1、DOD-STD-2146 61 9999911 0032637 2 DOD-STD-2146(SH) 1 June 1983 MILITARY STANDARD DIRECT CURRENT GENERATORS AND MOTORS, LOW STRAY MAGNETIC FIELD, DESIGN OF (METRIC) FSC 6L15 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-2146(SH) 1 June 1983
2、DEPARTMENT OF THE NAVY NAVAL SEA SYSTEMS COMMAND Washington, DC 20362 Direct Current Generators and MotorsS.Law Stray Magnetic Field, Design of (Metric). I. This Military Standard is approved for use by the Naval Sea Systeme Command, Department of the Navy, and is available for use by all Department
3、s and Agencies of the Department of Defense. 2. Beneficial comments recommendations, additions, deletions) and any per- tident data which may be of use in improving this document should be addreased to: Commander, Naval Sea Systems Command, SEA 5523, Department of the Navy, washington, DC 20362, by
4、using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. li Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-234b 63 W 77777LL 0032639 b W DOD-STD-2146(SH) 1 June
5、 1983 1. This standard provides the designers of direct current (d.c.) generators and motors with techniques for reducing to a minimum the stray magnetic field produced by these motors and generators. iii Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,
6、-,-Paragraph 1. 1.1 1.1.1 1.1.2 2. 2.1 3. 3.1 3.1.1 3.1.3 3.1.5 3.1.2 3.1.4 3.1.6 3-1.7 3.1.8 3.1.9 3.1.10 4. 4.1 4.2 4.2.1 4.2.2 4.2.4 4.2.6 4.2.3 4.2.5 4.2.7 .4.2.8 4.2.9 4.2.10 4.2.12 4.2.11 5. 5.1 5.1.1 5.1.2 5.1.3 5.1.3.1 5.1.3.2 5.1.3.3 5. i .3 .i DOD-STD-2146(SH) 1 June 1983 CONTENTS Page - 3
7、 3 3 3 3 3 3 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Paragraph 5.1.3.4.1 5.1.3.4.3 5 -1.3.4 e2 5.1.3.4-4 5.1.3.4.5 5.1.3.4.6 5.1-3.4.7 5.1-3.4.8 5.1.3.4.9 5.1.3.4.10 511.4 5.2 5.2.1 5.2e1.1 5.2.2 5-2.3 5.2.4
8、5.2.461 5.2.4.2 5.2.4.3 5.2.4.4 . 5.2.5 5.2.5.1 5.2.5.1.1 5.2.5.1.2 5.2.5.2 5.2.5.2.1 5.2.5.3 5.2.6 5.2.6.1 5.2.6.2 DOD-CTD-2146(SH) 1 June 1983 CONTENTS - Continued Compensating (pole-face) winding - Arrangement of compensating winding - Arrangement of end connections to compensating winding8 - Pag
9、e 5 6 6 6 6 6 6 6 6 6 - 9 9 9 9 9 10 10 10 10 10 10 V Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-234b bL 7977733 0032642 b M DOD-STD-2146(SH) 1 June 1983 FIGURES Figure 1. Orientations of main field poles for minimization of the vertical
10、 component of the stray magnetic field -,-,-,-,- 2. Preferred and non-preferred methods of making 3. 4. 5. 6. 7. 8. connections to the field Coil8 Position of brush collector rings Typical connections and resulting current loops for machines with three-brush collector rings - Typical connections or
11、generators with two concentric brush ring collectors Arrangement of connections to commutating poles (interpoles) for low stray magnetic field - Compensating winding for a six-pole machine with Parallel cir.cuit compensating winding for an eight- four slots per pole-face pole machine with three slot
12、s per pole-face - Page 11 12 13 14 15 16 17 18 vi Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-2146 61 m 7777733 00326113 m DOD-STD-2146(SH) 1 June 1983 1. SCOPE 1.1 Scope. This standard covers the requirements for the design of d.c genera
13、tors and motors (machines) that will minimize the stray magnetic field emanated by the generators and motors. 1.1.1 Application. This standard applies specifically to the design of magnetic minesweeping generators since they generate large output currents and are used in minesweepers that will pass
14、over magnetic-influence mines. Conse- quently, they must produce as small a stray magnetic field as possible, in order to minimize the danger of detonating a mine under the minesweeper. The require- ments of this standard also apply to the design of any d.c. motor or generator for which a small stra
15、y magnetic field is an important consideration. 1.1.2 Limitations. This standard shall be used in conjunction with the requirements of technical specifications and standards for a specific d.c. generator or motor. In the event that any design features of this standard (see 4.2.1 and 4.2.2) conflict
16、with the requirements of other technical speci- fications and standards for the generator or motor, the design requirements of this standard shall apply. 2. REFERENCED DOCUMENTS 2.1 Issues of documents. The following documents, of the issue in effect on date of invitation for bids or request for pro
17、posal, form a part of this standard to the extent specified herein. STANDARD MILITARY DOD-STD-2133 - Cable Arrangement For Minimum Stray Magnetic DOD-STD-2141 - Definitions and Systems of Units, Magnetic Field (Metric). Silencing (Metric). (Copies of specifications, standards, drawings, and publicat
