1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2013 SAE International All rights reserved. No part of this pub
3、lication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970
4、(outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/ARP6131AEROSPACERECOMMENDED PRACTICEARP6131Issued 2013-10 Maintenance and Inspection
5、 Procedures for Rotary and Linear Mechanical Actuators RATIONALERotary and linear mechanical actuators are used in many critical aircraft applications. The proper function of these systems requires that the actuators be properly maintained and inspected for wear and damage. This document satisfies t
6、he need for having guidance material for developing detailed maintenance and inspection procedures as well as guidance material for use by personnel responsible for maintaining such actuators. TABLE OF CONTENTS 1. SCOPE 2 1.1 Purpose . 2 1.2 Field of Application 2 2. REFERENCES 2 2.1 Applicable Docu
7、ments 2 2.1.1 SAE Publications . 2 2.1.2 U.S. Government Publications 2 2.2 Definitions . 3 3. REQUIREMENTS . 3 3.1 Maintainability . 3 3.1.1 Maintainability Characteristics 3 3.1.2 Maintenance and Inspection Concept 3 3.1.3 Quantitative Maintainability . 3 3.1.4 Maintainability Verification 4 3.1.5
8、 Maintainability Validation 4 3.1.6 Ground Support Equipment 4 3.2 Rotary Actuator Assembly Inspection and Maintenance Procedures 4 3.2.1 Inspection 4 3.2.2 Maintenance 6 3.3 Linear Actuator Assembly Inspection and Maintenance Procedures . 6 3.3.1 Inspection 6 3.3.2 Maintenance 8 4. NOTES 9 SAE INTE
9、RNATIONAL ARP6131 Page 2 of 9 1. SCOPE This SAE Aerospace Recommended Practice (ARP) shall provide guidelines for the maintenance, inspection, and support of rotary and linear mechanical actuators on in-service and aging aircraft.1.1 Purpose This document establishes guidelines and general procedure
10、s for inspection and maintenance of rotary and linear mechanical actuators. Maintenance and inspection of only the elements comprising the primary transmission path are addressed by this document.1.2 Field of Application The rotary and linear mechanical actuators serve as the output device for, and
11、are part of, a mechanical actuation system. The output devices consist of, but are not confined to, gearing and gear boxes, mechanical brakes and clutches including no-backs and torque limiters, ball screws, sliding contact screws, roller screws, helical splines, rack and pinion assemblies, and skew
12、ed roller actuators. Maintenance and inspection of only the elements comprising the primary transmission path are addressed by this recommended practice. A typical actuation system may contain one or more of the following components (Although not limited to): a. Prime Mover (Hydraulic, Pneumatic, El
13、ectric, Manual) b. Connecting Members (Torque Shafts, Couplings, U-Joints) c. Sensors (RVTs, RVDTs, LVDTs, Tachometers, Hall Effects, Encoders, Limit Switches, Load Sensors) d. Miscellaneous Devices (Sequencers, Accessory Drives, etc.) These components may be configured and specified apart from or i
14、ntegrated with the rotary and linear mechanical actuator assembly. Guidelines for maintaining and inspecting these items are outside the scope of this document. Follow the recommended procedures as provided by the manufacturers of these items. 2. REFERENCES 2.1 Applicable Documents The following pub
15、lications form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and reference
16、s cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 87
17、7-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.ARP4386 Terminology and Definitions for Aerospace Fluid Power, Actuation, and Control Technologies 2.1.2 U.S. Government Publications Available from DLA Document Services, Building 4/D, 700 Robbins Avenue, Philadelphia, PA
18、 19111-5094, Tel: 215-697-6396, http:/quicksearch.dla.mil/.MIL-HDBK-838 Lubrication of Military Equipment SAE INTERNATIONAL ARP6131 Page 3 of 9 2.2 Definitions Definitions used herein are compatible with terminology and definitions of ARP4386. Where new terms are used the definitions are presented b
19、elow or within the lead paragraph of the topic. 2.2.1 AGING AIRCRAFT An aircraft is considered as aging when it reaches its initial Design Service Goal (Certified at time of Type Certification). This limit can be defined in terms of Flight Hours, Flight Cycles, and/or Calendar Time. 3. REQUIREMENTS
20、3.1 Maintainability 3.1.1 Maintainability Characteristics The ultimate maintainability goal of the actuator assembly design is to minimize maintenance requirements over the useful life of the program to ensure the continued airworthiness of flight hardware. The minimization of maintenance does not n
