Aerospace Gearbox Test Systems
As a result of Hydradyne's past experience in the test equipment area, we have now designed and manufactured test benches for several aircraft and aerospace test laboratories.
Large helicopter transmissions have an unusual high speed input/output configuration and require full load dynamic testing. Hydradyne's test benches are manufactured with a hydraulic energy absorbing bootstrap loading system because of its simplicity, controllability, reliability and overall size.
Helicopter transmission test benches are now available to repair and overhaul facilities at reasonable prices. For additional information contact the Hydradyne location nearest you.
Below are a few of the systems designed and manufactured by Hydradyne.
A multi-purpose test bench designed to subject the main gearbox & tail rotor gearbox of helicopters to a high speed/low torque and a high torque/low speed test. The bench is equipped with manual controls and digital panel meter displays.
A multi-purpose test bench designed to test the gearboxes to a dynamic load test of up to 350 HP @4006 RPM. Seven mounting fixtures are included, one for each type of gearbox under test. A hydraulic (energy absorbing) bootstrap system is used to circulate up to 350 HP through the gearbox or gearboxes, and then most of the power is recovered at the output and recirculated back to the input. The electric motor driven hydraulic drive requires 100 HP to control the speed and make up for system hydraulic and mechanical losses. The test bench is equipped with a computer/PLC-integrated system that controls the test and analyzes, monitors and records each test. Tests can be performed manually or the PLC will automatically sequence each gearbox through individual test procedures. Either way, the computer will display real time data, compare the results from each step against specifications, and keep a record of the results.
An FAA certified multi-purpose test bench designed to test the main gearbox, tail rotor gearbox and intermediate gearbox to a dynamic load test of up to 1600 HP. A hydraulic (energy absorbing) bootstrap system is used. The 1600 horsepower is circulated through the main gear box. Most of the power is then recovered at the output and re-circulated back to the inputs. The hydraulic drive system requires 600 HP to control the speed and make up for system hydraulic and mechanical losses. Drive power may be electric or diesel engine.
This bench is equipped with a computer/PLC integrated system that controls the test, displays real time data, compares the results along each step against customer specifications, and keeps a record of the results.
Aerospace and Military Hydraulic Systems
The Tampa Branch of Hydradyne specializes in hydraulic component test stands, central hydraulic power supplies, and electronic system integration of high-end systems for the aerospace community and for various branches of the Defense Department. With over 30 years of hydraulic component and system engineering expertise, there is no limit to the complexity of the systems that can be designed and manufactured to your specific requirements.
Most recently, the Tampa Branch supplied a central hydraulic power supply with four remote aircraft control stations to the Naval Aviation Rework Facility at Cherry Point Marine Base. The system provides 50 GPM at 5000 PSI to four control stations along an aircraft hangar wall. Each station splits this supply into three independently controlled supply lines connected to the aircraft, with a common return line. In order to minimize return line backpressure, the return line from the aircraft is plumbed to a separate fluid reservoir at each control station. A fluid return pump at each station then automatically returns the fluid back to the reservoir of the main HPU.
Typical systems designed by our Tampa staff include the Lockheed Martin F16 assembly line. This system includes a central power supply with 20 aircraft hydraulic control consoles. Supply and return headers were installed below floor level to connect the power supply to each console. Each console would then be connected to the aircraft with hoses. Three 3000 PSI supply lines and a return line were connected to the aircraft along with an auxiliary 4000 PSI supply line. After the aircraft hydraulic system is charged with fluid, all onboard hydraulic circuits are then hydraulically powered and tested prior to flight.
This dual console test stand with remote hydraulic power supply was designed for the Naval Aviation Rework Facility at the Norfolk Navy Base. The system provides variable flow and pressure up to 150 GPM at 5000 PSI for aircraft component testing. Digital displays were provided for monitoring of pressure, flow, temperature, and voltage and current for the variable AC and DC power supplies used to operate the UUT’s electronic control systems.
During the development period of 8000 PSI military aircraft hydraulic components and systems, several test stands and hydraulic power supplies were designed for aircraft and aerospace component manufacturers. The test stand pictured supplies 25 GPM at 8000 PSI to aircraft components under test using CTFE hydraulic fluid. At the time this program was started, CTFE fluid was only available from Wright Patterson Air Force Base at a cost of $300 per gallon. 8000 PSI systems were developed in the hopes of reducing aircraft hydraulic system weight by as much as 25%.
The ability to test submarine hydraulic components by Navy personnel was a high priority with the Pentagon. This required the procurement of multiple test stands that were utilized at various submarine bases and onboard Navy subtenders. The test stand pictured was designed for manual testing of various components including the hydraulic servovalve shown. This valve operates the hydraulic steering rudders onboard the submarine. Onsite system startup and test stand training was provided at all locations.
Fully automated test stands with computer touch screen part number selection, PLC sequence control, data acquisition and test report generation can also be provided. The dual station test stand pictured was designed to test hydraulic pumps and motors with various test specifications and test sequences. Once the test item was loaded and the part number was selected, the test chamber door would be closed, initiating the automatic break-in cycle and functional test. The operator was then free to remove the test item from the opposite test chamber, load a new test item and then start testing another pump or motor.
Several systems were designed to provide power to control valves and other hydraulic sub-systems on wind tunnels for the U.S. Air Force. Pictured is one of many hydraulic power units that replaced older systems on a 10-foot diameter Mach3 wind tunnel. The systems were designed for outdoor service with reservoir breather accumulators, stainless steel reservoir and piping, automatic temperature control systems, and Nema 4X electric control enclosures. Removal of the old systems, installation of the new systems with new welded stainless steel pipe and tubing, and all electrical field wiring lasted approximately one year.
Our Tampa staff has been involved in the design of some very unique hydraulic systems. The Large Blast Thermal Simulator at White Sands Missile Range in New Mexico was developed to simulate the thermal and pressure shock caused by a thermonuclear explosion. The hydraulic system was used to operate the louvers on the front end of the 80-foot high, 600-foot long simulator tunnel. As the blast approached the opened louvers on the front of the tunnel at the speed of sound, a 0-10 VDC signal was generated to operate seven proportional hydraulic systems to close the louvers in 1/3 of a second. Louver timing was critical in order to “pinch” the tail end of the shock wave at the right moment to prevent a vacuum from being developed within the tunnel. A vacuum would cause the test item to be subjected to a reverse shock force as air rushed back into the tunnel. Since the hydraulic system was mounted directly outside the tunnel louvers, the system and all electric control enclosures had to be designed to survive the resulting shock wave.
To discuss your specific system requirements contact the Hydradyne location nearest you.