Koyo Bearing

JTEKT North America’s technologies contribute to the movement of diverse industries in the forms of Automotive Systems and Components, Bearings, Machine Tools and Mechatronics.

MANUFACTURING INNOVATIVE PRODUCTS AND BUILDING DYNAMIC LEADERS

JTEKT North America Corporation, part of JTEKT Corporation, was founded in 2006 through the merger of Koyo Seiko, Co., LTD and Toyoda Machine Works, LTD, forming a new global company combining modern technology

with a rich heritage of quality.

With more than 6000 associates and 24 facilities, including 15 manufacturing sites, 2 Technical Centers and 5 Distribution Centers, JTEKT North America manufactures a broad range of products under three solid brands: JTEKT

Automotive Systems, Koyo Bearings and Toyoda Machine Tools.

2012/1

A brand mark symbolizing integration of JTEKT, KOYO and TOYODA was established.

2012/10

The Iga Test Course was opened.

2012/10

Toyoda Machine Works Torsen Co., Ltd. was merged and acuired.

2012/10

Sekiya Seisakusho Co., Ltd. changed the corporate name to JTEKT YAMAGATA Corporation.

2014/3

JTEKT AUTOMOTIVA BRASIL LTDA. started production of the Electric power steerings.

2014/4

Large Size Bearing Engineering Development Center was opened.

2014/10

Koyo Sales Co., Ltd. was merged and acuired.

JTEKT GLOBAL

JTEKT Corporation was established in January 2006 through the merger of Koyo Seiko Co., Ltd., a world-class bearing manufacturer, and Toyoda Machine Works, Ltd., a machine tool manufacturer excelling in world-leading

machining technologies.

Combining the most advanced technologies and the manufacturing passion of both companies, today JTEKT manufactures innovative products that satisfy the most demanding customers all over the world.

Koyo Angular contact Ball Bearing

Designed for high accuracy and excellent high-speed performance. Angular contact ball bearings are designed to carry combined loads: both axial and radial.Angular contact bearings are designed such that a contact angle between the races and the balls is formed when the bearing is in use.

The major design characteristic of this type of bearing is that one, or both of the ring races have one shoulder relieved, or higher than the other. In order for these bearings to function properly, they must be assembled with a thrust load. This loading (or preload) creates a line of contact (or contact angle) between the inner race, the ball and the outer race. The preload can be built into the bearing or created when the bearing is inserted into an assembly. The contact angle varies from 15° to 40° and is measured relative to a line running perpendicular to the bearing axis. Angular contact bearings are unidirectional thrust bearings that can withstand heavy thrust loads and moderate radial loads.Important dimensions to consider when searching for angular contact bearings include design units bore, outside diameters, and outer ring width.  Design units can be in either inches or metric units.  Some manufacturers may specify parts in both.

The bearing industry uses a standard number system for bearings with metric diameter bores.

AVAILABLE AS SINGLE OR DOUBLE ROW, MATCHED PAIR AND FOUR POINT CONTACT.

Designed for high accuracy and excellent high-speed performance. Angular contact ball bearings are designed to carry combined loads: both axial and radial.Angular contact bearings are designed such that a contact angle between the races and the balls is formed when the bearing is in use. The major design characteristic of this type of bearing is that one, or both of the ring races have one shoulder relieved, or higher than the other. In order for these bearings to function properly,

they must be assembled with a thrust load. This loading (or preload) creates a line of contact (or contact angle) between the inner race, the ball and the outer race.