18、ions required by contractors in connection with specific acquisition functions should be obtained from the contracting activity as directed by the contracting officer.) 3. DEFINITIONS 3.1 General magnetic silencing terms. The meanings of general magnetic silencing terms used in this standard are in
19、accordance with DOD-STD-2141. 3.1.1 Equalizer. connections. Equalizer connections connect lap wound arma- ture winding parallel circuits that, theoretically, are at the same potential. They are not, however, at the kame potential due to minor-variations in machine adjustment and materials. These vol
20、tage differences, if not corrected would cause equalizing currents through the brushes and cables connecting brush studs of the same polarity. These equalizing currents would generate stray magnetic fields. 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from I
21、HS-,-,-DOD-STD-214b b1 7777711 0012b44 T DOD-STD-2146(SH) 1 June 1983 3.1.2 Commutating poles (interpoles). Commutating poles are used to improve commutation. quently referred to as interpoles. Some d.c. machines have commutating poles but no compensating winding; other d.c. machines have commutatin
22、g poles and a compensating winding as well. in the commutating coils and in the connections to the coils. (The coils them- selves produce only a small stray magnetic field; hence, the problem involved in the design of the commutating circuit is to arrange the connections so that they will provide on
23、ly a small stray magnetic field.) They are located midway between the main field poles and are fre- Current in the commutating circuit is present 3.1.3 Compensating (pole-face) windings. Compensating windings are used on large d.c. machines to compensate armature reaction and improve performance. co
24、mpensating winding consists of conductors embedded in slots in the faces of the main field poles (hence, the alternative terminology of pole-face winding) and end connectors. The conductors in the faces of the main field poles are parallel to the axis of the machine. The end connectors connect the p
25、ole-face conductors together and are perpendicular to the axis of the machine. It is the end connectors that give rise to turns around the shaft and large stray magnetic fields, if they are not properly arranged. A compensating winding, as defined in this standard, is not intended to compensate stra
26、y magnetic fields. A 3.1.4 Current loop. A current loop is a closed electric conductor. It may have one or more turns of any size or shape and may. be arranged in any way. A simple current loop is a closed conductor making one turn in a single plane, or alternatively, making a number of turns which
27、are in the same plane or in parallel planes and so close together that,. t a first approximation, they can be considered to be physically coincident in space. loops can be resolved into a combination of simple current loops. More complicated current 3.1.5 Current take-off points. Current take-off po
28、ints are the points at which the armature current leaves one brush collector.ring and returns to another brush collector ring. 3.1.6 Machine. A machine is a generator or motor. 3.1.7 Magnetic minesweep cable. The magnetic minesweep cable is the inter- connecting cable between th magnetic minesweep g
29、enerators and the minesweep cable terminal box. 3.1.8 Magnetic minesweeping generator. A magnetic minesweeping generator is a generator which produces the current for the magnetic minesweeping tail. 3.1.9 Minimum magnetic moment. A minimum magnetic moment ha6 a magnitude close to zero. 3.1.10 Polar
30、leakage field. Polar leakage field is the stray magnetic field that is emanated by the field coils alone. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-2146(SH) 1 June 1983 4. GENERAL REQUIREMENTS 4.1 Cause-of stray magnetic field. Stray
31、magnetic fields in a d.c. machine are caused by current in the field circuit and armature circuit of the machine. In order to ;educe a machines stray magnetic field, the field circuit design shall be in accordance with the requirements of 5.1 and armature circuit design shall be in accordance with t
32、he requirements of 5.2. 4.2 Low stray field features in machine design. The low stray field features of 4.2.1 through 4.2.12 shall be incorporated into the design of.the machine. These features are described in detail in section 5. 4.2.1 Frame design. Frame design of a machine shall meet the followi
33、ng requir.ements : (a) The frame shall be either of two types, (1) one piece with no (b) (c) (d) The material of the frame shall be magnetPCally homogeneous (e) joints, or (2) laminated. The weld in the frame shall be at a main pole (see 5.1.3.4.2). The frame shall be machined inside and outside, to
