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CERAMIC & EXSEV BEARINGS

CERAMIC & EXSEV BEARINGS

Product catalog summary

Overview: This document is a technical catalog for ceramic and EXSEV bearings, focusing on their use in extreme environments such as high temperatures, corrosive settings, and clean rooms. It details specifications, applications, and manufacturing processes, emphasizing performance in challenging conditions.

Specifications and Composition:

Ceramic Bearings: Made from materials like silicon nitride, zirconia, and silicon carbide, these bearings are non-magnetic, insulating, and heat-resistant, suitable for high-speed and high-temperature applications.
Special Steel Bearings: Used with ceramic components to enhance performance in specific environments.

Lubricants:

Includes grease and solid lubricants tailored for EXSEV bearings to ensure optimal performance in extreme conditions.

Selection Criteria:

Guidelines for selecting bearings based on environmental conditions such as clean, vacuum, high temperature, and corrosive environments.

Special Characteristics:

Details on non-magnetic, insulating, and high-speed bearings designed for specific applications.

Application Examples:

Illustrates the use of these bearings in various environments, including clean rooms, vacuum, high temperature, corrosive, magnetic, and electric fields.

Supplementary Tables:

Includes tables for shaft tolerances, housing bore tolerances, and conversion factors, providing essential data for engineers and designers.

Key Data from Tables:

Mechanical Properties: Silicon nitride is highlighted for its superior load-carrying capability and service life compared to other ceramic materials.
Rolling Fatigue Tests: Silicon nitride shows the highest fatigue strength, making it the preferred material for high-performance applications.

Conclusion: The catalog emphasizes JTEKT's commitment to innovation in bearing technology, aiming to meet the demands of advanced technologies while contributing to environmental conservation and energy efficiency.

Specifications and Material Properties: Silicon carbide (SiC) and silicon nitride (Si3N4) are highlighted for their high corrosion and heat resistance, making them suitable for use in highly corrosive chemical environments. Silicon nitride is noted for its rigidity compared to high carbon chromium bearing steel, which affects the contact stress in bearings.

Rolling Fatigue Life of Ceramic Bearings: Tests comparing ceramic and steel bearings show that ceramic bearings have a service life equal to or longer than steel bearings, often exceeding calculated life expectations. Flaking was observed as a failure mode in both ceramic and steel bearings.

Load Ratings and Service Life: Ceramic bearings have dynamic load ratings comparable to steel bearings, while their static load ratings are higher due to the material's rigidity and resistance to permanent deformation. Hybrid ceramic bearings have a static load rating at 85% of steel bearings.

Impact Strength and Static Load Rating: Ceramic bearings exhibit high impact strength, comparable to their static load strength. The static load rating for hybrid ceramic bearings is based on the permanent deformation of their steel rings.

Fitting and Temperature Considerations: Fitting stresses and temperature changes must be considered due to the different coefficients of linear expansion between ceramic and steel materials. Maximum stress from interference should not exceed 150 MPa.

Bearings for Special Environments: EXSEV Bearings use martensitic stainless steel for clean environments and precipitation hardening stainless steel for corrosive environments. High-speed tool steel is recommended for high-temperature environments.

Lubrication: Lubrication is critical for bearing performance. Grease is preferred for its high-speed performance and load-carrying capability, but solid lubricants are used in environments where grease is unsuitable.

Solid Lubricants: Solid lubricants include soft metals and layer lattice materials. Silver and lead are used in ultrahigh vacuum environments, while molybdenum disulfide is used as a coating or additive.

Material Characteristics:

Solid Lubricants: Superior in heat resistance and load carrying capability, suitable for high temperature applications.
Layer Lattice Materials: Not recommended for clean environments due to high particle emissions.
Polymeric Materials: Coated on cages or bearing rings, ideal for clean or corrosive environments due to low dependency on ambient conditions.

Lubricant Characteristics:

Fluorinated Greases: Useful for high temperature and vacuum applications, known for low evaporation pressure and particle emissions.
Solid Lubricants: Include soft metals and layer lattice materials, with varying particle emissions and applications.

Service Life Estimation:

Service life of bearings is influenced by operating conditions and can be estimated using specific equations provided for different materials.

