Productivity, efficiency and other requirements of increasing hydraulic sensing technology meet opportunities

In the past few years, the demand for capacity, efficiency, reliability and safety of mobile machinery, such as construction and agriculture, is increasing. Most of these machines use hydraulics to realize the operation functions of propulsion, steering, lifting and so on. The requirements for power, efficiency and controllability are directly embodied in hydraulic components and systems.

As part of the hydraulic system, understanding the status and location of hydraulic components, such as pumps, motors, cylinders and valves, as well as the temperature and pressure of the oil in the tank, become an important part of mobile mechanical control. The new generation of sensing technology applied to mobile machinery has emerged as the times require, providing various information for the control system of the hydraulic components.

Honeywell is a global supplier of sensors and related components. Aiming at the mobile machinery market, the company has developed a standard platform to customize various hydraulic sensors.

The wheel loader is a good example. In order to make the machine work stably and efficiently, more and more kinds of sensors are adopted on wheel loaders, including temperature, speed, angle, position and pressure sensor.

The temperature sensor is used to monitor the temperature of the hydraulic oil in the hydraulic system. During the operation, the hydraulic pump pumps oil out of the tank and pumps it into the hydraulic cylinder with a certain pressure, and the hydraulic cylinder is directly connected with the load. In the working cycle, the reciprocating movement of the cylinder will produce heat in the hydraulic oil, which may cause the temperature to exceed the maximum working range of the system. When the hydraulic oil reaches a predetermined temperature, the temperature sensor sends out a control signal to turn on the cooling fan of the hydraulic oil cooler, so as to keep the temperature below the set range, thereby preventing overheating or system failure.

For many applications, Honeywell provides customized sensor platform, aiming to provide temperature sensors for building machinery manufacturers and corresponding motors, pumps and hydraulic cylinders suppliers. The modular design of the sensor platform can provide different probe length, thread specification, material, connector, shell, and output type. The Honey Well Company said the design can be used in component ways to ensure that sensors can be commercially produced in mass production.

Honey Well Company said that the sensor platform can also be applied to situations with limited space, size and weight, ensuring that the equipment developed is compact and durable, and can reduce the size of the whole system without sacrificing performance. In addition, the sensor can be designated to use a variety of shell materials to ensure the compatibility of various types of hydraulic oil.

In addition to the temperature sensor, the sensor is also used to measure the level of the liquid level in the hydraulic tank. Mechanical floating ball switches are usually used before liquid level monitoring. Honeywell said that the current non-contact infrared (IR) sensors are becoming more and more widely used in liquid level monitoring. The infrared sensor has more advantages, mainly with high precision and longer service life.

Speed sensor is the most widely used sensing element in mobile machinery. The speed sensor is often used to monitor the working speed of the hydraulic pump. When the hydraulic hub motor is driven in the machine, the speed sensor is usually used to detect the wheel speed and the direction of the wheel.

There is limited space to install sensors on the hydraulic pump. Honeywell can provide a customized integrated speed and temperature sensor for monitoring the speed of the pump and the temperature of the hydraulic oil. The device can also provide fault diagnosis information such as short circuit, so as to improve the safety and efficiency of the equipment.

In the application of the hydraulic hub motor, the sensor is used to monitor the speed and direction of the wheel. The solution proposed by Honey Well Company is to integrate two functions of detection speed and direction by using a Holzer effect magnetic induction sensor to prevent the jitter or false pulse caused by the hub motor's idling.

For example, if the wheel loader is positioned at a certain angle and then moves forward or backward, the electronic control system must be able to detect the angle of the machine and keep it stable. In this case, the sensor must be able to determine whether the wheel is moving or moving, and then transmit data to the electronic control module, providing feedback for the hydraulic system to compensate for the jitter.