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1、 NEMA CB 1 NEMA CB 1 B BRUSHESRUSHES FORFOR E ELECTRICALLECTRICAL M MACHINESACHINES Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:06:21 MDTNo reproduction or networking permi
2、tted without license from IHS -,-,- Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:06:21 MDTNo reproduction or networking permitted without license from IHS -,-,- NEMA Standar
3、ds Publication CB 1-2000 Brushes for Electrical Machines Published by: National Electrical Manufacturers Association 1300 N. 17th Street, Suite 1847 Rosslyn, Virginia 22209 Copyright 2001 by the National Electrical Manufacturers Association. All rights including translation into other languages, res
4、erved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works, and the International and Pan American Copyright Conventions. Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical
5、 Standards 1/9972545001 Not for Resale, 04/19/2007 08:06:21 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/20
6、07 08:06:21 MDTNo reproduction or networking permitted without license from IHS -,-,- CB 1-2000 Page i Table of Contents Page Foreword iii Section 1 GENERAL.1 1.1 Scope .1 1.2 Definition of Brush 1 1.3 Classification of Brushes According to Material 1 1.4 Classification of Brushes According to Size
7、1 1.5 Classification of Brushes According to Construction .2 1.6 Definition of Shunt 3 1.7 Definitions of Brush Surfaces .3 1.8 Brush Connections .11 1.9 Brush Clips .16 1.10 Brush Pads .20 1.11 Wear Indicators 22 Section 2 DIMENSIONS AND TOLERANCES 23 2.1 Brush Dimensions 23 2.2 Order of Brush Surf
8、ace Dimensions 24 2.3 DimensionsThickness (Tangential Dimension), Width (Axial Dimension), Length (Radial Dimension), and Diameter 24 2.4 TolerancesThickness (Tangential Dimension), Width (Axial Dimension), Length (Radial Dimension), and Diameter 25 2.5 Beveled Ends and Concave Faces 26 2.6 Brush He
9、ads 27 2.7 Chamfers 28 2.8 Holes, Counterbores, and Countersinks 29 2.9 Shoulders, Slots, Grooves, and Notches .29 2.10 Toes .30 2.11 Available Area at Top of Brush for Applying Pressure 31 2.12 Shunts 31 2.13 Terminations of Brush Shunts for Screw or Bolted Connection 33 2.14 Termination of Shunts
10、for Brushes to be Used in Cartridge-Type Holders 35 2.15 Quick Connect Terminals .37 2.16 Procedure for Describing Brushes, Including Shunts, etc. 38 Section 3 TEST PROCEDURE FOR PHYSICAL PROPERTIES.45 3.1 General 45 3.2 Scleroscope Hardness .46 3.3 Indentation Hardness .48 3.4 Resistivity .51 3.5 F
11、lexural Strength 52 3.6 Density .53 3.7 Porosity 58 3.8 Ash Content .59 Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:06:21 MDTNo reproduction or networking permitted without
12、 license from IHS -,-,- CB 1-2000 Page ii Section 4 TEST PROCEDURES FORSHUNTCONNECTIONS 61 4.1 General 61 4.2 Resistance of Shunt Connections.61 4.3 Strength of Type M and Q Shunt Connections 64 Appendix A Spring Design Information 65 Appendix B Coil Springs for Brushes.67 Appendix C Recommended Min
13、imum Clearances Between Brush and Brushholder .69 Appendix D International Electrotechnical Commission (IEC) Limits and Tolerances 71 Appendix E Recommended Width of Pressure Device .73 Appendix F Brush Voltage Drop and Coefficient of Friction .75 Appendix G Descriptive Terminology 77 Appendix H Geo
14、metrical Units and Symbols 79 Appendix I Commutator Surface Conditions 83 Appendix J Technical Questionnaire 85 Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:06:21 MDTNo repr
15、oduction or networking permitted without license from IHS -,-,- CB 1-2000 Page iii Foreword NEMA CB 1-2000, Brushes for Electrical Machines, revises and supersedes the previous edition, CB 1- 1995. It represents the general practice in the design and manufacture of brushes by the electrical manufact
16、uring industry and is issued to provide practical information and to assist the user in the proper selection of such brushes. The standards in this publication are the result of many years of research and investigation and have been developed through continual consultation among manufacturers, users
17、, and national engineering societies. When utilized by the industry, they have resulted in improved quality of electrical products and economy in manufacture. These standards are subject to periodic review. They have been revised from time to time to meet changing economic conditions and technical p
