Which of the following vacuum pump types has an automotive style piston with a connecting rod and a crankshaft?

The correct choice is based on the design and operation of the vacuum pump in question. A reciprocating vacuum pump utilizes a piston mechanism, which operates similarly to the internal combustion engines found in automobiles. The automotive-style piston is connected to a connecting rod that then connects to a crankshaft. This setup allows for the conversion of rotational motion into linear motion, enabling the piston to create the necessary vacuum by moving back and forth within a cylinder.

As the piston moves down, it creates a low-pressure area that draws air into the chamber, and as it rises, the volume decreases, compressing the air or expelling it out. This cycle mimics the operation of a traditional engine piston but is specifically designed for generating vacuum rather than driving an automotive vehicle.

The other types of vacuum pumps—radial flow, rotary, and screw—utilize different mechanisms for air movement and do not employ the same piston and crankshaft assembly found in reciprocating pumps. Radial flow pumps rely on centrifugal force, rotary pumps use rotating vanes or lobes, and screw pumps operate on the principles of mechanical interlocking screws. Each of these designs is distinct and serves specific applications within various fluid power operations.