GB/T 40731-2021Method of test and evaluation for lost motion of precision reducer (English PDF)
精密减速器回差测试与评价方法
This is a limited preview
Buy now to download the full PDF (20 pages)
Need quotation for your management?
Get a formal quotation for GB/T 40731-2021 in 30 minutes.
Issued by
SAMR; SAC
Level / Type
National · Recommended
Issue date
October 11, 2021
Implementation date
May 1, 2022
Scope
GB/T 40731-2021 is the English-translated version of 精密减速器回差测试与评价方法.
GB/T 40731-2021 sets out how to test and evaluate lost motion in precision reducers, the lag of the output angle when the input reverses direction. It applies to planetary, planetary cycloidal, harmonic gear and other precision reducers with lost motion requirements.
The document defines terms such as geometric, elastic and total lost motion, the hysteresis curve and transmission error, and specifies the test rig, with limits on shaft coaxiality, speed and torque fluctuation and angle measurement error.
It covers specimen installation and running-in, then a static test, in which the input is fixed and the output is loaded and unloaded to obtain the hysteresis curve, and a dynamic test based on bidirectional transmission error curves, each with its data processing, followed by the evaluation methods. It was issued on 11 October 2021 and has applied since 1 May 2022.
Found what you need?
Document preview — GB/T 40731-2021
National Standard of the People's Republic of China
- ICS
- 21.200
- Classification
- J 17
Issued by: State Administration for Market Regulation; Standardization Administration of the PRC
Contents
- Foreword3
- 1 Scope4
- 2 Normative references4
- 3 Terms and definitions4
- 4 Symbols, explanations, and units6
- 5 Testing equipment8
- 6 Test specimen and installation9
- 7 Test conditions9
- 8 Static testing and data processing9
- 8.1 Installation method9
- 8.2 Test procedure10
- 8.3 Data processing12
- 8.4 Number of test positions14
- 9 Dynamic testing and data processing15
- 9.1 Installation method15
- 9.2 Test speed15
- 9.3 Test procedure15
- 9.4 Data processing16
- 10 Evaluation methods17
- 10.1 General rules17
- 10.2 Methods17
- References20
Foreword
This document was drafted in accordance with the provisions of GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.
1 Scope
This document specifies the testing equipment, test specimens and installation, testing conditions, static testing, dynamic testing, data processing, and evaluation methods for the lost motion of precision reducers.
This document applies to the lost motion testing and evaluation methods for planetary, planetary cycloidal, harmonic gear, and other types of precision reducers (hereinafter referred to as "precision reducers") on which there are lost motion requirements.
2 Normative references
The provisions of the following documents constitute the essential clauses of this document through normative references in this text. Among them, for any dated reference, only the version corresponding to that date applies to this document; for any undated reference, the latest version (including all amendments) applies to this document.
GB/T 35089-2018 Precision gear transmission for robot - Test method
3 Terms and definitions
The following terms and definitions apply to this document.
3.1 Lost motion
The lag that occurs at the output angle when the direction of motion at the input end of a precision reducer changes and the direction of motion at the output end follows suit.
NOTE: In 8.3.3, when k=3, the value of "static test geometric lost motion" is equal to the value of "lost motion" in GB/T 35089-2018 and GB/T 36491-2018.
3.2 Lost motion curve
The curve formed by the lost motion values at each angular position within a 360° rotation range at the output end of the precision reducer.
3.3 Mean lost motion
The arithmetic mean of the lost motion values at each angular position within a 360° rotation range at the output end of the precision reducer.
3.4 Geometric lost motion
The lost motion in a precision reducer, which is caused by geometric factors (design, machining, assembly, etc.).
3.5 Elastic lost motion
The lost motion in a precision reducer under the rated torque due to elastic deformation.
3.6 Total lost motion
The lost motion in a precision reducer at rated torque, which is caused by the combined effects of geometric factors and elastic deformation.
