GB/T 10095-1988 English PDF (GB/T10095-1988)

GB/T 10095-1988: Accuracy of involute cylindrical gears
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GB 10095-1988
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
UDC 621.831/.833
Accuracy of involute cylindrical gears
渐开线圆柱齿轮精度
ISSUED ON: DECEMBER 10, 1988
IMPLEMENTED ON: OCTOBER 01, 1989
Issued by: State Bureau of Technical Supervision
Table of Contents
1 Subject content and scope of application ... 3 
2 Normative references ... 3 
3 Definition and code of gear, gear pair error, backlash ... 4 
4 Precision grades ... 9 
5 Gear blank requirements ... 10 
6 Gear inspection and tolerance ... 10 
7 Inspection and tolerance of gear pairs ... 12 
8 Backlash ... 12 
9 Others ... 13 
10 Drawing markings ... 13 
Appendix A Gear tolerance relation and calculation (Supplementary) ... 24 
Appendix B Gear blank tolerance (Supplementary) ... 26 
Appendix C Common normal length variation tolerance, gear pair tolerance
(Supplementary) ... 28 
Additional information: ... 30 
Accuracy of involute cylindrical gears
This standard equivalently adopts ISO 1328-1975 "Parallel involute gears - ISO system
of accuracy".
1 Subject content and scope of application
This standard specifies the error definition, code, accuracy grade, tooth blank
requirements, inspection and tolerance, backlash and drawing marking of involute
cylindrical gears and their gear pairs.
This standard applies to involute cylindrical gears and their gear pairs, for parallel shaft
transmission. Its normal modulus is greater than or equal to 1 mm; the basic tooth
profile is in accordance with GB 1356.
When the gear specification exceeds the range listed in this standard (the normal
module is greater than 40 mm, the diameter of the index circle is greater than 4000 mm,
the effective tooth width is greater than 630 mm), it can be specified in Appendix A
(supplementary).
2 Normative references
GB 1356 Basic rack tooth profile of involute cylindrical gears
GB 2821 Symbols for gear geometrical data
GB 3374 Basic terminology of gears
GB 1800 Tolerance and fitting - General standard tolerance and fundamental
deviation
has the highest precision; the 12th grade has the lowest precision. The precision grades
of the two gears, in the gear pair are generally the same; however, they are also allowed
to be different.
4.2 The tolerances and limit deviations of gears are divided into three groups
4.3 According to different requirements of use, different precision grades are allowed
to be selected, for each tolerance group. However, within the same tolerance group,
each tolerance and limit deviation shall maintain the same precision grade.
5 Gear blank requirements
5.1 The radial reference plane and the axial auxiliary reference plane of the gear, during
processing, inspection, installation, shall be as consistent as possible, AND marked on
the gear part drawing.
5.2 Tolerances of gear blanks include the size, shape, position tolerances of shafts or
holes, as well as the runout of the reference plane. The tolerance values are
recommended to be as specified in Table B1 of Appendix B (Supplementary).
6 Gear inspection and tolerance
6.1 According to the use requirements and production scale of the gear pair, in each
tolerance group, select an inspection group, to verify and accept the accuracy of the
gear.
Inspection group for tolerance group I:
ΔF'i;
ΔFp and ΔFpk;
ΔFp;
ΔF'i and ΔFw (when one of them is out of tolerance, the gear precision shall be
verified and accepted according to ΔFp);
ΔFr and ΔFw (when one of them is out of tolerance, the gear precision shall be verified
and accepted according to ΔFp);
ΔFr (For precision grade of 10 ~ 12).
Inspection group for tolerance group II:
Δf'i (if necessary, Δfpb can be added);
Δff and Δfpb;
Δff and Δfpt;
Δffβ (for helical gears or herringbone gears, which have an axial coincidence εβ
greater than 1.25, as well as a precision of grade 6 and above);
Δf'i (Tooth profile precision must be guaranteed);
Δfpt and Δfpb (For precision grades 9 ~ 12),
Δfpt or Δfpb (For precision grades 10 ~ 12).
Inspection groups for tolerance group III:
ΔFβ;
ΔFb (Only for helical gears, whose axial coincidence εβ is equal to or less than 1.25,
AND whose tooth line is not corrected);
ΔFpx and Δff (Only for helical gears, whose axial coincidence εβ is greater than 1.25,
AND whose tooth line is not corrected);
ΔFpx and ΔFb (Only for helical gears, whose axial coincidence εβ is greater than 1.25,
AND whose tooth line is not corrected).
