In a four-bar linkage with a 50 mm crank and 70 mm follower, what is the theoretical maximum coupler length for continuous follower oscillation________________________?
Show answer Hide answer
Answer: B. slightly less than 95 mm
Explanation
Grashof law and triangle inequalities dictate the allowable length limits for continuous follower oscillation in linkages. For the given 50 mm crank and 70 mm follower, the maximum coupler length must be slightly less than 95 mm. Exceeding this calculated threshold prevents the linkage from completing a full continuous rotation cycle. Grashof condition states that the sum of the shortest and longest links must be less than or equal to the sum of the other two. Triangle inequality rules ensure that physical link lengths can successfully form a closed-loop quadrilateral mechanism. Coupler lengths act as the connecting bridge between the input driving crank and the output follower arm.
A coupler length of 95 mm exactly reaches the geometric limit where continuous motion becomes impossible. Lengths significantly longer or shorter than this calculated limit violate linkage closure and Grashof criteria. Values like 45 mm represent minimum difference limits rather than the maximum allowable coupler length.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. Why are flexible couplings incorporated into power transmission shafts _____________________?
Show answer Hide answer
Answer: D. it prevents shock transmission and eliminates stress reversals
Flexible couplings absorb angular and axial misalignment between coupled rotating shafts. This compliance prevents shock load transmission and eliminates damaging stress reversals in shafts. Protecting drive components f...
Q2. If opposite links in a four-bar mechanism are equal in length, what geometric configuration do they always form_________________?
Show answer Hide answer
Answer: C. parallelogram
When opposite links in a four-bar mechanism are equal, they always form a parallelogram. Equal opposite side lengths guarantee that opposite links remain parallel throughout complete rotation cycles. This specific geomet...
Q3. How does an increase in the radius of gyration of a compound pendulum affect its oscillation frequency_______________?
Show answer Hide answer
Answer: A. less
A larger radius of gyration increases the mass moment of inertia of the compound pendulum. Higher inertia resists changes in rotational motion, slowing down the pendulum swing rate. Consequently, the oscillation frequenc...
Q4. If D1 and D2 represent driver and driven pulley diameters, how is belt speed related to them__________________?
Show answer Hide answer
Answer: D. D1
Belt linear speed depends on driver diameter and rotational speed in comparative relations. Standard belt speed formulas scale directly with the driver pulley diameter D1. Relating speed proportionally to D1 allows engin...
Q5. In an idealized mechanical machine, how does useful output compare to input energy_______________?
Show answer Hide answer
Answer: C. equal
In an ideal mechanical machine, efficiency is one hundred percent meaning no energy losses occur. Conservation of energy dictates that the useful output energy exactly equals the input energy. Theoretical machines omit f...
Q6. For an SHM cam, what is the follower's acceleration at the stroke ends versus the midstroke position__________________?
Show answer Hide answer
Answer: A. maximum and zero
At stroke ends, the follower stops momentarily and reverses direction, experiencing peak acceleration. At the midstroke position, velocity reaches its maximum value while acceleration crosses zero. Simple harmonic motion...