INA axial-cylindrical roller bearings are a type of bearing product under the INA brand of the Schaeffler Group, mainly used to bear large radial loads and medium axial loads. This type of bearing is particularly suitable for situations where the shaft is offset or tilted. The spherical raceway design of the outer ring realizes automatic self-alignment, allowing the inner and outer ring axes to tilt relative to each other by 1° to 2.5°. Structure and design features The core structure of INA axial-cylindrical roller bearings includes a spherical raceway design of the outer ring, and the inner hole is divided into two forms: cylindrical and conical. The taper of the conical inner hole is 1:12 or 1:30. In order to enhance the lubrication performance, the outer ring of the bearing is equipped with an annular oil groove and three evenly distributed oil holes to adapt to high impact loads. This type of bearing is widely used in metallurgy, rolling mills, mining, petroleum, papermaking, cement, sugar pressing and other industries, and is suitable for complex working conditions with heavy loads and impact loads. 1. Its self-aligning performance enables the bearing to work normally when the shaft is bent or tilted under force, which is particularly suitable for applications that need to withstand large radial and axial loads. INA axial-cylindrical roller bearings meet the brand’s precision manufacturing standards and are suitable for complex working conditions, reflecting the German industry’s technical accumulation in the field of rolling bearings. The product models cover multiple sizes and specifications, and the parameters are distinguished by digital coding.

In the demanding world of rotating machinery, where axial forces threaten stability and precision, INA Axial-Cylindrical Roller Bearings stand as engineered pillars of strength and reliability. Representing the pinnacle of Schaeffler Group’s bearing technology, these specialized components are designed for one primary, critical task: to support exceptionally high, unidirectional axial loads with minimal space requirement and unparalleled rigidity, while accommodating moderate rotational speeds.

Core Function & Distinguishing Design:

Unlike radial bearings or even axial ball bearings, INA axial-cylindrical roller bearings utilize cylindrical rollers as their rolling elements. These rollers are arranged with their axes parallel to the bearing axis, lying flat between hardened and ground raceway washers. This fundamental design principle yields significant advantages:

Exceptional Axial Load Capacity: The large line contact between the cylindrical rollers and the flat raceways distributes axial loads over a significantly greater surface area compared to the point contact of balls. This allows these bearings to handle extremely high axial forces – often several times higher than similarly sized axial ball bearings – without excessive deformation or premature failure.

Supreme Rigidity & Minimal Deflection: The line contact and optimized roller profile lead to extremely high axial rigidity. Under load, the bearing exhibits minimal axial elastic deformation (deflection). This is crucial in applications demanding precise axial positioning, minimal play under load, and resistance to shock or vibration forces that could cause unwanted movement. Think machine tool spindles, heavy press columns, or crane slewing rings where even micron-level deflection is unacceptable.

Compact Design & Space Efficiency: Axial-cylindrical roller bearings achieve their high load capacity within a remarkably low cross-section height (small axial space). This makes them ideal for applications with severe space constraints where traditional thrust bearing solutions might be too bulky. The “flat” profile is a key design advantage.

Positive Roller Guidance: INA designs often incorporate sophisticated cage designs or guiding elements (like ribs on the raceways) to ensure positive roller guidance and separation. This prevents skewing, minimizes friction and wear, promotes smooth rolling, and ensures optimal load distribution across all rollers, even under challenging conditions.

Key Design Variations:

INA offers a comprehensive range to suit diverse application requirements:

Axial Cylindrical Roller and Cage Assemblies (e.g., ZARN, ZARF series): These consist only of the cylindrical rollers held in a precision cage. They require separately supplied hardened and ground raceway washers (shaft and housing washers). This offers maximum flexibility, allowing the designer to integrate the washers directly into adjacent machine components, optimizing space and reducing total part count.

Advantages: Ultimate flexibility, potential for integrated design, cost-effective for high volumes where washers can be machined into components.

Considerations: Requires precise mounting surfaces on adjacent parts.

Axial Cylindrical Roller Bearings with Raceway Washers (e.g., ZKLN, ZKLF, ZARF-L series): These are complete, ready-to-mount units. They incorporate one or two precision-ground raceway washers integrated with the roller and cage assembly. Common configurations include:

Single Direction (e.g., ZKLN, ZARF-L): Designed to accommodate axial loads in one direction only. Requires a counter bearing (like a deep groove ball bearing) to handle radial loads and axial loads in the opposite direction. Features a flat back face (ZKLN) or a sphered back face (ZARF-L) for initial misalignment compensation.

Double Direction (e.g., ZKLF): Incorporates two sets of rollers and cages sandwiched between three washers (a central shaft washer and two housing washers). Can accommodate high axial loads from both directions within a single, compact unit. Requires separate radial bearing support.

