In almost all fairground rides, a hydraulic power pack is operating, hidden somewhere behind the beautiful facade. This power pack is not only responsible for driving it, it also guarantees the safety of the attraction.
When visiting a funfair, you want to have fun and to be happy. Hardly anybody’s thinking about the safety of a ride. All the more important, then, that the manufacturer of the ride, the power pack builder and the component suppliers have already taken care of this.
Indicative image of a hydraulic power pack
Reliability of the hydraulic power pack
High-quality components are a necessary basis for the reliable operation of the hydraulic power pack. In addition to the pump, valves and actuators, primarily the measurement technology must work extremely reliably. The operating conditions for these hydraulics are no fun.
Operating conditions of the hydraulic power pack
Pressure surges and pressure spikes are the usual challenge, caused by valves or the recoil from the cylinders. The pressure measuring instruments need to be protected by suitable measures. For this, attenuators in the pressure port (throttles) are a proven solution. A sensor with a larger pressure range can also ensure safe operation.
Operating temperatures of the hydraulic power pack
Ambient temperatures in outdoor installations are much more variable than in an industrial building. Therefore, the measurement technology should have the lowest possible temperature errors in order to reliably control the hydraulic power pack − for example, even in the height of summer.
Reliability of the components
Frequent and often very rapid pressure changes mean that the pressure measuring instruments are heavily stressed. As a result, the measured value wanders and the measurement accuracy deteriorates. The reason for this can be material fatigue or the setting behaviour of the pressure transducer itself (the Bourdon tube in the pressure gauge or the measuring diaphragm of the pressure sensor). During development and production, the manufacturer of pressure measuring instruments must provide for appropriate measures. The “autofrettage” of the pressure element in production means additional effort, but delivers the advantage of a significantly improved long-term stability. For this, it is loaded with twice the pressure of its later maximum value. As a result, stresses in the material are reduced even before the adjustment of the measuring instrument, and therefore not later when in use at the customer. An important component of any quality philosophy is the 100% test at the end of each production line.
Comprehensive condition monitoring: Pressure, temperature and level
Comprehensive condition monitoring of the hydraulic power pack includes not only the operating pressure, but also the temperature of the hydraulic oil and the level in the tank. By monitoring the temperature of the hydraulic oil, critical conditions can be identified early and the operational time for the oil can be extended. The monitoring of the fill level in the hydraulic oil tank, on the other hand, can signal oil deficiencies before the pump starts to suck in air. Thus, the safe operation of a hydraulic power pack is only fully ensured if pressure, temperature and level are adequately monitored.
Conclusion
The safety of the hydraulic circuit starts with the reliability of each individual component.
Selected WIKA measurement technology for hydraulic power packs
Note
WIKA produces indicators, electrical sensors and switches for all these parameters. WIKA takes the development of its measurement technology very seriously and manufactures it extremely conscientiously, so that others can have their fun. A selection of suitable measuring instruments can be found on the WIKA website.