A heavy-duty crank press hydraulic clutch-brake product test bench device

Abstract

A kind of heavy crank press hydraulic clutch brake product test bench device, including variable frequency motor and main shaft, variable frequency motor drives large pulley rotation by belt drive;Large pulley is rotatably supported on the outer surface of main shaft by bearing;Clutch and brake are respectively arranged at the both ends of main shaft, clutch is fixed on clutch mounting plate fixed with large pulley, brake is fixed on brake seat by brake mounting plate, brake seat is rotatably supported on the outer surface of main shaft by rotating bearing, variable rotational inertia device is arranged in the middle of main shaft, rotational speed encoder is arranged at the end of main shaft.Combination or disconnection of clutch and main shaft is to transmit or cut off power, brake or release main shaft to control the stop or rotation of main shaft.The clutch brake combination is separated from the heavy press machine, the actual working cycle can be simulated in the factory, and the combination test, single brake test and single clutch test are supported, which is convenient for performance verification before product delivery.

Description

Technical Field

[0001] This invention relates to the field of clutch and brake technology, and specifically to a test bench device for a heavy-duty crank press hydraulic clutch and brake product. Background Technology

[0002] The clutch and brake assembly is a core control component of heavy-duty crank presses and cold shears, and its performance directly determines the equipment's operational safety, production efficiency, and product quality. During the operation of a press or cold shear, there are two basic actions: the first is the execution of the work (such as pressing or shearing bar stock), a process characterized by high energy consumption; the second is the start and stop control of the crankshaft, i.e., controlling the timing and position of the execution actions. The first action is controlled by the second, and the frequent starting and stopping of the crankshaft is precisely the core aspect requiring precise control of the clutch-brake assembly, and also the part with the highest failure rate and most stringent performance requirements in the entire transmission system.

[0003] In the design and manufacturing of heavy-duty crank presses, the selection, performance verification, and reliability testing of hydraulic clutches and brakes are crucial steps in ensuring the overall performance of the equipment. Traditionally, after the clutches and brakes are selected and manufactured, they are typically installed and tested on the actual press machine. The clutch-brake combination's control performance on crankshaft speed, stopping position, and cycle time is tested by directly driving the crankshaft. This "on-machine testing" method is acceptable for small presses, but for heavy-duty crank presses with capacities of thousands of tons or more, it faces numerous insurmountable technical obstacles.

[0004] First, heavy-duty crank presses are large, complex, and expensive to manufacture, making it difficult to build a complete testing environment within the manufacturing plant. Performance testing of clutches and brakes often requires transporting the product to the user's site for debugging and testing on the pre-installed press. This significantly extends product development and delivery cycles, and if problems are discovered during testing, the cost of returning the product for modification or on-site repair is extremely high and time-consuming.

[0005] Secondly, to obtain accurate performance data of clutch-brake products under different operating conditions (such as engagement characteristics at different speeds, braking distances under different loads, and temperature rise curves at different cycle frequencies), it is necessary to frequently start and stop the press equipment and change the speed and load parameters. For heavy-duty crank presses, frequent start-stop operations not only consume a lot of energy and are economical, but also cause unnecessary additional wear and fatigue damage to other components of the equipment (such as the main motor, transmission gears, crankshaft support bearings, etc.), and may even affect the service life and accuracy retention of the main equipment.

[0006] Furthermore, existing technologies already include some performance testing devices for press clutches and brakes. For example, some solutions propose using counterweights to simulate the rotational inertia of a load to test the clutch / brake performance under specific inertia conditions; others propose test benches for mechanical press clutches and brakes, which adapt to different specifications of clutches and brakes by providing interchangeable shaft mounting holes on the drive shaft. However, these existing test benches still have the following shortcomings:

[0007] (1) Existing test benches can usually only test a single component of the clutch or brake independently, making it difficult to completely simulate the coordinated working cycle of the clutch and brake combination on the same test system. The accuracy and stability of the timing coordination between the clutch and brake are precisely the most critical factors affecting the control performance of the press.

[0008] (2) The existing test bench has limited ability to simulate rotational inertia. On the one hand, the variable rotational inertia mechanism of some devices is complex in design and cumbersome in adjustment operation, making it difficult to quickly replace the inertia block to meet the system inertia simulation requirements of different specifications of presses; on the other hand, the inertia adjustment range is narrow and cannot cover a wide range of inertia from small and medium-sized presses to heavy-duty thousand-ton presses.

[0009] (3) For wet clutches and wet brakes (which require a continuous supply of lubricating oil for cooling and lubrication during operation), existing test benches generally lack reasonable internal lubrication channel design, making it difficult to simulate the lubrication conditions in actual presses during the test, resulting in deviations between test data and actual working conditions. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention provides a test bench device for hydraulic clutch and brake products of heavy-duty crank presses. It overcomes the deficiencies of existing technologies, is rationally designed, and can replace the actual crankshaft with a spindle system with variable moment of inertia. It can simulate different working speeds with an adjustable speed drive system, thereby completely reproducing the actual working cycle of the clutch and brake when disconnected from the main machine. This provides a reliable test platform for factory debugging, performance verification, and new product development of hydraulic clutches and brakes for heavy-duty crank presses.

[0011] To achieve the above objectives, the present invention provides the following technical solution:

[0012] A test bench device for a heavy-duty crank press hydraulic clutch and brake product includes a variable frequency motor and a main shaft. The variable frequency motor is fixedly mounted on a motor bracket. The output end of the variable frequency motor is connected to a small pulley via a coupling. The small pulley is connected to a large pulley via a V-belt. The central shaft of the small pulley is mounted on the motor bracket via a bearing seat.

[0013] The large pulley is rotatably mounted on the outer surface of the main shaft via bearings. A clutch is mounted on one end of the main shaft, and a brake is mounted on the other end. The clutch is fixedly mounted on a clutch mounting plate, which is fixedly mounted on the large pulley, enabling the large pulley to drive the clutch to rotate synchronously. The brake is fixedly mounted on a brake mounting plate, which is fixedly mounted on a brake seat. A rotating support bearing is provided inside the brake seat, and the brake seat is rotatably supported on the outer surface of the main shaft via the rotating support bearing. A rolling bearing seat is sleeved on the outer surface of the main shaft, and both the brake seat and the rolling bearing seat are fixedly mounted on a support seat.

[0014] A variable moment of inertia device is installed in the middle of the spindle, a speed encoder is installed at the end of the spindle, and temperature sensors are installed on the clutch and brake to monitor the operating temperature.

