What are the different types of conveyors?
The major types of industrial conveyors are:
- Belt conveyor
- Gravity roller
- Chain conveyor
- Live Roller / CDLR
- Motorized roller conveyor / 24V MDR
- Slat conveyors
- Beam trolley systems
- Power and Free conveyors
- Over Under conveyors
- Lineshaft conveyors
Conveyor types, categories and uses
Industrial conveyors have many different designs and uses. Common types are belt, roller, motorized roller and overhead conveyors. We categorize them as floor style (mounted on the floor) or overhead. Use them to move products, create buffers and deliver products in sequence for a production line.
How are conveyors used?
Manufacturing engineers include conveyors in their production facilities for many reasons:
- Moving products from point A to B (to avoid wasted time walking, or to reduce movements of forklifts, etc)
- To carry products that are too heavy to for team members to lift
- To move a product while operators are working on it (or adding to it). Like a final assembly conveyor at an auto plant
- To avoid injury to workers from repetitive movement. Or to prevent damage to products caused by movement
- To deliver products to a robot for processing. Or to receive products from a robot that are ready for the next step
Storage and buffering uses
- To store products between processes or at the final process step
- To create a buffer or accumulation bank. This is a flexible storage system. Use it where the quantity of products in storage can be lower or higher as required to balance process flow
- To sequence or re-sequence products between processes. Power and free systems can provide this
Conveyors are one of the most flexible types of industrial equipment. When specified and installed they can improve productivity, efficiency and safety. Ultimation has solutions as affordable as a $50 gravity rollers, or as sophisticated as a $5M or more automated system. Conveyors are used to transport bulk material too, like gravel or iron ore.
How do you choose the right type of conveyor?
- We begin with the basic product information. It’s helpful for us to understand the productive role that your system will perform. Is it moving parts, storing them, re-sequencing them or providing a working surface while they move? Based on these factors we can then select from the various types available. Then see which ones can do the job and provide the best benefits.
- Next comes the constraints. Available space in production environments can be at a real premium. And although conveyors can add a lot of productivity, they can also get in the way of other operations. Carefully check the space they occupy. This gives us the input for our next decision point which is whether to use a floor level or overhead style.
Floor or Overhead?
- Conveyors are categorized as floor style or overhead style as this is an important decision point. Overhead styles can take many different forms (see this graphic here on the different types). But they all share the benefit that the system itself is mounted above the part it is moving. Therefore they use production space that is not occupied with other equipment. This can enable the overhead plant space to become productive, like using it for a buffer or storage bank. If more space is available, floor style systems may be more suitable. These include belt conveyors, gravity roller, skatewheel and slat conveyors.
- Consider how you want to load and unload the parts. Some processes need precise positioning of the part (like for robot loading or unloading). Systems equipped with tooling, pallets or carriers can accommodate this. A simple belt or roller conveyor by itself cannot maintain the part in a precise location.
- The speed required and investment available can drive the choices. Simpler, faster and more affordable systems are great. Other solutions need more sophisticated automated conveyor lines.
The material below has a short summary of each one of the more common conveyor types that are available.
Sometime our customers call these “Conveyor belts”. This is actually the belting material. A belt system is one of the simplest conveyor types. It moves parts from one end to the other. Speed can be variable with a variable speed drive. Don’s use belt systems as a working surface. They also can’t be used to present parts to a robot, or buffer or sequence parts. But their simplicity makes them one of the most common conveyor types available.
They belong to the floor mounted category. Belt conveyors typically move the belt across a supporting steel plate so that as the belt moves it slides. This style is a slider bed style. Or the belt can be supported on top of closely spaced rollers. This style is called a roller belt style or roller conveyor belt. Learn more about them here. Ready to buy? Here’s the range available for online purchase.
Gravity Roller Conveyor
Also one of the simplest types, they are very affordable. A series of rollers mounted on a side frame provides the rolling surface. When mounted on a decline angle, parts move by themselves. However if using gravity conveyors for parts of different size and weight it can be more difficult. you will need to control the speed and angle. Parts running into each other may cause damage. But compared with carrying parts from point A to point B, a gravity roller table is often a great starting point. It is a very simple productivity improvement. Learn more about them here. Ready to buy? Here’s the range available for online purchase.
