Hydraulic Dynamometers (Water Brakes)
Froude Invented the Water Brake Dynamometer
The Froude F Range Hydraulic dynamometers (also referred to as water brakes) have been designed to be compact, robust and to allow easy maintenance. Some of these models are available with a streamlined, fabricated base. This base is not only ultra durable due to the powder coating process, but also offers flexibility with water inlet/outlet placement and lifting eye locations.
These engine dynos are fitted with two half couplings which, with the rotor, are oil injected onto the shaft. The standard machines run in grease lubricated rolling element bearings.
The hydraulic dynamometer working compartment consists of special semi-circular shaped vanes cast into stainless steel rotor and stators. Water flowing in a toroidal vortex pattern around these vanes creates a torque reaction through the dynamometer casing which is resisted and measured by a precision load cell. The dynamometer load is controlled by a 'butterfly' water outlet valve, operated by a closed loop electro-hydraulic servo system. The power absorbed by the dynamometer is carried away by the water in the form of heat.
KEY to Model Letter Designations: R= Reversible, D= Dual Compartment, AV= Axial Vane (bi-directional), GT= Gas Turbine, FRR= Fixed Return Ring
KEY to Numeric: F359: 35 = rotor size (inches), 9 = 90° crop on rotor
|Model||Max Speed (RPM)||Torque Nm (lb.ft)||Power
|F24||9,000||2,700 (1,900)||750 (1,010)||002396|
|F246||9,000||2,700 (1,900)||750 (1,010)||003011|
|F246FRR||11,000||2,000 (1,480)||750 (1,010)||001980|
|F249||16,000||1,270 (940)||750 (1,010)||001253|
|RF24AV||10,000||1,780 (1,310)||750 (1,010)||004440|
|F35||6,000||7,120 (5,250)||1,640 (2,200)||002483|
|F35GT||6,000||10,780 (7,950)||1,640 (2,200)||004088|
|F359||9,000||5,220 (3,850)||1,640 (2,200)||001902|
|RF35AV||6,000||7,120 (5,250)||1,640 (2,200)||002475|
|F47||4,500||18,500 (13,650)||3,300 (4,425)||001774|
|F47GT||4,500||28,470 (21,000)||3,300 (4,425)||003981|
|F476||4,500||18,500 (13,650)||3,300 (4,425)||002847|
|F479||7,000||13,700 (10,105)||3,300 (4,425)||002476|
|RF47AV||4,500||17,850 (13,150)||3,300 (4,425)||004046|
|F63||3,600||50,000 (36,900)||6,700 (9,000)||001775|
|F639||5,000||37,000 (27,300)||6,700 (9,000)||002477|
|RF63AV||3,600||47,120 (34,800)||6,700 (9,000)||003917|
|F84||2,000||142,000 (104,750)||12,000 (16,100)||001776|
|F849||4,000||76,000 (56,100)||12,000 (16,100)||003531|
|RF84AV||2,000||101,400 (74,800)||12,000 (16,100)||004043|
|RF84D||2,000||142,000 (104,750)||12,000 (16,100)||001922|
|F84D||1,200||213,000 (157,000)||24,000 (32,200)||001894|
|F849D||4,000||101,700 (75,000)||29,840 (40,000)||004321|
As standard, the F type machines are fitted with two half couplings allowing connection at either end. These, along with the rotor, are oil injected on to the main shaft, thus eliminating stress raising keyways. Grease lubrication is replaced by the optional 'oil mist' system for the High Speed versions.
The dynamometer working compartment consists of special semi-circular shaped vanes cast into stainless steel rotors and stators. Water flowing in a toroidal vortex pattern around these vanes creates a torque reaction through the dynamometer casing which is resisted and measured by a precision load cell. The dynamometer load is controlled by a characterised water outlet valve, operated by a closed loop electro hydraulic servo system.
The power absorbed by the dynamometer is carried away by the water in the form of heat.
Development, production and post overhaul testing of:
- Automotive gasoline and diesel engine
- Industrial and marine diesel engines
- High performance competition engines
- Turboprop, turboshaft and power generation turbines
- Engine components
- Electric motors
The standard range of Froude F type Hydraulic dynamometers extends from 750 kW up to 25,000 kW and speeds up to 10,000 rpm. Torque measurement accuracy is ±0.25% of full rated torque of the dynamometer.
Speed is measured by a pulse pickup operating with a 60 tooth wheel and gives accuracy of ±1 rpm.
Froude dynamometers are painted traffic blue RAL 5017.
Download Fact Sheet:
- High speed versions up to 16,000 rpm
- Calibration equipment
- Shaft bearing thermocouples
- Water inlet pressure switch
- Water inlet valve, pneumatic or servo operation
- Water outlet valve fail-safe device
- Water inlet and outlet thermocouples
- Bi-directional machines
- Paint color
- Facilities planning and installation services
- Comprehensive in-house and/or on-site training courses
- Tailored preventative maintenance contracts
- Technical Support