shaft hoisting systems with travel speeds above 4 m / s, the safety brake control system must be designed so that the response time, i.e., the time from brake activation to engagement of the brake shoes, is less than 0.2 s.

[0004] In the course of the development of braking devices for shaft hoisting systems, safety has been continuously improved, as shown by the following sequence in the historical development of braking devices for shaft hoisting systems: 1. Hydraulic / pneumatic shoe or disc brakes with defined braking force and variable deceleration. 2. Hydraulic / pneumatic shoe or disc brakes with defined braking force. All brake force generators are assigned to a hydraulic / pneumatic and an electric channel. The deceleration is variable. 3. Hydraulic disc brakes with variable braking force and constant deceleration. All brake force generators are assigned to one hydraulic and one electric channel. 4. Hydraulic disc brakes with variable braking force and constant deceleration. Each brake force generator is assigned to a hydraulic channel. Two electrical channels are available. 5. The current state of the art is hydraulic disc brakes with variable braking force and constant deceleration. All brake force generators are assigned to several hydraulic and electrical channels.

[0005] A state-of-the-art braking system is manufactured and offered by Olko Maschinentechnik GmbH under the type designation COBRA01. The type approval (http: / / esb.bezreg-arnsberg.nrw.de / a 3 / a 3 010 / a 3 010 005 / a 3 010 02 B32 10 1 E rg1-Erg3 Verl .html - accessed on April 3, 2021) states that the COBRA01 braking system is an electrohydraulic brake control and regulation system with adjustable braking force for emergency braking of a hoisting machine. A key feature of the electrohydraulic brake control and regulation system is the adjustable braking force in the event of emergency braking in order to comply with the permissible deceleration rates. In the event of safety braking, a constant deceleration effect is always achieved regardless of the overload conditions and the direction of travel of the conveyor machine and regardless of fluctuations in the braking force due to the friction coefficient.

[0006] The hydraulic part of the brake control and regulation system of the COBRA01 braking system has a multi-channel design. The hydraulic circuits for controlling the braking force are present in multiple locations and are largely identical in design. The braking force generators of the braking system are grouped into several circuits. Each hydraulic circuit (hydraulic channel) is assigned a braking force generator group, meaning that, for example, three brake calipers are controlled by one channel or sub-control unit, with each brake caliper having a pair of braking force generators.

[0007] The multi-channel design is a fault-control measure and thus a key feature of the braking system's safety concept. In the event of a malfunction in one of the channels, the other channels must be able to properly stop the shaft hoist system through emergency braking. Therefore, the number of required braking force generators and the number of channels, as well as the allocation of the braking force generators to the channels, are determined on a system-specific basis.

[0008] The pressure generation device (pressure generator) for the various channels comprises a main and a standby pump and is only installed once. If one of the two pumps fails, the braking system can be operated with only one of the two pumps.

[0009] Each hydraulic channel of the braking system is assigned an electrical brake circuit controller. Each brake circuit controller is monitored by a higher-level master control unit. The brake circuit controllers and the master control unit together form the electrical part of the brake control and regulation system.

[0010] The information on the current speed of the hoisting machine of the shaft hoisting system is recorded by speed sensors on the hoisting machine of the shaft hoisting system or its peripherals and transmitted to the electrical part of the brake control and regulation system.

[0011] The use of long pipelines in the hydraulic channels of the multi-channel electro-hydraulic brake control and regulation system negatively impacts the controllability of the braking force. The electrical part of the multi-channel electro-hydraulic brake control and regulation system requires considerable effort to compensate for the negative effects of the hydraulics.

[0012] The laying of the hydraulic lines in a multi-channel electro-hydraulic brake control and regulation system between the groups of brake force generators and the central pressure generation device is also very complex.

[0013] Furthermore, the central pressure generation device must be extremely powerful in order to provide the required hydraulic energy for all braking force generators.

