Mechanical FAQ

Answers To Keep You Moving Forward

When it comes to motion control and mechanical power transmission, OTP’s engineers and technicians have the expertise to answer even your toughest questions. Below are some of the most common questions we receive from our customers—and the answers to go with them. Can’t find what you need? Simply contact our experienced staff today.

Q: The belts are slipping on my belt drive. What should I do?

A: Check your belt tension. If there is not enough belt tension, the belts will slip, which can cause heat build up and lead to premature failure. A wide variety of belt tension measuring tools are available to help you ensure proper tension.

Q: The belts on my multi-belt drive “whip” while in operation, sometimes to the point of coming off the sheaves (pulleys). And suggestions?

A: First, check for proper belt tension and pulley alignment. Improper tension or alignment could cause the belts to roll or whip out of their grooves. Next, check machine vibration. Excessive machine vibration also can often cause this problem. Finally, consider switching to a banded belt. Banded belts are multiple belts that have been banded together by the top cover. This arrangement provides uniform belt tension for each groove of the drive system and helps prevent any single belt from rolling out of its pulley groove.

Q: My chain coupling is failing prematurely. What should I look for?

A: Make sure the chain element of the coupling is properly lubricated and the shaft is properly aligned. Compared to elastomeric couplings, chain couplings are more sensitive to misalignment, so shaft misalignment could be the root cause of your chain coupling failure.

Q: Should I put a belt guard on my shaft mount reducer drive system?

A: Yes. Not only are you improving the safety of your workers, in many cases OSHA requires belts guards on systems. Installing a belt guard may help prevent a potential safety violation, which could result in a fine. Better safe than sorry.

Q: Worm gear reducer vs. helical gear reducer? Which is better?

A: This depends on your application. Each type of gear reducer has certain advantages.

A helical gear reducer is typically more energy efficient and has higher ratio and torque capabilities than a worm gear reducer.

A worm gear reducer has a better record of not “back driving,” while a helical gear reducer depends on the application and load to prevent back driving. A worm gear reducer is typically less expensive than a helical gear reducer.

Q: Which side of a drive should I install the idler?

A: Idlers should be installed on the slack side of the drive.

Q: My brand new speed reducer leaks. What should I do?

A: Check where the breather plug is located in the speed reducer.

Depending upon how the speed reducer is mounted, the breather vent might be below the oil level inside the reducer, which would cause an oil leak. You may have to vent differently or physically reorient your speed reducer.

Q: Will my gearbox be shipped with oil?

A: It depends upon the type of lubricant and the manufacturer. Grease lubricated gear boxes are typically shipped filled with the proper grade and quantity of grease. Oil lubricated gear boxes are many times shipped without oil due to spillage concerns during shipment. It is always good practice to check the gearbox prior to start-up and if not filled, refer to the manual for the proper type and quantity of lubricant.

Q: What are the big differences between V-belt drives and HTD belt drives?

A: HTD belts have higher load capabilities, are more efficient and are typically quieter.

Q: Can I use bearing grease to lubricate couplings?

A: No, most bearing grease uses lithium-based thickeners and additives which are known to separate from the oil with the centrifugal forces created by rotating equipment. When they separate, these additives may migrate to the critical working components of the coupling, forcing the oil away from the area and leading to premature failure.

Coupling manufacturers recommend using a grease with polyethylene thickeners—with a density closer to that of oil—which is much less susceptible to separation.