Bearing Selection for Environments:

Clean Environments: Use stainless steel bearings with low particle emission lubricants.
Vacuum Environments: Selection depends on cleanliness requirements; fluorinated grease is preferred for non-critical cleanliness.
High Temperature Environments: Use hybrid ceramic or full ceramic bearings for temperatures above 500°C.

Corrosion Resistance:

Special Steels: SUS630 offers better corrosion resistance than SUS440C.
Ceramic Materials: Silicon nitride is standard but may corrode in highly corrosive conditions; alternatives include zirconia or silicon carbide.

Corrosion Resistance: The document evaluates the anticorrosive performance of materials like Zirconia (ZrO2) and Silicon Carbide (SiC) against various chemicals. It uses symbols to denote resistance levels: ◎ (Fully resistant), ○ (Almost resistant), △ (Slightly susceptible), and × (Susceptible). For example, both materials show full resistance to water and saltwater but vary in resistance to acids and bases.

EXSEV Bearings: Different types of EXSEV Bearings are discussed, including Corrosion Resistant Hybrid Ceramic Bearings and High Corrosion Resistant Ceramic Bearings. These bearings are designed for use in environments ranging from slightly acidic to strongly alkaline and reactive gases. The document emphasizes the importance of evaluating the lubrication performance and corrosion susceptibility of bearings in solutions.

Performance Testing: Figures and tables illustrate the performance of bearings under specific conditions, such as mass reduction and bending strength deterioration in corrosive environments. The service life of bearings in water is also compared, highlighting the differences between standard and corrosion-resistant bearings.

Special Characteristics: The document details bearings with special characteristics, such as non-magnetic and insulating bearings. Hybrid Ceramic Bearings are noted for their high-speed performance and reduced power loss compared to steel bearings. They are suitable for applications like turbochargers and machine tool spindles due to their superior antiseizure characteristics.

Material Composition: Tables provide specifications for various bearing types, including the materials used for bearing rings, balls, and cages. The document highlights the use of materials like silicon nitride and non-magnetic stainless steel for specific applications.

Recommendations: The document advises consulting with JTEKT for specialized applications and emphasizes the importance of selecting the appropriate bearing materials and lubricants based on environmental conditions.

Specifications:

Dynamic Equivalent Load: Pr = XFr + YFa, where X and Y are coefficients.
Static Equivalent Load: P0r = 0.6Fr + 0.5Fa, with conditions for when P0r is smaller than Fr.
Permissible Radial Load and Limiting Speed: Detailed for each bearing type, with specific values provided in tables.
Basic Load Ratings: Provided in kN with factors Cr, C0r, and f0.

Product Types and Applications:

Ceramic Bearings: Suitable for ultrahigh temperature environments, often used in kilns and furnaces.
Hybrid Ceramic Bearings: Used in semiconductor and chemical processing systems, featuring corrosion resistance and water compatibility.
Stainless Steel Bearings: Lubricated with KHD grease, suitable for slightly corrosive environments like chemical and conveyor systems.

Performance and Environment:

Temperature Range: Varies by bearing type, with some suitable for -100 to 500°C.
Pressure Conditions: Bearings are designed for atmospheric to ultrahigh vacuum environments.
Material Composition: Includes silicon nitride ceramic, stainless steel, and fluoropolymer lubricants.

Additional Notes:

Bearings are available from stock or with specified lead times.
Color coding in tables indicates delivery periods.
Service life and performance are influenced by environmental conditions and material wear.

Specifications and Load Calculations: The document provides formulas for calculating static and dynamic equivalent loads for ceramic bearings. The static equivalent load is calculated as P0r = 0.6Fr + 0.5Fa, with a condition that if P0r is smaller than Fr, then P0r = Fr. The dynamic equivalent load is given by Pr = XFr + YFa, where X and Y are specific factors.

Usage and Limitations: Ceramic bearings can be used underwater, but in liquids with poor lubrication, the load should not exceed 10% of the bearing's basic dynamic load rating. The fatigue life under water is 3% of its rating life. For non-water applications, selection should be based on permissible radial load and limiting speed.

Product Specifications: The document lists various ceramic bearings with their permissible radial loads and limiting speeds. It also provides boundary dimensions and basic load ratings for different bearing numbers.

Material and Environmental Suitability: The bearings are made from corrosion-resistant silicon nitride and are lubricated with fluoropolymer, making them suitable for highly corrosive solutions. They can operate in environments with magnetic fields, electric fields, high speeds, corrosive conditions, vacuums, and high temperatures.

