Cargo Handling System PDU Cogging Torque Braking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional cargo handling systems require numerous braking rollers to maintain braking function in power-off states, leading to undesired resistance and space inefficiency, as solenoid brakes lose functionality in power-off conditions.
Innovation Solution
A cargo handling system utilizing a power drive unit (PDU) with a permanent magnet motor (PMM) that provides both static restraint braking through high cogging torque and dynamic control braking via motor regeneration, reducing or eliminating the need for additional braking rollers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solenoid brakes are used in the PDU, then braking function is provided in power-on state, but braking function is lost in power-off state
Solution Approach 1:
The patent merges the braking function into the PDU by integrating a brake assembly with the permanent magnet motor. The brake assembly includes a brake disc coupled to the motor shaft and brake pads that engage the disc, allowing the PDU itself to provide braking force in both power-on and power-off states without requiring separate braking rollers.
Solution Approach 2:
The permanent magnet motor provides self-braking capability through its inherent magnetic field. When power is removed, the magnetic field maintains a braking torque that prevents the tray from moving, allowing the system to serve its own braking needs without external braking components.
2Reliability
If braking rollers are added to provide braking force in power-off state, then braking function is maintained, but undesired resistance is imposed in normal operation
Solution Approach 1:
The braking function is merged into the PDU structure itself, eliminating the need for separate braking rollers. The brake assembly integrates the brake disc, brake pads, and actuating mechanism within the PDU housing, allowing braking force to be applied directly at the motor without requiring additional rollers that would create resistance during normal operation.
3Reliability
If braking rollers are added to provide braking function, then braking capability is improved, but space is consumed that could be used for transport rollers or restraint devices
Solution Approach 1:
The brake assembly is integrated within the PDU housing, utilizing the existing structural space of the power drive unit. The brake disc is coupled to the motor shaft, and the brake pads are positioned to engage the disc within the PDU footprint, eliminating the need for additional space-consuming braking rollers and freeing up tray space for transport rollers and restraint devices.
4Reliability
If numerous braking rollers are used, then braking function is ensured, but the number of components increases significantly
Solution Approach 1:
The patent consolidates the braking function into a single integrated brake assembly within each PDU, eliminating the need for multiple separate braking rollers. The brake assembly includes a brake disc, brake pads, and actuating mechanism that work together as one unit, dramatically reducing the total number of components while ensuring reliable braking function.
Solution Approach 2:
The PDU is designed with multi-functionality, serving both as the power drive unit and as the braking mechanism. The permanent magnet motor provides propulsion during power-on state and automatic braking during power-off state, eliminating the need for separate dedicated braking components and reducing overall system complexity.
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 PDU with PMM effectively reduces or eliminates the need for braking rollers, minimizing resistance and optimizing space usage while maintaining braking functionality in both power-on and power-off states, enhancing operational efficiency and system design.
Implementation Method 1
PDMs or, more specifically, permanent magnet motors (PMMs) may be utilized, which may provide a high degree of 'cogging torque' when in a stationary position
Implementation Method 2
dynamic control braking via motor regeneration
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
Disclosed is a cargo handling system (102), and a power drive unit (PDU) (100) for a cargo handling system, wherein the PDU comprises a permanent magnet motor (PMM) (200) and is designed to provide a first static restraint braking function (110) effectuated by designing the PMM to have a high cogging torque, and a second dynamic control braking function (116) effectuated by motor regeneration.