CN111896157A - A high-power and high-speed hydraulic dynamometer - Google Patents

Abstract

The invention discloses a high-power and high-speed hydraulic dynamometer, which is mainly composed of a stator (stator), a rotor, a guide ring, a casing, an end cover, a water seal, an oil seal, a bearing seat, a bearing seat support, a main shaft, a coupling, It consists of oil pan, water inlet valve, drain valve, centralized control box and vibration monitoring system. The power it absorbs increases or decreases in direct proportion to the amount of water flowing through the rotor, and the adjustment of the absorbed power is controlled by the intake/drainage control valve. The high-speed hydraulic dynamometer is integrated with a centralized control box (hub cabinet) and a vibration monitoring system, which can display the operation of the hydraulic dynamometer locally and remotely, and evaluate the status of the hydraulic dynamometer itself. The invention has excellent performances such as high measurement accuracy, sensitive response, strong operation ability, good maintainability, etc., and particularly relates to a hydraulic dynamometer, which can be suitable for high rotation speed, large absorption power, long repair life, high Adaptability and other characteristics, has excellent engineering application value.

Description

A high-power and high-speed hydraulic dynamometer

technical field

The invention is a high-power and high-speed hydraulic dynamometer used for engine power consumption and measurement.

Background technique

With the development of modern science and technology, especially the key technologies aimed at breaking through the "two machines" and promoting the implementation of the major special projects ("two machines" special projects) for the development of gas turbine products, major scientific research institutes are stepping up efforts to establish aero-engines and gas turbines. Basic research, technology and product R&D and industrial system for independent innovation of engines and gas turbines, and high-speed hydraulic dynamometers are essential dynamometer and power consumption equipment to verify the performance of gas turbines.

High-power and high-speed hydraulic dynamometer, as the key supporting equipment for gas turbine test, has the advantages of high measurement accuracy, sensitive response, strong operation ability and good maintainability. An essential means of post-repair performance testing.

At present, all the high-power hydraulic dynamometers on the market need to consume and measure power after the engine is decelerated through a reduction gear box, resulting in a large number of power consumption and measurement equipment, and a complex system. Because of its absorption power requirements, the hydraulic dynamometer itself is large in size, heavy in weight, and high in power starting point. Moreover, the entire dynamometer system is complex, the measurement is not direct, the accuracy is not high, the adjustment rate is slow, the system inertia is large, and the response is not sensitive. , It is inconvenient to disassemble and maintain, and in addition, it has high requirements for test matching.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the present invention provides a high-power high-speed hydraulic dynamometer for engine power consumption and detection. The intermediate link improves the test efficiency and has excellent performances such as high measurement accuracy, sensitive response, strong operation ability and good maintainability. Aiming at the technical deficiencies of the existing hydraulic dynamometer, the invention designs a hydraulic dynamometer with small volume, large absorbed power, high rotational speed, wide adaptability, easy maintenance and long service life, which can greatly improve the test accuracy and efficiency of the engine. , with extremely high engineering application value.

The main technical scheme of the present invention is: a high-power high-speed hydraulic dynamometer, comprising a stator, a rotor, a guide ring, a casing, an end cover, a water seal, an oil seal, a bearing seat, a bearing seat support, a main shaft, a coupling, Oil pan, water inlet valve, drain valve; the main shaft is used to transmit engine power, two rotors, water seal, oil seal and stainless steel sleeve are installed on the main shaft with a certain amount of interference fit, and the two rotors are installed on the main shaft opposite to the stator , the rotor impeller angle is 45 degrees; the two stators are fixed on the inside of the casing, and the position is in the center of the rotor; the angle of the stator impeller is 45 degrees from the axial bearing and opposite to the rotor blades, and its cavity is semi-elliptical; The sleeve rotor, stator and guide ring form two relatively independent water cavities; the guide ring is fixed on the inner side of the casing and radially located on the outer side of the rotor.

Preferably, in the middle of the two rotors, the part where the main shaft contacts with water is covered with a stainless steel sleeve, which is used to prevent the main shaft from rusting due to long-term operation when the hydraulic dynamometer runs at high power and high speed, and improves the life of the main shaft.

Preferably, two side discs are installed on both sides of the casing, and grooves are arranged in the interior for installing the sealing ring (gasket), and the casing and the casing form a sealed cavity of the hydraulic dynamometer.

