Electric Actuator Bearing Layout for Compact Linear Motion
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Solution Overview
Problem
Existing electric linear actuators face challenges in size reduction and design flexibility due to the placement of rolling bearings, which restricts layout and interferes with other components.
Innovation Solution
The use of a double-row bearing arranged on one side of the transmission gear mechanism allows for reduced interference with other components, enabling size reduction and increased design freedom by allowing the drive part to be positioned closer to the motion conversion mechanism, and the inclusion of a double-row angular contact ball bearing for stable support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rolling bearings are arranged on both sides of the nut while sandwiching the second gear, then the nut is supported stably, but the layout is restricted and interference with other components occurs
Solution Approach 1:
The patent extracts one of the two rolling bearings from the symmetric arrangement and replaces it with a double-row bearing on one side. This removes the interference problem with other components while maintaining support stability through the double-row bearing's enhanced load-bearing capability.
Solution Approach 2:
The patent transitions from a symmetric bearing arrangement (bearings on both sides) to an asymmetric arrangement (double-row bearing on one side only). This asymmetric configuration eliminates interference with components on the other side while the double-row bearing provides equivalent or superior support stability.
2Reliability
If rolling bearings are arranged on both sides of the nut, then the nut is supported stably, but the actuator size increases
Solution Approach 1:
By removing one bearing from the symmetric arrangement and using a double-row bearing on one side, the overall width and volume of the actuator are reduced while the double-row bearing maintains adequate support stability.
3Reliability
If the drive part is positioned far from the motion conversion mechanism, then the double-row bearing arrangement is maintained, but the actuator size increases
Solution Approach 1:
The patent allows the drive part to be positioned closer to the motion conversion mechanism in the radial direction (orthogonal to axial direction) since the double-row bearing on one side eliminates interference constraints, thereby reducing the overall actuator volume while maintaining support stability.
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
This configuration achieves size reduction and increased design freedom, enabling more compact and versatile electric actuator designs suitable for various applications.
Implementation Method 1
the double-row bearing can bear a radial load as well as axial loads in both directions, and can thus stably and reliably support the motion conversion mechanism part
Data Source
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AI summary
An electric actuator includes: a drive part (2); a motion conversion mechanism part (3) configured to convert a rotary motion from the drive part (2) to a linear motion in an axial direction parallel with an output shaft (10a) of the drive part (2); a driving force transmission part (4) including a transmission gear mechanism (28) configured to transmit a driving force from the drive part (2) to the motion conversion mechanism part (3); and a motion-conversion-mechanism support part (5) including a double-row bearing (40) configured to support the motion conversion mechanism part (3), wherein the double-row bearing (40) is arranged on one side in the axial direction with respect to the transmission gear mechanism (28).