Intech Power-Core Thermoplastics Engineering Blog

Intech Gears Could Eliminate Noise From Your Segway Gearbox

Posted by Alexander Bartosch on Jan 30, 2014 8:56:00 AM

Does your segway make too much noise? Have you ever wondered where it is coming from? Segway drive gears in the segway gear box are all metal (figure 1)

Segway Helical gear Gearbox

The metal on metal movement, in this beautifully constructed helical drive gearbox, creates noise. This noise can become worse with time as the gears wear.  See the video below for an example of the noise we are talking about.

Intech has conceptualized a segway replacement gear box to dampen vibration and reduce the noise of the segway metal on metal wear. Our simple bolt on attachment benefits from our  PA12GC Power-Core Cast Nylon (polyamide) which doesn't absorb moisture and won't crack in subzero conditions. The self-lubricating material allows our gears to run quietly and oil free. Removing another annoyance from the maintenance of your segway and its gearbox.

Using plastics to design high load, high shock, and highly critical applications is our specialty here at intech and being engineers the segway was always a toy we've wanted to tinker with. Making plastic gears for an application of this type was not without challenges. The first of which is the tooth root stress, you see metal gears can be much thinner and carry far more load than any plastic. The second is power transmission, very few - if any plastics can evenly and continuously transmit the power needed to drive a segway in the way its meant to operate. Imagine a right gear box transmitting less efficiently than the left and the circles or compensation a rider would need to make. Luckily, Intech's Power-core PA12GC material and its unique gravity casting process allows it to chemically bond to a metal core allowing it to transmit power evenly and continuously while perserving the benefit of a self lubricating gearing.

The retrofit is not inexpensive but if noise or vibration are causing you problems a new intech gearbox might be the solution to give you the quite and smooth riding personal movement device you've always wanted.

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Photocredit: http://segwaynz.files.wordpress.com/2012/08/gearbox.jpg

Tags: Power-Core gears, cast nylon 12, gear box, gear backlash, gear design, plastic gears, Power Train Design, Plastic gear box, plastic helical gears

Powercore Offers Unique Balance Of Properties

Posted by Alexander Bartosch on Jan 7, 2013 2:40:00 PM

From cheap plastics to the world’s most expensive composites, many types of polymers have been machined, molded or cast into power transmission components.  We’ve focused our development efforts on the use of a proprietary, gravity cast Polymer called Power-Core®.

Thanks to the interplay of its intrinsic physical properties and low-stress casting process, Powercore represents the ideal material choice for power transmission applications. Here’s why:

Remains Stable and Dampens Vibrations.  Power-Core has an unparalleled ability to maintain its physical properties under a broad range of operating conditions. This stability allows us to make highly accurate predictions of the material’s behavior and lifecycle even when the application has variations in moisture, temperature and chemical exposure.

In particular, Power-Core’s stability in persistent high-humidity or total-immersion conditions makes it uniquely well-suited to power transmission applications and sets it apart from other polymers. Unlike Power-Core, most high-performance polymers absorb moisture. As they do, they lose their tensile strength and swell. Power transmission components made from moisture absorbing, or “hygroscopic,” polymers can end up too weak to carry the loads they were designed for and too swollen to work with mating components.

For an idea of how severe the moisture problem can be, consider the difference between Power-Core and the much more common nylon 6. While both are nominally “polyamides,” powercore outperforms other nylon 6 and nylon 12's dramatically as moisture content increases.

Power-Core also exhibits excellent vibration damping characteristics, which contributes to its ability to reduce noise and absorb the shock loads commonly seen by power transmission components.

 

Eliminates Internal Stresses. Power-Core isn’t just a material but also a manufacturing approach that encompasses gravity casting and precision machining. We gravity cast the Power-core over metal hubs or thermally install it over rollers bearings to produce the beginnings of a cam follower, roller or gear. We then precision machine these blanks to form a finished component.

With engineering polymer applications, the interplay between manufacturing methods and the inherent polymer properties matters as much as the choice of the polymer itself.

Power-Core is no exception. In this case, the gravity casting contributes to low internal stress state that gives the polymer an inherently uniform crystalline structure. As a result, Power-Core components have a consistent machining resistance that improves overall machining precision–and allows the material to retain that precision over time. And under external load, the dense crystalline structure helps thwart the stress-induced cracks or swelling that sometimes force molded plastic components to fail prematurely.

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Tags: Power-Core, plastic rollers, Self-lubricating, plastic gears, PA12G, Power-Core material, Nylon 6 vs Nylon12

Anti backlash gear design at the heart of clear tomography imaging

Posted by Alexander Bartosch on Sep 21, 2012 1:58:00 PM

 

Special gear design is at the heart of clear image in multi-axis tomography device.

For the rotational machines used to gather dental X-ray images, motion chatter can produce a fuzzy image, which is not suitable for diagnostic purposes.

Panoramic radiography is a branch of rotational tomography where the creation of images are through the movement of a source and receptor in such a way as to cause the foreground and background structures to blur, leaving a defined focal trough.

As a panoramic radiographic device, the Vantage Panoramic X-ray System, designed and manufactured by Progeny, Lincolnshire, IL, incorporates a DC X-ray source, CCD digital receptor, distributed processing circuitry, and an LCD touchscreen control panel for ease of use. What makes the Vantage system unique is that it is adjustable to the patient’s height via a motorized, 3-speed, telescoping column. The use of multiple lasers is to locate the patient and configure the device to the patient’s morphology. In addition, a workstation coordinates the individual processors.

The system incorporates an overhead, swing arm (lateral Y-axis) that supports a C-arm, which is the rotating member that moves around the patient’s head. The C-arm includes a tube-head, which produces the X-ray beam, and a removable CCD sensor, which is the digital image receptor. If this arm does not operate smoothly, a distorted image results.