The preload can be built into the bearing or created when the bearing is inserted into an assembly. The contact angle varies from 15° to 40° and is measured relative to a line running perpendicular to the bearing axis. Angular contact bearings are unidirectional thrust bearings that can withstand heavy thrust loads and moderate radial loads.Important dimensions to consider when searching for angular contact bearings include design units bore, outside diameters, and outer ring width.  Design units can be in either inches or metric units.  Some manufacturers may specify parts in both.  The bearing industry uses a standard number system for bearings with metric diameter bores.  For bore sizes 04 and up multiply by 5 to obtain the bore in millimeters. Important operating specifications to consider when searching for angular contact bearings include rated speed, static radial load, and dynamic radial load.  The rated speed of a bearing running with grease lubrication is lower than that of a bearing with oil lubrication.  The static radial load is the maximum radial load a bearing can endure without excessive permanent deformation.  The dynamic radial load is the calculated constant radial load, which a group of identical bearings with stationary outer rings can theoretically endure for a rating life of 1 million revolutions of the inner ring.Manufacturers typically assign an ABEC rating to bearings.  ABEC (Annular Bearing Engineers’ Committee) ratings classify different accuracy and tolerance ranges for bearings. The higher the ABEC number the tighter the bearing tolerances.  Please consult the tables in the search form for Angular Contact Bearings for tolerances and other rating equivalents.Angular contact bearings can have a number of different styles of seals or shielding.  Seals and shields provide protection from contamination and serve as a retainer for lubricant.  Seals provide better protection and lubricant containment than shields, but have lower maximum speed capabilities.  The different types include single/double seal or single/double shield.  Angular contact bearings may be constructed of special materials including stainless steel, plastic, and ceramic hybrid. They may also be plated; common plating materials are cadmium and chrome.Bearing design for angular contact bearings can be one directional thrust, double directional thrust, double row, double row maximum capacity angular, duplex thrust, and four-pointed contact.  Thin-section bearings have small cross-sections with respect to their diameter.   Bearings with ball screw support are specially designed for use in ball screw or lead screw applications.  Some bearings may also be flanged.  Angular contact bearings may have a variety of lubrication options. They can be re-lubricated, pre-lubricated, or have solid lubrication.Angular contact ball bearings are suitable for applications which require high accuracy and good high-speed performance. This type of bearing is designed to carry a combined load.

Single-row angular contact ball bearings and matched pair angular contact ball bearings

The standard contact angles are 15°, 30° and 40°. They are identified, respectively, by the supplementary codes “C”, “A” (omitted) and “B”. Bearings with a smaller contact angle are more suitable for applications involving high-speed rotation. Those with a larger contact angle feature superior axial load resistance. Angular contact ball bearings are often preloaded to enhance their rigidity and rotating performance. For high-precision matched pair angular contact ball bearings of class 5 or higher, which are used in machine tools and other precision equipment, the standard preload is specified in three levels: light (L) , medium (M) , and heavy (H) .

When this type of bearing is loaded radially, an axial component of force is produced. In this case, two (facing one another) or more bearings are matched and assembled.

Double-row angular contact ball bearings

This type of bearings consists of two single-row angular contact ball bearings matched back-to-back, with inner and outer rings integrated.

Four point contact ball bearing

These bearings have a contact angle of 35° and an inner ring divided into two annular pieces. They are suitable for applications that involve either axial or combined loading, where the axial load makes up the major part of the load.  Another advantage is that they are able to support axial load and a certain degree of radial load. Each rolling element is in contact with each of the inner and outer rings at a single point. Both contact points lie on the contact angle line. The line runs to either the right or left depending on the direction of the axial load.It is essential to carefully examine the application conditions, especially load magnitudes, when choosing appropriate four-point contact ball bearings. Therefore, you are invited to consult JTEKT if you are considering installing this type of bearing in your product(s).

Tapered Roller Bearing

This bearing is designed so that the apex of the tapered face on the raceway face of the cone cup intersects with a single point on the bearing center line. Suitable for applications with heavy load and impact load.

This type of bearings is designed so that the cups, cones and rollers have tapered surfaces whose apexes converge at a common point on the bearing axis. This type is suitable for applications involving heavy or impact loading.Taper roller bearings consist of an inner ring (cone), an outer ring (cup), a cage and rollers which are profiled to distribute the load evenly.

They have high radial and axial (thrust) load capacities at low to intermediate speeds. Taper roller bearings are available in single-row, two-row and four-row designs. With single-row bearings, the thrust load capacity is about 60% of the radial capacity. Double-row bearings have a greater radial load capacity and can handle thrust loads in both directions. The rollers can be configured in such a way that the contact lines between the roller and the race converge or diverge towards the axis of rotation. Diverging double-row bearings increase the rigidity of the shaft mounting, while converging bearings do not. Other configurations for double-row bearings feature a single outer ring and two inner rings, or two outer rings and a single inner ring. Four-row tapered roller bearings consist of four rows of alternating converging and diverging rollers.Most taper roller bearings are made of alloy steels or low-carbon steels. Some applications require the use of case-hardened or through-hardened, high-carbon, bearing-quality steel.

Single-row tapered roller bearings

The single-row tapered roller bearings are able to carry radial and axial load in one direction simultaneously. Because an axial component of force is produced when this type of bearing is loaded radially, two or more bearings are matched and used together.

There are the standard, medium and steep types which differ in contact angle size. Medium-tapered metric series bearings are identified by the supplementary code “C” which is added as a suffix to bearing numbers.Bearings whose cup width, cup smaller inside diameter and contact angle are determined in accordance with ISO 355 specifications are identified by the supplementary code “J” as a suffix.Cone assemblies and the cups of such bearings are inter-changeable with those of bearings produced abroad if the bearing numbers are the same.

