ABMA 14212:1997 pdf download

ABMA 14212:1997 pdf download,Aerospace – Airframe ball bearings, single-row, rigid, sealed, torque tube design, extra-light duty Inch series
1 Scope
This Intemational Standard specifies the characteristics, boundary dimensions, tolerances, intemal clearances and permissible loads of inch series, single-row, sealed, rigid, light duty, ball bearings used in airframe applications. These bearings are full complement (without cage) with a single row of balls and flling slot. These bearings are designed to withstand only slow rotations and oscillations under load and are intended for use between fixed and moving parts of an aircraft structure and their control surfaces. The airframe ball bearings covered by this International Standard are designed to operate in the temperature range of- 54°Ct+ 150 °C.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision，and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IsO maintain registers of currently valid International Standards. ISO 683-17:- 1), Heat-treated steels, alloy steels and fee-cutting steels一Part 17: Ball and rllr bearing steels ISO 1132:1980, Rolling bearings – Tolerances – Definitions. ISO 2082:1986, Metalic coatings – – Electroplated coatings of cadmium on iron or steel. IsO 4520:1981, Chromate conversion coatings on electroplated zinc and cadmium coatings. ISO 5593:1997, Rolling bearings一Vocabulary. ISo 8075:1985, Aerospace一Surface treatment of hardenable stainless steel pats. ISO 14190:1998，Aerospace- Airframe rolling bearings: ball and spherical roller bearings 一Technical specification. AMS 2417E:1993, Plating, zinc-nickel aloy.2)
3 Definitions
For the purposes of this Intemational Standard, the defintions given in ISO 5593 apply.
4 Symbols
4.1 For the purposes of this Intemational Standard, the symbols given in ISo 1132 apply. The symbols (except those for tolerances) shown in figure 1 and the values given in tables 1 and A.1 denote nominal dimensions unless specified otherwise.
6. Materials
6.1 Low alloy through hardening bearing steel (code letters F, D, M and 2) Rings: bearing steel – – ISO 683-17, type 1, surface hardness 59 HRC to 64 HRC (710 HV to 840 HV). Balls; bearing steel一ISO 683-17, type 1, heat treated to 59 HRC to 64 HRC (710 HV to 840 HV). 6.2 Corrosion-resistant stainless steel (code letters C and H) Rings: bearing steel- ISO 683-17, type 21, hardness≥58 HRC (670HV)- Balls: bearing steel一ISO 683-17, type 21, hardness≥58 HRC (= 670 HV). 6.3 General Seals: polytetrafluoroethylene (PTFE) or poltetrafuoroethylene (PTFE) sheet, glass-fabric reinforced. Seal retainers: corrosion-resistant steel.
7 Surface treatment uuuurruuuwr34143.
7.1 All elements manufactured from corrosion-resistant steel which are not cadmium plated or zinc-nickel plated (code letter C) shall be passivated in accordance with Iso 8075 or cleaned by a mechanical method. 7.2 If made of corrosion-resistant steel, cadmium plating (code letter H) shall be subject to agreement between the customer and the manufacturer. 7.3 Where cadmium plating is specified (code letters D, M and H), it shall be in accordance with ISO 2082. The extemal surfaces of bearing rings, except the bore of the inner ring, shall be cadmium plated. Plating on the internal surtaces shall be at the manutacturers option, except the raceways shall not be plated. The thickness of the plating shall not be less than 7 um and not more than 15 μm, except plating on the chamfers of the bore may vary from the specified thickness. The bearing shall be embittlement-relieved within 4h of plating by heat treatment at 140 °C+10 °C for a minimum of 8 h followed by chromate treatment in accordance with ISO 4520 (code letters D and H only). 7.4 Where zinc-nickel plating is specified (code letter Z), it shall be in accordance with AMS 2417E, type 2. The surface coverage of the plating shall be as specified in 7.3. The thickness of the plating shaill not be less than 7 μm or more than 15 μm.