2-3 Verifying and examining load weights
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Verifying and examining load weights
The SHA series actuator incorporates a precise cross roller bearing for directly supporting an external
load (output flange). To demonstrate the full ability of the actuator, verify the maximum load moment
load as well as the life and static safety coefficient of the cross roller bearing.
Checking procedure
1
Verifying the maximum load moment load (Mmax)
Calculating the maximum load moment load (M
max
)
↓
Verifying the maximum load moment load (M
max
) is less than or equal to the permissible
moment load (Mc)
2
Verifying life
Calculate the average radial load (Fr
av
) and average axial load (Fa
av
).
↓
Calculate the radial load coefficient (X) and the axial load coefficient (Y).
↓
Calculate the life of the bearing and verify the life is allowable.
3
Verifying the static safety coefficient
Calculate the static equivalent radial load (Po).
↓
Verify the static safety coefficient (fs).
Specifications of the main roller bearing
The following table shows the specifications of the main roller bearings built in SHA actuators.
Table 1: Specifications of the cross roller bearings
Item
Model
Circular
pitch of the
roller (dp)
Offset
amount
(R)
Basic
dynamic
rated load
(C)
Basic static
rated load
(Co)
Permissible
moment
load (Mc)
Moment
stiffness
(Km)
mm
mm
kN
kN
Nm
x10
4
Nm/rad
SHA20A-SG
70
23.5
14.6
22
187
25.2
SHA20A-CG
70
19.5
14.6
22
187
25.2
SHA25A-SG
85
27.6
21.8
35.8
258
39.2
SHA25A-CG
85
21.6
21.8
35.8
258
39.2
SHA25A-HP
85
15.3
11.4
20.3
410
37.9
SHA32A-SG
111
34.9
38.2
65.4
580
100
SHA32A-CG
111
25.4
38.2
65.4
580
100
SHA32A-HP
111.5
15
22.5
39.9
932
86.1
SHA40A-SG
133
44
43.3
81.6
849
179
SHA40A-CG
133
29.5
43.3
81.6
849
179
SHA58A-SG
195
62.2
87.4
171
2180
531
SHA65A-SG
218
69
130
223
2740
741
