GB/T 40729-2021Fatigue life test method for precision gear transmission (English PDF)

3.1 Precision gear transmission

A transmission device that uses gears as an important component and has specific indicator requirements for diagonal position accuracy (such as backlash, transmission error, etc.).

3.2 Testing sample

A transmission device that is installed on a test bench and used for testing and measurement with purposes.

3.3 Load curve

The curve on torque and speed at the output end of the testing sample correlated with time.

NOTE: The curves are categorized as target loading curves and actual loading curves based on preset and measured values.

3.4 Failure

One or more technical indicators of the transmission device have irreversibly exceeded the product's permissible values, or physical damage has occurred to components (excluding consumable parts) of the transmission device.

NOTE: Consumable parts mainly refer to rubber seals, and may also include lubricants, but exclude transmission or support components such as gears, bearings, shafts, and housings. A list of consumable parts can be found in the manufacturer's product manual and other relevant documents.

3.5 Equivalent running time

Without changing the failure mechanism, the transmission device (including bearings, gears and other components) is loaded and operated under non-rated test conditions (speed and torque), which is equivalent to the running time under rated conditions.

3.6 Equivalent life

Without changing the failure mechanism, the transmission device (including bearings, gears and other components) is loaded and operated under non-rated test conditions (speed and torque) until failure, which is equivalent to the running time when failure occurs under rated conditions.

6.1 General requirements

6.1.1 It shall be able to start when the input end of the testing sample is at any phase angle position and shall have forward and reverse rotation functions.

6.1.2 Measuring instruments shall be calibrated or verified and within their validity period; their technical indicators (speed, torque, temperature requirements, range, accuracy, etc.) shall be compatible with the test requirements; shall have traceable energy values; and shall have automatic recording functions.

6.1.3 The test conditions of the test bench shall be calibrated for quantity value in a timely manner; and the calibration cycle should follow the recommendations of the test bench manufacturer.

6.1.4 All components (including the testing sample) shall be reliably connected to ensure rigidity.

6.1.5 It shall be able to freely set loading curves (e.g., small fluctuation operation curves, alternating operation curves, etc.).

6.1.6 Relative to the target loading curve, the speed fluctuation shall not exceed ±1.5 r/min; and the torque fluctuation shall not exceed ±1.5% of the rated value.

6.1.7 It shall have alarm and emergency stop functions; and should have some early warning function.

6.1.8 It shall have the function of long-term continuous operation and unattended operation.

6.2 Reciprocating operation test bench

6.2.1 It shall be able to simulate the working state of the testing sample's output end reciprocating motion within a certain angle range.

6.2.2 It shall be able to detect the output end torque and speed in real time; or obtain the output end torque and speed through real-time calculation by detecting other physical quantities.

6.2.3 When using inertia loading, there are two installation methods. horizontal and vertical, which are suitable for two working conditions in actual application. the test sample's central axis in actual application is horizontal (see Figure 1) and the axis is vertical (see Figure 2), respectively. […]