The types of air pumps used in suction devices can vary depending on the specific design and requirements of the device. Here are some common types of air pumps found in suction devices:

1. **Piston air pumps**: These pumps use a reciprocating piston to compress and expel air. They are known for their high pressure output and are commonly used in medical suction devices.

2. **Diaphragm air pumps**: These pumps use a flexible diaphragm to create a pumping action. They are often quieter and more compact than piston pumps, making them suitable for portable suction devices.

3. **Rotary vane air pumps**: These pumps use a rotor with vanes to create a vacuum. They are capable of generating a continuous flow of air and are commonly used in industrial and commercial applications.

4. **Centrifugal air pumps**: These pumps use an impeller to accelerate the air and create a pressure difference. They are often used in larger suction devices or systems where a high volume of air is required.

5. **Linear air pumps**: These pumps use a linear motor or solenoid to create a pumping action. They are typically smaller and more energy-efficient than other types of pumps.

 

The choice of air pump type depends on factors such as the required suction pressure, flow rate, noise level, and portability of the suction device. Different manufacturers may use different types of air pumps in their suction devices, so it's best to refer to the specific product documentation or consult the manufacturer for detailed information about the type of air pump used. Additionally, when using a suction device, it's important to follow the manufacturer's instructions for proper operation and maintenance to ensure its effectiveness and safety.