🔍 Key Concepts

• Crosshead function in a large slow-speed diesel engine • How connecting rod angle (angularity) changes through the power stroke • Difference between gas pressure on the piston and side forces on guides/bearings

💭 Think About

• Visualize the straight line of force from cylinder pressure through the piston and piston rod—does this create side thrust by itself? • Ask yourself when and why the crosshead guides need to resist sideways movement—what is pushing the crosshead sideways? • Consider which component’s angle changes as the crank rotates and how that angle would push sideways on the crosshead

✅ Before You Answer

• Identify which choices involve a change in direction of force (not just magnitude of force) • Distinguish between force acting axially along the piston rod vs. force acting laterally on the crosshead guides • Verify which part actually contacts the crosshead pin and can apply a sideways component during the power stroke