Today we wanted to look at the Gartech Glue System mechanical drive components located on and inside the mechanical glue unit. Its independent drive consists of a motor, timing pulleys, and a dual-positive timing belt. The working, movable parts of this system are shielded by a 2-piece or 3-piece cover set, mounted to the body of the glue unit with button-head cap screws.
We’ve offered some cosmetic variations to the cover over the years: some are brushed aluminum, some are clear plastic, some are treated to appear black or royal blue. A few are heavy-duty enough that the drive motor fastens directly to it. In the end, they all do the same thing: protect operators. Over the years, we’ve had a handful of customers surprised to learn of this internal system–even after years of operation–and we wanted to remove the guesswork, while explaining more about the purpose of each part.
We understand the difficulties of keeping up with all the equipment in a plant. This is one reason why we encourage our customers to schedule routine service calls. Whether it’s a matter of time, personnel, or simply not wanting to deal with it, you can rely on us to inspect your Gartech Glue System. We won’t replace a part without your permission, and will always offer training to personnel.
In the meanwhile, let’s look at how the system functions, starting with the working pulleys.
The Working Pulleys – Reducer & Glue Shaft
Don’t be overwhelmed. There’s no flashing red alarm waiting to sound if you remove a worn part or route the timing belt in the wrong direction. That said, do use caution. Always respect your facility’s written safety guidelines, and never work on these components while the machine is under power. We use this internal drive to ensure the wheels turn in a reliable and accurate fashion, meaning these moving parts produce pinch-points. Always keep the covers in place while running the Gartech Glue System.
Below, we’ve separated the drive into two layouts to better explain and illustrate how the assembly functions. What changes most on this system is the reducer and reducer pulley. Our systems using a 90-degree reducer (see Item No. 16) are the most common, so we’ve focused on that one here. Depending on your motor, AC or DC, the reducer pulley part number (see Item No. 11) will be different, and may not be interchangeable with other Gartech Glue Systems in your facility. Since the AC-based system is our standard, we’re using it as our example.
Here’s where we remind and encourage you to consider an upgrade of your Gartech Glue System.
From the reducer and its pulley, the Dual-Positive Timing Belt (see Item No. 12) interacts with the Glue Shaft (Drive) Pulley (see Item No. 07). The Gartech Glue System uses (2) of these interchangeable pulleys. They locate on the Glue Shaft (discussed in this entry) using a Glue Shaft Key (see Item No. 6). Over time, this key wears down and should be replaced. It’s a low-cost item, and we encourage users to maintain it since its failure leads to the failure of costlier parts and overall performance. Unlike the Reducer Pulley, which uses setscrews, we secure the Glue Shaft Pulley using a No. 6 Lock Washer and Lock Nut (see Items No. 8 & 9) that thread onto the Glue Shaft.
Items No. 02 & 03 above are there to help reduce the amount of paper dust, glue, and water entering the housing. Their purpose is similar to the exterior seals that sit behind the glue shafts.
The Drive Motor
From the above layout, Items No. 13-21 combine together to create the Drive Motor Assembly. Each item is replaceable on an individual level, and should be inspected for wear and proper fit. Item No. 20, the Nylon Drive Gear Coupling, and the manufacturer’s keys sold with each reducer and drive motor (Items No. 16 & 21) should be kept in good condition. We recommend keeping spares of these components, in the event of failure. Because we do not manufacture these items, we do not offer rebuild services for them. We can send “suspicious” failed components back to the manufacturer, however.
Customers sometimes ask if the direction of the motor matters. We’ve asked this question ourselves, and have received a variety of answers, at times from the same people. If your flexo allows for the motor to mount above the gearbox, even at an angle that doesn’t create obstruction, then we recommend that direction. If your flexo doesn’t allow for this, we ask that the gearbox on the reducer be kept in good condition. If it leaks, it runs into the motor. This has caused failure in the brushes of DC motors and their cooling fans.
A Tip About the Dual-Positive Timing Belt
It’s important that a rolling motion be present against the lower glue shaft pulley, since the wheel is designed to raise and lower. Because the corrugated blank is feeding through the mechanical glue unit, its two glue wheels rotate in opposite directions (upper – counterclockwise, lower – clockwise). This is determined by the timing belt, and the path its set in during assembly. If you have the belt correct, but notice the wheels are turning in the opposite direction, check the wiring of the motor.
The idler pulleys work like bumpers on a pinball machine, letting the working pulleys achieve a better fit or more grip with the timing belt. We’ll talk about those pulleys in the next section.
The Minor Pulleys – Idlers & Tensioners
Though small in size, the idler pulley (see Item No. 08 below) proves vital when it comes to achieving the proper performance of the dual-positive timing belt (Item No. 12 above). There are two types of idler pulley mounts found within the Gartech Glue System. The first mounts independently on a shoulder bolt (see Item No. 10 below). A shoulder bolt differs from a common bolt, in that its body looks like a chrome pin with a reduced, threaded end. The second type of mount is our drive belt tensioner (see Item No. 5 below). Its pin mimics the shoulder bolt, while a snap ring keeps the pulley assembly in position, while its body offers adjustment from a fixed center-point.
The idler pulley as an assembly is interchangeable. It can be used on a shoulder bolt or a drive belt tensioner, and can be swapped from a twenty-year-old glue unit into a system that’s one-week old. The only difference is the number of idlers required, and the number of drive belt tensioners used.
Worth noting: When you order a replacement idler pulley, we ship the complete assembly: pulley, bearings, and internal spacer (Items No. 07-09).
It’s worth noting here that the idler pulleys, tensioner brackets, and glue shaft pulleys fit every model of Gartech Glue System, gluing patterns up to 4″. At 4″ or wider, we offer larger glue shaft pulleys. The timing belt may differ, depending on the overall size of your glue unit housing. In 99.9% of our units, the belt length is either 57″ (as shown in this entry) or 75″ (reorder no. TP750H100).
One last note
It never hurts to ensure that the drive belt tensioner is secure. It’s designed to accommodate the rigidity of the timing belt. With age and wear, the belt stretches. We don’t want to adjust it so tight that the belt snaps when the wheels open, but it should have a sturdy feel to it when properly fitted.
If you’re seeing shredding on the edges of the belt, or grit in the bottom of the glue unit housing, please replace the belt. At the same time, however, it’s important to check for misalignment and wear in the pulleys, and to check the drive belt tensioner, as this causes the frayed edges.
Still have questions?
Please contact us. We know that the personnel responsible for bringing our system into your facility might have moved on, crews might have rotated elsewhere, and appreciate that equipment moves from location to location. In the end, we’re here to help make your job easier, and we thank you for letting us assist you.