6.2 For each precision grade, the tolerance values of various errors of the gear are
specified as follows:
Fp, FPk, Fr, F'i are specified in Table 1, Table 2, Table 3; F'i is specified in Appendix A
1; Fw is specified in Table C 1 of Appendix C; ff, fPt, fPb, f'i are specified in Table 4,
Table 5, Table 6, Table 7; f'i and ffβ are specified in Appendix A1; Fβ is specified in
Table 8; Fb and F'px are specified in Appendix A1.
For the small ripples, whose wavelength is greater or less than one pitch angle, in the
record curve of tangential composite error, special requirements are allowed when
necessary. The tolerance value is recommended to be the value of the tangential
composite tolerance f'i of one tooth.
When using the designed profile and designed tooth line, for the correction part of the
tooth form, it does not check ΔfPb; for the correction part of the tooth line, it does not
check ΔFb and ΔFpx.
7 Inspection and tolerance of gear pairs
7.1 The requirements of the gear pair include the tangential composite error ΔF'ic of the
gear pair, the tangential composite error Δf'ic of one tooth of the gear pair, the position
and size of the contact spot of the gear pair, the backlash requirements.
If the above four requirements of the gear pair can be met, the gear pair is considered
qualified.
7.2 The tangential composite error ΔF'ic of the gear pair AND the one-tooth tangential
composite error Δf'ic of the gear pair shall be measured after assembly, OR the sum of
the tangential composite error ΔF'i of a single gear AND the one-tooth tangential
composite error Δf'i shall be evaluated. The tangential composite tolerance F'ic of the
gear pair AND the one-tooth tangential composite tolerance f'ic of the gear pair are as
specified in Appendix C (supplementary).
7.3 When using the designed tooth form and designed tooth line, the distribution
position and size of the contact spots can be specified by themselves. Generally, the
distribution position and size of the contact spots of the gear pair are as specified in
Table C2 of Appendix C.
If the distribution position and size of the contact spots are guaranteed, the item of the
III tolerance group of a single gear, in this gear pair, may not be examined from
evaluation.
7.4 The axis parallelism tolerance fx and fy of the gear pair shall be as specified in Table
9.
8 Backlash
8.1 The backlash requirement of the gear pair shall be specified, by the maximum limit
backlash jnmax (or jtmax) and the minimum limit backlash jnmin (or jtmin), according to the
working conditions.
8.2 The center distance's limit deviation ±fa shall be specified in Table 10.
8.3 The upper deviation Ess and the lower deviation Esi of the tooth thickness limit
deviation are selected from Table 11.
For example: Select F (equal to -4fPt) for upper deviation and L (equal to -16fPt) for
lower deviation; THEN, the limit deviation of tooth thickness is represented by code
FL, as shown in the Figure below.
If the selected tooth thickness limit deviation exceeds the 14 codes, which are listed in
Table 11, it is allowed to specify by itself.
9 Others
9.1 The reference axis of the gear, it refers to the axis of the hole, for the gear with a
hole; it refers to the axis of the journal, for the cantilever shaft gear; it refers to the
common reference axis of the two journals, for the double-supported shaft gear,.
9.2 When it is necessary to number the tooth sequence of the gears, observe facing the
reference axis of the gear, with the marked surface upwards; arrange them in a
clockwise or counterclockwise direction.
9.3 When it is necessary to distinguish the flanks, facing the marked surface, observe
the state with the top of the tooth on the top and the root of the tooth on the bottom. The
right side is called the right flank; the left side is called the left flank.
9.4 When interchangeability is not required, the following elements are allowed as
nominal values:
a. Average value of actual tooth thickness;
b. Average value of the actual helix angle;
c. Average value of actual basic pitch.
At this time, the tooth thickness of the other gear, in the gear pair, shall be calculated
and determined, according to the nominal tooth thickness of the first gear.
10 Drawing markings
The letter code of the precision grade of the gear and the limit deviation of the tooth
thickness, shall be marked on the gear part drawing.
