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We’re looking at the benefits of 3D printing in key sectors, specifically those where additive manufacturing has become a mainstream production method to unlock benefits that go beyond rapid prototyping. In the final part of our series, we consider the benefits of automotive.

Automotive parts production has really embraced the potential of 3D printing, with small to medium volume manufacturers in particular using additive manufacturing for everything from interior body panels to tooling for production. Engine parts, body parts and even chassis have all been the focus of 3D printing too, and we’ve already seen a range of fully 3D-printed concept cars, assembled from a 3D-printed skeleton.

As with aerospace, automotive manufacturers are taking advantage of the ability to produce lightweight components without compromising on strength or quality, particularly in motorsport where the smallest savings can be critical to success.

3D printing is also used for on-demand production of replacement parts, facilitating faster and more cost-effective maintenance in the automotive industry, even reducing the need for extensive warehouses to store large inventories of replacement components.

3D printing will play a key role in the future of the automotive industry

Looking ahead, we can expect to see more car manufacturers switch to 3D printing throughout their manufacturing processes and when you consider the thousands of parts that go into each car, it’s easy to see the opportunities for improvement.

The ability to produce bespoke parts on-demand also unlocks huge potential for customisation options, which will give consumers the chance to change certain features at affordable prices, even in mass production models.

Incorrect bearing specification is one of the main causes of bearing failure. PV calculations are helpful for reducing failure by providing a guide to the ideal sliding bearing for your applications.

Let me help you get this right.

Why are PV calculations so important?

There are two reasons PV calculations are a helpful guide when specifying plain bearings:

1. Optimising performance– minimising wear, friction, and heat generation
2. Longer operational life – delivering longer Mean Time Between Failures, reducing maintenance costs and minimising downtime

PV value: a clear definition

Put simply, the PV value tells us the bearing’s load carrying capacity expressed in units of pressure multiplied by velocity. When calculating a PV value (P) represents the pressure exerted on the bearing and (V) represents the sliding velocity of the mating parts.

Here are the two calculations used to measure PV value:

1. Psi x ft/min
2. N/mm² x m/s

The higher the PV value, the greater the loads and sliding speeds the bearing can handle. Therefore, exceeding the recommended PV value for a particular bearing could lead to premature failure due to excessive wear.

Factors to consider when calculating PV values

Bearings are not a one-size-fits-all solution, and there will always be application-specific factors at play that alter bearing performance. Here are the factors to consider when calculating PV value:

• Operating temperature – high temperatures will alter the bearing material properties and reduce load carrying capacity
• Lubrication – Correct lubrication is critical to reduce friction and heat generation, improving the bearing’s life.
• Bearing material – the PV limits are considerably different depending on the bearing material chosen which will have a direct impact on load-carrying capacity and wear resistance

How to perform PV calculations for plain bearings

Here are three simple steps for calculating PV value:

1. Confirm the applied load (pressure) on the bearing (P)
2. Calculate the sliding velocity of the mating parts (V)
3. Multiply the pressure (P) by the sliding velocity (V) to get the PV value

REMEMBER:Always compare the calculated PV value with the recommended PV limit for the material you are planning to specify. If your PV value exceeds the stated limit for this material, this is not the right bearing for your application.

HELP IS AVAILABLE: Consulting an expert is always the best practice approach to bearing specification. I can help you determine the right bearing for your application based on PV value and other factors. Get in touch today!

3D printing is often associated with the birth of rapid prototyping, giving engineers the tools to perfect designs without the need for specialist tooling or die sets. However, while this remains a key function, 3D printing has evolved into much more than that – it’s now firmly a mainstream production method, delivering benefits for manufacturers and their customers across a wide range of sectors.

In the third part of our series exploring some of the sectors unlocking the greatest potential from 3D printing technologies, we discuss the benefits for aerospace and defence, one of the earliest adopters of additive manufacturing.

Of course, the main advantage for aerospace is the ability to reduce the weight of components, without compromising on strength or durability.

3D printing can boost efficiency and performance for the aerospace sector

3D printing is gaining traction as a manufacturing solution for lightweight yet robust components that help boost fuel efficiency and overall aircraft performance – enabling engineers to produce essential parts (including highly customised components, tailored to specific requirements) with precision, speed, and cost-efficiencies.

It also opens new opportunities for intricate and complex parts, that would be challenging or even impossible to achieve with traditional manufacturing methods.  This can include intricate air ducts, structural metal components, bespoke wall panels and much more.

Metal aside, the aerospace sector uses resin printing materials like PA11 to create gauges, jigs, fixtures and placeholder parts for designers and OEMs within the aerospace supply chain.

