Leno Selvedge Device with Segmented Stator
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Solution Overview
Problem
Existing leno selvedge devices for weaving machines are bulky and lack sufficient torque, leading to inefficient fabric cutting with wide cutting lanes and tissue loss, as they require synchronous movement with heald frames and cannot independently control shed opening or closure.
Innovation Solution
A slim, high-torque leno selvedge device with a circular ring carrier and magnetizable ring gears, featuring an electromagnetic drive with a laminated stator core and magnets, allowing for independent control of shed position and high acceleration without continuous synchronous rotation with heald frames.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional electromagnetic drives are used in leno selvedge devices, then the device structure is simple, but the torque is insufficient and the device becomes bulky
Solution Approach 1:
The stator core is segmented into multiple laminated plates stacked together, allowing the magnetic flux to be distributed across multiple paths. This segmentation increases the effective torque area without proportionally increasing the device volume, resolving the contradiction between torque output and compact size.
Solution Approach 2:
The drive system combines magnetizable material for the rotor with laminated ferromagnetic material for the stator core, creating a composite electromagnetic structure. This material combination optimizes magnetic flux density and torque generation within a compact form factor.
2Ease of operation
If continuous synchronous rotation with heald frames is implemented, then precise position control is achieved, but the device complexity increases
Solution Approach 1:
The drive system transitions from continuous synchronous rotation to dynamic on-demand rotation. The rotor can be accelerated independently to specific positions and held stationary, providing dynamic control flexibility without requiring continuous synchronization, thereby reducing control system complexity.
Solution Approach 2:
The mechanical synchronization mechanism with heald frames is replaced by an electromagnetic control system that uses magnetic fields to achieve positioning. This substitution eliminates complex mechanical linkages and allows independent control through electrical signals alone.
3Speed
If high acceleration values are achieved, then independent shed position control is enabled, but the force requirements increase
Solution Approach 1:
The electromagnetic drive uses periodic pulsing of coil currents to generate alternating magnetic fields that drive the rotor. By controlling the frequency and duty cycle of these periodic pulses, high acceleration is achieved during motion while average force requirements are reduced during holding positions.
Solution Approach 2:
The drive system changes operational parameters dynamically - using high current pulses for acceleration phases and lower holding currents for position maintenance. This parameter variation allows high acceleration when needed while minimizing overall force requirements and energy consumption.
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 efficient fabric cutting with reduced tissue loss by providing high torque and acceleration, allowing for independent control of shed opening and closure, reducing the need for precise position control and minimizing cogging torque and ripple.
Implementation Method 1
a plurality of coils (8) arranged in the laminated core of stator (6), with the laminated core of stator (6) having segments (7), each with one of the ring gears (14, 15) assigned to it
Implementation Method 2
a plurality of magnets (17) distributed on the outer circumference or outer casing of the carrier (11) in the area of the ring gears (14, 15)
Data Source
Figure 1
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AI summary
The invention relates to a device for forming a twisted edge (1), in particular for a weaving machine, comprising a stationary housing (5) and an annular or disc-shaped carrier (11) rotatably mounted in the housing (5) by a bearing (13), wherein the carrier (11) has at least two parallel toothed rings (14, 15) made of magnetizable material on its outer circumference, wherein in the region of the inner ring of the bearing (13) the carrier (11) has two diagonally opposite thread loops (3) for guiding twisted threads (20), wherein a plurality of magnets (17a) are arranged circumferentially distributed on the outer circumference of the carrier (11) in the region of the toothed rings (14, 15), wherein the housing (5) has an annular stator lamination stack (6) associated with the two toothed rings (14, 15) with a plurality of coils (8) arranged thereon, wherein the stator lamination stack (6) in Area of the coils (8) segments (7) each with one of the teeth (14a,15a) has the toothing (7a) associated with the toothed rings.