Classification of hydraulic systems for small excavators

[BONOVO]

According to the different power sources, the hydraulic system of single-bucket hydraulic mini excavatorcan be divided into: single pump single channel quantitative system, double pump double channel quantitative system, double pump double channel divided power scheduling variable system, double pump double channel total power scheduling variable system.

2. Single pump single channel quantitative system
Single pump single loop quantitative system is suitable for small and medium-sized hydraulic excavator, such as WLY60 wheel hydraulic excavator, its hydraulic pressure

The whole system is supplied by the double gear pump, and the south relief valve sets the pressure of the system operation to 14 MPa, and all the oil is returned through the filter and the radiator.

Grab hydraulic circuit, reverse circuit, bucket rod circuit, boom circuit, bucket circuit all use series multi-channel reversing valve to operate the hydraulic cylinder action. The bucket reversing valve is installed in the front of the oil inlet circuit. When the bucket hydraulic cylinder is in action, other reversing valves have no pressure oil source, and only the leg circuit, suspension balance circuit and the bucket circuit are in parallel.

Reverse hydraulic circuit: the rotary table reverses with pressure oil to drive the quantitative hydraulic motor, and the rotary table with a boom, bucket rod, bucket, and grab can be turned to any suitable Angle. Inverting hydraulic motor inlet and outlet oil circuit is provided with an active buffer pressure limiting valve (one-way relief valve), under normal circumstances, the relief valve is closed, when the hydraulic motor sudden break or reverse, the impact of the high pressure oil will burst the buffer pressure limiting valve overflow back to the tank, the low pressure oil circuit is filled by the check valve, and then eliminate the hydraulic impact. The buffer valve is arranged in pairs and can work in both directions, and the setting pressure of the buffer valve is appropriate or slightly lower than the pressure of the main relief valve, about 10 MPa.

Boom hydraulic oil circuit: The oil inlet road of the large chamber of the boom hydraulic cylinder is connected with a pressure limiting valve with a pressure of 18 MPa to ensure the locking force of the boom hydraulic cylinder. The small chamber of the boom hydraulic cylinder is equipped with a one-way oil refill valve, which can replenish oil from the oil return circuit when the boom drops rapidly.
Bucket rod circuit and bucket circuit: a pressure limiting valve with a pressure of 18 MPa is set on the oil inlet road of the bucket rod hydraulic cylinder and the bucket hydraulic cylinder to ensure the blocking force of the bucket rod hydraulic cylinder and the bucket hydraulic cylinder.

The advantage of the quantitative hydraulic system is that the structure is still relatively simple, the price is cheap, and the universal multi-way valve is used as the control element in the system. However, the shortcomings are also more, because the hydraulic pump output flow is always the same, when the system operates in a low pressure state, the power consumed by the system is far lower than the output power of the engine, making the entire hydraulic system power loss, low energy utilization rate, the operating speed of each implementation component is greatly affected by external load changes, and the trouble between each other when acting together is also large. Compound operability is poor.

Choose BONOVO for high-quality, customizable brush cutters for skid steers with fast delivery. Contact us today to discover how our superior products can enhance your land management tasks!

for more info just visit our website at www.bonovogroup.com
contact # : +86 158 6218 2088
email : sales@bonovogroup.com