[0014] Finally, the effort required for wiring a multi-channel electro-hydraulic brake control and regulation system is very high.

[0015] Retrofitting the braking systems of older shaft hoisting systems with a multi-channel electro-hydraulic brake control and regulation system is often not possible because the necessary infrastructure is not available or would require significant reconstruction measures.

[0016] DE 10 2005 027 338 A1 discloses a hoist, in particular for a container crane, with a first disc brake and a second disc brake arranged on a cable drum. A gear is arranged between the first and second brakes. Furthermore, the hoist has a control unit for controlling the two brakes. The control unit is connected to various sensors to test the brakes sequentially before operation of the hoist. A display unit for the hoist operator is provided on the control unit.

[0017] DE 10 2006 003 832 A1 discloses another hoist whose brakes are designed as so-called industrial brakes. They close under spring load and can be released via an electro-hydraulic release device that works against the spring force. A single hydraulic unit is assigned to both brake calipers of the hoist. Signals are transmitted via a control element to a single crane control system, which then act on a motor and the brakes of the hoist via corresponding control lines.

[0018] DE 10 2012 011 539 A1 relates to a disc brake system for mining machines, which is equipped with at least two brake circuits. Each brake circuit is assigned two brake calipers with associated brake pads, and each brake circuit is provided with a control unit with two redundant control circuits. The braking force is generated by preloaded springs and released hydraulically. At least one pump is provided for all brake circuits to generate pressure. However, two redundant pumps can also be installed, with one pump running and the second pump being used for short-term support. The control units and the pump units can be arranged on a tank as a compact unit together with other components of the control circuit.

[0019] Based on this prior art, the object of the invention is to provide a hoisting machine with a braking device whose hydraulic system requires fewer long pipes and which requires less installation effort.

[0020] This task is solved in a conveyor machine with a braking device of the type mentioned above in that - each brake calliper is assigned its own pressure generator for the hydraulic fluid, with the two brake ventilation devices of the brake calliper being fluidly connected to the assigned pressure generator, - each brake calliper has its own electrical control and regulation unit for the braking force, - whereby all pressure generators and all control and regulation units are arranged directly on the conveyor machine.

[0021] According to the invention, each brake caliper is assigned its own hydraulic fluid pressure generator. Since a comparatively small amount of hydraulic fluid is required to actuate the brake caliper's two brake release devices, the pressure generator requires only a small amount of installation space.

[0022] The pressure generators and the electrical control and regulation units are located directly on the hoisting machine, i.e., in the immediate vicinity of the brake calipers. The resulting short hydraulic fluid lines minimize the negative effects on controllability resulting from the long line runs of the current technology. Furthermore, the cabling effort is reduced.

[0023] Preferably, the pressure generators and / or the control and regulation units are mounted on the brake stands of the braking system, which are required anyway. This results in extremely short cable runs between the pressure generators and the brake calipers.

[0024] Alternatively, the pressure generators and / or the control and regulation units are arranged on a machine frame of the winding machine. The machine frame is the sum of the load-bearing parts of the winding machine. Steel structures, but also the machine foundation, can be considered as load-bearing parts. The arrangement can, for example, be made entirely or partially in a central control cabinet arranged on the machine frame if an arrangement on the brake stands is not possible in existing systems due to space constraints or if a large number of brake calipers prohibits the arrangement. Furthermore, several pressure generators and / or control and regulation units can be combined into assemblies that are distributed around the machine frame and / or a brake stand of the winding machine.

[0025] Each pressure generator is a piston / cylinder unit driven by an electric actuator that generates the required hydraulic fluid pressure to actuate the brake caliper's brake release device.

