An inverted modular low-speed engine connecting rod bearing test platform

Abstract

The purpose of the present invention is to provide an inverted modular low-speed engine connecting rod bearing test platform machine, including an upper box module and a lower box module, the upper box module is installed on the lower box module, and a three-phase asynchronous motor, a flywheel brake module, a reducer module, and a core motion module are installed in the lower box module. The three-phase asynchronous motor drives the flywheel brake module, and the flywheel brake module drives the reducer module. The core motion module includes a core module bracket, a hydraulic cylinder system, an eccentric shaft, a test connecting rod, and a test bearing are installed in the core module bracket. The hydraulic cylinder system is connected to the test connecting rod, and the test connecting rod is installed with a test bearing and connected to the eccentric shaft. The left support bearing seat and the right support bearing seat are respectively installed on the core module bracket, and the eccentric shaft is installed in the left support bearing seat and the right support bearing seat. The present invention can test the fatigue strength and life limit of the bearing through the testing machine, and qualitatively analyze the bearing life and fatigue limit through the test results.

Description

Technical Field

[0001] The present invention relates to a testing device, in particular to a low-speed engine connecting rod bearing testing device. Background Art

[0002] The connecting rod big-end bearing of a high-power marine diesel engine is the most important rotating friction pair in the diesel engine, accounting for over 5% of the total friction losses. Therefore, the connecting rod big-end bearing is a critical component of high-power medium- and low-speed diesel engines. Bearings can often suffer from numerous defects or deficiencies in structural design, product processing, parts installation and commissioning, and maintenance and inspection. These defects can cause vibration during operation, localized oil film pressure increases, and lubricant flashing. The intense flashing shock pressure can easily lead to fatigue pitting and spalling of the bearing alloy layer, even causing serious accidents.

[0003] At present, the commonly used research methods for the study of bearing fatigue, wear, bite and other mechanisms are: (1) laboratory specimen test method. The test conditions of this method are easy to control and have a wide range of variation. It is generally used for qualitative research on various friction and wear properties, or for reference tests to evaluate the performance of friction pair materials, processes and lubricants; 2) field test method. The test data obtained by this method has high authenticity and reliability, and can effectively reflect the actual situation of the mechanical parts in engineering operation. It is mainly used for verification tests in friction and wear application technology. Compared with the singleness of laboratory methods and the time-consuming and high-cost defects of field methods, the field methods are more convenient. Summary of the Invention

[0004] The purpose of the present invention is to provide an inverted modular low-speed engine connecting rod bearing test platform machine that can test the fatigue strength and life limit of the bearing and perform qualitative analysis on the bearing life and fatigue limit through the test results.

[0005] The object of the present invention is achieved like this:

[0006] The present invention discloses an inverted modular low-speed engine connecting rod bearing test platform machine, which is characterized in that: it includes an upper box module and a lower box module, the upper box module is installed on the lower box module, and a three-phase asynchronous motor, a flywheel brake module, a reducer module, and a core motion module are installed in the lower box module. The three-phase asynchronous motor drives the flywheel brake module, and the flywheel brake module drives the reducer module. The core motion module includes a core module bracket, and a hydraulic cylinder system, an eccentric shaft, a test connecting rod, and a test bearing are installed in the core module bracket. The hydraulic cylinder system is connected to the test connecting rod, and the test bearing is installed on the test connecting rod and connected to the eccentric shaft. A left supporting bearing seat and a right supporting bearing seat are respectively installed on the core module bracket, and the eccentric shaft is installed in the left supporting bearing seat and the right supporting bearing seat.

[0007] The present invention may also include:

[0008] 1. The input end of the eccentric shaft is connected to the reducer module, and the output end of the eccentric shaft is connected to the cylinder pressure control module.

[0009] 2. An oil filling hole is opened on the eccentric shaft, and lubricating oil is injected through the external oil filling plate. The channel for the oil to enter the test bearing is located on the joint surface between the eccentric part of the eccentric shaft and the test bearing.

[0010] 3. The three-phase asynchronous motor operates in the speed range of 50r / min-1000r / min, and the eccentric shaft operates in the range of 50r / min-300r / min.

[0011] The advantages of the present invention are:

[0012] 1. This system adopts an inverted modular structure design scheme. First, it ensures that the impact load and inertia force direction of the bearing are close to the actual operating conditions. Second, after the test is completed, the inverted modular scheme allows the test bearing to be easily removed from the top. Finally, with this scheme, each system submodule in the test bench can be separated from the adjacent transmission system and directly removed from the top as a whole, which facilitates the subsequent repair and maintenance of each system submodule of the test bench.