Aligning Seat Washers (e.g., ZBK, ZBE series): Often paired with bearings featuring sphered back faces (like ZARF-L), these seat washers have a concave sphered surface. This combination allows the bearing to compensate for initial misalignment (static misalignment) between the shaft and housing after mounting, typically up to 2°-3°. This is vital for ensuring proper load distribution and preventing edge loading in non-ideal mounting situations.

Material, Manufacturing & Surface Excellence:

High-Grade Steel: Manufactured from high-purity, through-hardened chromium steel (e.g., 100Cr6 / SAE 52100) or case-hardening steels, ensuring exceptional core strength and fatigue resistance.

Precision Grinding: Raceway surfaces undergo super-finishing to achieve extremely low roughness values (Ra < 0.1 µm), minimizing friction, wear, and heat generation. This precision is critical for high rigidity and long service life.

Optimized Roller Geometry: Rollers feature precisely controlled crowning or logarithmic profiles at their ends. This prevents detrimental edge stresses at the roller ends under load or misalignment, significantly enhancing load capacity and service life.

Advanced Cage Technology: Cages are typically made from robust materials like glass-fiber reinforced polyamide (PA66-GF25 – offering quiet operation, low friction, and tolerance to marginal lubrication) or machined brass/stampings for high-temperature or aggressive environments. Cage design ensures optimal roller spacing and guidance.

INA-Specific Advantages & Innovations:

Optimized Internal Geometry: INA continuously refines roller dimensions, profiles, and cage designs to maximize load ratings and operational reliability.

Special Materials & Coatings: Offerings include bearings made from high-temperature steels, corrosion-resistant steels, or featuring specialized surface coatings (e.g., INA’s “Durotect” coatings like B/S/C) for enhanced wear resistance, reduced friction, or corrosion protection.

Sealing Solutions: While less common than in radial bearings due to the open design, INA provides options for integrated seals or shields (designated by suffixes like -2RSR) in specific series where protection against contamination or lubricant loss is critical.

Lubrication Expertise: INA provides detailed recommendations for lubricant selection (oil or grease), relubrication intervals, and quantities tailored to specific operating conditions (speed, load, temperature).

Critical Applications:

INA Axial-Cylindrical Roller Bearings excel in demanding sectors where high axial loads and rigidity are paramount:

Machine Tools: Spindle supports (especially vertical spindles), ball screw supports, column guides in machining centers, grinding machines, and gear cutting machines. Precision and rigidity are non-negotiable.

Heavy Machinery & Industrial Gearboxes: Supporting axial thrust in large gear sets (worm wheels, helical gears), crane slewing rings, rolling mill stands, extruders, and presses.

Power Transmission: Wind turbine gearboxes (handling rotor thrust), large industrial fans, pumps, and compressors.

Material Handling: Heavy-duty conveyor drives, lifting equipment, and crane travel mechanisms.

Marine & Offshore: Stern tube bearings (thrust collars), deck machinery, propulsion systems.

Construction Equipment: Excavator slew rings, heavy-duty axle systems.

Selection & Mounting Considerations:

Load Direction & Magnitude: Clearly define the magnitude and direction (uni- or bi-directional) of the axial load.

Rigidity Requirements: Assess the criticality of minimal axial deflection.

Speed: While capable of moderate speeds, consider heat generation and lubrication needs at higher RPMs.

Space Constraints: The low-height profile is a major advantage

Misalignment: Determine if static misalignment compensation (using sphered seat washers) is needed.

Mounting Surfaces: For assemblies without washers (ZARN/ZARF), ensure adjacent surfaces are hardened, ground, and have adequate surface finish and perpendicularity.

Lubrication: Choose the correct type (oil/grease), viscosity, and supply method based on speed, load, and temperature. Relubrication is often essential.

Radial Loads: Remember these bearings are not designed to support significant radial loads. A separate radial bearing (like an INA cylindrical roller bearing or deep groove ball bearing) must always be used to handle radial forces.

Preload: Controlled preload may be applied to eliminate internal clearance and further enhance rigidity and running accuracy, but requires careful calculation and mounting.

Conclusion:

INA Axial-Cylindrical Roller Bearings are the engineering solution of choice when confronting the challenges of extreme axial forces and demanding rigidity requirements within compact envelopes. Their unique cylindrical roller/flat raceway design delivers unmatched axial load capacity and stiffness, outperforming axial ball bearings in these critical aspects. Offering flexibility through roller/cage assemblies or complete units with aligning options, and backed by INA’s commitment to precision manufacturing, material science, and surface technology, these bearings provide the robust, reliable foundation essential for high-performance machinery across diverse industrial sectors. When your application demands unwavering axial support and precision positioning under heavy load, INA Axial-Cylindrical Roller Bearings deliver the strength and stability engineered to endure. Always consult detailed INA catalogs, technical specifications (load ratings, speed limits, dimensions), and application engineering support for optimal selection and integration.