Belt + chain - Motion Control Tips

Space-age engineering: How the Jetsons undermined the understanding of an entire (gear) industry

November 5, 2017 By Lisa Eitel Leave a Comment

By Brian Dengel | General Manager • KHK USA Inc.

For those of us of a certain age, the thoughts of flying cars and home robots originated with watching popular 1960s cartoon The Jetsons. The Jetsons’ world was that of a simple family living a typical 1960s life, but in a futuristic setting. Mr. George Jetson had a job working at a factory while his wife Jane took care of the children and their home. Jane was typically preoccupied with the latest gadget, which usually left Rosie (their robot housekeeper) doing most of the cooking and cleaning. The Jetsons’ two children, Judy and Elroy, got sent to school each morning in a traveling capsule.

Mr. Jetson’s employer was Mr. Cosmo Spacely, the proud owner of Spacely Sprockets. In most episodes, Mr. Spacely engages his chief rival, Spenser Cogswell, the owner of Cogswell Cogs, in a manner that backfired for both companies — and George Jetson inevitably was the fall guy. Never mentioned in the show was, what a sprocket or what a cog was. What the show did accomplish was to make the viewer understand that these two distinct widgets were interchangeable and thus made Cogswell Cogs and Spacely Sprockets competitors. But Hanna & Barbera did a great disservice in presenting this assumption.

©Hanna-Barbera

As defined in the Merriam Webster dictionary, a cog is a tooth on the rim of a wheel or gear, but it can also be defined as a toothed wheel as well. In contrast, a sprocket is a toothed wheel whose teeth engage the links of a chain. So a sprocket is a cog that engages with a chain. But the inverse isn’t true, as there are several types of toothed wheels that aren’t sprockets. One example is a timing pulley — a toothed wheel that only engages a toothed belt. Another example of a cog is a spur gear. However, a gear only meshes with another gear. Thus, a gear is a cog … but not all cogs are gears.

With the understanding that all sprockets are cogs, but all cogs are not sprockets, it’s clear George worked for a company that specialized in one product type … and Mr. Cogswell’s company produced many types of similar products. As we await the time when flying cars or capsules are common, engineers must know the proper application for components they chose when creating a design and what the limitations of those products are. Even the simplest of machine components can have vastly different performance specifications within different applications, and interchangeability isn’t always possible.

Belt drive axes can reduce automation costs

October 26, 2017 By Paul Heney Leave a Comment

Cost-effective alternative for mechanical engineering: The self-lubricating and maintenance-free toothed belt axis, drylin ZLW eco from igus, executes simple positioning and adjustment tasks.

Mechanical engineers often need a basic, space-saving linear guide when designing technology that performs simple tasks, such as vending machines. Since such technology does not handle high loads, high speeds or high positioning accuracy, intricate linear guides are not necessary. However, most solutions on the market are very advanced, leaving manufacturers forced to either pay for features they do not need or develop their own linear guide.

Solution from igus: Toothed belt drive axis starting at $150
igus is now offering the drylin ZLW eco, a ready-to-install entry-level series that is making simple positioning and adjustment tasks extremely efficient and, above all, cost-effective. “A toothed belt axis of this entry-level series with a stroke length of 100 millimeters starts as low as 150 dollars,” said Stefan Niermann, head of igus’ drylin linear and drive technology division. “In comparison, a toothed belt axis from the standard series, which has high-performance features and is therefore unnecessary to use for simple operations, costs almost three times more.” The carriage and shaft end supports are produced by injection molding, which is more cost-effective than mechanical filling used for metal component production. “This also reduces the number of components and thus the installation efforts for every eco linear axis, which in the end is reflected in the low prices of this entry-level series,” explained Niermann. A further cost-saving element of the drylin ZLW eco is the plain bearings used in the sliding carriage, which are made of iglide high-performance plastics. “iglide bearings are forty percent more cost-effective than conventional rolling bearings and 100 percent maintenance-free in operation,” Niermann said. Without compromising the smooth-running operation and durability of the standard series, users can simply install the eco axes and save time and money with the maintenance-free, dry-running triboplastic bearings.

