Anti-backlash Gear Control via Dynamic Bias Summing
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Solution Overview
Problem
Existing gear systems experience backlash, leading to audible noise and performance issues due to gaps between gear teeth, which simple biases cannot effectively eliminate in all operating conditions, especially in situations requiring quiet operation.
Innovation Solution
An anti-backlash gear control device is introduced, comprising first and second bias modules to generate biases for motors connected to gears, and a command module to sum drive commands with these biases, ensuring continuous contact and minimizing backlash by controlling motor operations to prevent bias override.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bias is applied to maintain gear contact, then backlash is reduced, but the bias can be overcome in certain operating conditions allowing impact and noise to occur
Solution Approach 1:
The system dynamically adjusts bias application based on operating conditions. The control device monitors gear motor operation and selectively applies bias to the non-driven gear motor only when needed to maintain contact, rather than applying continuous static bias. This dynamic approach maintains reliable gear contact while preventing bias override during high-torque operations.
Solution Approach 2:
The driven gear motor's own torque production serves to maintain gear contact. When the driven motor produces sufficient torque, it naturally maintains contact with the driven gear, making additional bias application unnecessary. The system leverages the motor's inherent capability to self-maintain contact, reducing reliance on external bias mechanisms.
2Reliability
If excessive torque is applied to maintain gear contact, then backlash is eliminated, but power consumption increases
Solution Approach 1:
Instead of applying continuous excessive torque through bias, the system applies partial bias only when and where needed. The control device selectively applies bias to the non-driven gear motor during specific operating conditions where contact maintenance is critical, rather than applying full bias continuously. This partial action approach eliminates backlash when necessary while minimizing unnecessary power consumption during normal operation.
Solution Approach 2:
The system changes the torque parameter dynamically based on operating conditions. Rather than maintaining constant high torque through continuous bias, the control device adjusts bias magnitude and application timing based on motor current, speed, and load conditions. This parameter change strategy maintains gear contact reliability while optimizing power consumption by applying torque only when needed.
3Reliability
If bias is applied to prevent backlash, then gear contact is maintained, but the system complexity increases
Solution Approach 1:
The gear motor controller performs multiple functions: it controls the driven gear motor, monitors system state, determines bias requirements, and applies bias to the non-driven motor. By making the controller universal and multi-functional, the patent avoids adding separate dedicated bias control hardware, thereby maintaining reliability through active bias management while minimizing the increase in overall system complexity.
Solution Approach 2:
The bias control functionality is merged with the existing gear motor control system. Rather than adding a separate bias application mechanism, the patent integrates bias control into the motor controller's existing torque management capabilities. This merging approach maintains gear contact reliability while avoiding the complexity of separate bias control systems.
Data Source
AI summary
An anti-backlash gear control device is disclosed that includes a first bias module operable to generate a first bias to be applied to a first motor operable with a first gear, and a second bias module operable to generate a second bias, opposite the first bias, to be applied to a second motor operable with a second gear. The first gear and the second gear are operably connected to a load gear, such that rotation of at least one of the first gear and the second gear causes the load gear to move. Additionally, a command module can receive a drive command and output at least one of first and second command signals based on the drive command to be summed with the first and second biases, respectively, to generate first and second drive signals to operate the first and second motors to drive the first and second gears, respectively.