Howden Gýrol® Fluid Drives transmit power through a vortex of oil. The oil is accelerated by the blades of the impeller (connected to the driver) and decelerated as it strikes the blades of the runner (connected to the load). As the oil is accelerated, it absorbs energy from the driver. As it is decelerated, it releases this energy to the driven load. Since there is no mechanical connection between the driver and load, the fluid drive provides a smooth and continuous flow of power.
The vortex of oil is enclosed in a rotating casing (also connected to the driver). The volume of oil in the vortex can be changed using a moveable scoop tube. The scoop tube controls this oil volume by trimming or “scooping” oil from the rotating casing. This ability to change the volume of oil allows for stepless speed adjustment with a 5:1 turndown for variable torque loads and 4:1 turndown for constant torque.
The position of the scoop tube can be operated manually or automatically. The oil removed by the scoop tube returns to the reservoir which is also the fluid drive housing. From there a circulating oil pump, driven by the input shaft or by a separate electric motor, draws oil from the reservoir and sends it through an external heat exchanger to remove excess heat. Upon returning from the heat exchanger, some oil is diverted to the lube oil circuit to be filtered for lubrication of the fluid drive bearings. The rest is sent to the working circuit to return to the rotating casing for continuing the transfer of power.
Howden Gýrol® Fluid Drives are renowned for their simple and dependable service under the most demanding conditions and in the harshest environments. For more than 80 years, they have been operating 24 hours a day, seven days a week providing reliable power transmission and speed control to pumps, fans, compressors and more.
Read more by visiting the
Howden Gýrol® Fluid Drives product page.
26th April 2017
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