[0015] Preferably, two expansion sleeves are installed at both ends of the main shaft, and the gear hub of the clutch is detachably connected to the main shaft through the two expansion sleeves; the gear hub of the brake is detachably connected to the main shaft through the two expansion sleeves.

[0016] Preferably, a motor adjustment plate is fixedly provided on the side of the motor bracket, and a motor adjustment screw is threadedly connected to the motor adjustment plate. The end of the motor adjustment screw abuts against the side of the motor bracket. The surface of the motor bracket is provided with a plurality of adjustment elongated holes extending in the horizontal direction. The motor bracket is fixedly installed on the base by fastening bolts passing through the adjustment elongated holes. By rotating the motor adjustment screw, the motor bracket is pushed to move horizontally along the adjustment elongated holes to adjust the tension of the V-belt.

[0017] Preferably, a rotary shaft lip seal and an O-ring are provided between the brake seat and the main shaft, and between the large pulley and the main shaft, to prevent leakage of bearing lubricating grease.

[0018] Preferably, both ends of the main shaft are provided with an axial oil inlet and a radial oil outlet, and the radial oil outlet is connected to the gap between the two expansion sleeves; the lubricating oil enters from the axial oil inlet, flows into the gap between the two expansion sleeves through the radial oil outlet, and then enters the interior of the clutch and brake through the inner hole of the clutch and brake hub.

[0019] Preferably, a speed sensor is also fixedly installed on the spindle, and the speed sensor is electrically connected to an external control system for closed-loop control of the spindle speed.

[0020] Preferably, the variable moment of inertia device includes a detachable moment of inertia block, which is assembled from two semi-circular components. The two semi-circular components are fixed together by connecting bolts and mounted on the main shaft.

[0021] Preferably, it also includes a hydraulic power system and an electrical control system, wherein the hydraulic power system provides pressurized oil required for engagement / disengagement of the clutch and brake, and the electrical control system controls the speed of the variable frequency motor, the timing of the clutch and brake, and the cycle frequency.

[0022] Preferably, the clutch is fixedly mounted on the clutch mounting plate at the left end by hexagonal head bolts, and the clutch mounting plate is fixedly mounted on the large pulley by internal hexagonal screws.

[0023] This invention provides a test bench device for hydraulic clutch and brake products of heavy-duty crank presses, which has the following beneficial effects:

[0024] By separating the clutch-brake assembly of a heavy-duty crank press from the massive main machine, replacing the actual crankshaft with a variable moment of inertia spindle system, and replacing the press's main drive system with a belt drive system driven by a variable frequency motor, the actual working cycle of the clutch-brake is fully reproduced without the heavy-duty main machine. This allows for comprehensive debugging and performance testing of the clutch-brake product on the test bench of this invention before the product leaves the factory, eliminating the need to transport the product to the user's site for complete machine testing. This completely solves the industry problem of heavy-duty crank presses being too large to be frequently debugged and tested on-site.

[0025] This invention allows for both combined and individual clutch / brake tests on the same device. When the clutch engages and accelerates the spindle to a set speed, it disengages, and the brake engages, bringing the spindle's inertial system to a stop in a very short time. Using speed-time data recorded by a speed encoder at the spindle end and the known system moment of inertia, a complete brake performance curve can be precisely calculated. With the spindle stationary, the large pulley drives the clutch's gear ring to rotate continuously at a set speed. When the clutch engages, power is gradually transmitted to the spindle through the sliding friction of the friction plates, starting the spindle's inertial system until the spindle reaches a speed synchronized with the driving component. This process perfectly matches the actual operating conditions of a clutch starting a crankshaft from rest in a real press. By recording the spindle speed rise curve, the clutch's engagement characteristics, torque transmission, and thermal load capacity can be accurately evaluated.

[0026] By installing two expansion sleeves at each end of the spindle, the gear hubs of both the clutch and the brake are detachably connected to the spindle via these sleeves. This eliminates the need to machine keyways or splines on the spindle, thus avoiding stress concentration problems caused by keyway or spline machining and significantly improving the fatigue strength and reliability of the spindle. Furthermore, the expansion sleeve connection offers the advantage of easy installation and disassembly; simply tightening or loosening the locking screws achieves connection or separation. This facilitates quick replacement of clutches and brakes of different specifications, and by changing the expansion sleeves to different outer diameters, clutches and brakes with different inner bore sizes can be adapted without changing the spindle diameter, greatly expanding the applicability of the test bench. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this invention or the prior art, the accompanying drawings used in the description of this invention or the prior art will be briefly introduced below.

[0028] Figure 1 This is a top view structural diagram of the present invention;

[0029] Figure 2 This is a schematic diagram of the structure from the side view of the present invention;

[0030] Figure 3 for Figure 2 Schematic diagram of the cross section at point AA;

[0031] Explanation of the labels in the diagram:

[0032] 1. Variable frequency motor; 2. Motor bracket; 3. Coupling; 4. Small pulley; 5. V-belt; 6. Large pulley; 7. Bearing; 8. Main shaft; 9. Clutch; 10. Brake; 11. Hex head bolt; 12. Clutch mounting plate; 13. Support base; 14. Variable moment of inertia device; 15. Brake seat; 16. Brake mounting plate; 17. Expansion sleeve; 18. Socket head screw; 19. Rolling bearing seat; 20. Rotary shaft lip seal; 21. O-ring seal; 22. Motor adjusting screw; 23. Motor adjusting plate; 24. Speed ​​sensor; 25. Axial oil inlet; 26. Radial oil outlet; 27. Adjusting elongated hole; 28. Bearing seat. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0034] Example 1, as Figures 1 to 3As shown, a test bench device for a heavy-duty crank press hydraulic clutch and brake product includes a variable frequency motor 1 and a main shaft 8. The variable frequency motor 1 is fixedly mounted on a motor bracket 2, which is integrally mounted on the base of the test bench. The output end of the variable frequency motor 1 is connected to a small pulley 4 via a coupling 3. The small pulley 4 is connected to a large pulley 6 via a V-belt 5. Specifically, both the small pulley 4 and the large pulley 6 are grooved pulleys, and the V-belt 5 is wound around the belt grooves of the small pulley 4 and the large pulley 6. The speed of the variable frequency motor 1 can be steplessly adjusted by an external frequency converter, thereby achieving precise control of the speed of the main shaft 8 to simulate the working speed of the heavy-duty crank press under different working conditions. The central shaft of the small pulley 4 is mounted on the motor bracket 2 via a bearing seat 28. A rolling bearing is provided in the bearing seat 28 to support the rotating shaft of the small pulley 4 and ensure its rotational accuracy.

