ISO 4156-1:2021 真っ直ぐな円筒形インボリュートスプライン—メトリックモジュール、サイドフィット—パート1：一般性 | ページ 6

3.1

spline joint

connecting, coaxial elements that transmit torque through the simultaneous engagement of equally spaced teeth situated around the periphery of a cylindrical external member with similar spaced mating spaces situated around the inner surface of the related cylindrical internal member

3.2

involute spline

member of spline joint (3.1) having teeth or spaces that have involute flank profiles

3.3

internal spline

spline formed on the inner surface of a cylinder

3.4

external spline

spline formed on the outer surface of a cylinder

3.5

fillet

concave surface of the tooth or space connecting the involute flank and the root circle

Note 1 to entry: For generated splines this curved surface, as generated, varies and cannot be properly specified by a radius of any given value. For splines formed directly by a tool (e.g. broached, net formed) the fillet may be specified as a true radius.

3.6

fillet root

spline having a tooth or space profile in which the opposing involute flanks are connected to the root circle (D_eiorD_ie diameter) by a single fillet (3.5)

3.7

flat root

spline having a tooth or space profile in which each of the opposing involute flanks are connected to the root circle (D_eiorD_ie diameter) by a fillet (3.5)

3.8

module

m

ratio of the circular pitch (3.12) , expressed in millimetres, to the number π

3.9

pitch circle

reference circle to which all spline dimensions are related, and the circle on which the specified pressure angle (3.13) has its nominal value

3.10

pitch diameter

D

diameter of the pitch circle (3.9) , in millimetres, equal to the number of teeth multiplied by the module (3.8)

3.11

pitch point

intersection of the spline tooth profile with the pitch circle (3.9)

3.12

circular pitch

p

length of arc of the pitch circle (3.9) between two consecutive pitch points (3.11) of left- (or right-) hand flanks, which has a value of the number π multiplied by the module (3.8)

3.13

pressure angle

α

acute angle between a radial line passing through any point on a tooth flank and the tangent plane to the flank at that point

3.14

standard pressure angle

α_D

pressure angle (3.13) at the specified pitch point (3.11)

3.15

base circle

circle from which involute spline (3.2) tooth profiles are generated

3.16

base pitch

p_b

arc length of the base circle (3.15) between two consecutive corresponding flanks

3.17

form diameter

D_F

diameter used to define the depth of involute profile control

Note 1 to entry: In the case of an external spline (3.4) it is located near and above the minor diameter, and on an internal spline (3.3) near and below the major diameter.

3.18

basic circular space width

E

for 30°, 37,5° and 45° pressure angle (3.13) splines, half the circular pitch (3.12) , measured at the pitch diameter (3.10)

3.19

basic circular tooth thickness

S

for 30°, 37,5° and 45° pressure angle (3.13) splines, half the circular pitch (3.12) , measured at the pitch diameter (3.10)

3.20

actual space width

practically measured circular space width, on the pitch circle (3.9) , of any single space width within the limit values E_max and E_min

3.21

effective space width, circular

E_v

space width where an imaginary perfect external spline (3.4) would fit without clearance or interference, given by the size of the tooth thickness of this external spline, considering engagement of the entire axial length of the splined assembly

Note 1 to entry: The minimum effective space width (E_{v min}, always equal to E) of the internal spline (3.3) is always basic, as shown in Table 3.

3.22

actual tooth thickness

practically measured circular tooth thickness, on the pitch circle (3.9) , of any single tooth within the limit values S_max and S_min

3.23

effective tooth thickness, circular

S_v

tooth thickness where an imaginary perfect internal spline (3.3) would fit without clearance or interference, given by the size of the space width of this internal spline, considering engagement of the entire axial length of the splined assembly

3.24

effective clearance

c_v

<looseness or interference> effective space width, circular (3.21) of the internal spline (3.3) minus the effective tooth thickness, circular (3.23) of the external spline (3.4)

Note 1 to entry: For looseness, c_v is positive; for interference, c_v is negative.

3.25

form clearance

c_F

radial clearance between the form diameter of the internal spline (3.3) and the major diameter of the external spline (3.4) , or between the minor diameter of the internal spline and the form diameter of the external spline

Note 1 to entry: It allows eccentricity of their respective pitch circles (3.9) .

3.26

total pitch deviation

F_p

absolute value of the difference between the greatest positive and negative deviations from the theoretical spacing, measured at the pitch circle (3.9)

Note 1 to entry: See ISO 1328-1.

3.27

total profile deviation

F_α

absolute value of the difference between the greatest positive and negative deviations from the theoretical tooth profile, measured normal to the flanks

3.28

total helix deviation

F_β

absolute value of the difference between the two extreme deviations from the theoretical direction parallel to the reference axis

3.29

parallelism deviation

deviation of parallelism of a single spline tooth to any other single spline tooth

Note 1 to entry: See Figure 1 b).

3.30

alignment deviation

deviation of the effective spline axis with respect to the reference axis

Note 1 to entry: See Figure 1 c).

3.31

effective deviation

accumulated effect of the spline deviations on the fit with the mating part

3.32

deviation allowance

λ

permissible deviation between minimum actual and minimum effective space width, circular (3.21) or maximum effective and maximum actual tooth thickness (3.22)

3.33

machining tolerance

T

permissible deviation between maximum actual and minimum actual space width (3.20) or tooth thickness

3.34

effective clearance tolerance

T_v

permissible deviation between maximum effective and minimum effective space width, circular (3.21) or tooth thickness

3.35

total tolerance

T + λ

<general> machining tolerance (3.33) plus the deviation allowance (3.32)

3.36

total tolerance

<internal spline> difference between the minimum effective space width, circular (3.21) and the maximum actual space width (3.20)

3.37

total tolerance

<external spline> difference between the maximum effective tooth thickness, circular (3.23) and the minimum actual tooth thickness (3.22)

3.38

basic dimension

numerical value to describe the theoretically exact size, shape or location of a feature

Note 1 to entry: It is the basis from which permissible deviations are established by tolerances.