Solution for Oil Leakage in Piping Connections Above Rexroth Hydraulic Pumps

The friends who have used hydraulic pumps are informed that no matter which brands of hydraulic pumps, when they are used on the machine for a long time, we will find different degrees of oil leakage problems, and the factors of oil leakage are complex and multifaceted, so how should the oil leakage of the equipment piping connection above the Rexroth hydraulic pump be solved? 

Today XingYing Hydraulics will talk to you about the solution to the oil leakage of the equipment piping connection above the Rexroth hydraulic pump as follows:

First, the reason for oil leakage is: 

Control Valve and oil block both through oil orifice center distance "X" error caused by too large, 0-shaped sealing ring failed to oil block through oil orifice completely covered tight, Figure 5-4 shows the oil leakage between the two pieces.

A4VG Rexroth Axial Piston Variable Pump

The solution to the oil leakage: the use of process equipment (drilling template) drilling through the oil orifice, can completely solve the shortcomings of the two pieces of through the oil orifice between the error is too large.

① drilling template of various holes (large and small holes) in the coordinate boring machine to complete all the processing, hole spacing error can be controlled in Shi 0.006mm imitation: within the general hole spacing error requirements in Shi 0.1mm. to install the valve's four screw holes to locate the drilling template to install four locating pins, inserted into the valve body in the four mounting holes.

② The four mounting screw holes of the valve body should be scribed and drilled with threaded bottom holes first, and the drilling template should be positioned with these four holes and then drilled with oil-through orifices. This processing procedure ensures that the center distance "X" with the valve body of the oil through the hole alignment is accurate, even if the oil temperature rises to 60 ℃ oil leakage will not occur.

In addition, when installing the screws of the control valve, pay attention to the following:

① The length of the four screws for mounting the control valve should be more than twice the diameter of the screws.

② The depth of the screw holes should be more than 2.5 times.

③ The high strength alloy steel screws should be used for installation. In this way, the contact between the hydraulic valve and the oil circuit block can be tight, and the oil temperature rises to 601: there will be no oil leakage. Rexroth A4VTG Series Piston Pumps II. Oil leakage from metric threaded connections with end seals

① metric threaded connection, the end face of the hydraulic parts should be drilled and scribed planar fish-eye pit, 1mm deep, roughness should be Ra3.2μm, it must be perpendicular to the threads, using a combination of sealing washers and "welded end through the pipe fitting body" connection.

② the use of "ferrule type end straight through the pipe fitting", also by the end face sealing, its end face and threads should also ensure the perpendicularity of the connector body and components connected to the oil will not leak, if the error is too large, used for the Rexroth hydraulic pump oil temperature rises will leak oil.

③ Hydraulic components itself is very important to connect the threads and the verticality of the end face of the problem, is the hydraulic parts manufacturer in the process, by the process or tooling to ensure that. Specific practice is: drilling threaded holes on the drilling machine at the same time the thread tapping, and will be a plane-shaped fish-eye pit drilling countersinking out (component shells do not move), to ensure that the end face (fish-eye pit) and the perpendicularity of the threads. When the system oil temperature rises to 60°C, there is no oil leakage between the end face and the joint body. Figure 5-1 shows the connection form, shell and threads are not perpendicular to a X is too large.

A11VO190LRDH1 Rexroth Axial Piston Variable Pump

Methods of solving piping stress:

① on the system piping, must eliminate piping stress, pipe fitting body first installed on the combination of sealing washers, and then tightened on the hydraulic parts or oil block, this time do not put 0-shaped sealing ring;

② with two cold-drawn (a little longer than the actual size), first of all, "welded pipe fitting receiver" and two steel pipe respectively, blanching the end of the right;

③ to be cooled and tightened respectively with the two ends of the pipe joint body, note that this time to support the steel pipe, so that the nut will "take over" firmly, the two ends of the connection is firm, the long part of the saw off;

④ the length of the two sides has been appropriate, both ends of the nut should be tightened very tightly, at this time the two ends of the face is correct, and to hand away from the steel pipe when the two ends of the face is not open as a standard, the middle should leave 0.5mm of the intersection, at the same time to be on top of the two steel pipe seam circumference welded firmly;

⑤ an oil line pipe in the middle of more than one weld, such as cooling before unloading, so that the assembly of the flow path pipeline program, the stress can be completely eliminated. In accordance with the provisions of the purification process, all pipelines are thoroughly cleaned, and then the second installation, at this time, all kinds of seals will be installed, and tighten the connection parts with force. Using this procedure to install the system configuration piping, the working pressure reaches 31.5Mpa oil temperature rises to 60 ℃, the pipe joint parts will not leak oil.