Preferably, it also includes a bearing support at each end of the main shaft, a sliding bearing with thrust is arranged in the bearing support at the input end, a sliding bearing is arranged in the bearing support at the free end, and the two bearings use an integrated sliding bearing or a split type The sliding bearing makes the installation of the bearing and the main shaft more convenient and the service life is longer.

Preferably, the water seal is located in the lower part of the shell, and a peripheral drainage groove is provided. When the hydraulic dynamometer is running with full water or the water level exceeds the design standard water level, and the water seal cannot be sealed tightly, the drainage groove is used for outward drainage to ensure that the water is drained out. No flow into other areas of the hydro dynamometer.

Preferably, the hydraulic dynamometer also includes a water inlet pipe and a drainage pipe, the water inlet pipe and the drainage pipe are arranged at opposite positions of the casing, left and right or up and down, and a water stabilizer is installed at the water inlet and outlet, which is beneficial to the operation of the hydraulic dynamometer. , The stability of the internal flow field can better adapt to the high-power and high-speed operation of the hydraulic dynamometer.

Preferably, the hydraulic dynamometer further includes a coupling at each end, and when switching between forward and reverse rotations is required, the installation direction of the hydraulic dynamometer is reversed to realize effective switching of different steering directions.

Preferably, the hydraulic dynamometer is integrated with a centralized control box, after collecting and processing the front-end electrical signals of the hydraulic dynamometer, such as speed, torque, temperature, pressure, etc., and then transmitting it to the control cabinet through cables and Ethernet to realize local and remote control. .

Preferably, the hydraulic dynamometer is integrated with a vibration monitoring system, which can monitor the horizontal, vertical and axial vibration of the hydraulic dynamometer bearing in real time, so as to judge the operation of the hydraulic dynamometer and better adapt to the large size of the hydraulic dynamometer. Power high speed operation.

Preferably, the rotor, the stator and the guide ring are made of duplex stainless steel, which has higher hardness, high corrosion resistance, high cavitation resistance, and high weldability of the same material.

The invention is a new type of engine power detection device, which is a hydraulic dynamometer with excellent performances such as high measurement accuracy, sensitive response, strong running ability and good maintainability.

The main shaft is used to transmit the power of the engine. The place where the main shaft and the water contact (the middle of the stator) is covered with a stainless steel sleeve, which is used to prevent the main shaft from rusting due to long-term operation and improve the life of the main shaft.

The two rotors are installed on the main shaft opposite to the stator, and the rotor impeller angle is 45 degrees, which makes the hydraulic dynamometer have a greater absorption power characteristic and can better adapt to the high-power and high-speed operation of the hydraulic dynamometer.

The angle of the stator impeller is 45 degrees to the axial bearing and opposite to the rotor blade, and its cavity is semi-elliptical, which makes the hydrodynamic dynamometer have greater absorption power characteristics and can better adapt to the high-power and high-speed operation of the hydrodynamic dynamometer. . Two sets of rotors, stators (stators) and guide rings in the front and rear form two relatively independent water cavities.

The two guide rings are fixed on the inner side of the casing and are located on the outer side of the rotor, which together with the rotor and the stator constitute the main body of the hydrodynamic dynamometer to absorb power. Made of duplex stainless steel, it has the characteristics of high corrosion resistance, high cavitation resistance, and high weldability. It and the stator (stator) have a water outlet in the outer diameter direction, which can better adapt to the high-power and high-speed operation of the hydraulic dynamometer.

A stator, a guide ring and other components are installed inside the hydraulic dynamometer housing, and a calibration arm (beam) for calibrating the hydraulic dynamometer and a measuring arm (beam) for measuring the torque of the hydraulic dynamometer are installed on its side, and The calibration arm (beam) is symmetrically arranged with the measuring arm (beam), which has great rigidity and ensures the accuracy of calibration and measurement to the greatest extent.

The two bearings of the hydraulic dynamometer supporting the main shaft are selected as an integrated sliding bearing or a distinguishing sliding bearing according to the actual use situation, which makes the installation of the bearing and the main shaft more convenient and has a longer life. One set of bearings must be a thrust bearing, which can keep the rotor of the hydraulic dynamometer in the axial position and absorb the axial force. Bearings are lubricated and cooled with oil jets.