[0035] The outer surface of the main shaft 8 rotatably supports the large pulley 6 via bearings 7. That is, the large pulley 6 is not directly fixed to the main shaft 8, but is loosely fitted onto the main shaft 8 via bearings 7, allowing the large pulley 6 to rotate freely on the main shaft 8 without directly transmitting rotational motion to the main shaft 8. This structural arrangement is the basis for realizing the clutch to drive and control the main shaft.

[0036] One end of spindle 8 (e.g.) Figure 3 The left end shown is equipped with a clutch 9, and the other end of the main shaft 8 (as shown on the left end) is equipped with a clutch 9. Figure 3 The brake 10 is installed at the right end (as shown). Specifically, the gear ring of the clutch 9 is fixedly mounted on the clutch mounting plate 12 by hexagonal head bolts 11, and the clutch mounting plate 12 is fixedly mounted on the large pulley 6 by internal hexagonal screws 18. Thus, when the large pulley 6 rotates, it drives the gear ring (or driving part) of the clutch 9 to rotate synchronously through the clutch mounting plate 12, while the gear hub (or driven part) of the clutch 9 is connected to the main shaft 8. The engagement and disengagement of the piston and friction plate assembly inside the clutch 9 controls whether power is transmitted to the main shaft 8. When the clutch 9 is engaged: the gear ring (driving part) of the clutch 9 transmits torque to the gear hub (driven part) through the pressed friction plates, and the gear hub transmits torque to the main shaft 8. When the clutch 9 is disengaged: the friction plates between the gear ring and the gear hub separate, the torque transmission is cut off, and the main shaft 8 rotates freely or stops under the action of inertia and the brake.

[0037] The gear ring (braking part) of brake 10 is fixedly mounted on brake mounting plate 16, and the gear hub (rotating part) of brake 10 is connected to the main shaft 8 and rotates synchronously with the main shaft 8. Brake mounting plate 16 is fixedly mounted on brake seat 15, and a rotating support bearing is provided inside brake seat 15. Brake seat 15 is rotatably supported on the outer surface of main shaft 8 through rotating support bearing, that is, brake seat 15 can rotate freely relative to main shaft 8. However, since brake seat 15 is fixedly mounted on support seat 13, brake seat 15 remains stationary when working on the test bench. When brake 10 is in the engaged state: the stationary part of brake 10 applies braking torque to the rotating gear hub through the pressed friction pads. The braking torque is transmitted to main shaft 8 through expansion sleeve 17, and main shaft 8 decelerates until it stops. When brake 10 is in the disengaged state: the friction pads separate, no braking torque is applied to main shaft 8, and main shaft 8 can rotate freely.

[0038] A rolling bearing housing 19 is also fitted onto the outer surface of the main shaft 8, and a rolling bearing is installed inside the rolling bearing housing 19 to support the rotation of the main shaft 8. Both the brake housing 15 and the rolling bearing housing 19 are fixedly mounted on the support base 13, thereby reliably supporting the main shaft 8 on the test bench base.

[0039] A variable moment of inertia device 14 is installed in the middle of the main shaft 8. This variable moment of inertia device 14 is used to simulate the moment of inertia of the crankshaft rotation system of heavy-duty crank presses of different specifications. By installing moment of inertia blocks of different masses on the variable moment of inertia device 14, the total moment of inertia of the main shaft system can be precisely adjusted, thereby simulating the inertia characteristics of different systems from small and medium-sized presses to heavy-duty presses of thousands of tons.

[0040] A speed encoder is installed at the end of the spindle 8 to detect the spindle speed and angular displacement in real time. The speed encoder is preferably an incremental encoder or an absolute encoder with a resolution of not less than 1024 pulses / revolution to ensure high-precision detection of the spindle speed and stop position. Temperature sensors (not shown in the figure) are installed on the clutch 9 and brake 10. These temperature sensors are preferably thermocouples or resistance temperature detectors (RTDs) with a measurement accuracy of not less than ±0.5℃. They are used to monitor the operating temperature changes of the clutch 9 and brake 10 in real time during the test, preventing overheating damage and providing data support for evaluating the product's thermal performance.

[0041] Working principle:

[0042] Before operation, the clutch 9 and brake 10 to be tested are first installed at the left and right ends of the main shaft 8, respectively. Then, the variable frequency motor 1 is started. The output of the variable frequency motor 1 drives the small pulley 4 to rotate via the coupling 3. The small pulley 4 drives the large pulley 6 to rotate via the V-belt 5. The large pulley 6 drives the gear ring (driving part) of the clutch 9 to rotate synchronously via the clutch mounting plate 12. At this time, since the large pulley 6 is loosely fitted onto the main shaft 8 via the bearing 7, its rotational motion is not automatically transmitted to the main shaft 8. Whether the main shaft 8 rotates depends entirely on the engagement state of the clutch 9.

[0043] Initially, the test bench is in standby mode. The variable frequency motor 1 has started and is running at the set speed. The clutch 9 is disengaged (its internal cylinder has no pressurized oil, and the friction plate assembly is disengaged under spring force), cutting off the power input path, and the main shaft 8 does not rotate. The brake 10 is disengaged (its internal cylinder has no pressurized oil, and the friction plate assembly is disengaged under spring force), and no braking force is applied to the main shaft 8.

[0044] When a clutch-brake combination simulation test is required, the following action cycle is executed according to the preset control timing:

[0045] (1) First, confirm that the brake 10 is in a fully disengaged state to ensure that the main shaft 8 can rotate freely, and avoid the clutch engaging when the brake is not fully disengaged, which could lead to severe wear of the friction plate assembly or motor overload. Specifically, the control system detects the disengagement position sensor signal (or pressure sensor signal) of the brake 10 to confirm that the pressure in the brake 10 cylinder has been completely released and the friction plate assembly has been fully disengaged under the action of the return spring. If the brake 10 is not fully disengaged, the control system issues an alarm signal and prohibits entering the next stage. If the brake 10 is confirmed to be fully disengaged, the control system prepares to enter the clutch engagement stage.

[0046] (2) After confirming that the brake 10 has been fully released, the electrical control system sends an energizing signal to the solenoid directional valve of the clutch 9. Pressurized oil enters the cylinder of the clutch 9, pushing the piston to overcome the return spring force and press the driving and driven friction plates together. The clutch 9 then engages. The detailed process is as follows:

[0047] When pressurized oil enters the cylinder of clutch 9, the oil pressure gradually builds up and acts on the piston. Under the action of oil pressure, the piston moves to the right (or left, depending on the specific clutch structure), first eliminating the gap between the friction plates (i.e., the idle stroke stage), and then beginning to press the driving friction plate (connected to the clutch gear ring) and the driven friction plate (connected to the gear hub). As the oil pressure further increases, the normal pressure between the friction plates increases, and the frictional torque that can be transmitted also increases.