Applications: These bearings are used in various systems, including LCD film processing, aluminum film capacitor processing, plating systems, synthetic fiber manufacturing, and food container cleaning systems.

Performance Characteristics: The document highlights the advantages of ceramic bearings, such as longer service life in acidic or alkaline solutions compared to standard silicone nitride bearings, stable torque in magnetic fields, reduced temperature rise, and reduced vibration.

Delivery and Availability: The document outlines the availability of bearings from stock, with delivery times ranging from 30 to 45 days after receiving an order, depending on the classification of the bearing number.

Mounting Procedures for Linear Way Bearing Units:

1. Track Rail Installation:
Position the mounting reference plane of the track rail correctly to the bed's reference plane. Temporarily fasten the track to the bed using a small vice or suitable tool to ensure close contact. Securely tighten the bolts one by one to fasten the drive side track rail to the bed. The driven side track rail should remain temporarily fastened.

2. Slide Unit Installation:
Position the slide units on the table, align them with the drive side slide units, and fasten them together. One driven side slide unit should be fixed, while the other remains loosely tightened.

3. Final Fastening:
Before securing the driven side track rail, ensure smooth motion by moving the table. Tighten the fastening bolt step-by-step as the slide unit passes over it. Securely fasten the slide unit to the table.

Specifications and Dimensions:
The document provides detailed dimensions and specifications for various linear motion bearing units, including the LWHS and LWES series. It includes measurements for assembly, slide units, track rails, and static bending moment ratings.

Cross Roller Way Bearing Units:
These units consist of two raceway bases with V-shaped rolling surfaces and cylindrical rollers. They enable smooth and accurate linear motion. The document outlines the materials used, such as martensitic and austenitic stainless steel, and coatings like KDL grease and molybdenum disulfide.

Mounting and Preload Adjustment:
Ensure components are free from oil stains and contamination. Clean the mounting surfaces and remove any irregularities. Temporarily fasten the raceway bases, adjust preload using the preload adjustment screws, and ensure even torque application. The document provides a table for screw tightening torque values.

Key Considerations:
Maintain cleanliness and avoid mixing components from different sets. Adjust preload screws to eliminate clearance and ensure even preload distribution. Follow specified torque values for different screw sizes.

Specifications and Procedures:
The document provides detailed instructions for adjusting preload screws in a cross roller way bearing unit. It emphasizes the importance of applying torque close to the specified value and checking the smooth movement of the table without noise. Running accuracy is verified using a dial gauge.

Technical Data and Tables:
The document includes extensive tables detailing the specifications of various CRW series bearings, including dimensions, mass, and load ratings. It provides information on the boundary dimensions and mounting dimensions for different models, highlighting the importance of precise measurements for optimal performance.

High Ability Angular Contact Ball Bearings:
These bearings are optimized for high-speed performance in machine tool spindles. They offer reduced temperature increases and higher speed limits compared to conventional products. The document suggests referring to specific JTEKT catalogues for detailed specifications.

Ceramic Bearings and Balls:
Ceramic balls, made from silicon nitride, offer excellent resistance to wear, heat, and corrosion. They are lightweight and non-magnetic, making them suitable for various applications, including high-grade bicycle parts and automotive components.

Tolerance and Internal Clearance:
The document outlines the tolerance and internal clearance specifications for ceramic bearings, providing detailed tables for inner and outer ring dimensions and radial internal clearances. It emphasizes the importance of precise measurements to ensure optimal bearing performance.

Specifications and Tolerances: The document outlines various specifications and tolerances for bearings, including nominal outside diameter, radial runout, and radial internal clearance. It specifies deviation classes for outer ring width and bore diameter, with detailed tables indicating maximum allowable deviations and radial runout for different classes and bearing types.

Application Environments: The document categorizes applications into several environments: clean, vacuum, high temperature, corrosive, magnetic field, and electric field environments. Each section provides specific use conditions such as rotational speed, lubrication type, temperature, and ambient pressure.

Clean Environments: Bearings suitable for clean environments are highlighted for their low particle emissions and long service life. Applications include chemical vapor deposition equipment and wafer transfer devices, with conditions like rotational speeds of 10 to 200 min–1 and temperatures up to 200˚C.