If that’s not enough, aerospace component manufacturers and their customers also benefit from shorter lead times, in a sector where safety and efficiency matter more than ever.

Expediting the design-to-production timeline helps to ensure that innovative aerospace solutions can reach the testing and deployment phases more quickly, even in the most intricate, complex builds. But perhaps more importantly, rapid manufacturing also means spare parts can be produced and replaced at speed, on demand. This is equally as important in commercial aerospace, where lost time equates to lost profits.

Biscom, a sugar refinery in the Philippines, had used double row spherical roller bearings on its main line conveyor head shaft drives for five years. Bearing changeouts required 24 hours of plant downtime – incurring considerable delays for this 14,000-tonne capacity facility.

On the hunt for a faster solution that didn’t compromise performance, Biscom turned to Bowman’s regional brand representative, Kenneth Ruiz, for help.

“I knew immediately that our high-capacity Advanced split roller bearings would deliver significant time and cost savings,” said Kenneth. “The main Bagasse conveyors feed into two major boilers, which means removing large motors and gearboxes to access the bearings for inspection, maintenance and replacement – none of this would be necessary if Biscom switched to a high-capacity split roller bearing.”

Split to the shaft for faster installation

Split bearings eliminate the need for removing heavy ancillary equipment when accessing the bearings. They are split to the shaft and assembly radially, making them far easier and faster to install in trapped or space-limited applications.

Engr. Genaro Escarro, Mill Department Head for Biscom comments:

“Shutting down the plant for 24 hours every time a conveyor bearing needs replacing isn’t sustainable – we needed an alternative. Before the innovation of Bowman’s high-capacity split roller bearing, split bearings were not always capable of matching the performance and load carrying capacity of solid spherical bearings, but this is no longer the case.

When Kenneth told us that Bowman’s bearings could match the performance of our existing bearings, but provide a significant reduction in downtime, we were keen to perform an initial trial.”

Results

Kenneth provided onsite support and training during the installation of one trial unit. He removed the solid bearing and installed the new split bearing in just one hour – saving 23 hours of downtime.

After an initial assessment period, the mill team at Biscom were confident the Bowman Advanced split roller bearing was up to the challenge. They have since ordered further units for all their main line conveyor head shaft drives. Kenneth provides ongoing support and expertise for Biscom to ensure all potential downtime reductions are achieved.

Reduce your downtime

If you feel your application could benefit from higher precision, the answer could lie in removing the play (also called the “lash”) from the linear guide.

To do this, you’ll need an adjustable linear ball bushing bearing and an adjustable housing too. The good news is most Thomson linear ball bushing bearings are available in this format.

How do adjustable linear ball bushing bearings work?

Adjustable ball bushing bearings allow you to control the radial play between the shaft and the bearing surface by changing the internal diameter of the bearing. This is easy to do with an Allen (Hex) key.

Reducing the inner diameter of your linear ball bushing bearing will push the linear bearing surfaces towards the shaft. When the bearing is installed in its housing, the outside surface of the bearing plates (or bearing sleeve) sits against the housing bore. If the housing’s inside diameter is adjustable, and adjusted to a small diameter, the linear plates and balls move inward towards the shaft surface to reduce the radial play.

In doing so, the radial play can be reduced to zero clearance or a slight pre-load fit.

A note about pre-load

A slight amount of pre-load, particularly with larger sized bearings is usually ok, but avoid excessive pre-load when adjusting the radial play. Excessive pre-load will cause rough operation and may damage the linear bearing or shaft surface.

Which Thomson linear bearings are available in adjustable formats as standard?

All Thomson Super and Super Smart linear ball bushing bearings are adjustable for radial play when installed in an adjustable housing.

Closed A and MAM Bearings are not available in adjustable formats as standard but can be made to order.

Will better precision benefit your application?

Linear ball bushing bearings for high-load, high-speed applications allow for ultra-smooth travel along the shaft with precision, but only when the correct clearance is applied between the shaft and bearing.

If your bearings are not travelling smoothly, you may need to adjust the clearance to reduce preload. Likewise, if they are not precise in their movement, it is likely that the lash needs adjusting.

Here are four things you need to know when adjusting pillow blocks to remove the lash, avoid drag and optimise the precision of your linear bearings.

Simple steps to adjust the clearance

Pillow blocks have an adjustable inside diameter which allows engineers to reduce the lash, or play, which is of course the clearance between the shaft and the bearing.

Adjustments to the inside diameter could not be easier. Simply find the adjustment screw and use a hex/allen key to loosen it. Make sure the pillow block is mounted to the shaft (you can check this because it will rotate easily on the shaft) and tighten the adjusting screw gradually until the linear bearing just starts to grip the shaft.