Stabilizers are installed on the water inlet pipe and the drain pipe, so that the water flow into and out of the hydraulic dynamometer is uniform and stable, thereby making the operation of the hydraulic dynamometer more stable.

The rotor, stator (stator) and guide ring are protected by ordinary flame spraying, arc spraying, plasma spraying and high-speed flame spraying at their cavitation-prone parts to improve the cavitation-resistant ability of the cavitation-prone parts. Adapt to the high-power and high-speed operation of the hydraulic dynamometer, so as to better improve the overhaul life of the high-speed hydraulic dynamometer.

The bearing is lubricated and cooled by lubricating oil jet, and its input side (or free side) has a thrust surface, which can keep the rotor of the hydraulic dynamometer axially positioned, absorb the axial force, and better adapt to the high power of the hydraulic dynamometer. Running at high speed.

At least two labyrinth non-contact oil seals are set on the main shaft. The parent body is made of 20# steel, copper base (or other steel), and the top is made of tin bronze babbitt. The tin bronze babbitt itself includes multiple grooves. The water throwing ring installed on the main shaft can play a good sealing effect. Tin bronze babbitt and parent material use wedge-shaped connection to ensure reliable upper connection. During operation, as the main shaft rotates, a small amount of water that is not thrown out by the rotor is blocked by the water seal and is discharged to the outside of the cavity through the sewage pipe.

The coupling is connected with the main shaft by a key and an interference connection to ensure the full stability of the installation under high speed and high torque.

The casing is equipped with a measuring hole for measuring the water pressure in the cavity and its back-end instrument, so that when the hydraulic dynamometer is running, it is convenient to fully understand its internal operation, and through the inspection hole set on the surface of the casing, the hydraulic measurement can be carried out. Check the hole detector of the power device, find and deal with possible faults in time.

A compressed air injection port is installed on the shell. When the hydraulic dynamometer is running, a certain amount of compressed air is injected, which can effectively reduce the cavitation of the hydraulic dynamometer and improve the overhaul life of the hydraulic dynamometer.

There is a sewage communication pipe at the bottom of the shell, which is used to balance the water pressure fluctuation of the front and rear water chambers during operation. When the hydraulic dynamometer is out of operation, the water stored in the water cavity can be discharged through the sewage communication pipe to ensure that there is no water stored in the hydraulic dynamometer.

The hydro dynamometer also includes an oil pan for supporting the hydro dynamometer. Its function is to serve as the base of the hydraulic dynamometer to connect all parts of the hydraulic dynamometer into a whole, providing a stable support for easy installation and hoisting.

The hydraulic dynamometer oil pan is provided with a hydraulic dynamometer oil tank inside, which is used to store the lubricating oil required for bearing lubrication.

The dynamic balance of the rotor performed by the hydraulic dynamometer needs to be carried out after all the upper parts installed on the main shaft are installed to ensure the accuracy of the dynamic balance of the rotor, thereby ensuring the stability and safety of the hydraulic dynamometer in high-speed and high-power operation.

The novel engine power detection device of the present invention has excellent performances such as high measurement accuracy, sensitive response, strong operation ability, good maintainability, etc. In particular, it relates to a hydraulic dynamometer, which can be suitable for high rotational speed and large absorption capacity. Power, long overhaul life, high adaptability and other characteristics, have excellent engineering application value.

The high-power and high-speed hydraulic dynamometer of the invention has the advantages of high measurement accuracy, sensitive response, strong operation ability, compact size, good maintainability and the like, and can be applied to scientific research, equipment test and durability test of aviation, industrial and marine gas turbines , repair test and other high-power and high-speed fields. High-power high-speed hydraulic dynamometer is mainly composed of stator (stator), rotor, guide ring, shell, end cover, water seal, oil seal, bearing seat, bearing seat support, main shaft, coupling, oil pan, water inlet valve , drainage valve, centralized control box and vibration monitoring system. The power it absorbs increases or decreases in direct proportion to the amount of water flowing through the rotor, and the adjustment of the absorbed power is controlled by the intake/drainage control valve. The high-speed hydraulic dynamometer is integrated with a centralized control box (hub cabinet) and a vibration monitoring system, which can display the operation of the hydraulic dynamometer locally and remotely, and evaluate the status of the hydraulic dynamometer itself. Through the rational design of the working water chamber, rotor stator (stator) and guide ring, the protective layer of the erodible parts and the anti-cavitation parts are sprayed, and the rich interfaces ensure the smooth and safe operation of the high-power and high-speed hydraulic dynamometer.

