Multi-Row Ball Screw Groove Layout for Accurate U-Shaped Measurement
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Solution Overview
Problem
Accurately processing U-shaped spiral grooves in ball screws requires high measurement technique due to the absence of flanks on one side, making stable fixation and dimension measurement challenging.
Innovation Solution
A multi-row ball screw design featuring a nut with U-shaped first spiral grooves and continuous second spiral grooves, allowing for accurate oblique diameter dimension measurement and subsequent grinding of the first spiral groove.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a U-shaped spiral groove is used in the nut, then two-row balls can be accommodated for high rigidity, but accurate dimension measurement becomes difficult due to the absence of flanks
Solution Approach 1:
The nut's spiral groove is segmented into two distinct types: U-shaped first spiral grooves for ball accommodation and Gothic-shaped second spiral grooves for measurement. This segmentation allows each groove type to fulfill its specific function optimally without compromise.
Solution Approach 2:
The nut is designed with multi-functionality: the first spiral grooves serve the primary function of ball support for rigidity, while the second spiral grooves serve the measurement function. This multi-functionality resolves the contradiction by adding a measurement capability without removing the U-shaped groove's rigidity benefits.
2Quantity of substance
If a U-shaped spiral groove is used in the nut, then two-row balls can be accommodated, but stable fixation of the measurement ball becomes difficult
Solution Approach 1:
The measurement function is segmented from the ball accommodation function by using separate Gothic-shaped second spiral grooves. These grooves provide stable fixation points for the measurement ball through their flanked structure, while the U-shaped first grooves continue to accommodate the load-bearing balls.
Solution Approach 2:
The Gothic-shaped second spiral groove acts as an intermediary structure that facilitates stable measurement ball fixation. Its flanked geometry provides natural contact points that stabilize the measurement ball, solving the fixation problem without interfering with the primary ball screw function.
3Measurement precision
If Gothic-shaped spiral grooves are used for measurement, then accurate dimension measurement is possible, but the U-shaped groove structure for two-row balls is compromised
Solution Approach 1:
The spiral groove system is divided into functionally distinct segments: U-shaped first spiral grooves optimized for ball support and Gothic-shaped second spiral grooves optimized for measurement. This segmentation allows each groove type to be optimized for its specific purpose without compromising the other.
Solution Approach 2:
Different local qualities are applied to different regions of the nut: the first spiral grooves have U-shaped cross-sections suited for ball accommodation, while the second spiral grooves have Gothic-shaped cross-sections suited for measurement. This local differentiation resolves the contradiction by allowing optimal geometry for each function in its specific location.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables high dimensional accuracy of the U-shaped first spiral groove, facilitating stable operation and precise linear motion conversion in ball screws.
Implementation Method 1
a plurality of balls disposed so as to be rollable on rolling paths constituted by the plurality of spiral grooves of the nut and the plurality of spiral grooves of the screw shaft
Data Source
AI summary
A multi-row ball screw includes a nut having a plurality of spiral grooves on an inner peripheral surface thereof, a screw shaft having a plurality of spiral grooves on an outer peripheral surface thereof, and a plurality of balls disposed so as to be rollable on rolling paths constituted by the plurality of spiral grooves of the nut and the plurality of spiral grooves of the screw shaft. The spiral groove of the nut includes a U-shaped first spiral groove having left and right flanks that are respectively able to come into contact with two-row balls and separated from each other in an axial direction, and two second spiral grooves continuous with each row of the first spiral groove and each having left and right flanks that are able to come into two-point contact with the ball.