Floor mounted chain conveyors are great for heavy items. They are especially useful for items that have an uneven lower surface. The chains provide two or three contact points on the bottom of the load. As the chain moves it carries the product forward. They’re used to carry pallets and large industrial containers. If necessary, products are mounted on a fixture, or “skid” and the fixture is carried along the chains. This is a common application in auto plants. They are heavy duty, and generally move at slow speeds. Learn more about them here. Ready to buy? Here’s the range available for online purchase.
Live Roller Conveyor / Chain Driven Live Roller (CDLR)
If we combine the rollers from a gravity conveyor with the chains of a chain driven system, we can link the rollers. Add a motor and gearbox and now we have a live roller conveyor or chain driven live roller system. Sometimes people in the industry use the acronym CDLR. They are members of the floor conveyor family, and they are heavy duty material handling systems. Use them to transport pallets, seats (on skids or pallets), tires and containers. If fitted with loose plastic sleeves over the rollers as shown in the photo below, they can accumulate or buffer product. The rollers can keep moving even though the product on top is not moving. Chains are linked together from one roller to the next on the side. Learn more about them here.
Motorized roller conveyors – 24V MDR Conveyors
What if we put the motor inside the rollers? These modern motors are at the heart of today’s sophisticated distribution centers. With high speeds of 200 feet per minute or more, your Amazon and mail packages delivered to your home passed along miles of these type of conveyors. They use one or more motor driven roller per zone to create a series of zones along the conveyor.
Connecting MDRs to other rollers
The motorized roller connects to the other rollers in the same zone by plastic or reinforced belts. Photo eyes turn the motors on and off, and parts move to the next zone when space is available. This way the parts never touch, avoiding damage. We call this “zero pressure accumulation” and it’s a very valuable benefit. An added bonus? You can convert a gravity conveyor to a motorized roller system. Learn more the motors and how MDR conveyors work here. Ready to buy? We have a range of MDR conveyors, motors and power supplies available for online purchase.
A slat conveyor is simply a two-strand chain system with slats connected to the chain and a guiding system for the slats. This creates a smooth surface to which tooling details or fixtures are mounted. Use this to hold parts in the desired position. Sometimes the fixtures can also allow the part to rotate 90 degrees or 180 degrees as required in several planes. Therefore you can use slat conveyors as a working surface for assembly operations. Positioning of the part is also quite precise. So it’s common for robots to perform the loading or unloading operation at one or more ends of a slat conveyor. Learn more about them here.
Overhead hand push beam trolley systems
Moving on to the overhead family of conveyor types, the simplest systems are hand pushed beam trolley systems. We use enclosed track or I-beam section as a track. These types are extremely versatile, easy to set up and affordable. They are mounted above the workplace with roof-supported or floor supported steel structures. For more information on the nine different types of overhead style systems, see this graphic. Trolleys for these systems are under $50 each and the tracks are also very affordable. Learn more about them here or buy them online here. Beam trolley systems are especially popular for painting and finishing operations. The mechanism remains above the part and is not covered by the spray.
Motorized overhead conveyor / Monorails
One of the most common types is an overhead conveyor with the trolleys connected together with a chain. The chain can either be enclosed (“enclosed track”) or open below an I-beam. These style of conveyors are installed in nearly every high volume production facility. The chain is driven by a motor with a gearbox, and the parts to be moved are suspended from trolleys attached to the chain. Many different attachment types are available. For complex parts, use a fixture or carrier suspended from several trolleys to locate the part in position. The chain can be always running, or alternatively the system can index. This moves parts from one assembly station to the next at a predetermined interval. Learn more about them here.
Power and Free Conveyors
Also in the overhead family of devices is the power and free conveyor. It’s like a regular motorized overhead system, except it has two tracks. In one track, the chain is continuously running. In the other track, the trolleys move along with the chain using pusher mechanisms (known as “pusher dogs”). They’re mounted at regular intervals on the chain. When two trolleys are pressing against each other, the dogs can slide over the top. Likewise, a stop blade can be used with a pneumatic cylinder to replicate this geometry. This allow trolleys to start or stop movement virtually anywhere in the system. This versatility makes power and free conveyors the most productive style of overhead systems. They can start, stop, buffer and re-sequence parts with switches. Learn more about them here.
