Using a positive displacement gear pump or negative displacement better? Modification coefficient of the gear pump under normal circumstances is a standard, variable pump maintenance, are generally positive displacement, I do design for so many years, the variable displacement pump testing, has not been found negative change bits. A molded number of gear pump, the center distance, number of teeth, the displacement is the same, not the same as the thickness of the most gear, the displacement is not the same, repairs variable pump, resulting in a wide variety of different modulus displacement pump for Tractor models. ⑵ reasonably determine the work load of the traditional engineering mechanical design, both for the engine operating parameters selection or choice, often "by file selection", layers of overweight, the result is a design margin coefficient or power margin coefficients naturally it is enlarged, eventually leading to the product structure, size, progressively larger. Many machinery is in fact the "big horse car" working conditions, serious waste of energy. For energy conservation, variable displacement pump, it should work in a comprehensive analysis of the mechanism, conditions and prerequisites conditions, the use of optimized design, parallel design modern design methods, experimental design or finite element analysis, to replace the traditional experience, analogy, fine? ? reasonably determine the work load. Variable pump accessories | crystal create hydraulic preferred (certified) | Variable pump from Jinan Jing Chong Hydraulic Machinery Limited. Jinan Jing Chong Hydraulic Machinery Co., Ltd. (www.jnjcyy.com) (www.jnjcyy.com) Shandong Jinan, mining machinery leaders, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, the maximum meet customer needs. In the crystal creating hydraulic leadership with the staff warmly welcome all inquiries negotiations to create the crystal creating hydraulic better future.