Entry-level series in two sizes
The entry-level drylin ZLW eco has two installation sizes: 0630 and 1040. The base is an anodized drylin W profile made of clear anodized aluminum. At the ends of the profile are plastic shaft end supports for drive technology. A neoprene toothed belt is tensioned between the shaft end supports, which pushes and pulls a solid plastic carriage with a positioning accuracy of 0.3 millimeters. The stroke lengths can be individually adjusted by the user. Due to its lightweight construction, the toothed belt axes weigh only 0.3 kg and 0.7 kg, and can move loads up to 3 kg or 10 kg respectively. Matching motor kits also are available.

igus Inc.
www.igus.com

Where do chain drives still make sense?

October 13, 2017 By Miles Budimir Leave a Comment

Chain drives are a tried and true method of linear actuation and are used in much industrial machinery. A typical chain drive consists of two key components; a chain and a sprocket.

The chain itself is composed of several components including a pin, bushing, roller, pin link plate, and a roller link plate. The chain wraps around two sprockets; a driver sprocket and a driven sprocket. The driver sprocket is connected to the output of the motor or gear reducer and moves the chain,

This Low Noise roller chain from Tsubaki uses spring rollers that deform and absorb the force of impact with the sprocket, reducing noise and making them suitable for environments where low equipment noise is a requirement. (Image via Tsubaki)

while the driven sprocket connects to either the driven load or some other part of the system that is moved.

Perhaps the most significant benefit of roller chain drives is that they are a relatively straightforward and simple method of transmission of mechanical energy. They have been around for a long time and have a proven track record of functioning well in a range of applications and environmental conditions. This has made them mainstays of mechanical power transmission and for this reason chain drives still make sense in a host of applications.

Today’s roller chains feature high wear resistance, fatigue strength and tensile strength. Compared to other forms of drives such as belt drives, for instance, chain drives tend to have better efficiency due largely to less friction losses.

There are plenty of applications where chains are still used, a common one being in conveying applications. These systems can use chain drives for either horizontal, vertical or curved conveyor sections.

Operating environments can vary widely as well. There are uses in clean settings where the chain drives must operate lubrication free. Other applications expose chain drives to varying weather conditions, water, or harsh or corrosive chemicals. Examples include industries like wood or paper processing mills.

A common design requirement is for anti-corrosive chains. These can be either specially coated chains such as with special polymers, or materials such as stainless steel, titanium or nickel-plated chain. Other types include chains made from special lightweight plastic materials.

Differences between conventional belting and plastic modular belting for conveying

June 5, 2017 By Lisa Eitel Leave a Comment

Plastic modular belting has transformed manufacturing. Understanding the differences between it and synthetic fabric belting can help engineers plan and determine the most suitable conveyor for a given application.

By Kate Nadeau | mk North America

Conveyors are a part of everyday life. They are seen at the grocery store, in the gym, at the redemption center, and in the airport. Conveyors are also an integral part of manufacturing — used during all stages of assembly, packaging, and distribution.

The earliest conveyors date to the 18th century. They were constructed of wood with leather belts to transport goods and were driven via hand-cranks and series of pulleys. As new inventions were introduced, they were adapted to conveyors. The dawn of the 20th century brought with it a major development — the steel-belted conveyor. Steel-belted conveyors first grew in use for carrying bulk materials such as gravel and sand; soon they were adapted for use in the mining industry.

American slaughterhouses and Henry Ford paved the road for conveyors in modern manufacturing processes. World War II and its depletion of natural resources such as cotton and rubber forced inventors and industrialists to look for alternatives, and some of these materials (including synthetic rubber and polyurethane) ushered in a new era of conveyor technology.

Conveyors, of which there are many types, are primarily defined by the conveying medium — as belt conveyors, chain conveyors, and roller conveyors, for example. Conveyors referred to as belt conveyors more often than not are synthetic belt conveyors that use the synthetic fabric belting materials pioneered during WWII. This type of conveyor belt is seen most often at grocery-store checkout stations. It’s a continuous loop of fabric that delivers continuous motion through use of friction between the bottom belt surface and a motor-driven conveyor pulley.