[0048] As the torque transmitted by clutch 9 gradually increases, when the transmitted torque exceeds the static friction torque of the spindle 8's inertial system (bearing friction, etc.), the spindle 8 begins to accelerate from a stationary state. During the sliding grinding process, the spindle 8 continues to accelerate under the drive of the clutch-transmitted torque until its rotational speed approaches that of the active component. During this process, a speed encoder detects the rotational speed of the spindle 8 in real time and records the speed change curve over time. By differentiating the speed curve, the angular acceleration of the spindle and the torque transmitted by the clutch during the acceleration process can be calculated.

[0049] When the speed of the main shaft 8 reaches near synchronization with the speed of the large pulley 6 (speed difference less than 2%), the friction plates of the clutch 9 no longer slip relative to each other, and the clutch 9 enters a fully engaged state. At this time, the torque transmitted by the clutch 9 is equal to the resistance torque of the main shaft's inertial system (bearing friction, wind resistance, etc.), and there is no additional acceleration torque. The main shaft 8 then rotates at a stable set speed, simulating the working speed of the press crankshaft during the shearing / pressing process. Throughout the acceleration process, the speed of the large pulley 6 (the driving part of the clutch) is maintained constant by the variable frequency motor 1 through belt drive, providing the power source for the continuous torque transmission of the clutch.

[0050] (3) When the main shaft 8 reaches the set speed and runs stably, the control system maintains the engagement of the clutch 9 and the disengagement of the brake 10, so that the main shaft 8 continues to rotate at a constant speed for a period of time at the set speed. This stage corresponds to the working execution stage in the actual operation of the heavy-duty crank press, that is, the process of the slide descending to complete the pressing or shearing action.

[0051] (4) When the simulation work phase ends, the electrical control system sends a power failure signal to the electromagnetic reversing valve of the clutch 9, the pressure oil is released from the oil cylinder of the clutch 9, the piston retracts under the action of the return spring, the positive pressure between the friction plate group is eliminated, and the torque transmission between the active part and the driven part of the clutch 9 is cut off.

[0052] After the clutch is released, the main shaft 8 is no longer driven by the large pulley 6 and continues to rotate solely by inertia. Because the main shaft 8 and its mounted variable moment of inertia device 14, brake hub, and other components have a large moment of inertia, the main shaft 8 will not stop immediately but will continue to rotate freely at a speed close to its original speed (due only to minor resistance torques such as bearing friction and air resistance, the speed decreases very slowly). At this time, the large pulley 6 is still driven by the variable frequency motor 1 to rotate at the set speed, and the gear ring of the clutch 9 continues to rotate with the large pulley 6. However, the gear hub is now synchronized with the main shaft 8, and their speeds may no longer be the same (when the clutch is disengaged, the gear hub and gear ring can rotate freely relative to each other).

[0053] (5) After the clutch 9 is fully disengaged, the electrical control system sends an energizing signal to the solenoid directional valve of the brake 10, and pressurized oil enters the cylinder of the brake 10, pushing the piston to press against the brake friction pads, and the braking torque begins to act on the main shaft 8. The detailed process of this stage is as follows:

[0054] After pressurized oil enters the cylinder of brake 10, the piston moves to eliminate the gap between the friction plates, and then presses together the driving friction plate (connected to the stationary brake seat 15) and the driven friction plate (connected to the gear hub and main shaft 8). Under pressure, the friction plates generate sliding friction, converting the rotational kinetic energy of the main shaft 8 into heat energy, thus applying a reverse braking torque to the main shaft 8. Under the action of the braking torque, the main shaft 8 rapidly decelerates from the set speed. Because the braking torque of brake 10 is much greater than the bearing friction resistance torque, the deceleration of the main shaft 8 is large, and it can be decelerated to a stop in a very short time. During this process, a speed encoder continuously records the instantaneous speed of the main shaft 8 at a sampling frequency of not less than 1000Hz, providing data for subsequent braking performance analysis.

[0055] When the rotational speed of the spindle 8 drops to zero, the spindle 8 comes to a complete stop. At this time, there is no longer any relative sliding between the friction plates of the brake 10, and the brake 10 keeps the spindle 8 stationary by relying on static friction.

[0056] (6) After the main shaft 8 comes to a complete stop, the control system maintains the brake 10 in the engaged state (the solenoid valve is continuously energized), so that the main shaft 8 remains stationary under the static friction torque of the brake 10. This stage functionally corresponds to the working condition in an actual heavy-duty crank press where the crankshaft is stopped at the top dead center position. In an actual press, the crankshaft must be precisely stopped at the top dead center position after each working cycle to ensure that the slide is at its highest position, facilitating safe feeding and unloading operations for the operator, and preparing for the next working cycle.

[0057] The time interval for each of the above cycles is measured in seconds (typically 0.5 to 5 seconds), and the timing and duration of each action are precisely controlled by a hydraulic power system and an electrical control system.

[0058] It is important to note that in the six stages of the complete cycle described above, the variable frequency motor 1 operates continuously throughout the entire cycle, driving the large pulley 6 and the gear ring of the clutch 9 to rotate continuously at a set speed. This is because in actual heavy-duty crank presses, the flywheel continuously rotates and stores energy throughout the entire operation of the equipment, and does not start or stop with the crankshaft. The device of this invention fully follows this actual working condition, ensuring that the driving part of the clutch 9 is already rotating each time it engages, which is completely consistent with the actual working condition, thereby ensuring the authenticity and reliability of the test results.

[0059] Through the above-described working process, this invention fully simulates the actual working state of hydraulic clutches and brakes for heavy-duty crank presses. It allows for the completion of product engagement and disengagement tests, hydraulic system tests, and electrical control tests at the manufacturer's testing site, thereby obtaining accurate product performance data.

[0060] This invention separates the clutch and brake assembly from the heavy-duty crank press for independent testing, avoiding the high cost and operational inconvenience of testing the entire machine. Through variable frequency motor speed control, a variable moment of inertia device, and precise timing control, the working cycle of the heavy-duty crank press can be completely reproduced on a test bench, allowing for performance verification and optimization before the product leaves the factory.

