What are the types of automatic transmission oil pumps?
3 Answers
Automatic transmission oil pumps include: internal gear pumps, rotor pumps, and vane pumps. The automatic transmission oil pump is installed behind the torque converter and is driven by the shaft sleeve at the rear end of the torque converter housing. Its function is to generate hydraulic oil of the required pressure to supply the torque converter, actuating elements, electronic control system, and valve body, as well as to provide lubrication for the internal components of the transmission that require lubrication. The components of an automatic transmission include: 1. Torque converter; 2. Transmission gear mechanism; 3. Oil supply system; 4. Automatic shift control system; 5. Shift operating mechanism. Maintenance of automatic transmissions: 1. Check whether the automatic transmission fluid level is normal; 2. Regularly replace the transmission fluid.
As a beginner driving an automatic transmission car, I was curious about the types of oil pumps when I first bought my car and only understood after asking a technician. Automatic transmission oil pumps mainly include external gear pumps, which work like two gears meshing together and rotating to push oil flow. This type is simple and durable, and my Toyota Corolla uses it. There are also internal gear pumps, which consist of an internal gear paired with an external ring gear, offering compact space and fuel efficiency, commonly found in Honda models. Vane pumps use vanes sliding in rotor slots to pump oil, providing high efficiency but requiring precision, and are preferred in high-end cars like BMW and Mercedes. Each design affects the transmission's response, and keeping the oil clean is crucial; otherwise, pump wear can cause gear shift jerks or overheating. I learned to perform regular oil changes and maintenance to ensure the system runs smoothly.
With years of experience in auto repair, I'm very familiar with automatic transmission oil pumps. Mainstream types include external gear pumps, which have a straightforward structure where gear rotation directly pumps hydraulic oil; internal gear pumps that operate via eccentric rotation of inner and outer gears; and vane pumps that generate pressure through spring-loaded vane sliding. Each has its characteristics—external gear pumps are reliable and durable but slightly noisy; internal gear pumps provide stable flow, making them suitable for compact cars; vane pumps are quiet but prone to wear. In application, external gear pumps are used in mass-market brands like Ford, internal gear pumps are common in Japanese vehicles, while vane pumps are selected for high-performance models. During maintenance, pay attention to oil quality and pressure to avoid wear-induced shifting issues.