In 1970, Intralox founder J. M. Lapeyre pioneered plastic modular belting. These belts are pieces of plastic that join together in an interlaying brick fashion. Conveyors that use such belting are called plastic modular belt conveyors or (by some manufacturers) modular plastic-belt conveyors.

While plastic modular belting has transformed the conveyor industry and various manufacturing processes, understanding the differences between synthetic fabric belts and plastic modular belts can help in planning and determining the suitable type of conveyor for use in specific applications.

Design features and conveyor applications for fabric belts

Synthetic fabric belts are the belts most commonly seen in everyday situations at airports, retail stores, fitness centers, and in and around agricultural (farm) settings. Versatility is one of their main benefits. Synthetic belts also excel in industries and applications such as printing and tapes where plastic modular belts cannot be used.

Conveyors with a modular design give engineers more flexibility.

Synthetic belts are monofilament in design and fabrication. This results in two distinct and important advantages — high tensile strength and an excellent width-to-strength ratio. Synthetic belts are lightweight but very strong and flexible. This flexibility lets synthetic belts run on very small pulleys and even knife edges. With diameters down to 3 mm in some cases, knife edges are ultra-thin conveyor ends defined by small-diameter rollers or (more commonly) fixed bars tapered to make a rounded point. Such knife edges facilitate the transfer of small parts on and off the conveyor surface.

Some advanced modular plastic-belt variations work well with small pulleys, but they still cannot compete with traditional belts on knife edges. Traditional belts combine flexibility with availability in low overall thicknesses (often less than 1 mm and almost always less than 2 mm) so are suitable for transferring small and delicate parts between conveyors as well. This is because the thickness of a conveyor’s belting adds to the overall radius of the pulley transferring parts — and the smaller this dimension, the smaller the part that can be transferred.

Many synthetic belts can easily flex over small conveyor pulleys, such as this 20-mm rolling nose bar; this enables the transfer of small delicate parts between conveyors.

While the size of the part to be conveyed is one consideration, another important factor in determining what type of belt to use is the speed of the conveyor. Synthetic fabric belts can handle a greater speed range than plastic modular belts. At high speeds, plastic modular belts can become loud, making them undesirable in locations where excessive noise is an issue for workers or processes.

However, synthetic fabric belts are not without their design and implementation challenges. Where fabric-belt limitations leave applications unserved is where plastic modular belts excel. Conveyors that use fabric belts are friction drive systems, meaning the friction between the underside of the belt and the drive pulley or drum causes the belt to move. If conveyor designers and fabricators fail to account for the material and finish of the pulley in relationship to the load, speed, and other environmental concerns, then the conveyor will not operate as intended.

Furthermore, designers must adhere to design specifications for the drive pulley as outlined by the belt manufacturer. While this seems simple in principle, designers often implement pointed crown pulleys instead of trapezoidal crown pulleys. This results in conveyors that don’t run … or that run but with belting that doesn’t track or stay on the conveyor frame.

In fact, a major downside of fabric belts and their associated conveyors concerns tracking — the ability of a belt to stay centered on the conveyor. Proper conveyor design and installation are necessary to get optimal belt tracking. There are some schools of thought that this hurdle can be overcome by adding a v-guide to the underside of the belt (or less often to the topside outside edges). This v-guide is a small trapezoidal polymer rope that travels in a channel or notch on the conveyor frame. In theory, as long as the v-guide remains in the notch, then the belt remains tracked. This method of belt tracking is considered suboptimal by most belt manufacturers, as the v-guide is simply another possible point of failure and doesn’t guarantee that the belt will remain tracked.

Plastic modular belts: Design features and operation in conveying

Tracking ability is one of the biggest selling features of plastic modular belt. Unlike fabric belts, which rely on friction for the means of driving, plastic modular belts are based on positive drive. This means that a series of sprockets engages with the underside of the belt to propel it forward. This positive engagement — the fitting of sprocket teeth into specific pockets on the underside of the belt — is what ensures belt tracking.