Description of drawings

Fig. 1 is the principle diagram of high-power high-speed hydraulic dynamometer of the present invention;

Figure 2 is a schematic diagram of the spindle installation and dynamic balance of the high-power and high-speed hydraulic dynamometer;

Figure 3 is a schematic diagram of the rotor of the high-power and high-speed hydraulic dynamometer;

Figure 4 is a schematic diagram of the stator (stator) of a high-power and high-speed hydraulic dynamometer;

Figure 5 is a schematic diagram of a high-power and high-speed hydraulic dynamometer housing;

Figure 6 is a schematic diagram of the oil pan of the high-power and high-speed hydraulic dynamometer;

Figure 7 is a schematic diagram of a high-power high-speed hydraulic dynamometer water stabilizer;

Figure 8 is the schematic diagram of the high-power high-speed hydraulic dynamometer junction box;

Figure 9 is a schematic diagram of the vibration monitoring system of a high-power and high-speed hydraulic dynamometer;

Figure 10 is a schematic diagram of the coupling of the high-power and high-speed hydraulic dynamometer (two forms);

In the figure, 1-main shaft, 2-main bearing oil seal, 3-bearing seat, 4-side disc, 5-housing, 6-stator, 7-guide ring, 8-rotor, 9-custom bearing, 10- Bearing, 11-Drainage, 12-Stainless steel sleeve, 13-Coupling.

Detailed ways

The invention discloses a high-power high-speed hydraulic dynamometer. The load generated by the engine is transmitted to the main shaft of the high-speed hydraulic dynamometer through the coupling, the main shaft drives the rotor to rotate, and the rotor drives the water in the water cavity to pass through the stator and the guide ring. The high-speed flow in the formed water cavity generates kinetic energy due to the continuous change of speed and main direction of the water in the flow, and transmits it to the casing through the stator (stator), thereby generating the torque of the hydraulic dynamometer. The water in the water cavity enters the water inlet through the water dynamometer inlet, and then enters the working water cavity through the various water inlets on the stator blades. With the rotation of the rotor, the water in the water cavity is stirred by the rotor and the stator (stator). The water vortex is generated, forming a hydraulic dynamometer to absorb the load of the engine. Figure 1 is a schematic diagram of a high-power high-speed hydraulic dynamometer. It shows the relative positional relationship of each component of the high-power and high-speed hydraulic dynamometer and the movement of water flow in the hydraulic dynamometer.

As shown in Figure 1, in the middle of the main shaft, there is a protective sleeve made of stainless steel to reduce the occurrence of cavitation and water corrosion and prolong the life.

The load absorbed by the hydro dynamometer is determined by the amount of water in the water chamber. The amount of water in the water chamber is adjusted by the intake and discharge volume (the opening of the intake and discharge valve) to ensure that the heat generated by the water eddy current in the water chamber of the hydraulic dynamometer is discharged in time.

The support of the hydraulic dynamometer housing is supported by self-centering bearings (Figure 1). Self-centering bearings can ensure the flexible movement of housing components and the accuracy of torque transmission.

Before the overall assembly of the hydraulic dynamometer, it is necessary to perform high-precision dynamic balance on the main shaft and the parts installed on it to ensure the stable and safe operation of the high-speed hydraulic dynamometer. Figure 2 is a schematic diagram of the high-precision dynamic balance of the rotating parts of the high-power and high-speed hydraulic dynamometer.

Figure 3 is a schematic diagram of the rotor of the high-power and high-speed hydraulic dynamometer, which is made of cavitation-resistant duplex stainless steel, and the angle of the impeller (blade) relative to the rotation direction is 45 degrees.

Figure 4 is a schematic diagram of the stator (stator) of the high-power and high-speed hydraulic dynamometer, which is made of cavitation-resistant duplex stainless steel. The angle of the impeller (blade) relative to the rotation direction is 45 degrees, and it is opposite to the rotor. The water inlet of the hydraulic dynamometer enters the working water chamber composed of the rotor, the stator and the guide ring through the water inlet hole on the stator (stator).