18、rogress. In keeping with the policy of the U.S. National Committee of the International Electrotechnical Commission (IEC), an effort has been made to bring this publication into conformity with existing IEC publications to the extent practical. This revision incorporates provisions of the IEC public
19、ations where practical and where they can be achieved without hardship to the user and the industry. This standards publication is, therefore, not in complete conformity with IEC standards. With reference to dimensional data, it should be noted that the bracketed values represent conversion of SI un
20、its and are not necessarily IEC specified values. To avoid confusion to the user, brushes manufactured in conformity with IEC tolerances should be so identified. In the preparation of this standards publication the input of users and other parties of interest has been solicited through American Nati
21、onal Standards Committee C64. Inquiries, comments, and proposed or recommended revisions should be submitted to the concerned NEMA product subdivision by contacting the: Vice President, Engineering Department National Electrical Manufacturers Association 1300 N. 17th Street Rosslyn, Virginia 22209 T
22、he Carbon/Manufactured Graphite Section developed this standards publication. Section approval does not necessarily imply that all section members voted for its approval or participated in its development. At the time it was approved, the group/section was composed of the following members: Carbone-
23、Lorraine North America Corporation Parsippany, NJ Fulmer Company Incorporated Westmoreland, PA Graphite Metallizing Corporation Yonkers, NY Helwig Carbon Products, Incorporated Milwaukee, WI Hoffmann Carbon, Incorporated Bradford, PA Kirkwood Industries Cleveland, OH Morgan Advanced Materials positi
24、on 10, the right side; position 11, the front; position 12, the left side; and position 13, the back. To determine the correct designation of locations, the following procedure is used: a. If the brush has a beveled top or bottom, or both (commutator type), observe with front side toward you in acco
25、rdance with Figures 1-41 and 1-43. b. If the brush has a greater thickness (tangential dimension) than width (axial dimension) (slip-ring type), observe in accordance with Figures 1-42 and 1-43. Hold with the front side toward you if beveled. c. If the brush is tapered or wedge-shaped (wedge commuta
26、tor type), observe with the thinner side to the left in accordance with Figure 1-44. d. If the brush has no top or bottom bevel and has a top clip, the side of the brush attached to the clip is considered as the back if the width (axial dimension) is greater than the thickness (tangential dimension)
27、; otherwise, it is considered as the right side. Figure 1-41 Figure 1-42 COMMUTATOR TYPE SLIP-RING TYPE Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:06:21 MDTNo reproduction
28、 or networking permitted without license from IHS -,-,- CB 1-2000 Page 15 Figure 1-43 SPECIAL CASES Figure 1-44 WEDGE COMMUTATOR TYPE Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/20
29、07 08:06:21 MDTNo reproduction or networking permitted without license from IHS -,-,- CB 1-2000 Page 16 1.8.3 Shunt Length The shunt length (L) is the distance from the extreme top of the brush material to the center of the hole or slot in the terminal, or the center of the inserted portion of a plu
30、g terminal or, if there is no terminal, to the end of the shunt. To determine the length of the shunt, extend the cable straight from the top end in a line parallel with the axis of the brush. See Figures 1-45 and 1-46. LL LL Figure 1-45 Figure 1-46 SHUNT LENGTH (NO TERMINAL) SHUNT LENGTH (WITH TERM
31、INAL) 1.9 BRUSH CLIPS Brush clips, referred to as “clips“ in this publication, are parts attached to the brush which serve to accommodate the spring, spring finger, or hammer, or to act as guides. Where these serve to prevent the wear of the carbon due to the pressure finger, they are called “hammer
32、“ or “finger“ clips. Some clips serve the purpose of lifting the brushes or providing a stop. The width of the clips is designated by K. 1.9.1 Hammer Clips 1.9.1.1 A Type A clip consists of a strip formed to lie on the top of the brush and attached to the side of the brush. See Figure 1-47. 1.9.1.2