Sprockets for plastic modular belt mount on the drive shaft of the conveyor and engage with the underside of the belt to form a positive drive system.

As with synthetic belts, it is important for the conveyor designer to follow belt-manufacturer instructions for drive sprocket design. Using the correct number of sprockets and placement will ensure optimal belt and conveyor performance.

Furthermore, the concept of a positive drive provides for a friendlier and more flexible design. Plastic modular belt conveyors are low-tension systems, especially compared with synthetic belt (which requires proper tension for the friction drive to work). Lower tension allows use of fewer pulleys. Plastic modular belts also impart greater design freedom to let engineers dimension conveyors with more latitude. To illustrate, synthetic belt conveyors typically require a length-to-width ratio of 2:1 to track properly. In contrast, plastic modular belts allow conveyor designs that are wider than they are long while still maintaining belt tracking.

Plastic modular belts excel in applications where a conveyor must travel around corners. While corners can be negotiated using synthetic belts, these conveyors are highly customized and often cost-prohibitive. Plastic modular belt conveyors can travel straight, go around corners, straight again, incline and decline all using one belt and one motor — one conveyor.

Shown here is a curved conveyor from mk North America. Plastic modular belt conveyors can easily be designed with curves provided that the correct type of belt is used.

Plastic modular belts and their conveyors are often considered too expensive compared with other conveyor types because of the way which the belts are fabricated. While the small plastic blocks or modules that are used to construct such belts are relatively inexpensive, it requires manpower to assemble them. It is this human effort needed to construct them that drives up their cost. All belt manufacturers have assemblers who piece together the belt bricks and join the rows using rods. No manufacturer has yet found an effective way to automate the assembly of these belts.

Choosing between various conveyor-belt options

With all of these different features, benefits, drawbacks, and design considerations, it can feel like a daunting task to pick the right belt type and the correct conveyor type for an application. Reviewing design options with a belting representative or sales engineer from a conveyor company is a good starting place. Both will help account for various factors that ultimately determine the best selection — or if a different (non-belted) conveyor style is necessary. Working directly with a conveyor supplier can and should help design engineers consider various belting types and even different belt companies.

Click to enlarge.

When working with either type of company, the engineer must ultimately determine the best fit for the application. Both belting types come in a variety of materials, finishes, and styles. However, plastic modular belts have limitations because they are designed around pitches. This means that once a pitch is selected and the conveyor is designed around it, the conveyor can only use belts of that pitch. To further complicate matters, many belt manufacturers make the same pitch belt but in different series. Because of innate characteristics of a design (such as belt thickness or sprocket design and style) a conveyor may be able to accept only belts in that series. Synthetic belts are not limited in this aspect. There are many more options from which an engineer can choose when making post-install changes. For this reason, the lifecycle of the product being conveyed is another important parameter.

Other product aspects such as temperature and material also can affect the selection. Generally speaking, synthetic fabric belts have a wider range of accepted exposure temperatures. The choice of belt option also can depend on the specific-purpose equipment with which the belt may be used. These specific purposes include conveyors for X-ray machines, static-sensitive areas, cleanrooms, and food manufacturing.

Both belt types are available with top slide flights or cleats. These paddle-like attachments are designed to aid in conveying product up inclines or provide for crucial pocketing or spacing on assembly lines. With synthetic belts the cleats are typically welded ultrasonically to the belt. These cleats are seen as permanent, so if the spacing needs to change, a new belt is needed. Likewise, if one of the cleats breaks it cannot be simply glued on; here too, a new belt would be needed. Plastic modular belt cleats are specialized modules with the belt brick and cleat injection molded into one solid piece. This allows for easier changing of cleat height and spacing. If one gets broken, only the associated module needs replacing. Both styles come in a variety of heights and side profiles (including straight up and scoop style).

Synthetic belt conveyors as on this horizontal incline conveyor can be outfitted with corrugated sidewalls that act as side rails and contain product on the width of the belt. This belt also has cleats for aiding product upward on inclines.