34、 insure uniform cross section throughout (see 5.1.3.4.3). throughout (see 5.1.3.4.4). smooth surface of revolution with its axis coincident with the axis of the generator. There shall be no magnetic.feet or other major projections of magnetic material on the outside of the frame (see 5.1.3.4.5). The
35、y shall go through some part of the machine enclosure which is non-magnetic.(see 5.1.3.4.6). The outside of the magnetic material in the frame shall be a (f) Current-carrying leads shall not be taken through the frame. 4.2.2 Number of field poles. The machine shall have an adequate number of field p
36、oles in accordance with 5.1.3.1. 4.2.3 Symmetry and uniformity. The following requirements of symmetry and uniformity shall be applied: (a) (b) (c) Air gaps shall be uniform (see 5.1.3.4.7). In machines which have commutating poles, there shall be as many commutating poles as main poles (see 5.1.3.4
37、.8). Coils of the same type (such as, shunt field coils and commutating pole coils) shall be of the same size and have exactly the same number of turns (see 5.1.3.4.9). 4.2.4 Wiring around the frame. Wiring around the frame of a machine shall meet the following requirements: (a) Connections to the s
38、hunt field coils shall have no net turns (b) around the shaft and no uncompensated current loops (see 5.1.4). End connections to the commutating coils and the compensating winding shall have no net turns around the shaft andno un- compensated current loops (see 5.2.6.2 and 5.2.7.2). 3 Provided by IH
39、SNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-2146(SH) 1 June 1983 4.2.5 Lap-wound armature. Lap-wound armatures shall have equalizer con- nections in the form of rings of uniform cross section throughout (see 5.2.1.1). 4.2.6 Brush collector rings. Brush
40、 collector rings shall meet the fol- lowing requirements: (a) The brush collector rings shall be complete rings, concentric with the axis of the machine,and of uniform cross section throughout the entire circumference (see 5.2.4). (b) There shall be either: (1) three brush collector rings equally sp
41、aced in the direction parallel to the axis of the machine, with the center ring carrying full positive (or negative) current and each of the two outer rings carrying one-half of the negative (or positive) current; or (2) two concentric rings, one larger than the other, mounted in the same plane perp
42、endicular to the axis of the machine (see 5.2.4.1). be either: (1) in-line with the axis of the machine for machines with three brush collector rings; or (2) in a plane passing through the axis of the machine for machines with two concentric brush rings inthe same plarle (see 5.2.4.2). (c) The curre
43、nt take-off points for the brush collector rings shall 4.2.7 Connections from brush collector rings. Connections from brush collector rings of a machine and the associated circuit shall be arranged with a central conductor carrying full current and two symmetrically placed flanking conductors, each
44、carrying half current, all so arranged as to avoid unbalanced current loops (see 5.2.5). 4.2.8 Double-armature machines. Machines with two armatures on the same shaft shall be designed in accordance with the principle of mutual compensation; the two armatures shall be as nearly alike as possible and
45、 have their connections so arranged that the magnetic field of one is in opposition to the other. 4.2.9 Angular position of take-off points. The current take-off point from one brush collector ring shall be at the same point where one set of brushes is connected to the ring (see 5.2.4.4). 4.2.10 Num
46、ber of commutator bars. The number of commutator bars shall be equal to an integral multiple of the number of field poles (see 5.2.2). 4.2.11 Brush rigging. Brush rigging shall be designed in a manner to force a well-defined current path between a set of brushes and the brush collectorring. axis of
47、the machine (see 5.2.3). This current path shall he in a plane which passes through the 4.2.12 Position of brush collector rings. The axial distance from the brush collector rings to the commutator risers shall be selected in a manner to minimize the efect of unequal current division between differe
48、nt sets of brushes (see 5.2.4.3). 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-2146 hL W 77779LL 0012b1i7 5 W DOD-STD-2146(SH) 1 June 1983 5. DETAILED REQUIREMENTS 5.1 Field circuit design. 5.1.1 Applicability. Since minesweeping generators are separately excited generators,. the requirements of 5.1.3.1 through 5.1.4 apply specifically to the field circuit of a separately excited generator. applied to the design of field circuits for self-excited, d.c. shunt motors and generators. Simil