[0061] In Embodiment Two, as a further preferred embodiment of Embodiment One, two expansion sleeves 17 are installed at both ends of the main shaft 8. Specifically, two expansion sleeves 17 are installed at the left end (clutch mounting end) and two expansion sleeves 17 are also installed at the right end (brake mounting end) of the main shaft 8. The gear hub of the clutch 9 (i.e., the driven part of the clutch 9, the key component for transmitting torque to the main shaft 8) is detachably connected to the main shaft 8 via the two expansion sleeves 17; the gear hub of the brake 10 is also detachably connected to the main shaft 8 via the two expansion sleeves 17. The expansion sleeve 17 (full name: expansion coupling sleeve or expansion connecting sleeve) is a keyless connection device, whose structure typically includes an inner ring, an outer ring, and a locking screw. By tightening the locking screw, the inner ring and outer ring generate huge contact pressure with the outer surface of the main shaft 8 and the inner surface of the gear hub, respectively, transmitting torque and axial force by friction. The two expansion sleeves 17 are arranged side by side along the axial direction of the main shaft 8, which can transmit greater torque and has better centering and load-bearing capacity.

[0062] By adopting an expansion sleeve connection, there is no need to machine keyways or splines on the spindle 8, thus avoiding stress concentration problems caused by keyway or spline machining and significantly improving the fatigue strength and reliability of the spindle 8. Furthermore, the expansion sleeve 17 connection has good coaxiality, ensuring precise alignment between the clutch 9's gear hub and the spindle 8, reducing vibration and noise during operation.

[0063] Meanwhile, the expansion sleeve connection also has the advantage of convenient installation and disassembly. Connecting or disassembling can be achieved simply by tightening or loosening the locking screws, facilitating quick replacement of clutches 9 and brakes 10 of different specifications. This is particularly suitable for scenarios requiring frequent replacement of test pieces during product development. For clutches and brakes of different specifications, their gear hub inner diameters may differ. By replacing the expansion sleeve 17 with the corresponding specification (i.e., expansion sleeves with different outer diameters), clutches 9 and brakes 10 with different inner diameters can be adapted without changing the diameter of the main shaft 8, greatly expanding the applicability of the test bench.

[0064] Alternatively, the clutch 9's gear hub and the main shaft 8 can also be connected by a flat key. While the flat key connection is simple and reliably transmits torque, it requires remachining the keyway on the main shaft 8 or using an adapter sleeve when changing to products with different inner bore specifications, making the operation less convenient than with the expansion sleeve 17. Therefore, the expansion sleeve 17 is the preferred connection method of this invention.

[0065] In embodiment three, as a further preferred embodiment one, a motor adjustment plate 23 is fixedly provided on the side of the motor bracket 2. A motor adjustment screw 22 is threadedly connected to the motor adjustment plate 23. The end of the motor adjustment screw 22 abuts against the side of the motor bracket 2. A plurality of horizontally extending adjustment holes 27 are provided on the surface of the motor bracket 2. The motor bracket 2 is fixedly installed on the base by fastening bolts passing through the adjustment holes 27.

[0066] When adjusting the tension of the V-belt 5, first loosen the bolts passing through the adjustment hole 27, allowing the motor bracket 2 to move freely on the base in the horizontal direction (i.e., the extension direction of the adjustment hole 27). Then, rotate the motor adjusting screw 22. Since the motor adjusting screw 22 is threadedly connected to the motor adjusting plate 23, and the motor adjusting plate 23 is fixedly mounted on the base or other fixed components, rotating the motor adjusting screw 22 will push the side of the motor bracket 2, causing the motor bracket 2 to move horizontally along the adjustment hole 27. When the motor bracket 2 moves, the frequency converter motor 1 and the small pulley 4 fixedly mounted on it move synchronously, thereby changing the center distance between the small pulley 4 and the large pulley 6, achieving precise adjustment of the tension of the V-belt 5. After adjustment, retighten the bolts passing through the adjustment hole 27 to fix the motor bracket 2 on the base, ensuring that it does not shift during operation.

[0067] The length of the adjusting hole 27 is preferably 30mm to 80mm, and the corresponding center distance adjustment range is 15mm to 40mm, so as to meet the needs of tension adjustment of the V-belt 5.

[0068] The motor adjusting plate 23, motor adjusting screw 22 and adjusting elongated hole 27 work together to achieve rapid and precise adjustment of the tension of the V-belt 5, ensuring the efficiency and stability of the belt drive and avoiding slippage caused by an overly loose belt and excessive wear of the bearings caused by an overly tight belt.

[0069] In Example 4, as a further preferred embodiment of Example 1, a rotary shaft lip seal 20 and an O-ring seal 21 are provided between the brake seat 15 and the main shaft 8, and between the large pulley 6 and the main shaft 8, to prevent leakage of bearing lubricating grease.

[0070] Specifically, at the mating point between the brake housing 15 and the main shaft 8, at least one rotary shaft lip seal 20 (commonly known as a skeleton oil seal) and at least one O-ring seal 21 are provided axially. The lip of the rotary shaft lip seal 20 is tightly attached to the outer surface of the main shaft 8, forming a dynamic seal when the main shaft 8 rotates, effectively preventing the lubricating grease in the bearing inside the brake housing 15 from leaking outward along the main shaft 8, while also preventing external dust, chips, and other impurities from entering the bearing area. The O-ring seal 21 is provided on the mating surface between stationary parts, forming a static seal to prevent lubricating grease from leaking from the stationary mating surface. At the mating point between the large pulley 6 and the main shaft 8, a rotary shaft lip seal 20 is also provided, with its lip tightly attached to the outer surface of the main shaft 8 to prevent the lubricating grease in the bearing 7 inside the large pulley 6 from leaking.

[0071] Example 5, as a further preferred embodiment of Example 2, provides a detailed description of the internal lubrication structure of the wet clutch and brake during the test. For the wet clutch 9 and wet brake 10 (i.e., the type where the friction plates are immersed in lubricating oil for cooling and lubrication during operation), clean lubricating oil needs to be continuously supplied to their interior during the test to simulate the working conditions in an actual press and to prevent the friction plates from being damaged due to overheating.

[0072] Both ends of the main shaft 8 are provided with axial oil inlets 25 and radial oil outlets 26. The radial oil outlets 26 connect to the gap between the two expansion sleeves 17. Specifically, an axial oil inlet 25 is provided on the left end face (clutch end) of the main shaft 8, which extends inward along the axis of the main shaft 8. A radial oil outlet 26 is provided at the position corresponding to the gap between the two expansion sleeves 17, which extends radially along the main shaft 8, connecting the axial oil inlet 25 to the outer surface of the main shaft 8. The oil inlet structure at the right end (brake end) of the main shaft 8 is exactly the same.

