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Structure & Advantages | Load rating & Rated Life | Housing | Precausion | Application | Part Number

Structure & Advantages

FR type is supplied as a set which would include a bush and a shaft. Constructed with combination of a load carrying outer cylinder and a load free ball recirculation cover, it is engineered to smoothly handle compound motions. For ease of mounting, the FRA type which has the FR bush pre-installed into a factory made housing is also available.

High load capacity & high rigidity

High load capacity, high rigidity, and long life are achieved through bearings place all around the inner space between an outer cylinder and a linear shaft.

Smooth motion

Although it is an all-ball bearing construction, load carrying bearings are designed to align along the linear movement to provide smooth motion in both linear and rotational directions.

High accuracy

Each set of a shaft and a bush is matched and controlled to ensure smooth and highly accurate motion.

(873KB)

Load rating and Rated Life

Load Rating Rated Life are defined as follows.

Rated Life

When a group of identical slide rotary bush is operated under equal condition, a number of rotation which 90% of the group can achieve without causing flaking.

Basic dynamic load rating

A constant direction and magnitude of load which achieves 10⁶ rotations of life.

Basic static load rating

A static load constant in direction and magnitude which applies contact stress at the center of contact area between the most heavily stressed rolling element and the race way.
Relation between applied load and rated life of Slide Rotary Bush is established in following equation (1)

Since slide rotary bush is used in combined linear and rotary motion, rated life is calculated using equation (2) and (3)

When linear and rotary motions are combined

When only linear motion is involved

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Housing

NB Slide Rotary Bush FR type is manufactured with a properly controlled clearance between the shaft and bush. When designing a custom housing, the recommended inner diameter tolerance of the housing should be either H7 or H6. Anti-rotation tab option (Z) is recommended when rotational motion is involved to prevent the bushing from rotating within the housing. Please refer to the recommended dimensions for housing when using the anti-rotation tab. FRA type is provided with anti-rotation tab as standard feature.

Use and handling precaution

Bearing ball dropout
FR type is a set of a bush and a shaft. Ball elements are not retained inside the bush and will dropout if the bush is removed from the shaft. If the bush must be removed for installation, use a dummy shaft identical to the FR shaft diameter.

Lubrication
Purpose of lubrication includes reducing friction between rolling elements and raceway, reducing mechanical wear, and preventing rust. Condition of lubrication can have large effect on FR type's performance and life therefore it is important to select and maintain proper lubrication for required operational conditions. The FR type is shipped pre-lubricated with lithium soap grease No. 2 and is ready to be used without additional lubrication. Please re-lubricate as necessary with similar type grease depending on its operating condition.

Operating temperature range
Please use FR type within the temperature range of -20 to 80 degree Celsius.

Application examples

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Part Number Structure

FR Type

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FRA Type

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(873KB)

Required load capacity and accuracy must be calculated according to the application conditions in order to select appropriate linear system.      Please refere to the Engineering Information page.
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