Rotation speed.

Description

The microphone sensor is designed for the reading of the turbine rotation speeds of all the Sames sprayers.

The principle of rotation speed reading is acoustic-based. An air arrives at the level of the bell ; it is guided by a groove and directed at each bell revolution to create a pressure variation that flows up to the sensor. This signal is then converted into electrical variations in order to adjust the bell rotation speed.

The turbine rotation speed reading system can also be carried out by optical fibre. This solution is possible with the new range 7 of Sames sprayers.

The reading of the turbine rotation speed is made thanks to a fibre optics principle. An "optical fibre Kit" unit (refer to diagram 3, KFO) includes the sprayer elbow. One of both fibres emits a continuous luminous signal that reflects itself on the turbine shaft in a discontinuous signal of which frequency gives the rotation speed (2 luminous pulses/turbine revolution). This discontinuous signal is transmitted by the second fibre towards the optoelectronic converter (refer to diagram 3, CFO), thanks to an optical fibre kit of 8-m long (refer to diagram 3, FO). The electricalpulse signal at converter outlet is recovered and analysed by the converter system Frequency/ Voltage (CFU). At a 65000 rpm rotation speed, the frequency will be at 2.16 kHz.

Custumer benefits

The rotation speed reading is made via an acoustic-based principle that presents numerous advantages :
• Longer service life : pneumatic hose through the robot arm and not through a cable (torsion, numerous movements ...)
• Simple and reliable : the connecting components are not sensitive to the dirt (paint)
• Pneumatic signal not influenced by electrostatic phenomena or CEM (electromagnetic compatibility).
• 100 % compatible use with high voltage (breakdown, creeping ...)