Spur Gear Rolling Test Tolerances Calibrated by End-of-Line Results
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Solution Overview
Problem
The challenge in the series production of spur gears is the complexity and reliance on experienced personnel for rolling inspections due to unknown tolerances, making the process non-robust and inefficient.
Innovation Solution
A method involving rolling and end-of-line testing with statistical checks for repeatability and reproducibility, setting order-specific tolerance limits based on good parts from end-of-line inspection, and adjusting rolling test tolerances to align with end-of-line results, using separate rolling and gearbox test rigs for spur gears.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If rolling inspection is performed with unknown tolerances, then measurement precision is improved, but device complexity and operation difficulty increase
Solution Approach 1:
The patent applies preliminary action by performing end-of-line testing on a sample of spur gears before establishing the rolling inspection tolerances. The results from these preliminary tests are used to define the tolerance limits for subsequent rolling inspections, eliminating the need for complex setup procedures and making the inspection process robust and repeatable.
2Reliability
If end-of-line testing is performed on all spur gears, then reliability is improved, but productivity decreases
Solution Approach 1:
The patent applies partial action by performing end-of-line testing only on a sample of spur gears (e.g., 5-10 pieces) rather than on all produced gears. This partial testing provides sufficient statistical data to establish reliable tolerance limits for rolling inspection, while significantly increasing productivity compared to 100% end-of-line testing.
3Productivity
If rolling test tolerances are set without reference to end-of-line testing, then productivity is improved, but measurement precision deteriorates
Solution Approach 1:
The patent applies feedback by using the results from end-of-line testing to continuously refine and adjust the rolling inspection tolerances. The tolerance limits are defined based on the actual performance data obtained from end-of-line tested gears, ensuring that the rolling inspection criteria are both accurate and reliable.
Data Source
Figure 1(A)~1(D)
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AI summary
A method comprising the following steps: rolling test of spur gears (16) using a rolling test rig (28, 46), wherein the results of the rolling test are statistically checked for repeatability and reproducibility and a standard deviation for the results of the rolling test is determined; hard finishing of a plurality of spur gears (16), wherein one tooth (17) of each spur gear (16) is hard finished; rolling test of the plurality of hard finished spur gears (16) using the rolling test rig (28, 46) for which the standard deviation has been determined; end-of-line testing of the plurality of hard finished spur gears (16) using a gear test rig (58); evaluation of the results of the end-of-line testing of the plurality of hard finished spur gears (16), wherein the spur gears (16) are declared as good parts or bad parts based on at least one quality criterion;Evaluation of the results of the rolling test of the majority of hard-finished spur gears (16), wherein the results of those spur gears (16) that have been declared as good parts according to the end-of-line test are evaluated, wherein the results of the rolling test each include an order analysis, and wherein a tolerance limit is defined for one or more orders.