Avoid over-tightening

Stop tightening the adjustment screw as soon as you feel a slight increase in force when rotating. This indicates zero play (near frictionless movement) or slight preload (the force acting on the rolling elements) to minimise ball skidding and reduce axial play.

Ideally, you want to be able to move the linear bearing along the shaft without roughness and rotate it without drag, using only light pressure.

The dangers of high preload

If you find you can’t move the bearing using only light pressure, then the preload is too high. It is important to avoid excessive preload because this will cause rough operation, can shorten the lifecycle of the linear bearing and may lead to damage to the bearing or shaft.

Twin pillow blocks

Finally, if using a twin pillow block, one linear bearing should be adjusted while the other one is loose. Note the positioning of the adjustment screws (e.g. 10 o’clock or 2 o’clock) or torque wrench reading of the adjustment screw for the first bearing, then loosen it and adjust the second linear bearing. Once the clearance in the second bearing is correct, then return the first bearing to its correct setting.

A team of researchers and engineers are pioneering the use of wasp-inspired 3D printing drones to build emergency shelters – and we think it’s brilliant!

The drones, or “ariel robots”, deposit a cement-like material in carefully positioned layers to create a structure tall enough to provide emergency shelter for those displaced by war or natural disaster, particularly in hard to reach or cut off regions.

Wasp-inspired swarms

Taking inspiration from wasps and bees that work in swarms to deposit material and build large but intricate structures, the researchers set out to create a swarm of ariel robots that could work together to erect emergency shelters quickly and safely.

This research signifies an industry-first breakthrough as the first time 3D printing had ever been achieved by a free-flying robot – and it wasn’t without its challenges!

Achieving accuracy in flight

To make a 3D printed structure strong and secure, each layer must be printed with faultless precision – something that many considered impossible to achieve with free-flying technology.

To overcome this, researchers introduced scanning drones to their swarm of robot wasps, capable of accurately measuring the print in progress and automatically telling the printing drones where to deposit the next layer.

Counteracting natural flight behaviour

The next challenge was overcoming the natural flight behaviour of the drones so that they could hold their coordinates while they print.

Drones naturally drift in flight, especially outdoors, so the experts created a print head that adjusted its position to compensate for the drone’s drifting movements.

The result was millimetre-perfect printing precision and an intricate filigree pattern of construction.

Improving humanitarian efforts with 3D printing drones and scanners

This research took ground-breaking steps towards arming governments with technologies that could propel forward our global humanitarian efforts. The use of semi-autonomous teams of wasp-like 3D printing drones will hopefully become a reality for disaster zones in the not-so-distant future – giving us the ability to provide well-constructed shelters even in remote or cut-off areas.

Looking for some more information on this topic? check out the links below!

Full research report: https://www.nature.com/articles/s41586-022-04988-4

Video: https://www.youtube.com/watch?v=pDKNEO0gDuE&t=1s

Self-lubricating bearings are a popular choice for applications where regular lubrication intervals are logistically impossible or cost prohibitive. But remember – self-lubricating bearings still require some additional lubrication and getting this wrong is one of the top causes of bearing failure.

Here are three common mistakes made when it comes to specifying and maintaining self-lubricating bearings, and how to avoid them:

Mistake one: Using grease instead of oil

Grease and oil have different lubrication properties that make them ideal for specific applications. Using them incorrectly will lead to bearing failure and unplanned downtime:

 

• Grease should be used in high load applications.
• Oil should be used in high-speed applications.

 

To avoid making this mistake, make sure you understand the temperature, speed, load, and environmental conditions that will impact the bearing during operation to determine whether oil or grease is the right lubricant. If you aren’t sure, speak to your manufacturing partner for consultative advice before placing an order.

Once the bearing is installed, always follow the manufacturer’s guidance on which lubrication is right for you.

Mistake two: Specifying dry lubricants when they are not appropriate

When specifying bearings for high-maintenance applications like heavy loads or extreme temperatures, dry lubricants are not the right option for you because you will need to replace the entire bearing every time.

These bearings offer limited corrosion protection too, which can render them inappropriate for applications where corrosion protection is important.

Dry lubricant bearings are ideally suited for environments where liquids, oils and greases should be avoided such as high- and low-temperature, or high- and low-pressure applications, which may freeze or degrade the lubricating substance.

The only way to avoid this mistake is to understand your application thoroughly before you specify the bearing and seek advice from a manufacturer that offers a vast portfolio of bearing options.

Mistake three: Specifying the wrong additives for certain shaft types

Self-lubricating bearings use additives like graphite plugs or PTFE lining to create a thin film between the shaft and the mating surface of the bearing. When specifying these products it’s critical to understand the characteristics of the shaft material and how it could affect the lubricant film being generated.

