BZZ1 80 Hydraulic Steering Unit

Hydraulic Steering Unit (BZZ1, BZZ2, BZZ3)

Hydraulic steering control units (BZZ)
BZZ1, BZZ2, BZZ3 Hydraulic steering control units(SCU), new design,   better performance. Widely applied to low speed and heavy load vehicles E.g. construction machinary, forklift, tractor, harvester and helm control etc.

The advantages of the hydraulic steering control units: 

• 1.Low cost, reliable. 
• 2.No load reaction on the steering wheel comfortable. 
• 3.Manual operation available when the pump doesnt work. 
• 4.Low control torque, continuous operation. 
• 5.According to the system, different function and pressure level valves available.

Note 1: represents Function Code, BZZ2 can be chosen for SCU with the displacement of 50-200mL/r. BZZ1 or BZZ3 can be chosen for SCU with the displacement of 50-1000mL/r. 
Note 2: “Flow” that we suggest to use is the flow of 1.25 times as much as that at the steering wheel’s rotation speed of 60 r/min. If the design of the system can't meet the requirements, the flow is allowed to be adjusted a little bit. 

The installation and use of full hydraulic steering note

1  installation precautions:

• (1) When installation steering gear must ensure coaxiality with column, must have a gap of 1 mm in the axial direction. 
• (2) The depth of screw connection to the steering column tightening steering column is ≤15mm.
• (3) After steering gear installed, must check steering wheel turns to ensure the flexibility of the return position. 
• (4) Connection pipeline: P oil port connects to the oil supply pump, T oil port connects to the oil tank, and A and B oil ports respectively connect the left and right oil chambers of the steering gear.

2  oil flow rate considerations:

• (1) The oil supply circuit connected to the P oil port, the oil flow rate in the pipe is recommended to be ≤1.5m/s.
• (2) The pressure circuit of the oil cylinder connected to the A and B ports is recommended. The oil flow rate in the pipe is recommended to be ≤4~5m/s.

3  other matters needing attention: 

• (1) The diameter of the steering wheel must not exceed 500mm. 
• (2) A return filter with a filter accuracy of 30 μm should be installed in the return line of the steering gear. The position of tank is generally higher than installation position of steering gear, and return pipe is inserted below oil level, so oil can be filled only when the manpower is turned, and air can be prevented from entering the oil line.
• (3) The oil viscosity of steering gear is 17cst~33cst. It is recommended to use low-condensation hydraulic oil. Steering gear allows normal working oil temperature 20°C to 80°C, and the limit working oil temperature range is -30°C to 100°C. Reminder: In case of abnormal oil temperature, steering performance will decrease.
• (4) After steering system assembled, it shall be tested: clean oil tank before operation, inject hydraulic oil to the max oil level.Loosen cylinder nipple and allow pump to run at low speed until it is out of oil. Remove link,turn the steering wheel so that the piston reaches left or right position, and then fill the tank to specified level. Tighten all thread connections, connect the piston rod, and check if the steering system is working properly.
• (5) It must be ensured that the oil is clean to prevent the dirt to cause steering failure. Always check the condition of the filter element and the oil. If necessary, give a replacement. 
• (6) If steering failure, must be carefully check the reason first. The steering wheel must not be pulled hard, and the steering gear should not be disassembled to avoid damage to parts. It is forbidden for two people to turn the steering wheel at the same time. 

Troubleshooting of Metering Pump