PTO2 power take-off torque transducer with slip ring ± 5 000 N·m

PTO2: torque and speed through a slip ring, one spline size per transducer

The PTO2 measures the torque and the speed of a power take-off shaft. It is a tubular strain gage transducer with the female PTO spline machined into it; a male splined shaft is bolted to it for the implement. Each PTO2 is made for one spline size: 1 3/8 in with 6 or 21 teeth, rated ± 2 500 N·m, or 1 3/4 in with 6 or 20 teeth, rated ± 5 000 N·m. The 350 Ω full strain gage bridge is read across the integrated B4-2W/E60 instrument slip ring. A 60-tooth tone wheel on the slip ring rotor and a Hall effect sensor on its stator give 60 pulses per revolution. Non-linearity and hysteresis are ± 0.5 % of full scale. It weighs 3.7 kg with a 1 3/8 in spline. The slip ring is also available non-weatherproof, and with or without the encoder.

Two spline locking blocks, held by eight M4 screws, lock the female spline onto the groove of the tractor PTO shaft; the implement drive shaft goes on the male splined shaft. Two spring-loaded restraint cables, routed in opposite directions to fixed parts of the tractor, hold the slip ring stator: a rigid restraint would damage the slip ring. The torque signal leaves through the connector on the slip ring stator, the speed signal through the connector of the Hall effect sensor. The bridge output, in mV/V, is zeroed with no torque on the shaft and converted to N·m with the sensitivity or the 100 kΩ shunt given in the calibration documents. The slip ring seals are non-contacting: they keep out weather and water spray, but the assembly is not sealed against submersion. It is delivered pre-calibrated. The Transducer Display Module adds signal conditioning, an analog output and a display.

It is used to measure the mechanical power that a tractor delivers to the implement during field work, as an input to tractor transmission development.