Product Introduction of Oil Seal Seat Assembly
The oil seal housing assembly is an important sealing installation component for the reciprocating motion part of the power end of the plunger pump. It is usually installed at the position where the crosshead rod, plunger rod or corresponding reciprocating rod passes through the power end housing, and is used to install and position the oil seal and maintain the correct sealing fit between the oil seal and the reciprocating rod.
During the operation of the plunger pump, the crankshaft and connecting rod drive the crosshead and crosshead rod to reciprocate, while the power end requires lubricating oil to lubricate the bearings, crosshead and related moving parts. At the position where the reciprocating rod passes through the power end, a reliable oil seal structure must be set up to control the leakage of lubricating oil along the rod.
The oil seal housing assembly is not a single oil seal, but an installation component formed by taking the oil seal housing as the main body and matching one or more oil seals, retaining parts, gaskets and fasteners according to the pump type. The oil seal seat provides an accurate installation cavity, support position and fixing conditions for the sealing parts, enabling the oil seal to work stably around the reciprocating rod.
Main function
1. Installation and positioning of oil seals: The interior of the oil seal seat is equipped with an installation cavity that matches the oil seal, which supports and positions the outer circle and axial position of the oil seal to prevent abnormal movement of the oil seal during reciprocating operation.
2. Control the leakage of lubricating oil at the power end: The lip of the oil seal forms a dynamic seal with the outer circle of the crosshead rod or plunger rod, reducing the leakage of lubricating oil at the power end along the reciprocating rod.
3. Isolating the power end from the external area: In coordination with the oil seal, gasket and installation end face, it forms a seal and isolation for the opening of the power end housing, which helps maintain the internal lubrication environment of the power end.
4. Maintain the working position of the oil seal: The oil seal seat, the reholder and the fastening screw jointly restrict the axial movement of the oil seal assembly, allowing the sealing lip to stably act on the surface of the reciprocating rod.
5. Facilitate oil seal maintenance and replacement: Some plunger pumps adopt detachable oil seal seats. During maintenance, the entire oil seal seat can be removed, the internal oil seal replaced, and then reassembled without disassembling the entire power end.
Installation location and working relationship
The oil seal housing assembly is generally located at the front of the power end of the plunger pump, that is, on the side where the crosshead rod or the corresponding reciprocating rod extends from the power end housing to the hydraulic end. The reciprocating rod passes through the center of the oil seal seat, and the oil seal is installed inside the oil seal seat and forms a dynamic seal around the rod.
In the publicly disclosed structure of the reciprocating plunger pump, the oil seal seat is installed in the cage or the power end installation hole and is fixed by screws. Some structures also set a sealing gasket between the oil seal seat and the body to ensure the sealing of the external static mating surface of the oil seal seat.
The composition of the oil seal seat assembly
The composition of oil seal seat assemblies for different plunger pumps is not exactly the same. Common structures may include the oil seal housing body, one or more oil seals, oil seal housing retainers, installation gaskets, and fastening screws, etc.
For instance, in the publicly disclosed D65 series reciprocating pump oil seal seat assembly, the oil seal seat, oil seal, oil seal seat retaining part, fastening screw and gasket are respectively listed as assembly parts. Therefore, when purchasing the "oil seal housing assembly", it is necessary to confirm whether the complete component is required or only the oil seal housing body is needed.
The difference from oil seals
Oil seals and oil seal housing assemblies belong to different levels of parts.
The oil seal is a dynamic sealing component that directly contacts the crosshead rod or plunger rod, and its lip is responsible for controlling the leakage of lubricating oil. The oil seal housing is responsible for accommodating, supporting and positioning the oil seal, and fixing the entire sealing assembly at the power end installation position.
Therefore, when oil leakage occurs at the power end rod, it is necessary not only to inspect the lip of the oil seal, but also to check the inner hole of the oil seal seat, the installation cavity of the oil seal, the external gasket of the oil seal seat and the installation end face.
Common failures and inspection sites
When overhauling the oil seal housing assembly, special attention should be paid to inspecting the oil seal lip, the oil seal installation cavity, the outer circle of the oil seal housing, the installation end face and the fastening screw holes to observe whether there is any wear, knocking, deformation, corrosion or damage to the sealing surface.
If oil leakage still occurs after replacing the new oil seal, the contact area between the crosshead rod or plunger rod and the oil seal should be checked simultaneously. When there are grooves, scratches, uneven wear or obvious runout on the surface of the rod, it may prevent the new oil seal from forming a stable seal even.
For structures that use multiple oil seals, it is also necessary to confirm the installation direction of each oil seal during installation. Some publicly available maintenance data for plunger pumps clearly stipulate that the oil seal lip should be installed facing the power end. The actual direction should be based on the maintenance manual of the corresponding pump type.
Key points for selection
The oil seal seat assembly is a dedicated component that directly matches the dimensions of the power end and the reciprocating rod. When purchasing, it is recommended to focus on confirming the following information:
1. Brand, series and specific model of plunger pump;
2. Power end model;
3. Diameter of the crosshead rod or plunger rod;
4. Outer diameter and total length of the oil seal seat;
5. Inner diameter, depth and step structure of the oil seal installation cavity;
6. Quantity, inner diameter, outer diameter and thickness of oil seals;
7. Installation direction of oil seal;
8. Positioning and fixing methods of the oil seal seat and the body;
9. Whether it is equipped with retaining parts, gaskets and installation screws;
10. Original part number, physical component or technical drawing.
Installation and Maintenance
Before installing a new oil seal, the inner cavity of the oil seal seat and the surface of the reciprocating rod should be cleaned. Check whether there are burrs, sharp edges or scratches in the area through which the sealing lip passes to avoid cutting the oil seal during assembly.
When the oil seal is pressed into the oil seal seat, it should be kept level and straight. The sealing part should not be tilted or undergo local deformation. The multi-channel oil seal structure should be assembled in the prescribed direction and sequence. It is not advisable to judge the installation direction by oneself based on the appearance.
When the oil seal seat is fitted over the crosshead rod, it is necessary to avoid the rod end threads, steps or sharp edges scratching the oil seal lip. For structures that require the use of installation guide sleeves or protective sleeves in the original maintenance manual, the corresponding assembly tools should be used in accordance with the regulations.
After installation is completed, it is necessary to confirm that the fasteners of the oil seal seat are reliable and check whether the reciprocating rod moves smoothly. During the initial operation of the equipment, it is also necessary to observe whether there is any abnormal oil leakage or temperature rise in the oil seal area.
Procurement Instructions
Juli Petroleum Drilling and Production Equipment Co., Ltd. provides oil seal seat assemblies and sealing accessories for the power end of plunger pumps. The oil seal seat assemblies of different pump types may vary in terms of rod diameter, number of oil seals, installation dimensions of oil seals, holding structure and fastening method. When purchasing, it is recommended to provide the model of the plunger pump, the model of the power end, the size of the crosshead rod, the original part number, physical components or technical drawings to accurately verify the product.