FDA-approved belts in both synthetic and plastic modular types are available for food manufacturing facilities. There has been a huge shift recently in the food industry toward the primary use of plastic modular belts. The driving factor in this shift is the ability to easily sanitize plastic modular belts. Because of the more intricate and interlocking belt design, one might assume just the opposite. However, the ease in taking plastic modular belts apart or off a conveyor makes it easy to clean them and to clean the conveyor.

Plastic modular belts are suitable for conveying food products such as pizza due to their ease of cleaning.

With fabric belts, a belt-lifting device is needed on the conveyor to assist sanitization. This device lifts the belt off the conveyor so that the conveyor under it (as well as the underside of the belt) can be cleaned. But this process is cumbersome and nearly impossible with long or wide conveyors. That’s why plastic modular belting is increasingly common in such applications. In the baking industry as well as meat, poultry, and seafood processing, plastic modular has become the standard. Even so, fabric belts are still widely used in the confectionery industry (because of product-release capabilities) and in pharmaceuticals (due to the size of the various medications and pills processed).

This is a food-grade fabric belt carrying strawberries.

Fabric belts also remain the suitable choice in many consumer-oriented markets such as security systems in courthouses and airports, bottle and can-redemption machines, grocery stores, and treadmills. Because these conveyor types are commonplace in public venues, they are what most people think of when they hear the word conveyor. However, plastic modular belts are making inroads into the carwash industry, which was once dominated by chain conveyors.

High-speed applications as found in mail and logistic industries still heavily rely on synthetic belts because plastic modular belts cannot handle the speeds needed.

Choosing the right belting style for a given application might seem like a matter of personal preference, but the two belt styles that predominate in industry settings today have distinct advantages and disadvantages that may make them right for some applications but not others. Plant and design engineers owe it to themselves to discuss the relative merits and demerits with a knowledgeable conveyor-company representative or belting manufacturer and then choose wisely.

mk North America | www.mknorthamerica.com

Tech trends impact belt & pulley design

April 27, 2017 By Miles Budimir Leave a Comment

Belts and pulleys are a mainstay of power transmission systems. Far from being obsolete, companies are innovating and offering smart solutions to contemporary motion system designs. Belt and pulley systems of all shapes and sizes are used in a range of applications from agricultural equipment to factory floor applications where they are an integral part of power transmission.

The Shaftloc series from SDP/SI is used for connecting a pulley to a shaft. They feature a simple design with few parts, no marring of shafts and easy repositioning or synchronizing of rotating components.

However, when asked about the importance of design simplicity, Cris Ioanitescu, Application Engineering Manager at SDP/SI, had an interesting take. “Contrary to popular belief, I don’t think that design should always be a race to simplicity,” says Ioanitescu. “Simplicity at times can dilute a product rather than distilling it. Especially in the miniature line of pulleys and sprockets, we follow the principal of making the product small but robust as well.”

For example, Ioanitescu points out that narrow pulleys used for tight enclosures use shaft locks with complex shapes that can handle much higher torques than the initial clamp type or set screw type connection. To achieve the best performance they require careful designing of each component, including tight dimensional and geometrical tolerances.

SDP/SI offers fast prototyping for small quantities of custom gears, pulleys and sprockets. A pulley (pictured) can be made from either plastic or metal including stainless steel and aluminum.

Asked about what technology changes are influencing belt and pulley design, Ioanitescu points to the advent of 3D printing. “3D printing eliminates assembling components to produce a pulley,” notes Ioanitescu. “Subassemblies, such as a pulley, can be created as a one-piece construction in either metal or plastic.” Benefits for the end user include a fast turnaround time and no tooling charges. Customers can also submit their own models and have parts made directly from them.

Drives Chain Facility at Timken completes ISO audit and achieves API Q1 recertification

March 13, 2017 By Lisa Eitel Leave a Comment

The Drives chain facility of the Timken Co. has completed their ISO recertification audit and also achieved American Petroleum Institute (API) Q1 recertification.

The Drives facility, located in Fulton, Ill., successfully completed the certification audit to the ISO 9001:2015 Quality Management Systems Standard, ensuring all the Drives’ chain processes and practices meet the exacting standards of these two governing organizations.

