Internal Gears - Maryland Metrics

SIR
Steel Ring Gears
The Catalog Number for KHK stock gears is based on the simple
formula listed below. Please order KHK gears by specifying the
Catalog Numbers.
(Example)
Internal Geas
S I R 1 - 60
No. of teeth (60)
Module (1)
Miter
Gears
Catalog Number of KHK Stock Gears
CP Racks
& Pinions
Racks
P.O. Box 261 Owings Mills, MD 21117 USA
ph: (410)358-3130 (800)638-1830
fx: (410)358-3142 (800)872-9329
email: [email protected]
http://mdmetric.com
RFQ form: http://mdmetric.com/rfq.htm
Helical
Gears
Internal
Gears
KHK products are available from
MARYLAND METRICS
Internal
Gears
Page 369
Bevel
Gears
m2 ～ 3
Others (Ring Gear)
Type (Internal Gear)
Material (S45C)
Material
S
S45C
Type
I
Internal Gears
Other Information
R
Ring Gears
■ Feature Icons
RoHS Compliant
Product
Stainless Product
Re-machinable
Product
Resin Product
Finished Product
Copper Alloy
Product
Heat Treated
Product
Injection Molded
Product
Ground Gear
Black Oxide
coated Product
Screw
Gears
Page 368
Spur
Gears
Newly added
m 0.5 ～ 3
Other
Bevel
Worm
Products Gearboxes Gear Pair
SI
Steel Internal Gears
365
Internal Gears
Characteristics
KHK stock internal gears are offered in modules 0.5 to 3 in
50 to 200 teeth. They can be used in many applications including planetary gear drives.
Catalog No.
SI
SIR
Module
0.5 ～ 3
2～3
Material
S45C
S45C
―
―
Cut
Cut
Heat Treatment
Tooth Surface Finish
Precision JIS B 1702-1:1998
N8
Secondary Operations
Possible
Possible
A popular type of internal
gear; low cost and suitable for many applications.
Ring gear large in size /
number of tooth. It can
be cut to make segment
gears and corner racks.
Features
Established equipment and technology.
Custom Gears are also available.
Diameter φ700mm maximum, Module 6.5 maximum,
Cutting Stroke 170 mm
N9
NOTE 1
〔Note 1〕 The Product accuracy class having a module less than 0.8 corresponds to 'equivalent' as shown in the table.
Selection Hints
Please select the most suitable products by carefully considering
the characteristics of items and contents of the product tables. It is
also important to read all applicable notes before the final selection.
1. Caution in Selecting the Mating Gears
2. Caution in Selecting Gears Based on Gear Strength
KHK stock internal gears can mate with any spur gears of the
same module, however, there are cases of involute, trochoid and
trimming interference occurrences, depending on the number of
teeth of the mating gear. Various types of interference and their
symptoms and causes are tabulated below, also shown, the number of teeth of allowable mating pinions.
■ Interferences and the symptoms
TYPE
SYMPTOMS
The tip of the internal gear
digs into the root of the
pinion.
Gear cutting by CNC Gear Shaper
The gear strength values shown in the product pages were computed by assuming a certain application environment. Therefore,
they should be used as reference only. We recommend that each
user computes his own values by applying the actual usage conditions. The table below contains the assumptions established for
these products in order to compute gear strengths.
■ Calculation assumptions for Bending Strength of Gears
CAUSES
Catalog No.
Item
SIR
Too few teeth on
the pinion.
Formula
The exiting pinion tooth conTrochoid interference tacts the internal gear tooth.
Too little difference
in number of teeth
of the two gears.
Rotation
100rpm
Durability
Over 107cycles
Pinion can slide in or out
Trimming interference axially but cannot move radially.
Too little difference
in number of teeth
of the two gears.
Involute interference
Formula of spur and helical gears on bending strength（JGMA401-01）
NOTE 1
30
No. of teeth of mating gears
Impact from motor
Uniform load
Impact from load
Uniform load
Bidirectional
Direction of load
Allowable beam stress at root σFlim（kgf/mm ）Note 2
19
Safety factor S F
1.2
2
■ Allowable Mating Pinions and Number of Teeth
No. of teeth of Allowable Mating Pinions
No. of teeth of
Internal Gear Lower limit No. of teeth Upper limit No. of teeth Upper limit No. of teeth
by Involute interference by Trochoid interference by Trimming interference
50
60
80
100
120
160
200
366
SI
22
21
20
19
19
19
18
41
51
72
92
112
152
192
33
43
64
84
104
144
184
■ Calculation assumptions for Surface Durability (Except where it is common with bending strength)
Formula
NOTE 1
Kinematic viscosity of lubricant
Gear support
Allowable Hertz stress σHlim（kgf/mm2）
Safety factor SH
Formula of spur and helical gears on surface durability (JGMA402-01)
100cSt（50℃）
Symmetric support by bearings
49
1.15
〔Note 1〕 The gear strength formula is based on JGMA (Japanese Gear
Manufacturers’Association) The units for the rotational speed (rpm)
and the stress (kgf/mm2) are adjusted to the units needed in the
formula.
