Static-Drive Capping Head for Decoupled Rotary and Linear Motion
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Solution Overview
Problem
Existing capping heads face issues with power consumption and wear due to the constant lifting and lowering of heavy weights, and require complex constructions and adaptable drive mechanisms for translational and rotary motions.
Innovation Solution
A capping head with a self-standing module for rotary motion, using a stationary motor and bushings to decouple translational and rotary motions, allowing adaptation to either mechanical cams or electric motors for translational drive, with stationary power and signal components, and a detachable decoupling joint for smooth operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the rotor of the rotary motor is integral with the rotating and translating shaft, then the rotary motion is directly transmitted, but the constant lifting and lowering of the rotor causes considerable inertial actions, higher power consumption and greater wear
Solution Approach 1:
The drive system is segmented into two independent parts: a stationary rotary motor and a separate translating mechanism (cam or linear motor). The rotary motor remains fixed while only the shaft and cap-handling members translate, eliminating the inertial problem of moving the motor rotor during translation.
Solution Approach 2:
A cam profile or linear motor acts as an intermediary mechanism to convert the stationary rotary motor's output into the desired translating motion of the shaft. This mediator allows the motor to remain stationary while achieving the required translational movement.
2Device complexity
If a mechanical cam is used to impart translational motion, then the construction is simpler, but the cam must extend along the whole advance path and requires precise profiling
Solution Approach 1:
The stationary motor housing is designed to serve dual purposes: it houses the rotary motor and simultaneously provides the cam profile surface. This multi-functional design eliminates the need for a separate cam component, reducing construction complexity while maintaining manufacturing feasibility.
3Adaptability or versatility
If electrical actuators are used to impart translational motion, then the construction is more flexible, but the actuators and cables must move with the head which hinders machine movements and is expensive
Solution Approach 1:
The electrical actuator (linear motor) is extracted from the moving head assembly and fixed to the stationary machine frame. Only the necessary mechanical components (shaft, cap-handling members) translate, while the expensive and complex electrical actuator remains stationary, eliminating the movable wiring problem.
4Ease of operation
If the motor housing moves with the shaft during translation, then the motor can be directly coupled to the shaft, but the power and signal cables must be movable which hinders machine movements
Solution Approach 1:
Instead of moving the motor with the shaft, the invention inverts the arrangement by fixing the motor to the stationary housing and allowing the shaft to move independently. The motor drives the shaft through a stationary coupling mechanism, reversing the conventional approach to eliminate movable wiring.
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
Reduces power consumption, simplifies construction, and allows easy adaptation to different drive types, minimizing wear and assembly complexity while ensuring reliable operation and reduced maintenance.
Implementation Method 1
a first electric motor for driving the rotary motion of the shaft, the motor having a rotor and a stator
Implementation Method 2
transfer the rotary motion of the rotor to the shaft thanks to the cooperation between ribs provided on an inner surface of the bushing and grooves provided on an outer surface of the shaft
Data Source
AI summary
A capping head for applying pre-threaded caps to containers includes a rotating and translating shaft, a first electric motor for driving the rotary motion of the shaft, the motor having a stator and a rotor coaxially arranged around the shaft and mounted in a stationary housing so as to be decoupled from the shaft as far as the translational motion is concerned, and a first bushing, which is mounted at one end of the stationary housing, is passed through by the shaft and is arranged to transfer the rotary motion of the rotor to the shaft. The head further includes a second bushing that is mounted at a second end of the stationary housing, opposed to the first one, to seal the internal cavity thereof also at that second end, and is passed through by the shaft that is mounted in the same bushing in a freely rotatable manner.