3.7 Hysteresis curve
A closed torque-rotation angle curve that is plotted using multiple sets of output end torque and rotation angle values recorded in the situation where the input end is fixed, the output end is gradually loaded to the rated torque and then unloaded, and then, the load is gradually loaded in reverse to the rated torque and then unloaded. As shown in Figure 1. [Source: GB/T 36491-2018, 3.9, with modifications]
3.8 Mean value curve
fm(T)
The curve that is formed by the average value of the output rotation angle corresponding to the same output torque in the rising curve f+(T) and the decline curve f-(T) of the hysteresis curve. As shown in Figure 1.
3.9 Transmission error
The difference between the actual output rotation angle and the theoretical output rotation angle at the output end. [Source: GB/T 36491-2018, 3.11]
3.10 Bidirectional transmission error curve
Within a 360° rotation range at the output end, the forward and reverse transmission error curves of the precision reducer shown at the corresponding speed and torque.
3.11 Static test of lost motion
The lost motion test that is completed by fixing the input end of the precision reducer and obtaining the hysteresis curve through loading and unloading at the output end.
3.12 Dynamic test of lost motion
The lost motion test that is completed by obtaining the lost motion curve through testing the bidirectional transmission error curve of the precision reducer.
4 Symbols, explanations, and units
The symbols in Table 1 apply to this document.
5 Testing equipment
5.1 The composition is illustrated in Figure 2 (not limited to horizontal type or vertical type).
5.2 The coaxiality error between adjacent unit axes shall not exceed 0.01 mm.
5.3 At the rated speed of the test specimen, the fluctuation value of the drive speed shall not be greater than ±1 r/min.
5.4 When performing a dynamic test of lost motion, the load torque shall be kept stable, and the fluctuation value of the load torque shall not exceed ±1.5% of the rated torque of the test specimen.
5.5 The rotation angle measurement error shall not exceed 1/3 of the allowable lost motion value of the test specimen.
5.6 The specifications, accuracy, dynamic response, etc., of torque and speed sensors and angle sensors shall be adapted to the test requirements.
6 Test specimen and installation
The test specimen shall be a product or prototype suitable for lost motion testing. The test specimen shall have manufacturer-specified inspection records available for test analysis.
The installation of the test specimen shall meet the following requirements.
-- It shall be installed according to the designed power flow transmission direction.
-- The coaxiality error between the axes of the input and output ends and the axes of adjacent units shall not exceed 0.01 mm.
-- Operation shall be flexible and smooth.
7 Test conditions
7.1 Before the lost motion test, the test specimen shall undergo a running-in test in accordance with the design requirements. The running-in time shall be agreed upon by the supplier and the buyer.
7.2 During the running-in test, the following shall be observed and recorded.
-- Check whether there is looseness at each connector and fastener.
-- Check whether there is any oil leakage or seepage at each sealing point and each joint.
-- Check if the operation is smooth and if there is any impact or abnormal noise.
-- Check whether there are any abnormal fluctuations in the output speed.
7.3 Lost motion tests shall be conducted under thermal equilibrium conditions and within the permissible operating temperature range of the test specimen.
8 Static testing and data processing
8.1 Installation method
See Figure 3 for the schematic diagram. The input end of the test specimen shall be fixed before loading, unloading, and reverse loading operations can be performed on the output end of the test specimen. […]
......
This preview omits tables, figures, formulas and parts of the technical clauses. The complete document — 20 pages — is available in the English PDF.
Referenced standards
Normative references
Similar standards
How to Download GB/T 40731-2021
- 1
Add to cart
Click "Download PDF" on this page and choose "Buy this standard". You can add more standards before checkout.
- 2
Checkout
Enter your email and billing details. Payment is processed securely by Stripe (cards or bank transfer). Prefer bank details? Request a quotation (min. order $300).
- 3
Instant delivery (0–9 sec)
Delivery is automatic: within seconds of payment you'll receive an email with a secure download link. The link stays valid for 72 hours.
- 4
Invoice included
A tax invoice is attached to the confirmation email. Need a custom invoice? Contact us.
Related Standards
GB/T 35089-2018 — Precision gear transmission for robot—Test method
GB/T 10003-2026 — Biaxially oriented polypropylene (BOPP) film
GB/T 10004-2026 — Plastic/Plastic laminated films and pouches for packaging
Secure payment via Stripe
Payments accepted
GB/T 40731-2021
$270.00