Over Under Conveyors
As the name implies, they go over, and they go under. Available in hand push, motorized and power and free versions.
Inverted monorails and inverted power and free
Just like their overhead configurations, except the track is on the ground and the load is above the track. Useful in paint finishing applications to avoid dust or oil dripping onto parts. Widely used in automotive final assembly operations.
How do the Electrical Controls for conveyors work?
Just as there is a diverse range of conveyors that are used for any application, so are the electrical control systems. The simplest systems don’t require electrical control. These types include gravity roller and hand push overhead style beam trolley or enclosed track systems. Motorized systems can use simple start-stop switches for simple applications. However it’s more typical to have a control system that is uses input from sensors. Sensor types include photo eyes, limit switches or proximity sensors. These sensors can tell a processor when to stop, start or perform another function.
More advanced controls
Programmable logic controllers (PLCs) are for larger systems. They can control conveyors and also any other process equipment. These systems are often also fitted with a variable frequency drive (VFD) to adjust the speed of AC motors. And finally, the DC electric motors in 24V systems have their own specialized motor controllers. This enable inputs from sensors, processing of outputs and network connectivity via ethernet.
How do you design a conveyor?
The amount of time spent designing a conveyor application can range from minutes to weeks or even months. Generally the longer the conveyor, the more time it will take during the conveyor design stage. Let’s consider three categories of simple, intermediate and advanced conveyor design:
- Simple. Most of the conveyors purchased from our click and buy online store are in this category. They are roller, belt or simple hand push overhead applications that are less than 20 feet long. Their primary use is to move product from point A to point B in a straight line. The design process is pretty simple and mainly involves choosing the best conveyor for the job. Should it sit on the floor? Then use a belt, roller or motorized roller conveyor. Can it be above the work zone? Then use an enclosed track or I-beak style hand push type. This category is also pretty simple to install. It might be as easy as assembling the legs on a roller conveyor or MDR conveyor. If it’s a motorized MDR or belt conveyor, plug it in to a regular outlet and once the legs are assembled it’s ready to run.
- Intermediate. Most of our customers in this category are maintenance team leaders, manufacturing engineers or hands-on business owners who have a good understanding of their process requirements, but need some help configuring the best system. We love helping do that and many of these customers can do some or all of the final installation themselves. The design process here has a couple more steps which would include a more detailed understanding of the product being carried . The process requirements also impact the design. For example if a conveyor system passes through a robot cell or a paint booth.For these intermediate systems many customers do the majority of the design work, and often do the installation as well. If you are planning an overhead style system, Ultimation has this great video that walks you through the steps of how to design and install motorized overhead conveyors. For Intermediate category systems, the customer doesn’t need to pay for any project engineering cost. We can prepare what is known as a “Bill of Material” for the conveyor components that specifies everything you’ll need to install and get your system running. Occasionally we also provide a quotation for what is known as “Installation Supervision”. The customer or their contractor do the installation work, but we send a mechanical or electrical engineer to supervise the installation and commissioning process.
- Complex. These type of projects are where the customer wants a “Turnkey” conveyor system and where substantial conveyor design and specialist conveyor engineering skills are required. Projects move from the intermediate category to the complex category as the total lengths of the system and the number of conveyor path alternatives increase. Switches, bypasses, buffers, cross-overs, lifting stations, and other specialty conveyors are used. More complex conveyor technology like power and free conveyors sometimes fall into this category. Installation for these systems is always done by an experience contractor, typically either Ultimation or a specialist conveyor installer that we can help you select.
What happens when you call or email us for help in selecting the best system?
Call or email us today to get started. We can help make your process more efficient.
We know that running a growing business can get complicated. Material handling challenges can hold you back from growing faster. Call us on 586-771-1881 or email [email protected] . We answer every phone call with a live operator during business hours.