[0013] 2. The current common method for supplying oil to test bearings is to drill an oil hole in the large end cap, and then drill an oil flow channel at the bottom of the bearing. This test device drills an oil hole in the eccentric shaft, injects lubricating oil through an external oil pan, and the oil enters the bearing at the interface between the eccentric portion and the test bearing. This is consistent with the actual oil supply state of the bearing, ensuring the authenticity of the bearing lubrication conditions.

[0014] 3. In this system, the temperature of the lubricating oil of the test bearing can be continuously changed from 40℃ to 100℃, and the size of the abrasive particles can be quantitatively changed according to the requirements of the test. In this way, the effects of different temperature and lubricating oil cleanliness level and other parameter variables on bearing fatigue can be observed.

[0015] 4. The test specimens of this test system are engineering principle specimens, i.e. full-size engineering specimens, which are essentially different from standard test specimens. This can fully reflect the actual operating conditions of the workpiece, which is of great significance for judging the fatigue strength and life prediction of key parts of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the present invention;

[0017] Figure 2 It is a structural schematic diagram of the present invention;

[0018] Figure 3 It is BB view;

[0019] Figure 4 This is the AA view. DETAILED DESCRIPTION

[0020] The present invention will be described in more detail below with reference to the accompanying drawings:

[0021] Combine Figure 1-4 The present invention mainly includes: an upper box module 1, a three-phase asynchronous motor 2, a flywheel brake module 3, a reducer module 4, a left bearing support seat 5, a core motion module 6, a test bearing 7, an eccentric shaft 8, a right bearing support seat 9, a cylinder pressure control module 10, a test connecting rod 11, a stress testing unit 12, an oil inlet hole 13, a pressure valve 14, a hydraulic cylinder system 15, a lubrication system 16, an electrical control system 17, and a lower box installation module 18.

[0022] The three-phase asynchronous motor 2 drives the flywheel brake module 3 to rotate, which in turn drives the reducer module 4 to rotate, ultimately transmitting torque and speed to the eccentric shaft 8. The eccentric shaft 8 drives the test connecting rod 11 and the test bearing 7 to rotate, and the connecting rod 11 drives the piston of the hydraulic cylinder 15 to reciprocate. In this way, the rotational motion of the motor is converted into the reciprocating motion of the hydraulic cylinder through the motion of the eccentric shaft hinge reciprocating mechanism, which is the reverse motion compared to the reciprocating motion of the diesel engine.

[0023] The core bearing test module adopts an overall modular design. The eccentric shaft 8, connecting rod 11 and hydraulic cylinder 15 are assembled with the core module base to form an integrated core motion module unit 6. The core motion module unit 6 is installed in the core module mounting hole on the lower box mounting module 18 by hoisting. Then the eccentric shaft input end of the core motion module 6 is connected to the tail end of the transmission system reducer, and the eccentric shaft output side is connected to the tail cylinder pressure control module system 15. Finally, the core motion module 6 is connected to the lower box 18 as a whole.

[0024] The lubricating oil system primarily supplies lubricating oil to the main support bearings and test bearings on both sides. The test bearing lubricating oil temperature can be adjusted from 40°C to 100°C. After flowing out of the main and test bearings, the lubricating oil flows through the upper holes of the core module into the oil collecting shell of the lower box. Finally, the oil return pump extracts the lubricating oil from the oil collecting shell, filters it uniformly, and dissipates the heat before recirculating it into the lubricating oil circulation system.

[0025] The test platform machine is driven by a variable frequency speed regulation motor. The motor speed is controlled by the frequency converter, and the motor can be controlled to operate within the speed range of 50r / min-1000r / min. The platform machine operates in a relatively wide operating range. By selecting a reasonable reducer, the eccentric shaft can operate in the operating range of 50r / min-300r / min. Such an operating space can ensure that the speed range of the eccentric shaft can cover the entire low-speed machine operating speed range. Therefore, the test platform machine can cover the entire speed range of the low-speed machine and provide a comprehensive speed change range for the low-speed machine bearing.

[0026] The entire system adopts PLC centralized control, and controls each actuator according to the test outline requirements. Under the optimized control strategy, it is conducive to the stable and coordinated operation of the system, and various tests and data readings are carried out smoothly according to the test outline requirements.

