Sand Casting Technology of Gear Oil Pump Shell

Sand casting is one of the pillar industries of industrial production with a wide range of applications. Sand castings have low price, good economic performance and certain dimensional accuracy. Sand castings account for a large proportion of equipment in industries such as metallurgy, minerals, energy, aerospace and ocean exploration. Gear oil pump is suitable for conveying all kinds of lubricating liquids with temperature not higher than 70 ℃. If high temperature of 200 ℃ is required, it can be equipped with high-temperature resistant materials. Gear oil pump has been widely used in agriculture, automobile, petroleum, aviation and other industries. Gear oil pump is generally not suitable for transporting corrosive, hard particles or fibers, highly volatile or low flash point liquids, such as gasoline, benzene, etc. Based on the analysis of the sand casting characteristics and difficulties of gear oil pump housing castings, a sand casting process design method for gear oil pump housing castings is proposed.

There are many problems in the sand casting process scheme of gear oil pump housing, from the initial parting scheme design to the gating system design. The theoretical knowledge has been fully tested in practice, and many deficiencies have also been found. First of all, the sand casting process of castings is analyzed. First, the structural characteristics of castings are analyzed. According to the structural characteristics, the appropriate parting scheme is selected, and the possible problems and defects are analyzed, and solutions are proposed, so that the subsequent design can be carried out smoothly.

In selecting process parameters, you can select a part of them to complete the design content according to the design needs and part drawings. The most important part of the design is the gating system. There are many data and relevant calculations in the design of the gating system, and its selection should be as reasonable as possible. In the design, two boxes with one box and two pieces are selected for sand casting of small castings, and then the reasonable runner size is found through calculation and the gating system is drawn. Then the sand core, riser and chill are designed. There are two vertical sand cores in the sand casting. The riser design is mainly used to feed the sand casting. Suitable risers are set at the highest part of the sand casting and most of the wall thickness to realize the feeding. Most of the wall thickness is easy to form hot spots, and chill is required. Finally, according to the placement of the sand castings to be formed and the design of the gating system, the sand box with appropriate size is designed.

After completing the design part, it is necessary to simulate the designed gating system with 3D software to predict whether the design is reasonable or has defects. The gear oil pump housing is a complex sand mold casting, which has few defects after simulation. The main problems are that the top part of the sand mold casting will have small shrinkage and most of the wall thickness will have hot spots. The defects of the design are tested by simulation, and then the riser is set at the shrinkage position for feeding. The chill is set for most of the wall thickness, so that the sand casting can be formed without defects.