[0026] To achieve the short response time required by the TAS for safety braking—i.e., the time from brake release to the brake shoes contacting the braking surface—a linear actuator with a planetary roller screw is preferably used as the electric actuator. Linear actuators with an integrated planetary roller screw require less installation space at the same speed than linear actuators with a ball screw or planetary roller drive and can therefore be advantageously arranged directly on the brake pedestal of the braking system, next to the associated brake caliper. Furthermore, a planetary roller screw has a longer service life than a ball screw or planetary roller drive due to the high load ratings resulting from the large number of load-bearing contact surfaces.Despite its compact dimensions, the linear actuator is therefore particularly suitable for safety-relevant use as a component of a braking device on a conveyor machine.

[0027] Depending on the required deceleration of the braking system, the electric actuator adjusts the hydraulic fluid pressure in the piston / cylinder unit and transmits it to the two venting devices of the brake caliper. The resulting braking force is transferred to the braking surface of the hoisting machine, decelerating the rope carrier of the shaft hoisting system.

[0028] By continuously comparing the setpoint / actual value of the hoisting machine's speed, the deceleration is monitored, in particular kept constant. For this purpose, the electrical control and regulation units for the braking force assigned to each brake caliper access the signal from at least one sensor for detecting the speed of the hoisting machine, wherein the at least one sensor is preferably a rotary encoder for detecting the rotational speed of a main shaft of the hoisting machine. Optionally, additional rotational speed sensors can be arranged, for example, on a cable pulley of the shaft hoisting system. If the setpoint / actual value comparison indicates a need for control, each control and regulation unit is configured to control the electrical actuator of the pressure generator, taking into account the speed signal and the signal from a hydraulic sensor assigned to the pressure generator.The hydraulic sensor measures the pressure of the hydraulic fluid in the hydraulic system of each brake caliper.

[0029] If the braking system requires a larger volume of hydraulic fluid, an extremely short response time, or a combination of both for design reasons, each brake caliper is assigned at least one pressure accumulator to hold the hydraulic fluid. The at least one pressure accumulator is fluidly connected to the two brake release devices of the brake caliper, and the fluid connection to each pressure accumulator can be shut off by means of an electrically operated directional valve. A gas pressure sensor is arranged on one gas side of each pressure accumulator.

[0030] In an alternative design of the braking system, several brake calipers share at least two common pressure accumulators for storing the hydraulic fluid. For redundancy reasons, the TAS specifies two pressure accumulators; otherwise, one common pressure accumulator would generally suffice. In this embodiment, too, the fluid connection to each common pressure accumulator can be shut off using an electrically operated directional control valve.

[0031] If the hydraulic system of a brake caliper has at least one pressure accumulator, the associated control and regulation unit is designed to control not only the electric actuator of the pressure generator, but also each electrically operated valve for opening or shutting off the pressure accumulator, taking into account the signals of the hydraulic sensor and the signal of the detected speed of the conveyor machine.

[0032] The control and regulation units for several of the brake calipers are connected via a network and can synchronize and control each other.

[0033] The brake force generators and the actuators are preferably provided with a position monitoring device, for example position sensors, whereby a permanent comparison of the position sensors with each other detects inadmissible deviations in the position of the brake force generator and / or actuator.

[0034] The invention is explained in more detail below with reference to the drawings. Fig. 1 a schematic overall view of a conveyor machine with a braking device, Fig. 2 a brake stand of a braking device in side and front view, Fig. 3 a brake stand of a braking device in side and front view with a control cabinet arranged on the machine frame of the conveyor, Fig. 4 a schematic representation of a first embodiment of a brake caliper of the braking device with a hydraulic circuit, Fig. 5 a representation of the brake calliper according to Fig. 4, Fig. 6 a schematic representation of a second embodiment of a brake caliper of the braking device with a hydraulic circuit comprising a pressure accumulator, Fig. 7 a representation of the brake calliper according to Fig. 6, Fig. 8 a schematic representation of a third embodiment of a brake calliper of the braking device with a hydraulic circuit comprising two pressure accumulators, Fig. 9 a representation of the brake calliper according to Fig. 8, Fig. 10 a schematic representation of a fourth embodiment comprising an assembly with two brake calipers and two common pressure accumulators, Fig. 11 a representation of the assembly according to Fig. 10, Fig. 12 a diagram illustrating the operation of a braking device with brake calipers according to Fig. 5, Fig. 13 a diagram illustrating the operation of a braking device with brake calipers according to Fig. 7 and Fig. 14 a representation to illustrate a braking device with brake calipers according to Fig. 9.