21、ecessarily eliminate the need for periodic inspection. Inspection intervals should be determined during development and further tuned while in service. Factors such as complexity, accessibility, visibility, testability, simplicity and interchangeability should influence maintenance design. Maintaina
22、bility requirements should be clearly documented within the appropriate Aircraft Maintenance Manual (AMM) or Component Maintenance Manual (CMM).3.1.2 Maintenance and Inspection Concept When an actuator assembly requires maintenance or inspection, the procedure should state the desired maintenance an
23、d level of maintenance that will apply. All attempts should be made to mitigate requirements for maintenance labor hours, Aerospace Ground Equipment (AGE), personnel skills, and technical publications/data. The level of maintenance or inspection should be classified/defined as:a. Organizational Leve
24、l or Flight Line (Maintenance - performed on the aircraft) b. Hangar and/or Depot/Repair Station (Inspection - performed on an actuator while removed from the aircraft) 3.1.3 Quantitative Maintainability Each applicable level of maintenance should specify a detailed mean/average to repair period sta
25、ted in maintenance man-hours, personnel skill level, and support equipment requirements. To assist in determining the maintenance specific quantitative and qualitative maintainability tasks. Analyses can be performed, which can consist of: a. Maintainability Modeling b. Maintainability Allocations c
26、. Maintainability Predictions d. Failure Mode and Effects Analysis (FMEA) - Maintainability Information e. Maintainability Analysis f. Maintainability Design Criteria The Maintainability Analysis requirements for a procuring activity can be a combination of two or more of the analysis approaches tha
27、t best meet the actuator assembly maintainability design objectives. SAE INTERNATIONAL ARP6131 Page 4 of 9 3.1.4 Maintainability Verification Once maintainability requirements have been defined, verification requirements defined in the specification can be used to demonstrate and validate the actuat
28、or assembly maintenance features and repair times. Verification should be conducted under the auspices of the: a. Maintainability Demonstration, and b. Testability Requirements. It is also recommended that maintenance of critical actuators (i.e., for pitch trim applications) be included in the Syste
29、m Safety Assesment (SSA), and this analysis will determine whether it shall be a candidate Certification Maintenance Requirement (CMR). This could place a mandatory requirement on operators to perform the maintenance. 3.1.5 Maintainability Validation Maintenance validation should be accomplished dur
30、ing qualification testing, if required. Lubrication intervals should be validated during qualification testing. Doubling of lubrication intervals during test may be required by certification authorities to demonstrate robustness. 3.1.6 Ground Support Equipment As a goal Ground Support Equipment (Spe
31、cial Tools) should not be required for the Organizational or Flight Line levels of maintenance. Ground Support Equipment may be required for the Hangar and/or Depot Level/Repair Station for complete teardown, inspection, repair and functional check. 3.2 Rotary Actuator Assembly Inspection and Mainte
32、nance Procedures 3.2.1 Inspection Inspection of all of the rotary actuator components should follow Component Maintenance Manual (CMM) guidelines. These inspections are intended to be performed while the actuator is removed from the aircraft.3.2.1.1 Visual Check of Rotary Actuator Assembly A visual
33、check of the actuator assembly should be performed for any abnormalities. At minimum, major load carrying components should be disassembled and visually inspected. Visually inspect for any corrosion or loss of coating protection. Inspect the input and output splines and journals for apparent wear or
34、 degradation. The complete gearbox should be inspected for signs of external leakage. 3.2.1.2 No Load Free Run Test The unit should be run through full stroke at no load at nominal operating rate and monitored for operation free from binding, excessive noise, excessive breakaway torque, torque varia
