Couplings

Question 1

What is a link?

Answer 1

Is an elementary part of an industrial robot that compose the mechanism together with the kinematic pairs.

Question 2

Types of link.

Answer 2

• Crank (360°)
• Connecting rod (rotate and traslate)
• Rocker (rotate <360°)
• Frame (fixed)

Question 3

What is a coupling?

Answer 3

Is a kinematic pair between two mechanical elements (links) that are in relative motion.

Question 4

Definition of class of a kinematic pair.

Answer 4

Is the number of DoF that are allowed by the coupling.

Question 5

What are the conjugate surfaces?

Answer 5

They are a type of surfaces that enables the relative motion between two links.

Question 6

All lower pairs (surface contact)

Answer 6

• Revolute pair 1R
• Prismatic pair (slider) 1T
• Helical pair (screw) 1R + 1T
• Cylindrical pair 1R + 1T
• Spherical pair 3R
• Plane pair 1R + 2T

Question 7

All higher pairs (also linear and point contact)

Answer 7

• Slotted spherical pair (universal joint) 2R
• Planar cam pair 1T + 1R
• Sphere slotted cylinder pair 1T + 2R
• Sphere cylinder pair 1T + 3R
• Cylinder plane pair 2T + 2R
• Sphere plane pair 2T + 3R

Question 8

The two type of kinematic pair.

Answer 8

• Form closed: use constraints
• Force closed: use pure forces