Technical Calculation Software
| File Name | Catalog Page | File Size | Uncompressed File Size |
|---|---|---|---|
| Linear Guides · Ball Screws Technical Calculation Software Ver.2.0 | - | 6.79 MB | 6.85MB |
Allowable Rotational Speed
Ball screw lead is determined based on required feed speed and the lead. The speed needs to be kept below the allowed max. speed.
The allowable speed needs to be evaluated based on both the screw's critical speed and ball recirculating speed limitation DmN value.
Critical Speed
Allowable rotational speed is defined as 80% of the Critical Speed where the rotating shaft coincides with the shaft's natural frequency.
The Allowable Rotational Speed can be calculated with the following formula.
Additionally, it can be obtained from the Allowable Rotation Speed Graph in Table 2.
Allowable Rotational Speed Calculation Example
Obtain an Allowable Rotational Speed for condition of Fig. 2.
Application Condition
- ・Screw Dia. Ø15, Lead 5
- ・Mounting Method Fixed - Supported
- ・Load Applicable Span Distance l2 790mm
Calculation Method
g=15.1 since the mounting method is Fixed – Supported, and the Allowable Rotational Speed will be
Therefore, make the rotational speed to 3024-min-1 or less.
■Table 1. Allowable Rotational Speed Graph
Satisfying Ball Screw Calculation Example
Application Condition
- ・Screw O.D. 20
- ・Supported Span 1500mm
- ・Mount Method Fixed – Supported
Calculation Details
- (1) Find an intersection of a vertical line from Supported Span 1500mm and Shaft Dia. Ø.
- (2) Read the Allowable Rotational Speed at Fixed – Supported scale to obtain the Allowable Rotational Speed.
Application Condition
- ・Supported Span Distance 2000mm
- ・Max Rotational Speed 1000min-1
- ・Mounting Method Fixed – Fixed
Calculation Details
- (1) Find an intersection of a vertical line from Supported Span 2000mm and a horizontal line from Fixed – Fixed 1000min-1.
- (2) A shaft diameter within the range of the intersection is a diameter that satisfies Max. Speed of 1000min-1.
DmN Value
When the recirculating ball's orbital velocity increases within a nut, impact from the balls can damage the recirculating components. Such limitation is the DmN Value.