35、tion throughout stroke, etc.3.2.1.3 Backlash (Free play) Because some actuator assemblies may be sliding contact devices and subject to wear, it is critical that the end play be measured as a stand-alone item and not in combination with other sources of free play. The actuator assembly overall backl
36、ash should be performed before cleaning and applying grease and may be determined as follows. Lock the rotation of the input shaft or actuator itself. Measuring instruments should read relative rotational movement between the fixed input and movable output member. Apply a set load in one direction,
37、hold, and zero the measuring instrument. Apply the same set load in the opposite direction, hold and record the free play. The magnitude of the set load need only be large enough to “seat” all free components for an accurate measurement. If a frequently used section of the actuator is known or throu
38、gh observation, a backlash check should also be performed in that area. SAE INTERNATIONAL ARP6131 Page 5 of 9 3.2.1.3.1 General Note on End Play Checks In some systems the static load applied to the output member can be relatively high; the load values applied to the actuator must be sufficient to o
39、vercome any surface static load and allow components in the load path to be seated in each load direction during measurement. If these loads are too high to develop a reasonable test procedure then an alternate approach could be to fix the surface with rig pins or blocks and measure the input shaft
40、rotational free play at a set value of input torque in each direction. This method is less accurate than direct measurement so should only be used when other methods are impractical. 3.2.1.4 Efficiency Test under Load Unit may be tested for the proper efficiency at specified output torque levels.3.2
41、.1.5 Visual Check of Lubricant A visual check of the lubrication should be performed for amount and condition. Lubricant should be wet and show presence throughout the traveled portion of the actuator assembly. Blackened, dark, or dried lubricant would indicate possible abnormalities. Check for debr
42、is and/or particulate matter in the lubricant. For a more definitive check, grease samples can be analyzed to determine if grease has been exposed to contamination. The presence of contamination and any metallic particles in the used grease removed from the actuator is cause for further detailed ins
43、pection. If oil or semi-fluid lubricated, check may be performed for amount and condition through sight window if applicable. Visually inspect housings at joints and seal edges for evidence of lubricant leakage. 3.2.1.6 Wear/Degradation The major actuator components should be monitored for wear. Com
44、ponents should be gauged to insure wear limits are not exceeded. Refer to manufacturers CMM for data. Check for signs of uneven wear which may indicate misalignment in the actuator assembly. Components should be cleaned of all grease and contaminants and inspected for any signs of distress including
45、, but not limited to scuffing, pitting, lockup, galling, and/or seizure. Wear rate should be considered in determining the inspection and service requirements intervals. Record and track free play to determine if wear is increasing and the inspection interval should be decreased. Ensure that inspect
46、ion interval has been approved by the appropriate agency. Attachment points should be inspected for signs of damage and wear. Size limits should be within OEM specifications found in the CMM. Repair of excessively worn journals should be made per CMM recommendations. Nicks, burrs, or raised edges sh
47、ould be smoothed and repaired. Cause of such defects should be investigated for other defective components.Mechanical brakes and clutches should be inspected for indications of wear and degradation as well as evidence of contamination. Checks for wear limits should be within OEM specifications found
48、 in the CMM or by wear limit indicators on the components. 3.2.1.7 Cleaning If possible the actuator assembly should be disassembled and thoroughly cleaned to remove contamination and any old and dried lubricant. Cleaning and cleaning solutions should be in accordance with the manufacturers recommen
49、dation or CMM procedures. Improper cleaning process or lack of removal of contaminant may cause improper rebuild size measurement or backlash values. 3.2.1.8 Redundant Load Path Requirements within Output Member Any redundancies in load paths in addition to the primary load path should be checked and verified for integrity during actuator assembly teardown off aircraft. SAE INTERNATIONAL ARP6131 Page 6 of 9 3.2.1.9 Seals Seals, if any, shoul