[0035] Fig. Figure 1 shows a hoisting machine (1) of an above-ground shaft hoisting system. The hoisting machine (1) essentially consists of a cable carrier (4), a drive motor (2), and a braking device composed of several components described in more detail below.

[0036] The cable carrier (4) is arranged in a rotationally fixed manner on a main shaft (3) extending between the drive machine (2) and a bearing (6). Four brake callipers (14) act on brake rings (5) on the outer edge of the side cheeks of the cable carrier (4), with two brake callipers (14) being arranged on opposite brake stands (8) on either side of the two brake rings (5). The brake stands (8), as well as the bearing (6) and the drive machine (2), are fastened to a machine frame (11) of the hoisting machine (1). Furthermore, a control cabinet (9) for connecting control and regulating units (13) of the braking device is arranged on the machine frame (11).

[0037] The structure of the individual brake calipers (14) is best seen in the Fig. 4, Fig. 5. Each brake caliper (14) comprises two brake force generators (14.1), hereinafter also referred to as a brake force generator pair, and a brake release device (14.2) arranged on each brake force generator (14.1) and actuated by hydraulic fluid. Each brake force generator (14.1) has a piston (14.3) acted upon by a spring assembly (23), the spring assembly (23) generating a braking force acting axially in the direction of the brake rim (5). The brake release device (14.2), arranged on each brake force generator (14.1) opposite the spring assembly (23), generates a force opposing the braking force to release the brake pad (24) by means of hydraulic fluid supplied via the hydraulic line (15), which acts on the side of the piston (14.3) opposite the spring assembly (23).

[0038] Each brake calliper (14) is assigned its own pressure generator (12) for the hydraulic fluid, as is particularly evident from Fig. 2 and Fig. 3. The pressure generator (12) has, as can be seen in particular from Fig. 4 and Fig. 5, a piston-cylinder unit (22, 26) driven by an electric actuator (20), wherein the electric actuator (20) is a linear actuator with a planetary roller screw drive. To detect the position of the actuator (20), the actuator has a position detection device (21) designed as a position sensor. A hydraulic pressure sensor (25) is arranged at the output of each piston-cylinder unit (22, 26). The hydraulic pressure sensor (25) continuously detects the pressure of the hydraulic fluid in the hydraulic line (15), which depends on the position of the actuator (20), acting on the two brake ventilation devices (14.2) of the brake caliper (14). Finally, the hydraulic line (15) has a prescribed vent (18) and a filling / filter unit (19) for the hydraulic fluid, as shown in Fig. 4 recognizable.

[0039] Each brake calliper (14) is assigned its own electrical control and regulation unit (13) for the braking force (see Fig. 2). The electrical control and regulation unit (13) is connected to the hydraulic pressure sensor (25) via a signal line (17) and to a rotary encoder (7) on the main shaft (3) of the drive motor (2) via a further signal line (17). On the output side, the control and regulation unit (13) is connected to the actuator (20) of the associated pressure generator (12) of the brake caliper (14) via electrical lines (16). The separate control and regulation unit (13) assigned to each brake caliper (14) therefore has the signal from the hydraulic sensor (25) and the speed signal from the rotary encoder (7) to control the electrical actuator (20) of the pressure generator (12).

