Linear bearings are precision-bored mechanical components with sliding or rolling elements along the bore that enable low-friction straight-line axial movement on round or square shafts. Sliding plain bearings handle extreme temperatures, dirt, and vibration better, while rolling-element linear ball bearings offer lower friction, higher speeds, and stronger cantilevered-load performance. Linear bearings tend to be standardized around inch, ISO metric, and JIS metric shaft sizes. Open-shelled variants provide clearance for rail-supported shafts and profiled rails.
In this category, PBC Linear offers sliding plain linear bearings, rolling linear ball bearings, and cam roller pillow blocks. The flagship Simplicity® products are sliding plain linear bearings with FrelonGOLD® PTFE-based liners bonded directly to the bore, delivering self-lubricating, maintenance-free motion without metal on metal contact in harsh environments involving extreme heat, dirt, welding splatter, particulates, debris, vibration, shock, contamination, washdowns, or where costly downtime from bearing replacement is a concern. As a cost-saving polymer-lined alternative, injection-molded EconoGlide® plain bearings are offered for less severe operating conditions. Plain linear bearings support linear, rotational, and oscillating motion, and the Simplicity bearings include standard cylindrical, twin, flanged, die set, pillow block bearings and sleeve bearings for round shafts, as well as square bearings for square shafts.
Linear ball bearings are rolling-element bearings used when higher-speed motion, low friction, and cantilevered-load performance are more important than the dirt, shock, vibration, or contamination resistance of plain bearings. They use recirculating steel balls to travel on round shafts and are not limited by the 2:1 binding rule that applies to plain bearing systems. Linear ball bearings feature durable heat-treated outer rings and quiet resin retainers, with standard, twin, flanged, thin-wall and pillow block styles available.
Roller pillow blocks are another form of rolling element bearing, using open-shelled aluminum housings with one or more sets of three opposing coated steel cam rollers that travel on rail-supported round shafts for long linear travel.
PBC Linear Specifications for Simplicity Plain Linear Bearings:
- Self-Lubricating Bearing Liner is Bonded to the Bore ID: FrelonGOLD® is standard;
- Optional liners: Frelon®J for corrosive chemical conditions; Frelon®W (FDA compliant)
- Temperature Rating: -400°F/+400°F or -240°C/204°C
- ID Sizes: Available from 3/16” to 4” Inch Series, 5mm to 80mm Metric Series
- Maximum Horizontal Static Load: 2,165-100,500 lb (982- 45,586 kg)l
- Maximum Speed: Up to 8 m/s (315 in/s)
- Shaft Lengths: Up to 12 feet
- Shell Material: Standard is aluminum; stainless steel shells are available
- Self-Lubricating: Provides oil-free operation
- Seal Options: Nitrile rubber, urethane, and viton seals available from ½” ID and up or 20mm and up
- Mounting Options: O-ring and retaining ring grooves for multiple mounting options
- External Lubrication: Optional feature for added lubrication
- Vibration Damping: Ensures smooth and quiet operation
Specifications for EconoGlide Plain Linear Bearings:
- Injection Molded Polymer Bearing ID Liner
- Temperature Rating: -58ºF/+194ºF (-50ºC/+90ºC)
- ID Sizes: 3/8” to 2” and 8mm to 50mm
- Maximum Speed: 1.5 m/s
- Shell Material: standard is aluminum; stainless steel shells are available
- Self-Lubricating: Provides oil-free operation
- Mounting Options: O-ring and retaining ring grooves for multiple mounting options
- External Lubrication: Optional feature for added lubrication
- Vibration Damping: Ensures smooth and quiet operation
- Bearings available in inch and metric sizes; Flanged bearings are in metric sizes
Specifications for Linear Ball Bearings:
- Temperature Range: -4/+176°F (-20/+80°C)
- ID Sizes: Available from 1/4" to 2” Inch Series, and 8mm to 50mm Metric Series
- Static Load Capacities: Up to 1700 lb (7900 N)
- Dynamic Load Capacities: Up to 850 lb (3800 N)
- Interchangeable: Size interchangeable with industry standards and the Simplicity plain linear bearing series
- Low Coefficient of Friction: Ensures smooth operation
- Heat Treated Alloy Steel Shell: Provides durability
- Resin Retainer: Reduces noise
- Double Seals: Included as standard at no additional cost
Specifications for Roller Bearing Pillow Blocks:
- Use a floating "F" part number for each opposing block on parallel shafts to accommodate imperfect alignments.
- A set of opposing roller bearings consists of 1 fixed side roller, 1 eccentric side roller (to account for any misalignment) and a top support roller
- FUBK Series replacement kits include one new roller for each of the three in a set
- Order two replacement kits to cover more than one set of opposing bearings
Frequently Asked Questions
What is the difference between plain linear bearings and linear ball bearings?
Plain linear bearings use self-lubricating liners and are ideal for harsh environments, while linear ball bearings use recirculating steel balls for low friction and higher-speed performance.
What are the benefits of plain linear bearings?
Plain linear bearings provide maintenance-free, self-lubricating operation and perform well in environments with heat, dirt, debris, and vibration.
What are the advantages of linear ball bearings?
Linear ball bearings deliver high-speed, low-friction performance and eliminate the 2:1 binding limitation of plain bearings in cantilevered applications.
Which linear bearing is best for dirty or harsh environments?
Plain linear bearings are best suited for dirty or harsh environments because their self-lubricating liners resist contamination from dust, debris, and moisture.
Which linear bearing is best for high-speed applications?
Linear ball bearings are ideal for high-speed applications due to their low coefficient of friction and recirculating ball design.
When should cam roller pillow blocks be used?
Cam roller pillow blocks are ideal for heavy-load, long-travel applications, using coated steel cam rollers in open housing designs for durable performance along rail-supported round shafts.
Do linear ball bearings require lubrication?
Yes, most linear ball bearings require lubrication for optimal performance and service life, unlike self-lubricating plain bearings.
What motions do plain linear bearings support?
Round shaft plain bearings support rotary, linear, and oscillating motion, while square shaft versions support linear and oscillating motion only.
Are linear bearings interchangeable with industry standards?
Yes, most linear bearings are dimensionally interchangeable with industry-standard sizes.
What sizes are available for linear bearings?
Linear bearings match standard shaft sizes and are available in inch, metric, and JIS sizing.
What is the difference between plain linear bearings and linear ball bearings?
What are the benefits of plain linear bearings?
What are the advantages of linear ball bearings?
Which linear bearing is best for dirty or harsh environments?
Which linear bearing is best for high-speed applications?
When should cam roller pillow blocks be used?
Do linear ball bearings require lubrication?
What motions do plain linear bearings support?
Are linear bearings interchangeable with industry standards?
What sizes are available for linear bearings?
Types of Linear Bearings: Linear Plain Bearings, Linear Plain Bearing Flange Mounts, Linear Plain Sleeve Bearings, Linear Plain Pillow Block Bearings, Linear Plain Bearing Flange Die Set Bushings, Linear Plain Square Bearings, Linear Ball Bearings, Linear Ball Bearing Flange Mounts, Linear Ball Bearing Pillow Blocks, Roller Pillow Block Bearings, Single Roller Pillow Block Bearings, Double Roller Pillow Block Bearings, Twin Roller Pillow Block Bearings
Suggested Reading:
Features of Linear Bearings
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Case Study - Weld Splatter Pushed Aside
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