New Design,Ball Screw with 6mm-Nominal Diameter and 6mm-Lead customized encouragement.

Ball Screw Design Resources When you need ball screw, we will introduce you to the specification process.In this article, you'll find some basic design information, explanatory terms, and useful diagrams.

The critical speed is the angular speed at which the screw (or nut) vibrates violently.Regardless of installation direction, the ball screw assembly must operate at its critical speed to avoid vibration, noise, and possible failure.

The size and position of the shaft imbalance, the length of the shaft, the diameter of the shaft and the type of Bearing support are the factors affecting the critical speed.Determination of ball screw life The service life of a ball screw assembly, usually measured in one million inches of travel.The workload rating is a major factor in determining the life of ball screws.Each application is unique;Duty cycle and environment also play a role. We encourage customers to consult with our engineering staff to discuss the specific requirements of their application.

Determining Ball Screw Life

The useful life of a ball screw assembly, usually given in terms of one million inches of travel. The operational load rating is a major determinate of ball screw life. Every application is unique; duty cycle and environment also have an effect. Customers are encouraged to consult with our engineering staff to discuss the specific requirements of their applications.

Determining Ball Screw Load

The amount of load to be moved is used to select the proper screw size.

Vertical load move: The nut load is equal to the weight to be moved plus the friction load.

Horizontal load move: The nut load is determined by multiplying the weight by the coefficient of friction.

Loads can also be measured with a spring scale or dynamometer, which is recommended for loads that are neither vertical or horizontal. The higher the load, the larger the size of the screw and nut is needed. The load capacity of a ball screw can be increased by increasing screw diameter, nut length, quantity of internal balls or ball diameter.

Lead Error Standards

Lead error refers to the error in lead length per turn, compared to the basic lead specified. We manufacture Ground Ball Screws up to ANSI Class 2 or DIN/JIS Class 1 specification.

Standard	Specification
ANSI C2, DIN/JIS C1	0.0002 in/ft or 5 μm/300mm
ANSI C5, DIN C3	0.0005 in/ft or 12 μm/300m
ANSI C7, DIN C5	0.001 in/ft or 25 μm/300mm
ANSI C8	0.006 in/ft or 150 μm/300mm

Ball Screw Cause/Effect Considerations

The following chart indicates the relationship between various design specifications and operation parameters.

INCREASE IN:	AFFECTS:	HOW:
Screw Length	Critical Speed	Decreases
	Column Load	Decreases
Screw Diameter	Critical Speed	Increases
	Inertia	Increases
	Stiffness	Increases
	Load Capacity	Increases
	Column Load	Increases
Lead	Torque	Increases
	Load Capacity	Decreases
	Positioning Accuracy	Decreases
	Angular Velocity	Decreases
Angular Velocity	Critical Speed	Decreases
Mounting Rigidity	Critical Speed	Increases
	System Stiffness	Increases
Load	Life	Decreases
Nut Length	Load Capacity	Increases
	Stiffness	Increases
No. of Balls	System Stiffness	Increases
	Load Capacity	Increases
Preload	Positioning Accuracy	Increases
	System Stiffness	Increases
	Drag-Torque	Increases
Ball Diameter	Life	Increases
	Stiffness	Increases
	Load Capacity	Increases
	Lead	Increases

Ball Screw Assembly

Ball Screw Mounting & ball nut Styles

Ball Screw Mounting Styles: Four standard mounting styles are available. Fixed ends offer the highest column load support and the highest resistance to vibration.

Fixed-Free

Fixed-Support

Support-Support

Fixed-Fixed

Ball Nut Styles: For standard ball nut styles are available. Internal and external returns can be applied to all styles.

Single Nut (1 piece)

Middle Flange Nut (1 piece)

Double Nut (2 pieces)

Flange to Flange Nut (2 pieces)

Ball Screw Customization

Your ball screw will be configured with the options you specify, and can be further customized for a complete turn-key solution that is quick and easy to install, saving you time and money. Customization options:

Ball nut configuration (single or double nut, 2-piece flange to flange nut, middle flange nut)
Internal or external ball returns
Wipers & End Seals
Custom journal ends (view typical journal end specs)
Custom housing & mounting blocks