Rotary Tablet Press Sealing Arrangement Axial Movement
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Solution Overview
Problem
Rotary tablet presses face challenges in achieving effective sealing with minimal wear and friction, leading to dust leakage and contamination issues during operation and cleaning processes.
Innovation Solution
A ring-shaped holder with a sealing arrangement that moves axially between two positions, ensuring complete sealing during standstill and reducing engagement with the punch guiding during operation, allowing for automatic control of sealing forces to minimize friction and wear, and enabling cleaning without disassembling the rotor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lip sealings are mounted on the rotor and punch guiding to achieve sealing, then sealing effectiveness is improved, but wear and heat generation increase
Solution Approach 1:
The patent replaces the mechanical lip sealing system with a pneumatic sealing system. Instead of using contact-based lip seals that frictionally engage with the housing, the invention uses a pneumatic seal that is actuated by pressure differences to create the sealing action, thereby eliminating continuous mechanical contact and the associated wear and heat generation.
Solution Approach 2:
The patent applies pneumatic principles by using pressure differences to actuate the sealing mechanism. The pneumatic seal is opened or closed based on pressure conditions, replacing the mechanical friction-based sealing with a pressure-driven system that minimizes contact wear and heat generation.
2Ease of repair
If the rotor is made detachable for cleaning, then cleaning accessibility is improved, but device complexity increases
Solution Approach 1:
The patent extracts only the necessary sealing components from the rotor assembly, allowing the rotor to remain integrated while enabling access to specific sealing areas for cleaning. This selective extraction approach maintains the overall structural integrity and simplicity of the rotor while providing cleaning accessibility where needed.
Data Source
AI summary
A rotary tablet press, with a rotor driven by a driving motor, which has a die plate as well as an upper and a lower guiding for upper and lower punches, which co-operate with bores of the die plate, a stationary housing closely surrounding the rotor, which constitutes a pressing room, and with at least one ring-shaped sealing arrangement, which seals the housing against a punch guiding, wherein the sealing arrangement has a ring-shaped holder inside the housing, wherein the ring-shaped holder is axially movable between a first and a second position by means of a stationarily arranged lifting device, the sealing arrangement has a first sealing portion, which is continuously in engagement with a first sealing surface of the housing in the first and in the second position, and a second sealing portion which is in engagement with a second sealing surface of the punch guiding with a first sealing force in the first position and is in engagement with the second sealing surface in the second position either with a second sealing force, which is smaller than the first sealing force, or is out of engagement with the same.