〔Note 2〕 Since the load is bidirectional, the allowable bending stress at root
σFlim calculated is set to 2/3 of the value.
KHK Technical Information
Application Hints
③ To use as a planetary gear drive, the following conditions must be satisfied.
In order to use KHK stock internal gears safely, read the Application
Hints carefully before proceeding. Also“1. Caution on Performing Secondary Operations”,“3. Notes on Starting Operations”and“4. Other
Points to Consider in Applications”in the spur gear section should be
consulted (Page 36).
Condition on number of teeth in planetary mechanism
● Condition 1 ･･･ zc ＝ za ＋ 2zb
1. Point of Caution in Assembling
za ＋ zc
● Condition 2 ･･･　＝ Integer
N
① KHK stock internal gears are designed to give the proper backlash when assembled using the center distance
given by the formula below. The amount of backlash is
given in the product table for each gear.
Where
a ：Center distance
d 1 ：Pitch diameter of Pinion
d 2 ：Pitch diameter of Internal Gear
d2 － d1
2
a＝
② Note that the direction of rotation of the internal gear
is different from that of two spur gears in mesh.
● Condition 3 ･･･ zb ＋ 2 ＜（za ＋ zb）sin
za ：No.
zb ：No.
zc ：No.
N ：No.
No. of teeth of
internal gear
No. of planet No. of teeth of No. of teeth of Reduction ratio of Reduction ratio of Reduction ratio of
gears
sun gear
planet gears
planetary type
solar type
star type
60
80
80
100
100
−
3
3
3
3
3
18
16
40
20
50
21
32
20
40
25
Drive
Driven
n1, z1
n2, z2
1.3
1.2
1.5
1.2
1.5
－ 3.333
－5
－2
－5
－2
Types of planetary gear reduction mechanism
C (Fixed)
B
n2, z2
Driven
Internal gear is driven
z2
n1
＝
z1
n2
C
C
B
B
n1, z1
Drive
A (Fixed)
z：No. of teeth
n：Rotational speed
(a) Planetary type
D (Fixed)
D
D
Internal gear is drives
Application Examples
Output
4.333
6
3
6
3
−
＋
Gear Ratio i ＝
teeth of Sun Gear
teeth of Planet Gears
teeth of Internal Gear
Planet Gears
■ Example of combinations
Gear Ratio and Direction of Rotation
＋
of
of
of
of
180°
N
A
A
(b) Solar type
(c) Star type
* The illustration is a design example, not a design for machinery or a device in
actual use.
Input
Output
Reduction Ratio 3
Reduction Ratio 60
No. of teeth of a Sun Gear
：40
No. of teeth of a Planetary Gears ：20
No. of teeth of a Internal Gear ：80
No. of a Planetary Gears
：3
Planetary Gear Mechanism used in a reduction gear *
Input
No. of teeth of a fixed Sun Gear ：60
No. of teeth of a Planetary Gears ：25
No. of teeth of a rotating Sun Gear：61＊
*Negative dislocation
Mechanical Paradox Gear Mechanism used in a large reduction gear
367
Module 0.5 ～ 3
SI
Steel Internal Gears
Steel Internal Gears
Newly added
E
Specifications
Pressure angle
20°
Material
S45C
Helical
Gears
Heat treatment
Internal
Gears
Racks
CP Racks
& Pinions
Miter
Gears
Bevel
Gears
Screw
Gears
Other
Bevel
Worm
Products Gearboxes Gear Pair
―
Tooth hardness less than 194HB
＊ The precision grade of products with a module of less
than 0.8 is equivalent to the value shown in the table.
T1
Module
Internal dia. Pitch dia. Outside dia. Face width Allowable torque (N·m) Allowable torque (kgf·m)
No. of
Shape
teeth
A
C
D
E Bending strength Surface durability Bending strength Surface durability
SI0.5-60
SI0.5-80
SI0.5-100
m0.5
60
80
100
T1
T1
T1
29
39
49
30
40
50
50
60
70
5
5
5
SI0.8-60
SI0.8-80
SI0.8-100
m0.8
60
80
100
T1
T1
T1
46.4
62.4
78.4
48
64
80
75
90
105
8
8
8
SI1-60
SI1-80
SI1-100
m1
60
80
100
T1
T1
T1
58
78
98
60
80
100
90
110
130
SI1.5-50
SI1.5-60
SI1.5-80
SI1.5-100
m1.5
50
60
80
100
T1
T1
T1
T1
72
87
117
147
75
90
120
150
m2
50
60
80
100
T1
T1
T1
T1
96
116
156
196
50
60
80
50
60
T1
T1
T1
T1
T1
120
145
195
144
174
Catalog No.
New items indicated in blue letters.