[0073] During the test, an external lubricating oil pump pressurizes clean lubricating oil and delivers it into the spindle 8 through the axial inlet 25 on the end face of the spindle 8. The lubricating oil flows along the axial inlet 25, and after reaching the radial outlet 26, it flows out of the outer surface of the spindle 8 under oil pressure and enters the annular gap between the two expansion sleeves 17. Since the two expansion sleeves 17 form a sealed space between the spindle 8 and the gear hub, the lubricating oil accumulates in this gap and then enters the interior of the clutch 9 (or brake 10) through the oil hole opened on the inner hole of the gear hub, providing forced lubrication and cooling for the friction plate assembly.

[0074] By setting axial oil inlets 25 and radial oil outlets 26 at both ends of the main shaft, and using the gap between the two expansion sleeves as a transition oil chamber, effective lubrication and cooling of the internal friction plates of the wet clutch and brake are achieved. This allows the test bench to realistically simulate the working conditions of the wet clutch / brake in an actual press, providing a reliable test method for evaluating the thermal load performance and durability of the product.

[0075] In Example 6, as a further preferred embodiment of Example 1, a speed sensor 24 is also fixedly installed on the spindle 8. The speed sensor 24 is electrically connected to an external control system (PLC or industrial computer). The speed sensor 24 is preferably a magnetoelectric speed sensor or a Hall effect speed sensor. Its detection principle is as follows: a gear disk or magnet is fixedly installed on the spindle 8. When the spindle 8 rotates, the tooth tips of the gear disk or the magnet periodically pass through the sensor probe, and the sensor outputs a pulse signal. The real-time speed of the spindle 8 can be calculated by measuring the pulse frequency. The detection accuracy of the speed sensor 24 is not less than ±1 r / min, and the response time is no more than 10 ms, which can meet the requirements for accurate measurement of the dynamic changes in spindle speed.

[0076] The output signal of the speed sensor 24 is transmitted to an external control system (such as a PLC or industrial computer). The control system adjusts the output frequency of the variable frequency motor 1 in real time according to the deviation between the preset target speed and the actual detected speed through the PID (proportional-integral-derivative) control algorithm, so as to realize closed-loop precise control of the spindle speed 8.

[0077] During the clutch-brake simulation test, the control system can accurately determine the following key states based on the feedback signal from the speed sensor 24:

[0078] (1) Clutch engagement time: When the clutch 9 is engaged, the spindle 8 begins to accelerate. The speed sensor 24 detects that the speed is rising from zero. The control system records the time from the clutch engagement command to the start of spindle rotation, which is the clutch response time.

[0079] (2) Acceleration performance: Record the time required for the spindle 8 to accelerate from zero to the set speed, and evaluate the torque transmission capability of the clutch 9.

[0080] (3) Braking performance: When the brake 10 is engaged, the spindle 8 begins to decelerate. The speed sensor 24 detects the speed drop curve. The control system records the time from the issuance of the brake engagement command to the complete stop of the spindle, as well as the angular displacement when the spindle stops (whether it stops accurately at the top dead center position), and evaluates the braking performance and positioning accuracy of the brake 10.

[0081] (4) Speed ​​stability: During the uniform speed operation of the main shaft 8, the speed fluctuation is detected to evaluate the smoothness of the transmission system.

[0082] Example 7, as a further preferred embodiment of Example 1, the variable moment of inertia device 14 includes a detachable moment of inertia block, which is assembled from two semi-circular components. The two semi-circular components are fixed together by connecting bolts and mounted on the main shaft 8.

[0083] Specifically, the inner diameter of each semicircular component is slightly larger than the outer diameter of the spindle 8 (clearance fit) to facilitate assembly and disassembly. Flange connections are provided on the mating surfaces of the two semicircular components. Connecting bolts pass through the bolt holes on the flange connections, securing the two semicircular components together to form a complete annular moment of inertia block. After the moment of inertia block is installed, it can be circumferentially fixed to the spindle 8 using keys or set screws, ensuring that the moment of inertia block rotates synchronously with the spindle 8 without relative slippage. The moment of inertia block is made of a high-density material, preferably 45# steel or ductile iron, but high-density materials such as lead alloy or tungsten alloy can also be used to obtain a wider range of inertia adjustment. The outer diameter of the moment of inertia block is determined according to the required moment of inertia value; different specifications of moment of inertia blocks have different outer diameters or axial thicknesses, thus providing different moments of inertia.

[0084] By adopting a semi-circular assembly structure design, installation is not required to axially insert the components from the end of the main shaft 8. Installation can be completed simply by closing and fixing the two semi-circular components at the middle of the main shaft 8. This is particularly suitable for situations where clutches 9 and brakes 10 are already installed at both ends of the main shaft 8. The quickly replaceable semi-circular moment of inertia block structure allows for flexible adjustment of the main shaft system's moment of inertia, enabling the same test bench to simulate various press conditions ranging from light to heavy-duty, greatly expanding the test bench's applicability and testing flexibility.

[0085] Example 8, as a further preferred embodiment of Example 1, also includes a hydraulic power system and an electrical control system. The hydraulic power system includes a hydraulic oil tank, a hydraulic pump, a pressure regulating valve group, a directional control valve group (such as a solenoid directional valve), an accumulator, pipelines, and filters. The hydraulic power system is connected to the oil inlet of the clutch 9 and the oil inlet of the brake 10 through pipelines, respectively, to provide the pressurized oil required for engagement / disengagement of the clutch 9 and the brake 10.

[0086] Specifically, the hydraulic pump draws hydraulic oil from the oil tank, and after being adjusted to the required working pressure by the pressure regulating valve group, it supplies the clutch 9 and brake 10 respectively through the directional control valve group. The engagement and disengagement of the clutch 9 and brake 10 are controlled by the solenoid directional valve in the directional control valve group. When the solenoid directional valve is energized, pressurized oil enters the cylinder of the clutch 9 (or brake 10), pushing the piston to press the friction plate, thus achieving engagement; when the solenoid directional valve is de-energized, the pressurized oil in the cylinder of the clutch 9 (or brake 10) is released through the return oil circuit, and the spring force causes the friction plate to separate.

[0087] The electrical control system includes a programmable logic controller (PLC) or industrial computer, a touch screen human-machine interface (HMI), a frequency converter, relays, and signal conditioning modules. The electrical control system is electrically connected to components such as the variable frequency motor 1, speed sensor 24, temperature sensor, and solenoid valves of the hydraulic power system, and is used to control the speed of the variable frequency motor 1, the timing of the clutch 9 and the brake 10, and their cycle frequency.