Vacuum Environments: Bearings used in vacuum environments are designed for high reliability under high temperatures and low pressures. Applications include X-ray tubes and turbo molecular pumps, with rotational speeds ranging from 1 to 60,000 min–1.

High Temperature Environments: High temperature applications require bearings that can withstand temperatures up to 500˚C. These are used in kilns, tube annealing furnaces, and corrugated cardboard production facilities.

Corrosive Environments: Corrosion-resistant bearings are used in environments with strong acids and alkaline solutions. Applications include aluminum foil electrolytic capacitor production and synthetic fiber manufacturing systems.

Magnetic Field Environments: Non-magnetic bearings are used in environments with strong magnetic fields, such as electron beam exposure machines and MRI motors.

Recommendations and Best Practices: The document recommends using specific types of bearings based on environmental conditions to ensure optimal performance and longevity. It emphasizes the importance of selecting the right lubrication and material coatings to enhance corrosion resistance and reduce particle emissions.

Corrosive Environments: Ceramic bearings are used in semiconductor multilayer production processes to maintain wafer surface evenness. These bearings operate at a rotational speed of 100 min–1, with fluorine polymer lubrication at room temperature.

Electric Field Environments: Hybrid Ceramic Bearings are employed to prevent electrical pitting in motors and provide insulation in high voltage environments. They are used in applications such as photographic film production and wind turbine generators, with varying rotational speeds and lubrication conditions.

High-Speed Applications: Hybrid Ceramic Bearings are noted for their reliability in high-speed rotations, used in applications like polygon scanner motors, switched reluctance motors, and turbochargers. They offer extended service life, improved acceleration response, and reduced oil supply needs. Specific use conditions include rotational speeds up to 210,000 min–1 and temperatures up to 350˚C.

Supplementary Tables: The document includes tables detailing shaft and housing bore tolerances, providing deviation classes for various nominal diameters. These tables are essential for ensuring the correct fit and performance of bearings in different applications.

Specifications and Standards: This document outlines the specifications for ceramic bearings and bearings designed for extreme special environments. It includes cleanliness classes based on particle count per cubic foot, referencing the FED-STD-209D and JIS/ISO standards. The document notes that the U.S. Federal Standards are no longer in effect but are still commonly referred to in Japan and the U.S.

Procedures and Recommendations: The document provides detailed specifications sheets for selecting the most suitable bearings, emphasizing the need for comprehensive detail. It covers aspects such as bearing size, application (new design or repair), required performance (life, speed, dust generation, etc.), operating conditions, and environmental factors like temperature and pressure.

Global Network: The document lists contact information for JTEKT and KOYO offices and plants worldwide, including locations in Korea, China, Australia, Europe, the Americas, and Asia. This section is crucial for global operations and customer support.

Environmental Considerations: The publication highlights the use of recycled paper and soy ink, indicating a commitment to environmental protection.

Catalog excerpts

CERAMIC BEARINGS BEARINGS EXTREME SPECIAL ENVIRONMENTS TM This catalog has been printed on paper of recyceled paper pulp using environmentally friendly soy ink. CERAMIC BEARINGS AND EXSEV BEARINGS FOR EXTREME SPECIAL ENVIRONMENTS FOR CERAMIC BEARINGS AND BEARINGS AND CAT. NO. B2004E Printed in Japan '08.12-2CDS ('05.06) FOR EXTREME SPECIAL ENVIRONMENTS CAT. NO. B2004E

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û JTEKT CORPORATION does not export its products and engineering know-how unless in compliance with the Foreign Exchange and Foreign Trade Control Act and other applicable trade-related regulations, if they are so covered by such act and regulations. Accordingly, please contact our branch office or sales office if you intend to export any product described in this catalogue. CERAMIC BEARINGS AND EXSEK BEARINGS FOR EXTREME SPECIAL ENVIRONMENTS it The contents of this catalogue are subject to change without prior notice. We took special care in preparing the contents of this catalogue. JTEKT does...