[0040] The four pressure generators (12) and the four control and regulation units (13) for each of the four brake calipers are attached to the two brake stands (8) of the braking device, as can be seen in particular from Fig. 2. This results in extremely short hydraulic lines (15) between the pressure generator (12) and the brake calipers (14), as well as short cabling routes for the signal lines (17) and the electrical lines (16). At the same time, the pressure generators (12), each assigned to a single brake caliper (14), are extremely compact. The extremely short hydraulic lines (15) minimize the negative effects on the controllability of the brake calipers (14) that occur in the prior art. At the same time, the costs for infrastructure and installation are significantly reduced. Furthermore, the costly central pressure generation devices that are common in the prior art are no longer required. Furthermore, it can be seen that the components required for the hydraulic and electrical control of the braking system can be easily attached to the existing brake stands (8) and can therefore be retrofitted.

[0041] The braking device according to Fig. 3 differs from the braking device according to Fig. 2 in that parts of the components of the electrical control and regulation units (13) for each of the four brake calipers (14) are accommodated in the control cabinet (9).

[0042] Fig. 6 in conjunction with Fig. Figure 7 shows an embodiment of the braking device for the conveyor machine (1), in which each brake caliper (14) is additionally assigned a first pressure accumulator (27). The first pressure accumulator (27) is fluidly connected to the two brake release devices (14.2) of the brake caliper (14) via the hydraulic line (15). The hydraulic line (15) to the pressure accumulator (27) can be shut off by means of an electrically operated first directional control valve (29). The pressure accumulator (27) stores the hydraulic fluid under pressure. The pressure of the hydraulic fluid compresses a gas above a diaphragm or piston (31) on a gas side of the pressure accumulator (27). A gas pressure sensor (32) is connected to the gas side of the pressure accumulator. Otherwise, the structure of the hydraulic system of the brake caliper (14) corresponds to that according to Fig. 4, so that the explanations to Fig. 4 is referred to in addition.

[0043] The gas pressure sensor (32) is connected to the control and regulation unit (13) of the brake caliper (14) via another signal line, so that it can consider the signal from the gas pressure sensor in addition to the signal from the hydraulic sensor and the signal from the rotary encoder (7) on the main shaft (3). Taking the aforementioned signals into account, the control and regulation unit (13) controls not only the electric actuator (20) of the pressure generator (13) but also the electrically operated first directional control valve (29).

[0044] Out of Fig. 7 it can be seen that the first pressure accumulator (27) and the pressure generator (12) are combined to form a compact assembly.

[0045] The embodiment according to Fig. 6 and Fig. 7 with the first pressure accumulator (27) serves the purpose of achieving a short response time of the braking system, ie, the contact pressure is reached particularly quickly. The contact pressure is the pressure at which the brake pads (24) contact the braking surface (5) but do not yet decelerate.

[0046] Fig. 8 and Fig. 9 show a braking device which is different from the braking device according to Fig. 6 and Fig. 7 in that each brake caliper (14) of the braking device is assigned a first and second pressure accumulator (27, 28) for receiving hydraulic fluid. Both pressure accumulators (27, 28) are fluidly connected to the brake ventilation devices (14.2) of the brake caliper (14) via the hydraulic line (15). The fluid connection to each of the two pressure accumulators (27, 28) can be shut off independently of one another by means of the first and second electrically operated valves (29, 30). A gas pressure sensor (32) is arranged on the gas side of each pressure accumulator.

[0047] Out of Fig. 9 it can be seen that the first and second pressure accumulators (27, 28) and the pressure generator (12) are combined to form a compact assembly.

[0048] The embodiment according to Fig. 8 and Fig. 9 with two pressure accumulators (27, 28) serves the purpose of reducing the pressure in the hydraulic system particularly quickly. This also allows the holding pressure to be reached particularly quickly. The holding pressure is the pressure at which the brake pads (24) lock the braking surface (5) with triple safety.

[0049] The Fig. 10, Fig. 11 shows a further variant of the braking system with two first pressure accumulators (27). Two brake force generators (14) share at least two synchronized first pressure accumulators (27).

