TECHNICAL SUPPORT
Published 2026-03-04
When developing new products or modifying equipment, do you always feel unsure when it comes to hydraulic steering gear selection or system design? Worried about insufficient flow, unstable pressure, or simply not turning? Don't worry, today we will break down the hydraulic system, the blood supply system of the "Hercules", and talk about it.
Many friends have installed their equipment, but as soon as they turn on theservo, theservoshakes, crawls, or even doesn't move at all. Eighty percent of this is because the hydraulic system is not working well. The steering gear is a precise actuator, which requires a stable supply of "blood". If the oil is dirty, the flow rate fluctuates greatly, and the pressure is not enough, it will get angry. Just like a person working hungry, he will definitely not do well. Understanding this, we can prescribe the right medicine to solve the problem fundamentally.
Choosing a pump is like fitting an engine to a car. If it's too small, it won't run, and if it's too big, it will waste fuel. For steering gear applications, three key parameters are:pressure, flow, and control method. The pressure should meet the maximum thrust, leaving a 10%-20% margin. The flow rate is calculated based on the speed of theservo. Don’t forget to add system leakage. In terms of control method, if the movements are frequent, servo or proportional variable pump is the first choice, which is energy-saving and accurate.
️Whatare the advantages of variable pumps?
Compared with fixed-displacement pumps that always operate at full displacement, variable-displacement pumps provide oil according to demand. When the steering gear is not working, it almost does not discharge oil, which greatly reduces oil heating and energy consumption. Imagine the difference between having the faucet on at home and turning it on whenever you want. In the long run, it can help you save a lot of electricity and cooling costs, and the system stability will be higher.
️Can a gear pump be used?
If it is a simple open-loop system that works intermittently, such as only pushing and pulling, a gear pump is completely sufficient and cheap. However, if precise positioning and speed control are involved, the problems of large flow pulsation and low control accuracy of the gear pump are exposed, which will lead to unstable operation of the steering gear. At this time, you have to put on the plunger pump honestly.
This is the most common "hidden killer" of hydraulic systems. The servo valve core has a very small gap, and a piece of dirt invisible to the naked eye can jam it, causing movement failure. Therefore, the filtration system must be paid attention to. Install high-precision filters on the pump outlet and oil return pipeline. When using it for the first time and when changing the oil regularly, be sure to filter according to the precision. Don't worry about this.
1. Choose the appropriate filtration precision.For servo or proportional valve controlled servos, it is recommended that the filtration precision be no less than NAS level 7 (approximately 5 microns). For ordinary reversing valve control, NAS level 9 is enough. Never buy a low-quality filter element, as it will cause trouble for the system.
2. Regularly test the oil.The filter element alone is not enough. It is best to do an oil test once a year. Check whether the moisture, acid value, and particle size exceed the standards. Just like regular physical examinations, if problems are detected early and dealt with early, a major repair can be avoided.
If the pressure is unstable, the steering gear will vibrate. The reasons usually include: the relief valve is stuck, a large amount of air is mixed in the oil, or the variable mechanism of the pump fails. In this case, don’t blindly increase the pressure. First listen to the pump to see if there are any abnormal noises (like air being sucked in), and then check whether the oil level and the oil return pipe are exposed to the liquid level. Exhausting air and cleaning the valve core are often more effective than adjusting pressure.
️Can accumulators resolve pressure fluctuations?
sure. The accumulator acts like a surge tank, absorbing pressure pulsations in the system. Especially when the steering gear requires a large flow rate in an instant, it can replenish oil quickly to avoid a sudden drop in pressure. At the same time, it can also be used as an emergency energy source. If the pump or motor fails, the stored pressure oil can reset the steering gear to a safe position. This is a very practical safety backup.
When the oil temperature is high, the oil becomes thinner, the lubrication performance decreases, leakage increases, and the steering gear becomes weak. The main reason for the temperature rise is the low efficiency of the system. For example, when a quantitative pump is equipped with a relief valve to regulate speed, a large amount of energy is turned into heat. Solution ideas: First, use a variable pump to reduce heat sources; second, equip with sufficient radiators (air-cooled or water-cooled), and ensure that the radiators are clean and the fans work properly.
️Doesthe size of the fuel tank matter?
Of course there is. The fuel tank not only stores oil, but is also responsible for dissipating heat and settling impurities. Theoretically, the tank volume should be 3-5 times the pump's flow rate per minute. If space is limited, the cooler power must be increased to compensate. In addition, a partition should be added inside the fuel tank to separate the oil return and oil suction, giving the oil enough time to settle bubbles and impurities. This detail directly affects the stability of the system.
No matter how good the system is, it is afraid of being "lazy". Routine maintenance is actually very simple: before starting work every day, check the oil level and see if there are any leaks in the pipelines. Listen to see if the pump sounds normal. Most importantly, pay attention to the color and smell of the oil. Be alert if the oil turns white (water intrusion) or black (high temperature oxidation). Be diligent and replace the oil return filter every few months, and the system will have a long life.
After reading this, do you know more about the hydraulic steering gear system? Next time you encounter problems with the servo shaking and losing power, do you know where to start?
Thinking back to your application scenario, do you think the most troublesome problem with hydraulic steering gear currently encountered is "unstable pressure" or "excessive oil temperature"? Welcome to chat about your views in the comment area. If you find the article useful, don’t forget to like and share it so that more friends can see it!
Update Time：2026-03-04
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