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When our Rexroth gear pumps experience oil trapping, do we know how to take the right measures to minimize damage? Today, let’s take a look at what to do when oil trapping occurs in a Rexroth gear pump. In Rexroth gear pumps, the pressure of the oil acting on the outer edge of the gears is not uniform; it increases gradually from the low-pressure chamber to the high-pressure chamber as the gears rotate. As a result, the gears and shaft are subjected to radial unbalanced forces. The higher the operating pressure, the greater these radial unbalanced forces become. When these forces are severe enough, they can cause the pump shaft to bend, forcing the tooth tips to press against the low-pressure side of the stator, which leads to uneven wear of the stator. It also accelerates the wear of the bearings, reducing their service life. To reduce the effect of radial unbalance forces, it is common to reduce the size of the oil pressure inlet, so that the pressure in the oil pressure chamber acts only over a range of one tooth to two teeth. At the same time, the radial clearance is increased appropriately to prevent metal contact between the tooth tips and the inner surface of the stator, and needle bearings or sliding bearings are often used for support. Automatic compensation for leakage passages and end face clearance in Rexroth gear pumps. In hydraulic pumps, sealing between moving parts is achieved through tiny gaps; these gaps form friction pairs from a kinematic perspective. At the same time, it is inevitable for oil from the high-pressure chamber to leak into the low-pressure chamber through these gaps ； The pressure oil in the gear pump’s pressure chamber can leak into the suction chamber through three pathways: first, through the gap at the gear meshing line – the Meshing-Teeth Side Clearance; second, through the radial gap between the inner bore of the pump’s stator ring and the tooth tips – the Teeth Tip Clearance; third, through the gap between the end faces of the gears and the side plates – the Side Plates-end Face Clearance. Among these three types of gaps, the end-face gap has the highest leakage rate; the higher the pressure, the more hydraulic fluid leaks through this gap. Therefore, in order to improve the pressure and volumetric efficiency of gear pumps and achieve higher pressures, structural measures are required to automatically compensate for the end-face clearance. The commonly used automatic end-face clearance compensation devices are of two types: floating bush bearing type and elastic side plate type. The principle in all of them is to introduce pressure oil to force the shaft sleeve or side plate to fit tightly against the gear end face; the higher the pressure, the smaller the gap, which allows for automatic compensation for end face wear and reduction of the gap. The floating bushing of the gear pump is mounted in a floating manner; the cavity on the outside of the bushing is connected to the pressure oil chamber of the pump. When the pump is operating, the oil pressure acts on the floating bushing, pushing it against the gear end faces and thus compressing the two sides of the gears, which compensates for the end-face clearance. The above are the measures that should be taken when a leakage problem occurs in a Rexroth gear pump; knowing these will help to avoid panic when such a situation arises. The oil trapping phenomenon in Rexroth gear pumps is actually quite common; we just need to pay more attention to it.