[0050] The first pressure accumulators (27) are used in the braking device according to Fig. 10, Fig. 11 also serves the purpose of achieving a short response time of the braking system. The brake ventilation devices (14.2) of the two brake calipers (14) are fluidly connected via the hydraulic lines (15) to the two common first pressure accumulators (27) for receiving the hydraulic fluid. Each of the two pressure accumulators (27) has a pressure sensor (32) on a gas side of the pressure accumulator (27). The hydraulic lines (15) to the two common pressure accumulators (27) can be shut off independently of one another by means of the two first directional control valves (29). From a technical point of view, it would be sufficient to provide only one of the two pressure accumulators (27). For reasons of redundancy, however, two synchronized first pressure accumulators (27) must be provided for operation in mining.

[0051] The operation of the various designs of the braking devices is described below using the Fig. 12 to 14 are explained in more detail. To explain the operation, the following pressures in the hydraulic systems of the brake calipers are defined as follows: 1. The release pressure is the pressure required to lift the brake pads (24) of the brake caliper (14) from the braking surface (5). The distance is approximately 2 - 3 mm from the braking surface (5). 2. The contact pressure is the pressure at which the brake pads (24) of the brake caliper (14) are in contact with the braking surface (5), but are not yet decelerating. At a braking pressure below the contact pressure, the braking system is already decelerating, but not yet with the constant deceleration required by the TAS in the event of emergency braking. 3. The residual pressure is the pressure at which the constant deceleration required by the TAS is achieved in the event of emergency braking. The residual pressure varies depending on the load conditions. 4. The holding pressure is the pressure at which the brake pads (24) of the brake caliper (14) lock the braking surface (5) with triple safety. This holding pressure is typically achieved when the system is depressurized.

[0052] During standard operation of the braking system of the winding machine (1), the pressure in the hydraulic system of the brake pressure generators (14) alternates exclusively between the release pressure and the holding pressure. During operation of the winding machine (1), the brake pads (24) are released, i.e., lifted from the braking surface (5). The winding machine (1) brakes the conveyor frame to a standstill. After the stop, holding pressure is applied to the braking surface, thus blocking the drive motor (2) of the winding machine (1).

[0053] The following is based on Fig. 12 the sequence of a safety braking for a braking device according to the Fig. 4 and Fig. 5 explains in more detail: In a first step, the brake pads (24) are released by compressing the hydraulic fluid through the piston / cylinder unit (22, 26) by means of the actuator (20). The control and regulation unit (13) sets the release pressure to approximately 140 bar.

[0054] In a second step, the brake pads (24) are applied by compressing the hydraulic fluid through the piston / cylinder unit (22, 26) by means of the actuator (20). The control and regulation unit (13) sets the application pressure to approximately 105 bar.

[0055] In a third step, the braking force is controlled by the control and regulation unit (13) by compressing or decompressing the hydraulic fluid by means of the actuator (20) through the piston / cylinder unit (22, 26). The residual pressure effective during deceleration ranges between 40 and 105 bar.

[0056] In a fourth step, the braking force control is terminated by completely decompressing the hydraulic fluid through the piston / cylinder unit (22, 26) by means of the actuator (20). This complete decompression sets the holding pressure to 0 bar, and the brake pads (24) block the braking surfaces (5).

[0057] The following is based on Fig. 13 the procedure for a safety braking operation for a braking device according to the Fig. 6 and Fig. 7 explains in more detail: In a first step, the brake pads (24) are released by compressing the hydraulic fluid through the piston / cylinder unit (22, 26) by means of the actuator (20). The control and regulation unit (13) sets the release pressure to approximately 140 bar.

[0058] In a second step, the first directional control valve (29) is opened. The pressure accumulator (27) absorbs the hydraulic fluid, and the contact pressure is suddenly established. As the hydraulic fluid is absorbed by the first pressure accumulator (27), the pressure drops from the release pressure of approximately 140 bar to the contact pressure of approximately 105 bar.

