Ultra high speed dynamometer, over 120,000 rpm test
Ultra high speed dynamometer test applications for 120,000 rpm or above is especially for high speed electric spindle, fuel cell air compressor or centrifugal hydrogen fuel cell compressor, electric supercharger, small turbo compressor, aviation turbocharger, ultra high speed electric drives and vacuum cleaner turbocharger. The development of these new products are growing.
Based on the short product development period and qualification cycle, the demanding technology and operating conditions are required. The required ultra high speed dynamometer testing should cover ultra high speed applications like 120,000rpm testing, high stress (resilience, vibrations, dynamics) and complex testing conditions and automation requirements for safety issues.
For the development and the test of these devices, a test stand is necessary which can apply variable mechanical load to the tested item at high and low speeds. We offer ultra high speed dynamometer for over 120000 rpm for development of ultra high speed electric machines. It is based on a combination of dynamometer and gearbox (or pure dynamometer without gearbox can be considered). The ultra high speed dynamometer is operated in four quadrant mode by a frequency inverter, which allows to drive and to brake the tested item. It is possible to operate the drive-in speed or torque control mode.
Ultra high speed dynamometer generally consists of high speed dynamometer, torque and speed sensor, coupling, test rig, etc. For ultra high speed testing, they may also include ultra high speed gearbox (such as speeding up to 160,000 rpm). The dynamometer plus gearbox can be used to achieve 160000 rpm testing.
For high speed transmission system, the flexible coupling is required. The flexible coupling solves the misalignment problem causing by mounting error and thermal expansion between shafting components without additional axial and radial loads. Some factors must be considered before selecting coupling, especially for high performance applications where the weight and weight distribution of the coupling is important.
The speed can be increased to more than 120000 rpm testing through the gearbox, the high speed power can reach 100 kW and the torque can reach 50 N.m. The transmission ratio of the high speed gearbox should not be too high, so the ultra high speed dynamometer needs to be matched according to the actual required speed to make the best solution. Special couplings are required for high speed transmission system.
120,000 rpm test application
High speed electric spindle test
The high speed generator driven by the gas turbine is small in size, has high maneuverability. These high speed spindle can be used as backup power source for some important facilities, or can be used as independent power source or small power station to make up for the shortage of centralized power supply. The high speed spindle has important practical value.
Centrifugal hydrogen fuel cell compressor test
Clean air of the required pressure and flow are provided to the fuel cell based on the fuel cell stack output power. In an air supply system, the air pressure and flow have the large impact on the performance of the fuel cell system (energy density, system efficiency, water balance and heat loss), cost and size of the stack.
Electric supercharger test
The electric supercharger is mainly powered by the battery. The ECU electronic control system directly controls. It is not affected by the speed and can be turned on and off at any time. The electric supercharger solves the problem which the turbocharged engine does not enjoy the power addition of the turbine at low speed, and there is a certain delay in the power when the throttle is deeply stepped on.
Small scale turbo compressor testing
The research on ultra compact turbo compressor is conducted on active flow control concepts for ultra high lift coefficient. This principle allows for short take-off and landings, and enables drag reduction during cruise and, therefore, lower fuel consumption during long distance flights.
Aviation turbocharger testing
The bearing for turbine main shafts is used for the turbine driven by ultra high temperature exhaust gases exceeding 800°C as the power source, and it must withstand ultra high speed of over 200,000 revolutions while continuously immersed in oil.
Ultra high speed electrical drive testing
The new permanent magnet motor is designed with smallest volume and weight. A special rotor construction allows highest loads or stresses and makes the ultra high speed possible.
Turbo charger for vacuum cleaner testing
Following eco design principles, new EU regulation 666/2013 introduces stringent requirements for rated input power, dust pickup, maximum sound power level and life. This means that efficiency needs to be increased to achieve the same suction power as current models but with a lower power input.
Turn-key ultra high speed dynamometer solution requirement
- Testing high speed in wide operating range
- System quick implementation
- Flexible application of tested items with diverging requirements and specifications
- Easy and safe system handling including intuitive usage and automated procedures
- Adaptable to established development processes, test environment, standards and customer requirements
- Validated and tested
- Scalable and extensible
Germany high speed gearbox
In test facilities, reduction gears are often an indispensable tool to adapt the torque levels or rotational speeds between interfaces, to setup relationships between components, or to tense up a closed loop test rig. The high speed gearbox is extremely precise. Smooth rotational speeds up to 100,000rpm are achieved, and loads up to 100kW can be transferred. In addition to this, the standardised turbo gearboxes, with their high power-density, can often prove to be an economic option for basic operations.
The turbo and high speed gearbox can be applied in various areas including motor-sport test facilities, automotive, utility and agricultural vehicle components, and aviation customized gearbox and turbines, as well as in the testing of electrical machines and generators. The high speed gearbox is available as a standard product or it can be customised or fully automated. In addition, the complete mechanical drivetrain for the test stand can be provided as a turnkey unit. To secure and ensure test stand availability, planned preventive maintenance programs and a full maintenance service can be provided.
120,000rpm above ultra high speed dynamometer schematic overview
- Test bench
- Dynamometer section
- Coupling between dynamometer and gearbox
- High speed gearbox
- High speed coupling, including protective cover test piece bracket
- Test piece
The ultra high speed test system consists of dynamometer, dynamometer drive, brake resistor, gearbox, DC power supply, power analyzer or power meter, control system, mechanical system and sensor measurement system.
