JB/T 6742-1993 Commutator for small power motor

JB/T 6742-1993 Commutator for small power motor JB/T6742-1993 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Commutator for small power motors
1 Subject content and scope of application
JB/T6742-93
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of commutators for small power motors.
This standard applies to commutators for small power motors (hereinafter referred to as commutators) used under general environmental conditions. This standard does not apply to disc commutators.
Cited standards
GB5171
GB1801
GB1804
GB1184
GB2828
GB2829
GB12350
General technical requirements for small power motors
Tolerances and fits·Dimensions up to 500mmbZxz.net
Tolerances and fitsLimit deviations of dimensions without tolerancesShape and position tolerancesProvisions for tolerances without tolerancesBatch-by-batch inspectionCounting Sampling procedures and sampling tables (applicable to the inspection of continuous batches) Periodic inspection counting sampling procedures and sampling tables (applicable to the inspection of the stability of the production process) Safety requirements for small power motors
Basic environmental test procedures for electrical and electronic products Test Ca; Steady damp heat test method
JB/DQ3619 General rules for quality classification of small power motor products 3 Terminology codes
3.1 Nominal working voltage
The rated voltage of the small power motor equipped with the commutator or the working voltage under the specified full load. 3.2 Nominal working speed
The rated speed of the small power motor equipped with the commutator or the working speed under the specified full load. 3.3 No-load speed
The no-load speed of the small power motor equipped with the commutator. 4 Product classification
4.1. Nominal diameter of commutator
This standard refers to the nominal diameter of the commutator, which is the diameter of the finished commutator (excluding the heightened sheet size) mm. The specific sizes are as follows: 3.15, 4, 5, 6.3, 8, 10, 12.5, 14, (15), 16, (17), 18, (19), 20, (21.5), 22.4, (23.5), 25.5, (26.5), 28, (30), 31.5, 35.5, (37.5), 40, 45, 50, 56, 63. Note: The sizes in brackets are not recommended supplementary sizes and should be avoided as much as possible. 4.2 Commutator structure
4.2.1 According to the insulation structure between the commutator segments, it can be divided into: a. Mica sheet insulation plastic pressing structure;
No mica sheet plastic pressing structure.
Approved by the Ministry of Machinery Industry on August 21, 1993
Implemented on October 1, 1993
According to the wiring type, it is divided into:
Hook type;
Slot type.
According to the mechanical strength, it is divided into:
Ordinary type;
Enhanced type.
According to the inner hole structure, it is divided into:
With bushing;
Without bushing.
Technical requirements
General requirements
JB/T6742-93
Commutators shall be manufactured according to the drawings and technical documents approved by the prescribed procedures. 5.1.1
The surface of the commutator shall be complete and smooth, without scars, cracks, burrs and other obvious defects. 5.1.2
5.1.3 The commutator segments of the commutator shall be evenly distributed along the circumference, and the lower wire groove or hook shall be located in the central part of the commutator. 5.2 Dimension requirements
Limit deviation of the inner hole diameter of the commutator
5.2.1.1 The inner hole with a bushing shall not exceed H7 specified in GB1801. 5.2.1.2 The inner hole without a bushing shall not exceed H8 specified in GB1801. Note: For inner hole diameters less than 6mm or with special requirements. The limit deviation of the inner hole diameter of the commutator can be determined by negotiation between the demander and the manufacturer. 5.2.2 The axial length tolerance of the commutator shall not be greater than JS15 specified in GB1804. 5.2.3 The segment inclination of the commutator segment to the axis shall not be greater than 1/2 (or 1/3) of the nominal insulation width between the segments. Note: 1) If necessary, it shall be proposed by the demander. 5.2.4 The radial runout tolerance of the commutator working surface shall not be greater than Class 10 specified in GB1184. Insulation resistance
The insulation resistance between the commutator segment and the shaft shall not be less than that specified in Table 1. Table 1
Test conditions
Cold state (normal temperature)
After damp heat test
Insulation resistance
2 (used as basic insulation)
10 (used as reinforced insulation)
Withstand voltage
The insulation between the commutator segments shall be able to withstand a 2s withstand voltage test without breakdown or flashover. The frequency of the test voltage is 50Hz, and the waveform is basically a sine wave. The effective value of the test voltage is as specified in Table 2. Nominal working voltage of commutator
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