[0059] In a third step, the braking force is controlled by the control and regulation units (13) by compressing or decompressing the hydraulic fluid by means of the actuator (20) through the piston / cylinder unit (22, 26). The residual pressure effective during deceleration ranges between 40 and 105 bar.

[0060] In a fourth step, the control is terminated and the pressure is adjusted to approximately 40 bar by the actuator (20) using the piston / cylinder unit.

[0061] In a fifth step, the braking process is completed. The pressure in the hydraulic system is completely released by the actuator (20) and the piston / cylinder unit (22, 26). The filling volume from the first pressure accumulator (27) is absorbed by the piston / cylinder unit (22, 26). The holding pressure is established in the hydraulic system, and the braking surface is blocked.

[0062] In a sixth step, the first directional control valve (29) is closed again.

[0063] The following is based on Fig. 14 the sequence of a safety braking for a braking device according to the Fig. 8 and Fig. 9 explains in more detail: In a first step, the brake pads (24) are released by compressing the hydraulic fluid through the piston / cylinder unit (22, 26) by means of the actuator (20). The control and regulation unit (13) sets the release pressure to approximately 140 bar.

[0064] In a second step, the second directional control valve (30) is opened. The second accumulator (28) absorbs the hydraulic fluid, and the application pressure is established suddenly. As the second accumulator (28) absorbs the hydraulic fluid, the pressure drops from the release pressure of approximately 140 bar to the application pressure of approximately 105 bar. This is the pressure prevailing on the gas side in the second accumulator (28).

[0065] In a third step, the second directional control valve (30) is closed. In the third step, the braking force is controlled by the control and regulation unit (13) by compressing or decompressing the hydraulic fluid by means of the actuator (20) through the piston / cylinder unit (22, 26). The residual pressure effective during deceleration ranges between 40 and 105 bar.

[0066] In a fourth step, the control is terminated and the residual pressure is adjusted to approximately 40 bar in the hydraulic system by the actuator and the piston / cylinder unit (22,26).

[0067] In a fifth step, the first directional control valve (29) is opened. The residual pressure of approximately 40 bar in the hydraulic system is reduced to approximately 1 bar. The hydraulic fluid is drawn from the first pressure accumulator (27) via the now opened first directional control valve (29).

[0068] In a sixth step, the second directional control valve (30) is reopened. The pressure in the second accumulator (28) is reduced. The volume from the second accumulator (28) is absorbed by the first accumulator (27). A hydraulic fluid pressure of 1 bar is established in the entire hydraulic system.

[0069] In a seventh step, the first and second pressure accumulators (27, 28) are emptied by the piston / cylinder unit (22, 26) absorbing the volume of hydraulic fluid by means of the actuator (20). The hydraulic fluid pressure in the hydraulic system (27, 28) is 0 bar.

[0070] In an eighth and final step, the first and second directional control valves (29, 30) are closed.

[0071] The control and regulation units (13) of all four brake calipers are networked. Furthermore, all control and regulation units (13) have an interface to the decentralized machine control system of the conveyor (1). The connection to the machine control system is established via a cable. 1 conveyor machine 2 drive machine 3 Main shaft 4 cable carriers 5 Brake ring, braking surface 6 warehouses 7 rotary encoders 8 brake stands 9 Control cabinet 10 - 11 Machine frame 12 pressure generators 13 Control and regulation unit 14 brake caliper 14.1 Brake force generator 14.2 Brake release device 14.3 Piston 15 Hydraulic line 16 Electrical cable 17 Signal line 18 Ventilation 19 Filling / filter unit 20 Actuator 21 Position detection 22 cylinders 23 spring package 24 brake pad 25 Hydraulic pressure sensor 26 pistons 27 First pressure accumulator 28 Second pressure accumulator 29 First directional control valve 30 Second directional control valve 31 Diaphragm / piston 32 Gas pressure sensor 33 Independent power supply

