Medium Torque Type Ball Spline

With the medium-torque ball spline, the spline shaft has two to three crests on the circumference, and along both sides of each crest, two rows of balls (four to six rows in total) are arranged to hold the crest so that a reasonable preload is applied.
The rows of balls are held in a special resin cage incorporated inside so that they stay aligned and recirculate. With this design, balls will not fall even if the nut is removed from the spline shaft.

Precautions on Use

Types

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Medium torque type
Cylindrical type
Solid spline shaft
Hollow spline shaft

Splineshaftdiameter(mm) : 4,5,6,8,10,13,16,20,25,30,40,50,60,80,100

Medium torque type
Flanged type
Solid spline shaft
Hollow spline shaft

Splineshaftdiameter(mm) : 6,8,10,13,16,20,25,30,40,50

Medium torque type
Compact
Cylindrical type
Solid spline shaft
Hollow spline shaft

Splineshaftdiameter(mm) : 4,5,6,8,10,13,16,20,25,30

Medium torque type
Compact
Flanged type
Solid spline shaft
Hollow spline shaft

Splineshaftdiameter(mm) : 4,5,6,8,10,13,16,20,25,30

Lightweight
Medium torque type
Compact
Flanged type
Solid spline shaft
Hollow spline shaft

Splineshaftdiameter(mm) : 5,6,8,10,13,16,20,25,30

Lightweight
Medium torque type
Compact
Flanged type
Solid spline shaft
Hollow spline shaft

Splineshaftdiameter(mm) : 5,6,8,10,13,16,20,25,30

Features

Structure and Features

With the medium torque type Ball Spline, the spline shaft has two to three crests on the circumference, and along both sides of each crest, two rows of balls (four or six rows in total) are arranged to hold the crest so that a reasonable preload is applied.
The rows of balls are held in a special resin retainer incorporated in the spline nut so that they smoothly roll and circulate. With this design, balls will not fall even if the nut is removed from the spline shaft.

Large Load Capacity

The raceways are formed into circular-arc grooves approximate to the ball curvature and ensure angular contact. Thus, this model has a large load capacity in the radial and torque directions.

No Angular Backlash

Two rows of balls facing one another hold a crest, formed on the circumference of the spline nut, at a contact angle of 20° to provide a preload in an angular contact structure. This eliminates an angular backlash in the rotational direction and increases the rigidity.

High Rigidity

Since the contact angle is large and an appropriate preload is given, high rigidity against torque and moment is achieved.

Ball Retaining Type

Use of a retainer prevents the balls from falling even if the spline shaft is pulled out of the spline nut.(except for models LT4 and 5)

Types of Spline Shafts

Precision Solid Spline Shaft (Standard Type)

The raceway of the spline shaft is precision ground. It is used in combination with a spline nut.

Special Spline Shaft

THK manufactures a spline shaft with thicker ends or thicker middle area through special processing at your request.

Hollow Spline Shaft (Type K)

A drawn, hollow spline shaft is available for requirements such as piping, wiring, air-vent and weight reduction.

Hollow Spline Shaft (Type N)

A drawn, hollow spline shaft is available for requirements such as piping, wiring, air-vent and weight reduction.

Housing Inner-diameter Tolerance

When fitting the spline nut to the housing, transition fit is normally recommended. If the accuracy of the Ball Spline does not need to be very high, clearance fitting is also acceptable.

Table1 Housing Inner-diameter Tolerance

Housing Inner-diameter Tolerance	General conditions	H7
Housing Inner-diameter Tolerance	When clearance needs to be small	J6