Spindle Thread Clamping Assembly With Friction-Coupled Inner Sleeve
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thread clamping devices for spinning or twisting machines face issues with reliable connection between the inner sleeve and the spindle due to high demands on manufacturing, leading to material displacement and friction, which can cause blocking and failure.
Innovation Solution
A thread clamping device with a thread cutter that secures the axial position and connects the inner sleeve to the spindle for conjoint rotation, using a press-fit or frictional connection to eliminate the need for additional fixing elements and prevent material displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a knurled portion is used to connect the inner sleeve to the spindle, then a positive connection for conjoint rotation is established, but the inner sleeve is cut into and material is displaced, causing radial expansion and friction that leads to blocking
Solution Approach 1:
The harmful knurled portion is completely removed from the spindle design. Instead, a smooth connection surface is provided on the spindle upper part, and the inner sleeve is connected to the spindle through frictional contact without any cutting or material displacement, thereby eliminating the source of friction and blocking while maintaining reliable connection
Solution Approach 2:
The connection mechanism changes from a positive mechanical interlock (knurled portion cutting into plastic) to a friction-based connection (smooth surface contact). This parameter change in the connection method eliminates material displacement and radial expansion, preventing the friction and blocking issues while maintaining rotational reliability
2Reliability
If a toothed annular surface is provided on the inner sleeve for engaging with the spindle, then a positive connection is established, but high manufacturing precision is required for both the inner sleeve and spindle, and inaccurate toothing causes material displacement and radial expansion
Solution Approach 1:
The complex toothed annular surface and corresponding toothing on the spindle are completely removed. The invention replaces this high-precision mechanical interlock with a simple smooth connection surface on the spindle and a matching smooth inner sleeve surface, eliminating the need for precise toothing manufacturing while maintaining reliable connection through friction
Solution Approach 2:
The connection approach changes from form-closure (interlocking teeth requiring precise geometry) to force-closure (frictional contact). This parameter change in the connection mechanism eliminates the manufacturing precision requirements for toothing while maintaining connection reliability through adequate frictional force
3Strength
If the inner sleeve is pressed radially outward due to material displacement, then the outside diameter increases, but this causes friction between the inner sleeve and clamping element, leading to blocking and failure
Solution Approach 1:
The root cause of radial expansion (the knurled portion cutting into the inner sleeve) is completely removed. The smooth connection surface approach ensures no material displacement occurs, preventing radial expansion and the subsequent friction and blocking between the inner sleeve and clamping element
Solution Approach 2:
The design proactively prevents material displacement by using a smooth connection surface that does not concentrate stress or cause cutting action. This preliminary anti-action against material displacement prevents the chain of events leading to radial expansion, friction, and blocking before they can occur
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
The solution allows for easy and reliable mounting of the inner sleeve on the spindle, preventing deformation and friction-related failures, ensuring a stable and efficient thread clamping process.
Implementation Method 1
using a press-fit or frictional connection to eliminate the need for additional fixing elements and prevent material displacement
Data Source
AI summary
A thread clamping device for a spindle for detachably securing a thread in a clamping gap, comprising a first clamping unit with an inner casing that can be arranged coaxially to the spindle, a thread separator that can be secured in an axial direction on the inner casing, the first clamping unit being securable on an upper part of the spindle for axial positioning, and a second clamping unit having a clamping element that can be adjusted axially relative to the first clamping unit between a clamping position closing the clamping gap between the thread separator and the clamping element and an open position opening the clamping gap. The thread separator is designed to be secured on the spindle upper part for axial positioning and to be rotationally coupled to the spindle upper part, and the thread separator and the inner casing can be rotationally coupled to one another.