Claims

[1] Conveying machine (1) with a braking device comprising - at least one braking surface (5), - several brake calipers (14) each with a pair of brake force generators and a brake venting device (14.2) arranged on each brake force generator (14.1) and actuated with hydraulic fluid, wherein each brake force generator (14.1) generates a braking force acting axially in the direction of the braking surface (5) on a brake pad (24) and each brake venting device (14.2) generates a force opposite to the braking force for venting the brake pad (24), characterized by , that - each brake caliper (14) is assigned its own pressure generator (12) for the hydraulic fluid, wherein the two brake venting devices (14.2) of the brake caliper (14) are fluidly connected to the pressure generator (12), - the braking device for each brake caliper (14) has its own electrical control and regulation unit (13) for the braking force, - wherein all printing units (12) and all control and regulating units (13) are arranged directly on the conveying machine (1). [2] Conveyor machine (1) with a braking device according to claim 1, characterized by , that the pressure generators (12) and / or the control and regulating units (13) are arranged on brake stands (8) of the braking device. [3] Conveying machine (1) with a braking device according to claim 1 or 2, characterized by , that the printing units (12) and / or the control and regulating units (13) are arranged on a machine frame (11) of the conveying machine (1). [4] Conveying machine (1) with a braking device according to one of claims 1 to 3, characterized by , that each pressure generator (12) has a piston / cylinder unit (22, 26) driven by an electric actuator (20). [5] Conveying machine (1) with a braking device according to claim 4, characterized by, that the electric actuator (20) is a linear actuator with a planetary roller screw drive. [6] Conveying machine (1) with a braking device according to one of claims 1 to 5, characterized by , that each pressure generator (12) is assigned a hydraulic pressure sensor (25) set up to detect the pressure of the hydraulic fluid generated by the pressure generator (12). [7] Conveying machine (1) with a braking device according to one of claims 1 to 6, characterized by at least one sensor for measuring the speed of the conveying machine (1). [8] Conveying machine (1) with a braking device according to claim 7, characterized by , that the at least one sensor is a rotary encoder (7) for detecting the rotational speed of a main shaft (3) of the conveying machine (1). [9] Conveying machine (1) with a braking device according to one of claims 1 to 8, characterized by, that each brake caliper (14) is assigned at least one pressure accumulator (27,28) for receiving the hydraulic fluid, wherein the at least one pressure accumulator (27,28) is fluidly connected to the two brake venting devices (14.2) of the brake caliper (14) and the fluid-conducting connection can be shut off by means of an electrically actuated directional control valve (29,30). [10] Conveying machine (1) with a braking device according to one of claims 1 to 8, characterized by , that - the brake ventilation devices (14.2) of several brake calipers (14) are fluidly connected to at least two common pressure accumulators (27) for receiving the hydraulic fluid and - the fluid-conducting connection to each of the at least two common pressure accumulators (27) can be shut off independently of each other by means of an electrically actuated directional control valve (29). [11] Conveying machine (1) with a braking device according to claims 4, 6 and 7, characterized by, that the control and regulating unit (13) of each brake caliper (14) is set up to control the electric actuator (20) of the pressure generator (12) taking into account the signal of the hydraulic pressure sensor (25) and the detected speed of the conveying machine (1). [12] Conveying machine (1) with a braking device according to claim 4, 6, 7 and 9 or according to claim 4, 6, 7 and 10, characterized by , that the control and regulating unit (13) of each brake caliper (14) is configured to control the electric actuator (20) of the pressure generator (12) and of each electrically actuated directional control valve (29) to shut off the fluid-conducting connection to the at least one pressure accumulator (27) taking into account the signal of the hydraulic pressure sensor (25) and the detected speed of the conveying machine (1). [13] Conveyor machine (1) with a braking device according to one of claims 1 to 12, characterized by, that the control and regulation units (13) for several of the brake calipers (14) are combined in one module. [14] Conveying machine (1) with a braking device according to one of claims 1 to 13, characterized by , that the control and regulation units (13) for several of the brake calipers (14) are part of a network.

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