What are the common types of oil pumps in automatic transmissions?
1 Answers
There are three common types of oil pumps in automatic transmissions: internal gear pumps, rotor pumps, and vane pumps. Among these, the first two types are referred to as fixed-displacement pumps because they discharge the same amount of oil per revolution. Below are the specific details: 1. The drawback of these two types of pumps is that as the pump speed increases, the required driving energy also rises, even when the automatic transmission does not require excessive oil supply. 2. Vane pumps are further divided into fixed-displacement vane pumps and variable-displacement vane pumps. Since the hydraulic system of an automatic transmission is a low-pressure system, with working oil pressure typically not exceeding 2MPa, the most widely used type remains the internal gear pump.