In order to improve the anti-cavitation performance of the cavitation-prone parts of the high-power and high-speed hydraulic dynamometer, cavitation-resistant coatings are sprayed on the cavitation-prone rotors, stators (stators) and guide rings to protect the parts and prolong their life.

Figure 5 is a schematic diagram of the high-power and high-speed hydraulic dynamometer shell, which adopts a split-lobe form to facilitate the disassembly and maintenance of the hydraulic dynamometer. A water inlet and a water outlet are arranged on it. The bottom of the shell is provided with a balance water outlet and a sewage outlet relative to the water cavity, which can balance the pressure of the water cavity during high-speed and high-power operation, and discharge the water stored in the water cavity when it is out of use.

Figure 6 is a schematic diagram of the oil pan of the high-power and high-speed hydraulic dynamometer, which adopts the integrated structure of the support and the oil tank, which simplifies the auxiliary system equipment and facilitates the installation while ensuring the stability of the support.

The inlet and outlet of the high-power and high-speed hydraulic dynamometer adopts the traditional water inlet method to save installation space. In order to make the water flow into the hydraulic dynamometer relatively stable and reduce the interference to the operation of the hydraulic dynamometer, a hydraulic dynamometer stabilizer is installed at the inlet and outlet (Figure 7).

The high-power and high-speed hydraulic dynamometer control and sensor output signals are collected into the junction box, and transmitted to the control cabinet through the junction box, which greatly improves the transmission and installation efficiency, and avoids the complexity of signals and lines. The principle is shown in Figure 8.

When the high-power and high-speed hydraulic dynamometer is in operation, it is necessary to continuously monitor the vibration state of its bearing support and casing to determine its operating state and accumulate data for overhaul and life evaluation. The principle of high-power and high-speed hydraulic dynamometer vibration monitoring system is shown in Figure 9. According to different test requirements, vibration sensors measuring displacement, velocity and acceleration can be installed at different test points and directions.

According to the connection equipment of the high-power and high-speed hydraulic dynamometer and the required disassembly and assembly methods, the coupling and the main shaft can use the form of flat-key conical surface interference connection and hydraulic interference-torsion connection form, and the flat-key conical surface interference connection can be used. Due to its high processing requirements for the joint surface, the processing difficulty is relatively large. The hydraulic interference torque transmission has higher requirements on the processing surface itself, and only oil pressure is required for installation and disassembly.

In the present invention, two oppositely installed rotors are installed on the outer main shaft of the stator, the angle of the rotor blades is 45 degrees, and the direction is the direction of absorbing power. and other characteristics. Its blade (wheel) angle is 45 degrees to the axis bearing, which is better suited to the high-power and high-speed operation of the hydraulic dynamometer.

The two stators (stators) are fixed on the inner side of the casing and are located in the center of the inner side of the rotor. The stator is made of duplex stainless steel, which has the characteristics of high corrosion resistance, high cavitation resistance, and high weldability. The angle of the stator blade (wheel) is 45 degrees to the axial bearing and is opposite to the rotor blade, which can better adapt to the high-power and high-speed operation of the hydraulic dynamometer.

The hydraulic dynamometer has a cylindrical shell on which the stator, guide ring and other internal components are installed, and also the calibration arm (beam) used for calibrating the hydraulic dynamometer and the torque measuring device of the hydraulic dynamometer. Measuring arm (beam).

At least two labyrinth non-contact oil seals are set in the bearing frame at both ends of the bearing. The parent body is made of 20# steel, copper base (or other steel), and the top is made of tin bronze babbitt material. The tin bronze babbitt itself includes many The groove, together with the oil throwing ring installed on the main shaft, can play a good sealing effect. Tin bronze babbitt and parent material use wedge-shaped connection to ensure reliable upper connection. During the operation of the hydraulic dynamometer, the lubricating oil used to ensure the lubrication of the bearing is always in the lubricating oil cavity. At the same time, the leaked lubricating oil is collected and returned to the lubricating oil sump. It has the characteristics of compact structure and good sealing effect.

