When does a lead screw not back drive?
If the back driving torque is lower than the friction torque of the assembly, the screw is unlikely to back drive. A rule of thumb for lead screws: if the lead is less than one-third the diameter of the screw, the screw is not likely to back drive.
What is back driving torque and why is it important?
Back driving torque is based on the axial load, the screw lead, and the screw’s efficiency.
What do you need to know about back driving?
Be sure to check the manufacturer’s specification for the back driving efficiency. To determine the friction in the screw assembly, add the friction torque of the nut, seals, and end bearings—all of which can usually be found in the screw manufacturer’s catalog specifications.
When does back driving of a screw occur?
Although it can occur regardless of the screw’s orientation, back driving most often occurs in vertical applications when a load is stopped and the holding mechanism (typically a brake or counterweight) fails. What determines whether a screw will back drive?
Is it bad for your back to drive a truck?
However, while back problems can be a real pain for everyday drivers, they are far worse for those that have to drive for a living. As truckers, bus drivers, taxi drivers and delivery drivers have to spend day after day in their vehicles which can be a disaster for their bodies.
Can a car cut you off in traffic?
Keeping these following distances will be very tough at times, especially during heavy traffic. Other vehicles will continuously cut you off and close the gap. In a sense, they are taking advantage of your safe driving habits to try and get slightly further ahead.
Why is tailgating dangerous to both the driver and the car in front?
Tailgating is a ticketable offense, but more importantly, it is dangerous to both the driver who does the tailgating and the car that is being tailgated. The car in front might have to slam on its brakes suddenly, which leaves absolutely no time for the car in back to react to the situation.
When to increase the following distance when driving?
When driving during major inclement weather such as snow, ice, heavy rain, etc., you should increase your safe following distance to a minimum of 5 seconds (during extreme icing events, as much as 10 seconds is recommended).
Is it possible to be a safe driver every time you drive?
Even if you follow all of the other defensive driving techniques, you can’t possibly be a safe driver unless you follow this rule each and every time you drive. If you keep a proper distance from other drivers, you will almost always have an escape route, or will be able to take some sort of evasive action with ease.