[0088] Through the coordinated operation of the hydraulic power system and the electrical control system, precise timing control of the clutch-brake combination working cycle was achieved, fully replicating the actual working process of the heavy-duty crank press, and providing an automated and high-precision test platform for the comprehensive evaluation of product performance.

[0089] Example 9, as a further preferred embodiment of Example 1, provides a detailed description of the working mode of using this test bench device to conduct brake performance tests alone.

[0090] One important extended application of this test bench is that it can perform performance tests on the brake 10 independently, without the need for the clutch 9 (or with the clutch 9 disengaged). The test principle and procedures are as follows:

[0091] Step S1: Preparation Stage

[0092] The brake 10 to be tested is installed on the right end (brake end) of the main shaft 8 and fixedly connected by the expansion sleeve 17. Based on the required system moment of inertia to be simulated, a moment of inertia block of appropriate mass is installed on the variable moment of inertia device 14, and the total moment of inertia value J of the main shaft system is set. This moment of inertia value should be equal to or close to the rotational system inertia corresponding to the brake 10 in the actual press. Confirm that the speed encoder is working properly and that the oil inlet of the brake 10 is correctly connected to the hydraulic power system.

[0093] Step S2: Acceleration Phase

[0094] Start the variable frequency motor 1 and accelerate the spindle 8 to the set speed n0 according to the preset acceleration program. The set speed n0 is determined according to the design operating speed of the brake 10 under test, and the typical range is 100 r / min to 500 r / min. During acceleration, the brake 10 remains disengaged (released), the clutch 9 remains disengaged (or not installed), and the spindle 8 rotates freely under the drive of the large pulley 6.

[0095] Step S3: Steady Speed ​​Phase

[0096] After the spindle 8 reaches the set speed n0, the variable frequency motor 1 maintains this speed for 1 to 3 seconds, stabilizing the spindle 8's speed within the range of n0 ± 2 r / min. At this time, the entire spindle inertial system operates stably at speed n0, and the rotational kinetic energy of the system is... (in ).

[0097] Step S4: Braking test phase:

[0098] At t=0, the control system issues a braking command. Clutch 9 remains disengaged, and the variable frequency motor 1 stops driving (or switches to a free state). Simultaneously, brake 10 quickly engages, applying the rated torque to the spindle 8. Under the action of the braking torque, the spindle 8 begins to decelerate. The speed encoder continuously records the change data of the instantaneous speed n(t) of the spindle 8 with time t at a sampling frequency of not less than 1000Hz.

[0099] Step S5: Braking and stopping phase:

[0100] Spindle 8 continuously decelerates under the action of brake 10 until it comes to a complete stop (the speed drops to zero). The control system records the total time t from the issuance of the braking command to the complete stop of the spindle. total（ That is, braking time), and the total angle θ that the spindle rotates from the start of braking to the stop. total (i.e., braking angle).

[0101] Step S6: Data Processing and Performance Curve Plotting

[0102] After the test is completed, the control system (or host computer software) performs the following data processing based on the recorded rotational speed-time data n(t) and the known system moment of inertia J:

[0103] (1) Calculate the instantaneous angular velocity .

[0104] (2) Calculate the instantaneous angular deceleration (Obtained by numerical differentiation of ω(t)).

[0105] (3) Calculate the instantaneous braking torque (Ignore bearing friction and other resistance torques, or correct through no-load testing).

[0106] (4) Plot the speed curve n(t), braking torque curve M(t), and braking energy dissipation curve with time as the horizontal axis. .

[0107] (5) Extract key performance indicators: braking response time (the time from the issuance of the command to the establishment of the braking torque), maximum braking torque, average braking torque, braking time, braking angle, braking energy density (the braking energy dissipated per unit area of ​​friction pads), etc.

[0108] Through the above steps, a complete brake performance curve spectrum can be obtained, and the braking performance of brake 10 under different initial speeds, different system inertias, and different oil pressures can be comprehensively evaluated.

[0109] By setting different speeds By repeating the above tests under different moments of inertia J and different brake oil pressures, a family of brake performance curves can be plotted to comprehensively reflect the working characteristics of the brake.

[0110] This test bench can independently conduct comprehensive performance tests on brakes. Using speed encoder data and known system rotational inertia, it can accurately calculate key performance parameters such as braking torque, braking power, and braking efficiency, providing precise data support for the optimized design and quality inspection of brake products.

[0111] Example 10, as a further preferred embodiment of Example 1, details the working mode of conducting clutch performance tests independently using this test bench device. Another important extended application of this test bench device is that it can conduct performance tests on clutch 9 independently, without the need for brake 10 (or brake 10 being kept disengaged). The test principle and steps are as follows:

[0112] Step S1: Preparation Stage

[0113] The clutch 9 to be tested is installed on the left end (clutch end) of the main shaft 8 and fixedly connected by the expansion sleeve 17. Based on the required system moment of inertia to be simulated, a moment of inertia block of appropriate mass is installed on the variable moment of inertia device 14, and the total moment of inertia value J of the main shaft system is set. It is confirmed that the speed encoder is working properly and that the oil inlet of the clutch 9 is correctly connected to the hydraulic power system. The brake 10 is kept disengaged (or not installed) to ensure that the main shaft 8 can rotate freely.

[0114] Step S2: Initial state:

[0115] The variable frequency motor 1 continues to run, driving the gear ring (driving part) of the clutch 9 via the V-belt 5 and the large pulley 6 to set the speed. (Typical values ​​are 100 r / min to 500 r / min) Continuous rotation. At this time, clutch 9 is in the disengaged state, and main shaft 8 is stationary. This state simulates the working condition of the press when it is in standby mode, where the flywheel (large pulley) rotates continuously while the crankshaft (main shaft) is stationary.

[0116] Step S3: Clutch engagement test stage

[0117] At t=0, the control system issues a clutch engagement command, the hydraulic cylinder inside clutch 9 fills with oil, the piston pushes the friction plate assembly to press together, and the gear ring (driving part) and gear hub (driven part, i.e., the part connected to the main shaft 8) of clutch 9 gradually achieve synchronization. Power is transmitted from the large pulley 6 to the main shaft 8 through clutch 9, and the main shaft 8 accelerates from rest.

[0118] The speed encoder continuously records the change data of the instantaneous speed n(t) of the spindle 8 with time t at a sampling frequency of not less than 1000Hz until the speed of the spindle 8 reaches basic synchronization with the active part.

[0119] Step S4: Data Processing and Performance Evaluation

[0120] Based on the recorded rotational speed-time data n(t) and the known system moment of inertia J, the control system performs the following data processing:

[0121] (1) Calculate the instantaneous angular velocity .