The swing arm pivots on bearings located in the mounting casting fastened at the top of the column. Producing its motion is a ball screw drive, one end of which connects to the mounting casting and the other end to the swing arm. A step motor mounts at the column end. Both mechanical connections of the drive assembly are through ball bearing assemblies.

Suspension of the C-arm is on a pair of bearings mounted to the underside of the X-axis translation plate. The C-arm casting incorporates a 10" ID internal tooth ring gear that meshes with a pinion gear on a step motor mounted on the stationary X-axis translation plate. The motor is spring-mounted to maintain positive mesh and to minimize slop. The internal ring gear and pinion are sized and shaped to engage on the inside surface of the C-arm. With activation of the motor, the stationary pinion engages the teeth in the internal ring gear causing rotation of the C-arm.

The engineering team at Progeny worked with Intech to help design the C-arm casting and its interface with the gear drive for the C-arm’s rotation. Design of the company’s Power-Core products is specifically to reduce noise and vibration and run without lubrication, an important factor (a must) for medical equipment designers. Intech components are far lighter in weight than metal parts and offer longer life (less wear) and lower maintenance costs. Intech engineers used a proprietary gear load/life calculation to verify that the gears designed into the dimensionally restricted place would last at least 8,000 hours of operation or about 15 years in field use.

The challenge was to design a backlash free gear to produce a steady rotational movement of the image producing components. There was no room to employ the traditional split gear design. To eliminate backlash, installation of a spring, on slight angle relative to the axis connecting the gear centers attached to the pinion, pulls the pinion toward the 10" ID internal ring gear. The spring arrangement did eliminate the backlash, but caused the gear teeth to bottom out, resulting in chatter. The chatter registered on the X-ray image.

The precision gearing for the Vantage Panoramic X-ray System uses Intech’s Power-Core nylon materials for reduced chatter, resulting in clearer images from the system.

Drawing on its expertise in gear design, Intech engineers designed and precision-machined the pinion and the internal gear to incorporate a special contact surface, which allowed the components to control the center-to-center distance between the inner tooth gear and the motor pinion. Adding the center-to-center distance management element presented a method for precise gear positioning in the mesh, and drastically reduced system vibration generated by the spring force and the resulting bottoming out of the gear teeth in the earlier design.

This configuration provides precise control over gear mesh vibration and backlash, resulting in high image quality in both a clockwise and counterclockwise rotation of the C-arm. It also adds a robust design element, which helps to increase product life so that image quality does not degrade with component wear and tear. With no fuzzy imaging due to chatter, dentists can make better diagnosis and provide better service to their customers.

Shown is the Vantage Panoramic X-ray system with the C-Arm that holds the lasers as well as the removable CCD receptor..

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This article was featured in Today's Medical Developments magazine and can be viewed at http://www.onlinetmd.com/TMD-0912-motion.aspx

Tags: Power-Core gears, vibration, PA12GC, calculating backlash, plastic gears, PA12C, PA12G, anti-backlash backlash gers, Medical

Power-Core gear segment and pinion in high-speed card feeder

Posted by Simon Barrell on May 4, 2010 4:54:00 PM

A high frequency reciprocating gear and pinion being used in a feeder to insert postcards into magazines was suffering frequent breakdowns. Sealing the gearbox to permit lubrication that would prevent wear was not an option, and so Intech was approached to design a non-lubricated solution that could accommodate shock loads 5 to 10 times higher than the running torque of the application.

Intech Power-Core™ gears exhibit a high load sharing factor, an important quality when handling e-stops or shock loads. The load sharing factor, a measure of multiplying the load-bearing capacity of an individual tooth, is optimized for each application. Because the key way is cut into the metal hub and not the plastic, Power-Core eliminates the weak spot inherent in conventional plastic gears.

The metal hub absorbs all key way stresses, transferring maximum torque to the composite gear teeth. The teeth are made of a lightweight plastic composite, weighing just 0.037 pounds per cubic inch.



Intech Power-Core Segment Gear Pinion
A non-lubricated plastic pinion replaced a metal gear, eliminating breakdowns in a high-speed card feeder.

 

 

 

 

 

 

 

 

 

 

Torque of Power-Core gear approximates that of cast iron, but without the brittleness, weight, lubrication, and teeth breakage. As a result, Power-Core gears can reach higher speeds, increasing the throughput of your equipment. We can precisely calculate torque capacity, allowing Power-Core gears to replace metal gears in many applications.

Power-Core gears can operate without lubrication at pitch line speeds up to 15 feet per second. When a special friction-reducing coating is added, you can double gear speed to 30 feet per second.

Tags: Power-Core gears, lubrication-free, shock load, non-lubricated, plastic gears, friction-reducing coating, load-bearing capacity, card feeder, composite gear teeth, gear speed, metal gears, plastic pinion, running torque

Wear life of Power-Core gears can be calculated in advance

Posted by Simon Barrell on Aug 18, 2009 3:59:00 PM

The “Lewis Formula”, proven accurate in calculating the life of metal gears, often provides skewed results in plastic gears.

So our engineers at Intech have developed a proprietary gear durability calculation software program that enables us to precisely predict the operating life of the Power-Core™ gears that they design and build.

Parameters used in the gear calculation are based on data obtained at a leading university during a decade-long study. The calculation includes both tooth root stress and contact safety stress under a wide range of temperatures and rotational speeds.

The result: a calculation that accurately predicts performance, wear reliability, and the expected gear life for the given operating conditions, even before the gear is machined.

The calculation is also used to properly size a gear for any application, making the use of lubrication-free gears possible.

Tags: lubrication-free, gear life, Gear Calculation, plastic gears, Lewis formula, operating life, tooth root stress