This month, the API also re-certified that the quality management system of the Timken Drives facility was in conformance with API Specification Q1 for design and manufacture of chains and auger products.

“At Drives, quality has always been a cornerstone of our values and a strong part of our brand promise to our customers,” said Tom Young, director of the Drives business at Timken.

Drives has been certified to ISO 9001 since 1996 and also registered to API Q1 and licensed to use the API monogram since 2002.

“To meet the API quality system requirements and verifications and use the API monogram label, we must endure API product testing and meet or exceed product performance requirements for the critical applications in the oil and gas industry,” said Scott Meurs, senior quality engineer for Drives chain business at Timken. ”We apply these same thorough verifications and testing to all of our roller chains in order to make sure that we achieve industry expectations.”

“The longevity of Drives quality chain manufacturing combined with the history of Timken quality and brand reputation continues to set us apart,” added Young.

The Timken Co. engineers, manufactures and markets bearings, gear drives, belts, chain, couplings, and related products, and offers a spectrum of powertrain rebuild and repair services. The leading authority on tapered roller bearings, Timken today applies its deep knowledge of metallurgy, tribology and mechanical power transmission across a variety of bearings and related systems to improve reliability and efficiency of machinery and equipment all around the world.

The company’s growing product and services portfolio features many strong industrial brands including Timken, Fafnir, Philadelphia Gear, Carlisle, Drives, Lovejoy and Interlube. Known for its quality products and collaborative technical sales model, Timken posted $2.7 billion in sales in 2016. With more than 14,000 employees operating from 28 countries, Timken makes the world more productive and keeps industry in motion.

Thermoid launches redesigned website offering new product customization and selection tools

February 25, 2017 By Lisa Eitel Leave a Comment

HBD Thermoid, Inc., a leading manufacturer of industrial rubber products, is pleased to announce the launch of its new website, accessible via www.thermoid.com. With a completely new design, this website features improved navigation, access to updated and streamlined product information, and new tools designed to enhance the user experience and facilitate the product selection process.

Of these new tools, a new Product Selector provides users immediate access to Thermoid’s comprehensive product catalog, organized by product category. Through this tool, users are able to browse the different product specifications offered and select a product based on a specific need.

“For over 130 years, we at Thermoid have worked to provide valuable solutions to our customers across numerous industrial rubber applications, and the introduction of this vastly improved website is an extension of that mission,” said Christopher Denick, President, Rubber Products Group at HBD Industries.

“We have an incredibly large product catalog, but we want users to find what they need faster. Through our enhanced site layout, navigation and search capabilities, we are simplifying the way our customers find the products and customize solutions to fit very specific requirements.”

In addition to these features, the new website also offers easy access to Thermoid’s Partner Portal, a secure platform that provides registered customers real time access to inventory, current pricing, delivery tracking tools, order history, invoices, shipping information, and the ability to place orders.

Visit the new Thermoid website and find expanded product information at www.thermoid.com.

HBD Thermoid, Inc. is a leading manufacturer of industrial rubber products, including air, automotive, aviation, bulk transfer, chemical, hand-built, marine, water, welding and multipurpose industrial hose, industrial ducting, power transmission belts, conveyor belting, coated rubber fabrics, industrial rubber bands, rubber budding strips and rubber roll coverings. The company has represented excellence since 1883, and continues to deliver customer-focused solutions into all markets and applications.Thermoid® utilizes its engineering expertise to provide custom solutions for private labels, new product development and hose assemblies for even the most challenging environments across air, land, sub-sea and space.

Continental introduces new select ContiCleat conveyor belts for steep inclines

January 10, 2017 By Lisa Eitel Leave a Comment

Continental has introduced Select ContiCleat, a versatile conveyor belt for steep inclines and the most grueling conveyor applications.

“This is a very versatile belt, and can convey products whether you are dealing with steep inclines or simply need extra support to move material,” said Chris Marchant, product manager for conveyor belting. “We offer a wide range of U and V-shaped cleated belts.”

