Balls screws and lead screws

MISUMI offers a wide range of ball screws and lead screws. You can select between precision and rolled ball screws. Parameters, such as length and shape of the shaft end and the nut form, can be configured according to your design. For the spindle nuts with acme thread, you can choose between different models, such as block flange, round flange or square flange.

Rolled ball screws with up to 40% less volume

The rolled ball screw type and corresponding compact nuts offer up to 40% lower nut capacity. Of course, standard nuts and guide nuts are also available.

Various shaft end options

Several options are available for the shaft end of the ball screw:

Support side

  • No machining of the shaft end
  • Reversed ball nut alignment
  • No safety groove on the shaft end of the support side
  • Other processing of the shaft end of the support side
  • Other length of the shaft end of the support side

Fixed side

  • Key areas on the fixed side
  • Groove on the shaft end of the fixed side
  • Up to 2 clamping surfaces at the shaft end

Available lubricants for ball screws

The lubricants of the ball screws can be changed from the standard version to the following types.

The versions L or G permit proper operation by low particle emission during operation. The choices are:

  • ET-100 with excellentheat resistance/oxidationresistance and adhesion strength/cohesion strength, as well as minimum splashand low
  • LG2as cleanroom qualifiedspecial lubricantforlinear guides, ball screws, etc.

Precise mounting interface at ball screw

Precise mounting interface at ball screw

(1), (2) Radial run-out of the thread surface to the bearing axis of the threaded shaft. These parameters are affected by the "(8) total radial run-out of shaft" and may be subject to compensation.
(3) Radial run-out of drive component interface surface in relation to the bearing axis of the threaded shaft.
(4), (5) Perpendicularity of the bearing collars of the shaft relative to the bearing axis of the threaded shaft.
(6) Perpendicularity of the mounting surface for the ball nut flange (reference) in relation to the axis of the threaded shaft.
(7) Radial run-out of the outer circumference of the ball nut relative to the axis of the threaded shaft.
(8) Total radial run-out of shaft.

Selection of Ball Screws

The standard selection procedure for right ball screw:

  1. Decide on operating conditions of the ball screw: weight per part, movement speed, movement pattern, speed of threaded shaft, strokes, mounting direction (horizontal or vertical), life, positioning.

  2. Preliminarily select the specifications for the ball screw according to the operating conditions: precision category, shaft diameter, thread pitch and length of threaded shaft of ball screw.

  3. Standard safety check:
    1. Check permissible axial load: Make sure that the value of the axial load is within the safe range of permissible values for the threaded shaft.
    2. Check permissible speed: Make sure that the speed of the screw shaft is within the safe range of permissible values for the threaded shaft.
    3. Operating time: Calculate the lifetime of the threaded shaft and make sure that it is suitable for the required operations.
    Depending on the results of the safety check, it might be necessary to return to Step 1 and Step 2 to make adjustments to the setup. If the standard safety check is passed, continue to Step 4.

Considerations for required performance: The following confirmations are necessary if higher positioning speed and better control behaviour are required:

  1. Strength of threaded shaft
  2. Operating time variations due to temperature variations

Depending on the results of these considerations, returning to Steps 1 and 2 might be necessary in order to make corresponding adjustments

Permissible axial load of ball screws

Permissible axial load of ball screws
The allowable axial load represents the maximum load, including safety limits, which causes a bulging of the shaft. The maximal axial load on the threaded shaft must be less than or equal to the value for the permissible axial load.


1. Calculating the permissible axial load

Determine the value of the curve to the allowable axial load on the Ball Screw (Fig.2) using the following three factors:

  • Thread shaft-Ø
  • Mounting aid procedure (see Figure 3)
  • Distance between load points of action (see Figure 3)

* Use a formula in order to determine the exact value for the permissible axial load.

 

2. Calculation of maximal axial load

Use the following formulas to determine each axial acceleration, constant speed and deceleration (when installed horizontally). The largest load is considered the maximum axial load.

  • Constant speed ··· axial load (Pb)=μWg
  • Acceleration ··· axial load (Pa)=W +μWg
  • Delay ··· axial load (Pc)=W -μWg

*For vertical installation remove the "μ" from the calculation.

μ: linear guide friction constant (0:02 for the linear guides)
W: weight of parts
g: acceleration due to gravity 9.8 m/s2
α : acceleration (*)
(*) acceleration (α)=(Vmax/t)x10-3
Vmax: quick delivery speed
t: acceleration/deceleration time
3. Safety check

Check the curve for the permissible axial load (Fig. 2) to ensure that the value for the maximum axial load is less than or equal to the value for the permissible axial load.

* Use a formula in order to determine the exact value for the permissible axial load.

 

2. Calculation of maximal axial load

Use the following formulas to determine each axial acceleration, constant speed and deceleration (when installed horizontally). The largest load is considered the maximum axial load.

Video - Introduction balls screws

These videos were kindly provided to us by our USA subsidiary. Therefore, contact the US subsidiary for all related details. All products are also available in Europe.

Important information: Products of third-party suppliers (non MISUMI products) with a lead time of 4 days or less can be cancelled within 2 hours after order placement. Please refer to our cancellation policy and T&C for further details.