Double-row tapered roller bearings

These bearings are divided into the TDO type which has one double cup and two single-row cones, and the TDI type which has two single-row cups and one double cone.

Both accommodate radial and axial loading in both directions. These two also carry moment loads; however, the TDO type is superior to the TDI type, because the distance between load centers is longer in the TDO type. The spacer of the TDO type, or the TDI type, pre-adjusts the internal clearance to provide proper operating clearance after mounting.Features and benefits:Forged steel vs. seamless tubingImproved fatigue lifeReduced noise vibrationSuper finished racewaysCrowned inner ring, raceway & rollers

WHAT IS A KOYO SPHERICAL ROLLER BEARING?

Koyo Spherical roller bearings feature a large load rating and self-aligning capability. This type of bearing is suitable for low- or medium speed applications which involve heavy or impact loading. Spherical roller bearings are self-aligning, double-row, combination radial and thrust bearings. They use a spherical or crowned roller as the rolling element.

The outer ring contains a spherical race which allows for some misalignment of the shaft and housing. Spherical roller bearings are unequalled in their capacity for high loads and tolerance to shock loads, but have limited speed capabilities. They perform consistently, even under conditions of extreme speed, application-specific stress, and marginal lubrication.

The cage of a spherical roller bearing provides high dimensional accuracy and functionality. According to some estimates, spherical roller bearings have twice the running life of conventional bearings.

Therefore, spherical roller bearings are suitable for low/medium speed applications which involve heavy or impact loading. They come with cylindrical or tapered bores and can be supplied with adapter assemblies as well as withdrawal sleeves.These bearings are divided into R, RH(R) and RHA types, which differ in internal structure. Bearings with a tapered bore can be fit and removed easily using an adapter assembly or withdrawal sleeve.The ratio of the taper is identical among all bearing series:

240 and 241 series:          1:30 (supplementary code “K30”)

Others:                               1:12 (supplementary code “K”).Spherical roller bearings are available as double-row, combination radial and thrust bearings. They use a spherical or crowned roller as the rolling element. The race in the outer ring is spherical in shape, which allows for some misalignment of the shaft and the housing. Spherical roller bearings are unequalled in their capacity for high loads and their tolerance to shock loads, but have limited speed capabilities. They perform consistently, even under extreme conditions, such as application-specific stress and marginal lubrication. The cage of a spherical roller bearing provides high dimensional accuracy and functionality. According to some estimates, spherical roller bearings have twice the running life of conventional bearings.Most spherical roller bearings are made of alloy steels or low-carbon steels. Chrome-plated products are also available. Some applications require the use of case-hardened or through-hardened, high-carbon, bearing-quality steel. High-carbon grades of steel do not require carburizing and can be case-hardened by induction heating or through-hardened by conventional heating methods. When low-carbon, carburized grades of steel are used, carbon is introduced after the spherical roller bearings are machined to a depth sufficient to produce a hardened case that can sustain bearing loads. The addition of carbon and alloys ensures the proper combination of a hard, fatigue-resistant case and a tough, ductile core.Bore size and outside diameter (OD) are important specifications to consider when selecting spherical roller bearings. The bore size is the bearing’s smallest dimension. The outer diameter includes the bearing housing, but excludes the flange. Other important specifications for spherical roller bearings include overall width, rated speed (oil), static axial load, static radial load, dynamic axial load, and dynamic radial load. Static axial and static radial loads are, respectively, the maximum axial and radial loads that bearings can withstand without permanent deformation. Dynamic axial and dynamic radial loads are, respectively, the calculated axial and radial loads under which a group of identical bearings with stationary outer rings can endure for a rating life of 1 million revolutions of the inner ring.The R-type spherical roller bearing (two piece finger type) is contributing to a quiet operation by reducing the vibration. Our spherical roller bearings are also available with the following options:

Machined bronze retainer which is ideal for higher speed operation and ensures better performance under marginal lubrication conditions.

Asymmetrical roller design, which reduces sliding friction and has less tendency for roller skew while operating (R & RR types); this type uses two sets of convex asymmetrical rollers separated by a central inner ring rib.

Symmetrical roller design (RH Type Spherical Roller Bearing) with two rows of longer symmetrical roller and only a center guide ring instead of a rib.

R and RH Type Spherical Roller Bearings are also available with lubrication holes and grooves, which optimizes lubricant capability.

Self-alignment feature accommodates up to 2 misalignments.