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Koyo CERAMIC BEARINGS AND EXSEV BEARINGS FOR EXTREME SPECIAL ENVIRONMENTS Development and Manufacturing Facilities EXSEV Bearings: Composition and Selection 2 EXSEV Bearings and Other EXSEV Products 8 Tolerance and Internal Clearance of Ceramic Bearings Specifications Sheet

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Products and Applications Corrosive Ceramic Bearings and Full Complement Ceramic Ball Bearings Bearings for Extreme Special Environments SK Bearings are used for a wide range of the state of the art technologies. Corrosion Resistant Hybrid Ceramic Bearings Ceramic Bearings Corrosion Resistant Ceramic Bearings Corrosion Resistant Ceramic Bearing App li c a High Corrosion Resistant Ceramic Bearings ti o nR e High Speed qu ir e m en ts Electric field Full Complement Ceramic Ball Bearings Corrosion Resistant Hybrid Ceramic Bearings Ceramic Bearings Hybrid Ceramic Bearings Ceramic Bearings High Ability...

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Manufacturing Facilities improvements, Koyo Ceramic Bearings and EXSEV Bearings are applicable in more technologies than ever. Technologies are advancing rapidly and bearings are required to satisfy more complicated and varied requirements under increasingly hostile operating In response to such needs, JTEKT is committed to the development and manufacture of the EXSEV Bearing Series using the latest research / development and manufacturing facilities. JTEKT intends to supply products that live up to customers' expectations, while contributing to environmental conservation and energy saving through...

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CERAMIC BEARINGS AND EXSEV BEARINGS 1 Ceramic Bearings and Special Steel Bearings The EXSEV Bearing Series has been developed for use in special applications where conventional bearings are not The EXSEV Bearings incorporate components made from special material and use special lubricants, to be applicable in extreme special environments such as a clean room, vacuum, Ceramic Bearings Ceramic Bearings, including components made from ceramic, have the special properties that steel bearings do not have, such as being non-magnetic or insulating. They can be used in new applications where conventional...

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CERAMIC BEARINGS AND BXSEV BEARINGS 3) Ceramic materials suitable for rolling bearings Table 1 -3 shows the results of evaluating the ceramic materials in terms of their characteristics and the rolling fatigue strength. Among the ceramic materials tested, silicon nitride is the most suitable as rolling bearing material. JTEKT uses the silicon nitride produced by the hot isostatic pressing (HIP) method as the standard ceramic material for 4) Composition of ceramic bearings Koyo ceramic bearings are divided into Full Ceramic Bearings (with all components, namely, the outer ring, inner ring and...

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CERAMIC BEARINGS AND BXSEV BEARINGS 2) Static load rating of ceramic bearings The basic static load rating of a steel bearing represents a load that produces a localized permanent deformation in the rolling element/raceway contact area, impeding smooth rotation. However, ceramic materials, which are highly rigid, produce little permanent deformation. Therefore, the theory of the basic static load rating for steel bearings is not applicable to ceramic • Static load rating of Full Ceramic Bearings When exposed to continuous excessive loads, ceramic materials may break down; however, before breakdown...

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CERAMIC BEARINGS AND EXSEV BEARINGS 4) Fitting of ceramic bearings When using ceramic bearings, it should be noted that ceramic materials are largely different from steel materials in the coefficient of linear expansion. Attention should therefore be paid to fitting stresses and temperature rises. The following are the results of evaluating the fitting of a Ceramic Bearing on a stainless steel shaft. Outer ring Inner ring • Maximum stress produced by fitting Table 1-6 shows the results of a static strength test conducted on a ceramic ring fitted on a stainless steel shaft. Table 1-7 shows the...

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CERAMIC BEARINGS AND EXSEV BEARINGS 2 Lubricants for EXSEV Bearings Bearing performance depends on lubrication; it is no exaggeration to say that lubrication determines the service life of bearings. Grease or a solid lubricant is properly used to lubricate the EXSEV bearings. Compared with solid lubricants, grease is superior for the high speed performance, load carrying capability, and service life of bearings. Therefore, it is recommended to use grease as much as possible. Grease cannot be used for some application in an ultrahigh vacuum, high temperature, or clean environment. In an application...

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CERAMIC BEARINGS AND EXSEV BEARINGS 4) Service life of solid lubricants Bearings lubricated with a solid lubricant can provide stable running performance as long as the lubricant is supplied continuously. When the lubricant is used up, the metal components become in contact with each other, rapidly increasing running torque and reducing the service life of the bearing. The service life of bearings is greatly influenced by the operating conditions. As a consequence, it is not always possible to accurately estimate the service life of bearings lubricated with solid lubricant because of the variations...

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