German source REXROTH Rexroth gear pump

German source REXROTH Rexroth gear pumpSimple structure, high cost-effectiveness, strong reliability, widely used in various industrial equipment. The working principle of a Rexroth hydraulic gear pump is that hydraulic oil passes through an oil port or a gap, which is a hollow space of millimeters or micrometers, to separate the surfaces of two objects in relative motion. Lubricant is filled to avoid friction, and mechanical operation is carried out by using gears or screws to utilize the space generated by moving blades.

It consists of a pair of interlocking internal gears and a crescent shaped component, pump casing, etc. in between. The function of the crescent shaped component is to separate the suction chamber from the discharge chamber. When the driving gear rotates, a local vacuum is formed at the place where the gear disengages, and the liquid is sucked into the pump to fill the teeth of the suction chamber. Then, it enters the discharge chamber in two paths along the inner and outer sides of the crescent shaped part. At the meshing point of the gear teeth, the liquid present between the teeth is squeezed and sent into the discharge pipe.

Gear pumps have the characteristics of self-priming ability, independent flow rate and discharge pressure, and no suction valve or discharge valve on the pump casing. They have a simple structure, uniform flow rate, and reliable operation. However, they have low efficiency, high noise and vibration, and are prone to wear. They are mainly used to transport various oils that are non corrosive, non solid particles, and have lubricating ability. The temperature generally does not exceed 70 ℃, such as lubricating oil, edible vegetable oil, etc. The general flow range is 0.045-30ms/h, the pressure range is 0.7-20MPa, and the working speed is 1200-4000r/min.

Structural characteristics of ReXROTH gear pump from Germany

(1) Simple structure and affordable price;

(2) Low job requirements and wide application;

(3) The end caps and various inter tooth grooves of the gears form many fixed sealed working chambers, which can only be used as quantitative pumps.

The gear adopts a new technology at the international level of the 1990s - double arc sine curve tooth profile arc. Compared with involute gears, the prominent advantage of Z is that there is no relative sliding of the tooth profile during the gear meshing process, so there is no wear on the tooth surface, balanced operation, no trapped liquid phenomenon, low noise, long service life, and high efficiency. This pump breaks free from the constraints of traditional design, allowing gear pumps to enter a new field in design, production, and use.

The pump is equipped with a differential pressure safety valve as overload protection, and the full reflux pressure of the safety valve is 1.5 times the rated discharge pressure of the pump. It can also be adjusted according to actual needs within the allowable discharge pressure range. However, this safety valve cannot be used as a pressure reducing valve for long-term operation. The pressure reducing valve can be installed separately when needed.

The pump shaft end seal is designed in two forms, one is mechanical seal and the other is packing seal, which can be determined according to specific usage and user requirements.

REXROTH Rexroth gear pumps are divided into external gear pumps and internal gear pumps. The external gear pump has a simple and sturdy structure, reliable performance, and extremely low cost, making it a commonly used gear pump in the market. Internal gear pumps, due to their compact structure, more precise manufacturing technology, and higher performance and efficiency than external gear pumps, are also more expensive. Generally, when our hydraulic system requires larger flow rates, ultra-high pressures, and low noise requirements, internal gear pumps can be used.The physical picture of the REXROTH Rexroth gear pump from Germany is as follows:

To achieve good gear pump efficiency, it is recommended to use it under low working pressure. When using a gear pump, the "noise" factor strictly related to size (flow rate) should be considered.