When running with a stainless-steel shaft Molybdenum Disulphide (MOS2) should be added to the oil as the stainless properties of the shaft prohibit a full oil film from being generated.

To overcome this problem, understand your shaft material at the point of specification and ask your bearing manufacturer to confirm how this will interact with the self-lubricating additives you want to use.

They will be able to either recommend a different product or suggest the use of something like Molybdenum Disulphide (MOS2) – a dry lubricant used to improve the coefficient of friction for stainless steel shafts.

Avoid mistakes with a consultative partner

With a consultative manufacturing partner in your corner, avoiding mistakes like these is easy. If you need advice from someone who can offer technical knowledge on a broad range of bearings for applications across North America, DM me to arrange a meeting.

According to the Organisation for Economic Cooperation and Development, if our consumption of finite resources (like metals) continues to grow at its current pace, we will need 2.3 planets by 2040. (Source)

If your company is pushing circularity as part of its sustainability agenda, reassessing your split roller bearing criteria could support your objectives.

In doing so, you’ll benefit from additional benefits like these identified by the Institute of Asset Management (IAM):

 

• Reduced reliance on lead times
• More uptime
• CAPEX savings

 

What is circularity?

For decades now we have lived in a take-make-waste culture, where we remove materials from the earth, make what we need, then throw it away and start the process over. This is called a linear economy.

A circular economy is based on the principles of reduce-reuse-recycle, where we actively reduce what we take from the earth by prolonging the operational life of the things we make, reuse products wherever possible, and recycle everything we can.

REDUCE AND REUSE: Use fewer natural resources (metals) by extending the operational life of your split roller bearings

The key to reducing reliance on natural resources is to extend the operational life of your assemblies and systems through predictive maintenance and well-considered specification:

 

• Predictive maintenance can be done manually or with condition monitoring sensors – either way, troubleshooting bearing performance issues when they can be fixed with a repair rather than a replacement allows you to keep most of the assembly (made from natural materials like metals) in operation. This reduces your reliance on finite materials and promotes circularity.
• When the time does come to replace your bearings, shop the market for one that meets the needs of your application – higher load capacity bearings for example can extend operational life in heavy industrial applications. If your company promotes circular economics, it’s critical you reevaluate your bearing specification to make sure you are using the brand that can offer the best performance efficiencies.
• Consider the reuse of existing components– like keeping your old housing in situ to reduce the need for further metal extraction and processing.
• Learn about state-of-the-art split bearing designs that use sustainable materials like 3D printed PA 11 which is made from 100% natural castor beans – these options reduce your reliance on finite materials by reducing your reliance on metal extraction.

RECYCLE: Keep packaging and bearing components out of landfill

The primary material for bearing construction is steel, meaning it can be recycled using scrap metal processes. If your bearing contains other materials like 3D printed resin, you can recycle it using similar local recycling services.

Remember, rings and rolling elements can be recycled separately as high-quality steel and grease can be removed, collected, and recycled separately according to local environmental legislation and regional waste management best practices.

Most bearing packaging can be recycled curbside or reused for storing other components or consumables.

To optimise load capacity of your linear ball bushing bearing, you need to orientate it in relation to the applied load. For maximum capacity the linear bearing must be oriented so that the load is distributed between load bearing tracks.

Using a polar graph to map the orientation of your bearing as a factor of maximum capacity, it’s easy to see the relationship between load vs orientation. This is called a load correction graph, and they are included on all Thomson linear ball bushing bearing data sheets to help you.

Here’s what the graphs tell us:

• Where the load is applied over multiple tracks, the capacity is at its highest
• Where the load is applied directly over the bearing track, it is at its lowest

What do we need to do?
When the load is only over one set of bearing tracks, we must derate the load capacity by clocking the bearing at a different angle inside its housing to distribute the load over multiple bearing paths – this is known as the correction factor of its maximum load.

What about open linear bearings?
In most cases it’s not practical to position open type linear bearings to maximise load capacity because the shaft supports restrict rotation.

That said, to optimise installation and performance, you should still have a clear understanding of how applying a load in different directions affects the load rating and design of your bearings.

Using polar graphs to map the load correction factor vs load orientation, we can see the forces that push the bearing down onto the rail are the same as with a closed bearing. But the capacity for loads pulling opposite the slot  (trying to pull the bearing off the rail) is greatly reduced. Some bearings can even resist a pull off load of around 25% of its maximum load.

If in doubt ask for support
Optimising load capacity is an important factor in getting the most out of your bearings, so be sure to ask your supplier for technical advice.

Bowman stocks a wide range of Thomson linear ball bushing bearings. DM me your questions on optimising load capacity, stock availability or delivery times.