[0027] After the lower box mounting module 18 is installed and seated, the transmission system is first installed on the lower box mounting module 18 of the test bench. The flywheel transmission and reducer system are installed first, and then the main drive motor is installed on the tail motor guide rail. Finally, the coaxiality of the entire transmission system is adjusted to meet the system's usage requirements. At the same time, the addition of a flywheel and a brake system to the entire transmission system is conducive to the balanced and safe operation of the system.

[0028] like Figure 2-4 The figure shows the design structure of an inverted modular low-speed engine connecting rod bearing test platform. The hydraulic cylinder system 15 is installed at the bottom of the core motion module 6. The protruding end of the hydraulic cylinder system 15 is connected to the fork-shaped part. The large end of the test connecting rod 11 is installed with a test bearing and connected to the eccentric shaft 8. This constitutes the core motion structure of the bearing fatigue test system. This structure is the overall force-bearing structure of the test bench system. The reaction force of the hydraulic cylinder on the bearing is mainly borne by the main bolts running through the entire core module. The box body mainly bears a small amount of rotational inertia and lateral torque.

[0029] Figure 2-4The design structure diagram shown is a schematic diagram of all the designed sub-modules fully assembled into the test bench system. After all the sub-modules of the test platform are assembled externally, they are installed into the base system respectively. The installation order is as follows: first, manufacture and install the lower box module 18, and then install the three asynchronous motors 2, flywheel brake module 3, and reducer module 4 on the lower box module in sequence. The above three subsystems constitute the transmission system module; secondly, install the left and right support bearing seats 5 and 9 on the core module bracket, and the eccentric shaft 8 is installed in the left and right support bearing seats. The hydraulic cylinder 15 is connected to the connecting rod 11, and the test bearing 7 is installed on the large end side of the connecting rod 11 and then connected to the eccentric shaft 8. The connecting rod 11, test bearing 7, eccentric shaft 8, and piston of the hydraulic cylinder 15 form a crank-connecting rod motion mechanism similar to that of an engine. After the above parts are connected, they form a core motion module 6, and the core motion module 6 is lifted and installed as a whole in the core module mounting seat hole of the lower box module 18; finally, install the upper box module 1, and use bolts to connect and lock the modules to each other. The entire test platform adopts a modular design, with each part manufactured independently and each structure installed in coordination with each other. During subsequent maintenance and repair, each module can be quickly disconnected from the adjacent system and then hoisted out of the test bench as a whole, facilitating the installation and subsequent maintenance of each module and avoiding the need for assembly within the test bench and the need to open a manhole specifically for installation, commissioning and maintenance.

Claims

1. An inverted modular low-speed engine connecting rod bearing test platform, characterized by: It includes an upper box module and a lower box module. The upper box module is installed on the lower box module. The lower box module is installed with a three-phase asynchronous motor, a flywheel brake module, a reducer module, and a core motion module. The three-phase asynchronous motor drives the flywheel brake module, and the flywheel brake module drives the reducer module. The core motion module includes a core module bracket, in which a hydraulic cylinder system, an eccentric shaft, a test connecting rod, and a test bearing are installed. The hydraulic cylinder system is connected to the test connecting rod, and the test bearing is installed on the test connecting rod and connected to the eccentric shaft. A left supporting bearing seat and a right supporting bearing seat are respectively installed on the core module bracket, and the eccentric shaft is installed in the left supporting bearing seat and the right supporting bearing seat, and the hydraulic cylinder system is installed at the bottom of the core motion module; the eccentric shaft, the connecting rod and the hydraulic cylinder system are assembled into an integrated core motion module unit with the core module bracket; the core motion module unit is installed in the core module mounting hole on the lower box module by hoisting; the input end of the eccentric shaft is connected to the reducer module, and the output end of the eccentric shaft is connected to the cylinder pressure control module; an oil filling hole is opened on the eccentric shaft, and lubricating oil is injected through an external oil filling plate, and the channel for the oil to enter the test bearing is located on the joint surface between the eccentric part of the eccentric shaft and the test bearing.

2. The inverted modular low-speed engine connecting rod bearing test platform according to claim 1 is characterized by: The three-phase asynchronous motor operates in the speed range of 50r / min-1000r / min, and the eccentric shaft operates in the range of 50r / min-300r / min.

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