This discussion focuses on determining the appropriate bearings for a manual crane capable of lifting a maximum weight of 1000 kg, with a winch pulling 1.24 m of cable per minute. The radial force (P) is calculated to be approximately 14.142 kN, leading to a dynamic load capacity (C) requirement of 299 kN for ball bearings, which exceeds standard catalog offerings. Participants emphasize the importance of accurately modeling forces, including axial and radial loads, and suggest using Free Body Diagrams (FBD) to visualize the forces acting on the crane's components.
PREREQUISITESMechanical engineers, crane operators, and anyone involved in the design and optimization of lifting equipment will benefit from this discussion.
The beams are in static equilibrium since they are in rest state but yeah i guess with the pulleys its not in equilibrium once it starts to lift, when we stop the winch then its in static equilibrium.erobz said:
The forces in the horizontal direction are unbalanced. The beam is not in static equilibrium with the loading your supervisors told you was correct.salamikorv said:
?? Do you wan't to find the actual loading on your mounting bracket?salamikorv said:
Im fine with the forces i have and what the studentassistant has told us, no offense by the way. I dont want to say my mates calculations are wrong since he has got a lot of help from the assistants , if i asked for help of an exercise in my book with these information given would you just ignore the information given and find it yourself? (poorly explained but i think you understand what im saying here). Just assume its 30kN directed as i drew it and 20kN on the side like i drew it, its alright. All i wanna understand is how to determine the bolts.erobz said:
Sizing the bolts requires having as close to an accurate loading as reasonably possible. If you don't care about having accurate loads, then why do you care about sizing the bolts accurately?salamikorv said:
Hhahaha yeah but im pretty confident he hasnt done any mistakes. Look, i can discuss this with him later on but i came here to get help from the problems i got, and that is to determine the bolts. If you re-did the calculations and got something else thats fine, but im only for understanding how to get the bolts. I dont get why you are so passionate about re-doing it, there's plenty of cranes with those exact loads he got, why cant you just help me understand how to get dimension the bolts, not even the loading but the general steps as in the formulas like Baluncore showed, i didnt give him numbers but he showed one way of determing the bolts. Let the force thats in compression be called K, no number, and the other force Q, so i got two loads. What principle/method do i have to use in order to determine the bolts?erobz said: