There are a wide variety of couplings in the world, each suited for its own purpose in countless different applications. As these applications change, so must their couplings. Some companies are looking to cut costs, while others are willing to spend more to upgrade to couplings that better fit their needs.
Gear and grid coupling users are increasingly looking at switching to metallic disc couplings or elastomeric jaw in-shear couplings. Both disc and jaw couplings offer advantages in terms of cost and environmental impact. The couplings are low-maintenance and, given that they do not require repeated lubrication, which reduces the possibility of leaks, are environmentally friendly. Disc couplings offer higher torque densities and backlash-free characteristics, while elastomeric jaw couplings provide vibration dampening, which is a common reason users select grid couplings.
being seen as a replacement for gear
and grid couplings.
Couplings in the fluid power and process control sectors, such as those being used on pumps, compressors and valve actuators, are also facing application driven changes. As more servos are being used in these applications, there is a growing demand to adapt metric dimensioned cylindrical shafts to splines, “D” profiles and other forms in both bellows and elastomer couplings.
Other areas, such as printing, paper finishing and other web processing sectors, are looking for the symmetry and stiffness of bellows couplings to help improve the resolution and precision of their finished products, as well as increase machine cycle rates.
Design requirements for more compact and torsionally stiff coupling varieties and configurations, which allow precision couplings to be used in a wider range of applications, are another driving force in the coupling industry. To address this trend, manufacturers are designing bellows couplings for a wider range of applications by configuring them to accommodate larger levels of misalignment and developing ultra-stiff versions to help facilitate the advancement of high-performance drive technology.
Flexible shaft couplings are also adapting to the demand for more compact, cost-effective couplings by using a custom design model. Custom designs allow for the most efficient use of potentially limited space within an application, while still meeting misalignment requirements.
According to Randy Kingsbury, vice president of sales and marketing for Helical Products Company, custom couplings can reduce the total part count of the equipment by incorporating features into the coupling design. There may be a need for a mating flange, gear to drive an accessory or other added feature that will make the coupling a more optimized solution than an “off-the-shelf” part.
efficient while preserving their flexibility.
It’s not just coupling design that is changing, how couplings are chosen and distributed are evolving as well. Over the last decade, users of motion control systems and distributors alike have been taking couplings more seriously. Finding automation solution providers assisting with the sizing, selection and supply of couplings, especially in cases involving a linear motion system, is more common today than it was even a few years ago. Historically, designers were on their own to select couplings for customer-designed drive shafts, rollers and so on. As couplings are increasingly viewed as having an important impact on drive performance, the supply of couplings by automation component distributors has increased.
More users are paying closer attention to the quality of the couplings they acquire as well. In the past, to compete with overseas suppliers, OEMs cut costs wherever they could, including in the manufacture of spindle and feed shaft couplings. Quality suffered, as a result, and customers found themselves spending more money on maintenance and replacement parts in the long run. According to Jon Davidson, sales specialist for Miki Pulley, this was tantamount to spending $100,000 on a brand new sports car, and then outfitting it with discount wheels and budget tires. In other words, an otherwise high-performance machine is hindered by poor components.
Recently, OEMs have started refocusing on quality over cost as a way to compete with overseas suppliers. They are counting on the frustrations and ongoing costs that frequently accompany less expensive, foreign couplings to draw customers back toward higher quality, domestic couplings that may have higher intial costs, but require less maintenance and have fewer long-term costs.