In 17 different profile options (14 USA-made), Continental Select cleated belts are ideal for conveying materials such as stone, sand, gravel, various would products and a multitude of recycling products by taking advantage of the many custom profiles and cleat designs that are available.

“In a one-inch cleat design with four different configurations, ContiCleat can convey products demanding up to a 45-degree incline,” Marchant said.

Profile options available from the ContiCleat Select portfolio include Wave Grip, Wave Grip Plus, Bucket Grip, Bucket Grip II, Signal, Backbone, Backbone Plus, Flux, Ultra Shift, Ultra Shift II, Master Grip, Crest Grip, Quadgrip, Summit, Pointer, Diamond Grip I and Diamond Grip II. For additional information, visit www.contitech.us.

Latest motion applications: Belts and pulleys in new designs

January 6, 2017 By Lisa Eitel Leave a Comment

Common where efficiency or accuracy are objectives are synchronous or high-torque drive belts. Applications from consumer-grade home printers to heavy industrial conveyors use these synchronous belts, because unlike V belts with trapezoidal cross-sections, they don’t slip.

This belt-drive application on a conveyor is a power-transmission and load-moving surface. It’s an Intralox ThermoDrive that (with durable construction and positive engagement between drive and belt) addresses problems of flat belting, including the need for tensioning adjustments and mistracking.

Motion applications often need customized belts and sprockets in urethane, double-sided, mini-pitch, and made-to-order (MTO) versions. Double-sided belts have covered teeth to transfer up to 100% of maximum-rated load from one or both belt sides. These come in trapezoidal timing configurations and HTD curvilinear tooth profiles. Some run to 14,000 rpm with speed ratios to 10:1, which is enough to replace gearsets in some cases.

Double-sided belts also excel as serpentine drives in riding mowers with counter-rotating blades, printing presses, and textile machines. Urethane belts maximize motion transfer, especially when incorporating polyester or aramid tensile members. Their tooth profile is a miniature version of belt with standard 40° angle teeth. Speed ratios reach 8:1 and torque output is to a couple lb-in. These belts excel on positioning axes, thanks to their low torque and minimal backlash — especially in printers and copiers that need clean operation.

Long belting (usually with L or H trapezoidal tooth or HTD profiles) can exceed 500 feet in some cases. They work for power transmission and axis synchronization — doing double duty as conveyors in many cases. Such belts complete with rack-and-pinion sets in machine tools and X-ray equipment as a viable drive for linear strokes. One caveat: These belts spliced transmit a quarter less horsepower than a comparable endless belt.

Shown here is a bucket elevator from Feeco International that uses an electric motor through a belt drive for operation.

MTO belts are mostly trapezoidal and HTD. Those for applications involving the assembly or transport of electronics or explosive substances include a body and tooth-facing fabric made of conductive material such as carbon to prevent static discharge. In contrast, belts for power tools and appliances are often made of non-conductive materials that insulate internal components. Belts that run in harsh environments incorporate oil-resistant and temperature-resistant compounds. Elsewhere, tensile members of aramid withstand shock loads, and steel members help belts maintain positioning accuracy. Engineers can even customize the twist of members to alternate or go one way to satisfy tracking requirements. Another option is thick or backed belts to convey or grip objects in tandem with mating belt drives. Backings can also extend belt life and address vibration.

LoPro is a guide-wheel-based linear actuator from Bishop-Wisecarver Corp. featuring 90o steel guide tracks. The steel tracks can be up to 20 feet long and can be readily butt joined for longer lengths. A pair of opposing tracks are mounted to aluminum track plates in sections of about 10 feet long. Polyurethane belting provides long mechanical actuation with good accuracy and high speed while generating little noise.

For industrial applications, most belt sprockets are made of either cast or ductile iron. That said, steel excels in designs that run at speeds exceeding those safe for iron pulleys — to 20,000 fpm. Likewise, aluminum pulleys run at high speed and have low inertia to boot. Another lightweight option is non-metallic pulleys — common in lawn equipment and power tools that transmit little torque and have relatively short design life. Other synchronous-sprocket options include specialty tooth profiles for better positioning accuracy or custom hub mounts and flanges.

