Tripod Actuator Rolling Bearing Support for Lateral Load Friction
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Solution Overview
Problem
Conventional actuators in tripod structures for driving simulators experience excessive frictional forces due to lateral loads, leading to shock and discomfort during turns, and existing solutions like ball splines are costly and difficult to manufacture.
Innovation Solution
The actuator employs a rolling bearing structure with multiple roller followers and a preload mechanism to reduce friction, replacing traditional sliding bearings, allowing for reduced manufacturing costs and improved load handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a sliding bearing is used to support the piston, then the structure is simple and manufacturing cost is low, but frictional force increases causing shock during turns
Solution Approach 1:
The patent replaces the sliding bearing mechanical system with a rolling bearing system. The rolling bearing includes an inner ring, outer ring, and rolling elements (balls or rollers) that convert sliding friction into rolling friction, significantly reducing the frictional force between the piston support and the actuator body while maintaining structural simplicity and manufacturability.
2Object-affected harmful factors
If a ball spline is used instead of sliding bearing to reduce friction, then frictional force decreases, but manufacturing cost and difficulty increase
Solution Approach 1:
The patent adopts a rolling bearing design that is more economical and easier to manufacture compared to ball spline. The rolling bearing uses standardized components with simpler geometry, reducing manufacturing costs and complexity while achieving the same friction reduction effect. The design prioritizes cost-effective solutions that meet performance requirements without unnecessary complexity.
3Strength
If a larger ball spline is used to handle excessive lateral load, then load capacity increases, but manufacturing difficulty and cost increase
Solution Approach 1:
The patent employs a rolling bearing design that dynamically handles lateral loads through its rolling elements and cage structure. The rolling elements can accommodate radial and axial loads while maintaining smooth operation. This dynamic load distribution allows the actuator to handle excessive lateral loads during tripod operation without requiring oversized components, keeping manufacturing difficulty and cost manageable.
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 solution significantly reduces frictional forces by half, minimizing shock during turns and expanding the use range of driving simulators while lowering manufacturing costs and time.
Implementation Method 1
a ball screw used as a feed screw and arranged within the pipe (221), a conversion nut used as a feed nut, arranged within the pipe (221) and screwed with the ball screw (222), the conversion nut (223) converting a rotary motion into a linear motion
Implementation Method 2
The support mechanism (226) is a rolling bearing structure including a plurality of roller followers (226A to 226D)
Data Source
AI summary
An object of the present invention is to provide an actuator capable of reducing a shock in acceleration at the time of a turn caused by a load in a lateral direction orthogonal to an axis of the actuator even when the load is excessive while reducing manufacturing cost and manufacturing man-hours, and a tripod structure including the actuator. An actuator according to the present invention includes: a pipe; a ball screw used as a feed screw; a conversion nut used as a feed nut and screwed with the ball screw; a piston fixed integrally to the conversion nut and driven to expand and contract from a free end which is one end of the pipe; and a rolling bearing unit being provided on a tip of the free end of the pipe and including a plurality of roller followers holding the piston movably.