Power transmission coupling and universal joint replacement technology by Twin Spring Coupling

1. What kinds of flexible shaft couplings can you replace.

We can replace most coupling units, our design is a hybrid of both types of traditional coupling units.

Not only can we swap out most of these couplings with a direct fit with the spline and key but also offer improved performance and reliability.

2. Why would Twin Spring’s Coupling be better than a universal joint?

Twin Spring Coupling

Twin Spring Couplings are made as a one piece coupling, made with a set of counter-wound springs, with no bearings that need to be constantly greased or replaced through wear or contamination, thus saving money on annual maintenance. The one piece design means no yokes that can crack so that means more savings. The coupling gets its flexibility from the two counter wound springs, making it more flexible than a universal joint and the two springs thickness allows for high torque, comparable to that of universal joints. The springs help in a number of ways 1. No bearings to get the larger angle of misalignment traditionally seen in a cardan joint or cv joint. 2. The springs can take more punishment than a standard uni joint without the bearing cross or yokes breaking, making them ideal for off-road, farming and mining use. All wrapped up in one coupling using the same splines that universal joints use whether it be shaft, keyway, splined, square/hex or non keyway. 

Universal Joint

A universal joint is flexible due to the bearing cross which contains 4 bearings, while this is what gives its flexibility but it is also where the maintenance is required as well. The bearings all need to be constantly kept supplied grease otherwise the ball-bearings inside the bearings will over heat with use and seize requiring it to be replaced, this seizure can also lead to the universal Yokes (which connect the misaligned shafts together) to crack, again needing to be replaced. The greasing is only one part of the maintenance, these bearings should only be used at a few degrees out of alignment otherwise the ball-bearings start to rub against the side of the bearing race, leading to side wall wear and failure. The third downside to a universal joint is the environment its being used in, as again the bearings being delicate precision pieces of equipment are easily contaminated with water, mud, dust and dirt. The universal joint has to be  covered by a rubber boot otherwise any contaminates lead to rapid failure of the bearings.

Outside of the bearing cross are the Universal joint yokes, these hold the bearing cross in place and while a cast steel product are more delicate around where the bearings are inserted, so this means that these yokes have a tendency to crack due to 1. bearing seizure 2. Joint being used at high angles of misalignment.

3. How is Twin Spring coupling better than the flexible shaft couplings used in Industrial machinery ?

Industrial machinery is machinery that does the same thing over and over again with little to no variation. Industrial machinery is built to have only very small angles of misalignment, as the equipment is in use 24/7/365. These small angles means these couplings usually dont require lubrication making them a longer lasting flexible coupling.

Predominately jaw and beam couplings either single beam or multi beam and some universal joints are used.

The only variation and issue becomes when the couplings have to be used at the extremes of the angle of usage, at most 4 degrees. This means any equipment like conveyor belts or any equipment where additional movement due to variations in weights means these coupling tend to wear out quicker.

The designers of this equipment don’t have much choice in couplings to use on their equipment because the only option in the past has been a universal joint but with the increased lubrication and bearing replacement schedule normally rules them out in use in equipment like this as the cost of its use and maintenance far outweighs its usefulness.

This is where Twin Spring coupling is a great new alternative, the no bearings design means it compares quite favorably with those of beam, bellows and Jaw type couplings typically used in industrial machinery, adding the benefit of increased angle of misalignment which traditional couplings CANNOT do, makes Twin Spring an ideal replacement for these couplings. Being available in all the industry standard splines, keyways and configurations means Twin Spring Coupling is a relatively easy retro fit, and increased torque capacity means Industrial OEM’s can now redesign their equipment to make it more efficient and take advantage of our coupling units. More FAQs follow

4. Can your couplings work with Farm equipment, tractors, attachments, PTO’s?

Yes we do, the standard universal joint whether its on road, off-road, mining, agriculture or marine are all the same design. The more abuse from offroad use has meant manufacturers like Spicer, Weasler, Walterscheid, Bondioli and Neapco all using the same technology have increased the size of the universal joint to make it work in these hostile environments.

Water is one of the biggest problems for bearings, as if water or mud penetrates the bearings they rust and will seize and need to be replaced. Outside of that, a universal joint used say on a farm gets far more work in a short period of time This means constant greasing to ensure the bearings don’t run out of grease, overheat seize and need to be replaced. The average universal joint in a PTO attachment needs to be re-greased every 8 hours, 8 hours for most farmers means less than once a week.

The design again of the universal joint means 3 pieces (bearing cross and 2 yokes) means that anything can go wrong with any of these pieces and the equipment cant be used.

Twin Spring Coupling is ideal for the farmer, 1 piece design, no bearings means no broken yokes, no bearings to replace or constantly grease. Adding to that the twin spring design means our coupling is more flexible than one of these off road uni joints and able to take the abuse of off road vehicles more than a uni joint as well. No bearings means water, mud, dust and dirt wont effect the coupling and with it able to handle 95HP @1000 RPM means it can work with most farm equipment like PTO based attachments, headers, combines etc.

5. Mining is tough on couplings, how do yours handles it?

Mining is where Twin Spring Coupling started, a coal miner in Australia was sick of replacing universal joints because they kept getting infiltrated with water and coal dust and were constantly being replaced. The downtime of equipment  The hostile work environment means universal joints fail more often due to the bearings failing at an increased rate.

Conveyor belts and power transmission require bearings and shafts but with a constant weight variation creates uneven wear on bearings and couplings, the Twin Spring coupling allows for the variation without effecting performance and with no internal bearings dont need replacing, as the downtime on mining equipment makes a coupling a very expensive component if it fails or constantly needs to be serviced.

A no bearings solution like Twin Spring Coupling means less downtime replacing failed bearings as well as cracked input and output hubs, the Twin Spring one piece design means an increased ROI which means more money. FAQ