CLAAS ACADEMY LEXION II Steering hydraulics Steering system Open centre = With steering controls in neutral, the oil from the pump circulates through the steering unit back to the reservoir Non reaction = With steering controls in neutral, shock loads acting on the rear wheels will cause no reaction on the steering wheel Valve components DANFOSS OSPB 250 with valve block OVP 20 -to machine no. 466-0345 454-0805 453-0041 452-0016 DANFOSS OSPC 250 with integral valve block -from machine no. 466-0346 454-0806 453-0042 452-0017 Key to diagram:
O = Orbitrol S = Steering P = Pump B = Version 250 = Oil displacement in cm 3 /min -1 V = Valve block 20 = Pressure setting of shock valve x 10 Components of the valve block The orbitrol – unit consists of a rotor assembly (metering unit) (229) with rotating steering valve (inner and outer spool) (609). The steering spindle operates the rotary disc valve (609) which in turn operates the rotor (229) via the pin. Neutral function In the neutral position, the oil flows through the one way valve (742) and the rotary valve (609) and back to tank (open centre). The back pressure must not exceed 20 bar. Both ends of the steering rams (323) are locked by the valve (609).
Pressure spikes caused by external influences, are eliminated by the shock valves (725), which opens to tank (Non reaction). 02/2001 2-9