[0122] (2) Calculate the instantaneous angular acceleration .

[0123] (3) Calculate the instantaneous transmitted torque (Ignore bearing friction and other resistance torques).

[0124] (4) Plot the speed curve n(t) and braking torque curve M(t) with time as the horizontal axis.

[0125] (5) Extract key performance indicators:

[0126] Clutch response time: The time from the issuance of the engagement command to the start of spindle rotation (speed rising from zero).

[0127] Grinding time: The time required from the start of spindle rotation until the spindle speed reaches 95% of the speed of the active part.

[0128] Average transmitted torque: The average value of the transmitted torque during the bonding process.

[0129] Engagement smoothness: evaluated by the smoothness of the speed curve and the fluctuation range of the transmitted torque.

[0130] Step S5: Series of tests under different operating conditions:

[0131] By changing the following parameters and conducting a series of tests, comprehensive performance data for clutch 9 can be obtained:

[0132] Change the set speed Test the engagement characteristics of the clutch at different speeds;

[0133] By changing the system's moment of inertia J (by replacing inertia blocks of different masses), the engagement capability of the clutch under different load inertia was tested.

[0134] By changing the engagement oil pressure (adjusting the hydraulic system pressure), the response characteristics of the clutch under different operating pressures were tested.

[0135] By setting different engagement speeds (by changing the throttling characteristics of the solenoid valve), the impact characteristics of the clutch at different engagement speeds were tested.

[0136] This test bench can independently conduct comprehensive performance tests on clutches. The clutch engagement process involves starting the spindle inertia system, fully simulating the actual working conditions of a clutch in a real press. By analyzing the speed rise curve and torque transmission changes, the clutch's engagement characteristics, thermal load capacity, and dynamic response performance can be accurately evaluated, providing a scientific basis for clutch optimization design and quality control.

[0137] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A test bench device for hydraulic clutch and brake products of heavy-duty crank press, characterized in that: The system includes a variable frequency motor (1) and a main shaft (8). The variable frequency motor (1) is fixedly mounted on a motor bracket (2). The output end of the variable frequency motor (1) is connected to a small pulley (4) via a coupling (3). The small pulley (4) is connected to a large pulley (6) via a V-belt (5). The central shaft of the small pulley (4) is mounted on the motor bracket (2) via a bearing seat (28). The large pulley (6) is rotatably mounted on the outer surface of the main shaft (8) via a bearing (7). A clutch (9) is mounted on one end of the main shaft (8), and a brake (10) is mounted on the other end of the main shaft (8). The clutch (9) is fixedly mounted on a clutch mounting plate (12), and the clutch mounting plate (12) is fixedly mounted on the large pulley (6), so that the large pulley (6) can drive the clutch (9) to rotate synchronously. The brake (10) is fixedly mounted on a brake mounting plate (16), and the brake mounting plate (16) is fixedly mounted on a brake seat (15). A rotating support bearing is provided inside the brake seat (15), and the brake seat (15) is rotatably supported on the outer surface of the main shaft (8) via the rotating support bearing. A rolling bearing seat (19) is sleeved on the outer surface of the main shaft (8). Both the brake seat (15) and the rolling bearing seat (19) are fixedly mounted on a support seat (13). A variable moment of inertia device (14) is installed in the middle of the main shaft (8), a speed encoder is installed at the end of the main shaft (8), and temperature sensors are installed on the clutch (9) and brake (10) to monitor the working temperature.

2. The heavy-duty crank press hydraulic clutch and brake product testing device according to claim 1, characterized in that: Two expansion sleeves (17) are installed at both ends of the main shaft (8). The gear hub of the clutch (9) is detachably connected to the main shaft (8) through the two expansion sleeves (17). The gear hub of the brake (10) is detachably connected to the main shaft (8) through the two expansion sleeves (17).

3. The heavy-duty crank press hydraulic clutch and brake product testing device according to claim 1, characterized in that: A motor adjustment plate (23) is fixedly provided on the side of the motor bracket (2). A motor adjustment screw (22) is threaded onto the motor adjustment plate (23). The end of the motor adjustment screw (22) abuts against the side of the motor bracket (2). A plurality of adjustment elongated holes (27) extending horizontally are provided on the surface of the motor bracket (2). The motor bracket (2) is fixedly installed on the base by fastening bolts passing through the adjustment elongated holes (27). By rotating the motor adjustment screw (22), the motor bracket (2) is pushed to move horizontally along the adjustment elongated holes (27) to adjust the tension of the V-belt (5).

4. The heavy-duty crank press hydraulic clutch and brake product testing device according to claim 1, characterized in that: Rotary shaft lip seals (20) and O-ring seals (21) are provided between the brake seat (15) and the main shaft (8) and between the large pulley (6) and the main shaft (8) to prevent bearing lubricating grease leakage.

5. The heavy-duty crank press hydraulic clutch and brake product testing device according to claim 2, characterized in that: Both ends of the main shaft (8) are provided with an axial oil inlet (25) and a radial oil outlet (26). The radial oil outlet (26) is connected to the gap between the two expansion sleeves (17). The lubricating oil enters from the axial oil inlet (25), flows into the gap between the two expansion sleeves (17) through the radial oil outlet (26), and then enters the interior of the clutch (9) and brake (10) through the inner hole of the gear hub.

6. The heavy-duty crank press hydraulic clutch and brake product testing device according to claim 1, characterized in that: A speed sensor (24) is also fixedly installed on the spindle (8). The speed sensor (24) is electrically connected to the external control system and is used for closed-loop control of the spindle speed.

7. The heavy-duty crank press hydraulic clutch and brake product testing device according to claim 1, characterized in that: The variable moment of inertia device (14) includes a detachable moment of inertia block, which is assembled from two semi-circular components. The two semi-circular components are fixed together by connecting bolts and mounted on the main shaft (8).

8. The heavy-duty crank press hydraulic clutch and brake product testing device according to claim 1, characterized in that: It also includes a hydraulic power system and an electrical control system. The hydraulic power system provides the pressure oil required for engagement / disengagement of the clutch (9) and brake (10). The electrical control system controls the speed of the variable frequency motor (1), the timing of the clutch (9) and brake (10), and the cycle frequency.

9. The heavy-duty crank press hydraulic clutch and brake product testing device according to claim 1, characterized in that: The clutch (9) is fixedly mounted on the clutch mounting plate (12) at the left end by a hexagonal head bolt (11), and the clutch mounting plate (12) is fixedly mounted on the large pulley (6) by an internal hexagonal screw (18).

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