- Dynamometer uses a high speed asynchronous machine to simulate the load and can be used for torque or speed control.
- Dynamometer drive is used to dynamically control the dynamometer in real time.
- Braking resistor is used to consume the energy generating by dynamometer during emergency braking.
- Gearbox is used to increase the speed of the dynamometer to higher speed to meet the demand of the test piece. The gearbox output shaft integrates the torque and speed measurement sensor which can directly measure the speed and torque of the test piece. This can avoid the influence of the gearbox transmission efficiencyon the measurement of the test piece torque and speed.
- DC power supply is used to power the test piece (optional).
- Power analyzer is used to measure the current, voltage and power of the test piece (optional).
- Control system is used to control the entire test rig including the control circuit and software system. It realizes the control of the speed and torque of the dynamometer, the gearbox control, DC power supply control and the processing of the sensor signals such as torque, speed, vibration, temperature and oil pressure. It also includes external communication and data transmission such as power meter.
- Mechanical system includes the mounting base, the test piecemounting tool and the coupling./li>
- Sensor measurement system includes a sensor and a back end processing system. The sensors of the ultra high speed dynamometer include: the torque and speed measurement sensor of the test item (integrated in the output shaft of the speed increase box); temperature, pressure, blockage and other detection sensors, vibration monitoring sensor for both gearbox and test item, oil temperature and bearing temperature monitoring sensor of the gearbox.
Test bench main structure
The mechanical structure of the test bench includes: test bench base, dynamometer mounting base, bearing support, test piece installation tooling, blockage mechanism and test piece connecting shaft.
Test bench base
The base of the test bench is integrally cast structural parts and the upper surface of the base is a mounting surface. After precision machining, four air spring shock absorbers are installed at the bottom of the base for vibration isolation and shock absorption.
Ultra high speed gearbox
The ultra high speed gearbox uses a two stage power distribution gearbox with coaxial input and output shafts. The parameters are as follows:
- Rated output speed: 165,000 rpm
- Rated output torque: Tout, rated = 1.5 Nm
- Rated power Pnom = 25 kW
- Service life of all gearbox components > 10,000 hours
As the key component of the ultra high speed gearbox system, it is extremely important to lubricate the pumping station, which is supplied by the ultra high speed gearbox supplier and is commissioned at the factory.
Test piece torque measurement
The torque measurement of the test piece is measured by direct measurement. Instead of installing the torque speed sensor at the low speed end, the transmission loss of the high speed gearbox is prevented from being included in the measurement data of the test piece.
Test piece connection
In order to facilitate the user to test different test pieces and replace the connection tooling, at the same time avoid the shaft system torsional vibration, the torque flange, transition spline flange and spline shaft are sequentially installed between the output end of the bearing housing and the input shaft of the test piece.
Test bench key technical item description
High dynamic control system
- The test system uses the very advanced system architecture which adopts embedded real-time controller as the control center. The real time controller is equipped with the main control program which is very stable and reliable.
- The controller and the inverter communicate in real time through the fastest and stable real time EtherCAT and dynamically control the dynamometer.
- The data acquisition system also adopts a modular structure and communicates with the real-time controller through EtherCAT for data interaction, which is very convenient for subsequent channel expansion.
- The host computer adopts special industrial computer and is equipped with human machine interface software as data display and storage and delivery of manual instructions.
- Since the host computer generally adopts Windows system, the system is not suitable as an industrial control operating system. Therefore, we use independent embedded real-time controller control.
- The real-time controller external touch screen can operate the test bench through the touch screen to prevent the host computer from crashing leading test bench not to be controlled.
- The dynamic response time of the system is better than 10ms, which can provide high dynamic control to meet complex variable conditions and simulation tests.
Ultra high speed gearbox
Since the rotational speed of the test piece reaches 165,000 rpm, the direct drive dynamometer is difficult to realize, and the ultra high speed gearbox is used to raise the speed of the dynamometer to the maximum speed of the test piece. The gearbox is specially designed to integrate a torque and speed measurement system on the shaft connected to the test item. This can directly measure the torque and speed values of the test item and avoid the impact of high speed gearbox transmission losses on the authenticity of the test itemmeasurement data.
Comprehensive security measures
- Real-time monitoring of the front and rear bearings and dynamometer temperature, dynamometer current and voltage, speed and torque.
- Real-time monitoring of bearing temperature and vibration of ultra high speed gearbox.
- The vibration of the test piece is monitored in real time.
- The safety shield is closed and interlocking protection is detected with the dynamometer.
- The electronic control system has short-circuit, leakage, power-off, over-current, over-voltage and other protection functions.
- The system software has safety detection function. When the monitored value exceeds the threshold, it will immediately alarm. The system has three levels of protection.
- For durability testing, the system automatically performs trend prediction based on historical data such as monitored vibrations. When a failure occurs in the prediction, the system will prompt user to pay attention.
Modular operating software
The test bench software adopts the modular design structure. User can customize the test process and working condition parameters. The system ranks users and develops different functional modules. The system has the automatic zero calibration function of the start-up, which can eliminate the invalid value of the sensor and improve the accuracy of the measurement. The software has a dedicated sensor calibration module that allows the user to calibrate the sensor on a regular basis.
Test bench operation environment
- Ambient temperature: -5 to 50°C.
- Relative humidity: 10~98% RH.
- Equipment operation power: single phase 220V±10% AC, 50±2Hz; three-phase 380V±7% AC, 50±2Hz.
Characteristic curve against torque curve
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