33、A Type A extra wide clip is similar to the Type A clip, except that it covers nearly the whole top of the brush. See Figure 1-48. Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 0
34、8:06:21 MDTNo reproduction or networking permitted without license from IHS -,-,- CB 1-2000 Page 17 K K Figure 1-47 Figure 1-48 TYPE A TYPE A EXTRA-WIDE 1.9.1.3 An Offset A clip is similar to the Type A extra wide clip, except that the rivet is not placed at the centerline of the brush. See Figure 1
35、-49. Figure 1-49 OFFSET A 1.9.1.4 An Extended A (Cantilever) clip is similar to the Type A clip but extends beyond the side of the brush to accommodate the brush pressure finger. Dimension “e“ is measured in the plane shown in Figure 1-50 and is taken to a straight edge. Minimum thickness of clip ma
36、terial is .03 inches (0.71 mm). See ASTM A480, A568 or B2483 for tolerances for thickness of the type of material used. An alternate method to dimension the A clip or protrusion shown in Figure 1-50 is to provide dimension U (see Figure 1-63). These methods may be applied to extended P measurements
37、(also see Figure 1-63). 3 Available from the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103. The titles are as follows: A480-80 General Requirements for Delivery of Flat-Rolled Stainless and Heat-Resisting Steel Plate, Sheet, and Strip A568-74 General Requiremen
38、ts for Steel, Carbon and High-Strength Low-Alloy Hot-Rolled Sheet, Hot-Rolled Strip, and Cold- Rolled Sheet B248-11 General Requirements for Wrought Copper and Copper-Alloy Plate, Sheet, Strip, and Rolled Bar Copyright National Electrical Manufacturers Association Provided by IHS under license with
39、NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:06:21 MDTNo reproduction or networking permitted without license from IHS -,-,- CB 1-2000 Page 18 Figure 1-50 EXTENDED A (CANTILEVER) A 1.9.1.5 An Angular A clip is similar to the Type A clip but is attached to an angle
40、 to accomplish the same purpose as beveling the holder end of the brush. See Figure 1-51. 1.9.1.6 A Channel A clip is similar to the Type A clip, except that it has the edges turned up as a guide to position the spring finger on top of the brush. See Figure 1-52. K K Figure 1-51 Figure 1-52 ANGULAR
41、A CHANNEL A 1.9.2 Lifting and Guide Clips 1.9.2.1 Type B is a lifting clip having two lugs, in one of which there is a hole and in the other a slot opening toward the side of the brush. The slot opening direction is optional, depending on the application. See Figure 1-53. 1.9.2.2 Type C is a guide c
42、lip. It is generally fastened into a groove in the brush by one or more rivets. See Figure 1-54. Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:06:21 MDTNo reproduction or net
43、working permitted without license from IHS -,-,- CB 1-2000 Page 19 K K Figure 1-53 Figure 1-54 TYPE B TYPE C 1.9.2.3 Type D is a bail-type lifting clip. The bail is fixed to the brush by a metal plate. See Figure 1-55. 1.9.2.4 Type E is a lifting clip formed into the shape of a hook. See Figure 1-56
44、. Figure 1-55 Figure 1-56 TYPE D TYPE E 1.9.2.5 Type F is a lifting clip similar to the Extended A (Cantilever type) hammer clip and is usually made in double thickness or two pieces. See Figure 1-57. The clip protrusion is dimensioned perpendicularly from the brush surface to the end of the clip. A
45、n alternate method to dimension the A clip or protrusion is to provide dimension U as shown in Figure 1-63. K K Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:06:21 MDTNo repr
46、oduction or networking permitted without license from IHS -,-,- CB 1-2000 Page 20 1.9.2.6 Type G is a lifting clip having a raised portion which projects outward from the side of the brush. See Figure 1-58. 1.9.2.7 Type H is a lifting clip similar to the Type E (hook type) clip, except that it has a
47、 minor projection which extends outward from the side of the brush. See Figure 1-59. 1.9.2.8 Type K is a lifting clip combining the features of a Type E lifting clip and an Angular A hammer clip. See Figure 1-60. K K Figure 1-57 Figure 1-58 TYPE F TYPE G K K Figure 1-59 Figure 1-60 TYPE H TYPE K 1.10 BRUSH PADS Brush pads, referred to as “pads“ (are designated by “P“) in this publication, are resilient parts attached to the brush top to absorb vibration. Pads are composed of a resilient material or a combination of resilient and nonresilient
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