A rotary oil pump operates by using rotating components to trap oil, move it through the pump, and discharge it at a higher pressure. A common type is the rotary vane pump, which utilizes a specific mechanism to achieve this.
The Basic Principle
Rotary oil pumps belong to the positive displacement pump family. This means they move a fixed amount of oil with each rotation cycle. Unlike centrifugal pumps that use speed to generate pressure, rotary pumps trap the fluid and physically push it through the system.
Inside a Rotary Vane Oil Pump
Based on the rotary vane principle, these pumps have a rotor that spins within a housing. Vanes are typically fitted into slots in the rotor and are designed to slide in and out.
Here's a breakdown of the process, incorporating insights from the reference:
- Chamber Creation and Intake: As the rotor turns, the vanes are pushed outwards against the inner wall of the pump housing (often due to centrifugal force or springs). The space between two vanes and the housing forms a chamber. On the intake side, this chamber expands as the vanes move apart and the chamber volume increases. This expansion creates a vacuum within the chamber, drawing oil into the pump inlet.
- Rotation and Transport: The trapped oil within the chamber is then rotated by the spinning rotor and vanes towards the pump's outlet side.
- Compression and Discharge: As the chamber continues to rotate towards the outlet, the space between the vanes and the housing decreases. This action compresses the oil within the chamber. The reference states these chambers "compress, rotate, and discharge gases and liquids". The decreasing volume pressurizes the contents, allowing the oil to be discharged through the pump's outlet port against the system pressure.
- Vane Action: Throughout the cycle, the vanes slide in and out and turn against the inner wall of the rotor and housing, maintaining contact and creating sealed chambers as they sweep the volume.
Essentially, the rotary vane pump contains two or more chambers that compress, rotate, and discharge gases and liquids. These chambers create a vacuum that pressurizes the contents, allowing them to travel through the pump's outlet.
Applications of Rotary Oil Pumps
Rotary oil pumps are widely used in various applications where reliable positive displacement is needed, such as:
- Engine Lubrication: Pumping oil to lubricate moving parts in car engines.
- Hydraulic Systems: Providing pressurized fluid for hydraulic power steering, lifts, and machinery.
- Industrial Processes: Moving various oils and viscous fluids.
The design provides a steady flow rate suitable for these critical functions.