GB 10095-1988
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
UDC 621.831/.833
Accuracy of involute cylindrical gears
渐开线圆柱齿轮精度
ISSUED ON: DECEMBER 10, 1988
IMPLEMENTED ON: OCTOBER 01, 1989
Issued by: State Bureau of Technical Supervision
Table of Contents
1 Subject content and scope of application ... 3 
2 Normative references ... 3 
3 Definition and code of gear, gear pair error, backlash ... 4 
4 Precision grades ... 9 
5 Gear blank requirements ... 10 
6 Gear inspection and tolerance ... 10 
7 Inspection and tolerance of gear pairs ... 12 
8 Backlash ... 12 
9 Others ... 13 
10 Drawing markings ... 13 
Appendix A Gear tolerance relation and calculation (Supplementary) ... 24 
Appendix B Gear blank tolerance (Supplementary) ... 26 
Appendix C Common normal length variation tolerance, gear pair tolerance
(Supplementary) ... 28 
Additional information: ... 30 
Accuracy of involute cylindrical gears
This standard equivalently adopts ISO 1328-1975 "Parallel involute gears - ISO system
of accuracy".
1 Subject content and scope of application
This standard specifies the error definition, code, accuracy grade, tooth blank
requirements, inspection and tolerance, backlash and drawing marking of involute
cylindrical gears and their gear pairs.
This standard applies to involute cylindrical gears and their gear pairs, for parallel shaft
transmission. Its normal modulus is greater than or equal to 1 mm; the basic tooth
profile is in accordance with GB 1356.
When the gear specification exceeds the range listed in this standard (the normal
module is greater than 40 mm, the diameter of the index circle is greater than 4000 mm,
the effective tooth width is greater than 630 mm), it can be specified in Appendix A
(supplementary).
2 Normative references
GB 1356 Basic rack tooth profile of involute cylindrical gears
GB 2821 Symbols for gear geometrical data
GB 3374 Basic terminology of gears
GB 1800 Tolerance and fitting - General standard tolerance and fundamental
deviation
has the highest precision; the 12th grade has the lowest precision. The precision grades
of the two gears, in the gear pair are generally the same; however, they are also allowed
to be different.
4.2 The tolerances and limit deviations of gears are divided into three groups
4.3 According to different requirements of use, different precision grades are allowed
to be selected, for each tolerance group. However, within the same tolerance group,
each tolerance and limit deviation shall maintain the same precision grade.
5 Gear blank requirements
5.1 The radial reference plane and the axial auxiliary reference plane of the gear, during
processing, inspection, installation, shall be as consistent as possible, AND marked on
the gear part drawing.
5.2 Tolerances of gear blanks include the size, shape, position tolerances of shafts or
holes, as well as the runout of the reference plane. The tolerance values are
recommended to be as specified in Table B1 of Appendix B (Supplementary).
6 Gear inspection and tolerance
6.1 According to the use requirements and production scale of the gear pair, in each
tolerance group, select an inspection group, to verify and accept the accuracy of the
gear.
Inspection group for tolerance group I:
ΔF'i;
ΔFp and ΔFpk;
ΔFp;
ΔF'i and ΔFw (when one of them is out of tolerance, the gear precision shall be
verified and accepted according to ΔFp);
ΔFr and ΔFw (when one of them is out of tolerance, the gear precision shall be verified
and accepted according to ΔFp);
ΔFr (For precision grade of 10 ~ 12).
Inspection group for tolerance group II:
Δf'i (if necessary, Δfpb can be added);
Δff and Δfpb;
Δff and Δfpt;
Δffβ (for helical gears or herringbone gears, which have an axial coincidence εβ
greater than 1.25, as well as a precision of grade 6 and above);
Δf'i (Tooth profile precision must be guaranteed);
Δfpt and Δfpb (For precision grades 9 ~ 12),
Δfpt or Δfpb (For precision grades 10 ~ 12).
Inspection groups for tolerance group III:
ΔFβ;
ΔFb (Only for helical gears, whose axial coincidence εβ is equal to or less than 1.25,
AND whose tooth line is not corrected);
ΔFpx and Δff (Only for helical gears, whose axial coincidence εβ is greater than 1.25,
AND whose tooth line is not corrected);
ΔFpx and ΔFb (Only for helical gears, whose axial coincidence εβ is greater than 1.25,
AND whose tooth line is not corrected).
6.2 For each precision grade, the tolerance values of various errors of the gear are
specified as follows:
Fp, FPk, Fr, F'i are specified in Table 1, Table 2, Table 3; F'i is specified in Appendix A
1; Fw is specified in Table C 1 of Appendix C; ff, fPt, fPb, f'i are specified in Table 4,
Table 5, Table 6, Table 7; f'i and ffβ are specified in Appendix A1; Fβ is specified in
Table 8; Fb and F'px are specified in Appendix A1.
For the small ripples, whose wavelength is greater or less than one pitch angle, in the
record curve of tangential composite error, special requirements are allowed when
necessary. The...