Rotor, stator (stator) and guide ring and other cavitation-prone parts are all sprayed on the surface by ordinary flame spraying, arc spraying, plasma spraying and high-speed flame spraying to improve the cavitation resistance of cavitation-prone parts.

Finally, it should be noted that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the The technical solutions described in the foregoing embodiments may be modified, or some technical features thereof may be equivalently replaced. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. a high-power high-speed hydraulic dynamometer is characterized in that, comprising stator, rotor, guide ring, casing, end cover, water seal, oil seal, bearing seat, bearing seat support, main shaft, coupling, oil bottom Shell, water inlet valve and drain valve; the main shaft is used to transmit the engine power. Two rotors, water seals, oil seals and stainless steel sleeves are installed on the main shaft with a certain amount of interference fit. The two rotors are installed on the main shaft opposite to the stator. The angle of the impeller is 45 degrees; the two stators are fixed on the inner side of the casing, and the position is at the center of the inner side of the rotor; the angle of the stator impeller is 45 degrees from the axial bearing and opposite to the rotor blade, and its cavity is semi-elliptical; the front and rear two sets of rotors , stator and guide ring to construct two relatively independent water cavities; the guide ring is fixed on the inside of the casing and radially located on the outside of the rotor. 2. high-power high-speed hydraulic dynamometer according to claim 1, is characterized in that, in the middle of two rotors, the main shaft and the water contact place are covered with stainless steel sleeve, for preventing high power in the hydraulic dynamometer When the speed is running, the spindle will be rusted due to long-term operation, which will improve the life of the spindle. 3. The high-power and high-speed hydraulic dynamometer according to claim 1 is characterized in that, two side discs are installed on both sides of the casing, and a groove is provided in its interior for installing a sealing ring (gasket), and is combined with the casing. The shell forms the sealed inner cavity of the hydraulic dynamometer. 4. The high-power and high-speed hydraulic dynamometer according to claim 1, further comprising a bearing support at both ends of the main shaft, a sliding bearing with a thrust is arranged in the bearing support at the input end, and a bearing support at the free end is provided. Sliding bearings are arranged in the seat, and the two bearings use an integrated sliding bearing or a split sliding bearing, which makes the installation of the bearing and the main shaft more convenient and the service life is longer. 5. high-power high-speed hydraulic dynamometer according to claim 1, is characterized in that, water is sealed in lower part of casing, and peripheral drainage groove is set, when hydraulic dynamometer runs with full water or water level exceeds design standard water level, water In the case that the seal cannot be sealed tightly, the drainage shall be carried out through the drainage groove to ensure that the water cannot flow into other areas of the hydraulic dynamometer. 6. The high-power and high-speed hydraulic dynamometer according to claim 1, wherein the hydraulic dynamometer also comprises a water inlet pipe and a drainage pipe, and the water inlet pipe and the drainage pipe are arranged at the relative positions of the casing, left and right or up and down, and The water stabilizer is installed at the water inlet and outlet, which is beneficial to the stability of the internal flow field when the hydraulic dynamometer is running, and can better adapt to the high-power and high-speed operation of the hydraulic dynamometer. 7. high-power high-speed hydraulic dynamometer according to claim 1, is characterized in that, hydraulic dynamometer also comprises a coupling at both ends, when needing to carry out forward and reverse switching, to reverse hydraulic dynamometer The installation direction of the device can realize the effective switching of different steering directions. 8. The high-power and high-speed hydraulic dynamometer according to claim 1, wherein the rotor, the stator and the guide ring are made of duplex stainless steel, and have higher hardness and high corrosion resistance of the same material, and high cavitation resistance, High weldability and other characteristics. 9. high-power high-speed hydraulic dynamometer according to claim 1, is characterized in that, hydraulic dynamometer integrates centralized control box, collects and processes the electric signal front-ends such as hydraulic dynamometer rotating speed, torque, temperature, pressure After that, it is transmitted to the control cabinet through cables and Ethernet to realize local and remote control. 10. high-power high-speed hydraulic dynamometer according to claim 1, is characterized in that, hydraulic dynamometer has integrated vibration monitoring system, it can monitor the horizontal, vertical and axial vibration of hydraulic dynamometer bearing in real time, in order to Judging the operation of the hydraulic dynamometer can better adapt to the high-power and high-speed operation of the hydraulic dynamometer.

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