Application example: Tight pulley connection helps robotics profile brain function

Now, BKIN Technologies sells machines that let neuroscientists and clinician scientists make scientific investigations into neurological conditions. The company’s KINARM is a robotic exoskeleton that moves with a patient’s arm to detect anomalies. When interacting with the robotic system, a patient either sits in a chair with robot arms affixed (in the case of a KINARM Exoskeleton Lab) or grasps two robotic manipulandums (in the case of a KINARM End-Point Lab). Then the setups run augmented reality software that creates virtual environments in which patients either direct hands to targets or interact with objects.

The robotic exoskeleton has a slotless motor that powers and drives the robot through a belt-and-pulley mechanism. The connection between motor and master pulley is critical, requiring zero backlash and no slippage. Early KINARM Labs used a pulley that attached to the motor shaft using set screws, but constant changing of motor direction during operation subjected this connection to high shock loads … loosening the screws and allowing backlash, shaft damage, and system failure. Now BKIN uses a more reliable connection called the Concentric Maxi Torque bushing system from Custom Machine and Tool Co. (CMT). The bushing offers zero backlash and high clamping torques. A low profile allows for direct coupling to the motor shaft — eliminating the need for a custom-length shaft and bellows coupler on the motor. The result of the mechanical shrink fit is ease of positioning and elimination of shaft damage.

In fact, CMT sells the pulley and bushing as an assembly. A mechanical shrink fit takes the form of a setscrew axial to the shaft that forces the tapered bushing into the hub’s matching taper. As the lever forces the two tapers together, the bushing slot compresses to clamp the pulley to the shaft. That same set screw can come off and go in the opposite hole to release the shrink fit and allow for removal or repositioning.

Continental introduces Synchrochain carbon belts at 2016 PTDA summit

October 26, 2016 By Lisa Eitel Leave a Comment

Continental has introduced at the Power Transmission Distributor’s Association (PTDA) Summit, Conti Synchrochain Carbon power transmission belts for a variety of applications and industries.

“Conti Synchrochain Carbon is the strongest synchronous belt that Continental offers,” said Brent Holstine, product specialist, power transmission products. “It uses ultra high strength polyurethane and carbon cord to deliver more power in a smaller package. It’s the carbon that makes the difference. It allows the belt a higher power capacity, longer service life with hardly any initial tension loss.”

The belt can transmit up to five times more power than conventional timing belts with the same overall width – belt width can be reduced by up to 80 percent. In addition, the great stiffness of the cord in Conti Synchrochain Carbon means initial tension loss is cut to almost zero.

“Over the lifetime of the belts this represents a further enhancement in drive efficiency,” said Holstine.

Conti Synchrochain Carbon is a light but durable polyurethane belt. It is high-tensile and, at the same time, longitudinally stable carbon for the tension member. “The intelligent design with high-quality materials ensures clean, smooth and particularly reliable power transmission both at high torques or dynamic loads,” Holstine added.

For additional information on Conti Synchrochain Carbon belts, visit www.contitech.us.

Continental develops intelligent technologies for transporting people and their goods. As a reliable partner, the international automotive supplier, tire manufacturer, and industrial partner provides sustainable, safe, comfortable, individual, and affordable solutions. In 2015, the corporation generated sales of €39.2 billion with its five divisions, Chassis & Safety, Interior, Powertrain, Tires, and ContiTech. Continental currently employs approximately 215,000 people in 55 countries.

As a division in the Continental group, ContiTech is one of the world’s leading industrial specialists. Its customers can be found in key industries such as machine and plant engineering, mining, the agricultural industry, and the automotive industry. With around 43,000 employees in 44 countries, the company uses its development and material expertise for products and systems made of rubber, plastic, metal, textile, and electronic components to combine these with individual services. ContiTech always thinks in terms of customer-friendly and environmentally friendly solutions – going well and truly beyond its roots as a producer of rubber products. With sales of €5.4 billion (2015), this international technology partner is active with core branches in Europe, Asia, NAFTA, and South America.