368
C
Standard full depth
D
Gear teeth
A
Spur
Gears
JIS grade N8 (JIS B1702-1: 1998) ＊
Precision grade
JIS grade 4 (JIS B1702: 1976)
SI2-50
SI2-60
SI2-80
SI2-100
SI2.5-50
SI2.5-60
SI2.5-80
SI3-50
SI3-60
m2.5
m3
3.75
4.85
5.97
Backlash
Weight
(mm)
(kg)
0.67
0.75
0.87
0.38
0.49
0.61
0.07
0.08
0.09
0.04~0.15 0.049
0.04~0.15 0.062
0.04~0.15 0.074
15.4
19.9
24.5
2.87
3.24
3.75
1.57
2.03
2.50
0.29
0.33
0.38
0.05~0.16 0.16
0.05~0.16 0.20
0.05~0.16 0.23
10
10
10
30.0
38.8
47.8
5.95
6.59
7.64
3.06
3.96
4.87
0.61
0.67
0.78
0.10~0.22
0.10~0.22
0.12~0.25
0.28
0.35
0.43
115
130
160
190
15
15
15
15
87.1
101
131
161
20.9
20.6
23.3
27.0
8.88
10.3
13.4
16.5
2.13
2.10
2.38
2.75
0.13~0.29
0.13~0.29
0.13~0.29
0.15~0.32
0.70
0.81
1.04
1.26
100
120
160
200
150
170
210
250
20
20
20
20
206
240
311
382
50.3
50.5
57.0
65.7
21.0
24.5
31.7
39.0
5.13
5.15
5.81
6.70
0.16~0.33
0.16~0.33
0.16~0.33
0.17~0.37
1.54
1.79
2.28
2.77
125
150
200
150
180
185
210
260
220
250
25
25
25
30
30
403
469
607
697
811
0.17~0.37
0.17~0.37
0.17~0.37
0.19~0.41
0.19~0.41
2.87
3.33
4.25
4.79
5.57
101
101
114
178
178
41.1
47.8
61.9
71.0
82.7
10.3
10.3
11.6
18.1
18.2
[Caution on Product Characteristics]
① The backlash values shown in the table are the theoretical values for the normal direction for the internal ring in mesh with a 30 tooth SS spur gear.
② The allowable torque shown in the table are the calculated values according to the assumed usage conditions. Please see page 366 for more details
③ Please check for the involute interference, trochoid interference and trimming interference prior to using internal gears.
[Caution on Secondary Operations]
① Please read“Caution on Performing Secondary Operations”(Page 36) when performing modifications and/or secondary operations for safety concerns.
Haguruma Kobo, the KHK's system for quick modification of KHK stock gears is also available.
② Avoid performing secondary operations that narrow the tooth width as it affects precision and strength.
SIR
Module 2、2.5、3
Steel Ring Gears
Internal Ring Gears
S45C
Heat treatment
Spur
Gears
Material
―
Tooth hardness less than 194HB
T1
Catalog No.
SIR2-120
SIR2-200
SIR2.5-120
SIR2.5-200
SIR3-120
SIR3-160
Module
Internal dia. Pitch dia. Outside dia. Face width Allowable torque (N·m) Allowable torque (kgf·m)
No. of
Shape
teeth
A
C
D
E Bending strength Surface durability Bending strength Surface durability
120
200
120
m2.5
200
120
m3
160
m2
T1
T1
T1
T1
T1
T1
236
396
295
495
354
474
240
400
300
500
360
480
286
446
355
555
424
544
20
20
25
25
30
30
413
677
807
1320
1390
1840
68.8
110
138
220
244
315
42.1
69.0
82.3
135
142
188
7.02
11.2
14.0
22.5
24.9
32.1
Backlash
Weight
(mm)
(kg)
0.17~0.37 2.98
0.20~0.41 4.80
0.19~0.41 5.55
0.22~0.46 8.94
0.22~0.45 9.28
0.22~0.45 12.1
① The backlash values shown in the table are the theoretical values for the normal direction for the internal ring in mesh with a 30 tooth SS spur gear.
② The allowable torque shown in the table are the calculated values according to the assumed usage conditions. Please see page 366 for more details
③ Please check for the involute interference, trochoid interference and trimming interference prior to using internal gears.
[Caution on Secondary Operations]
① Please read“Caution on Performing Secondary Operations”(Page 36) when performing modifications and/or secondary operations for safety concerns.
Haguruma Kobo, the KHK's system for quick modification of KHK stock gears is also available.
② Avoid performing secondary operations that narrow the tooth width as it affects precision and strength.
Other
Bevel
Worm
Products Gearboxes Gear Pair
Screw
Gears
Bevel
Gears
Miter
Gears
[Caution on Product Characteristics]
Helical
Gears
20°
Internal
Gears
Pressure angle
Racks
Standard full depth
CP Racks
& Pinions
Gear teeth
A
JIS grade N8 (JIS B1702-1: 1998)
JIS grade 4 (JIS B1702: 1976)
D
Specifications
Precision grade
C
E
You can download CAD data (DXF format) of KHK Products from the Web Catalog.
369
370