Front matter 3
Series MY3
Types of Moment Applied to Rodless Cylinders
Multiple moments may be generated depending on the mounting orientation, load and position of the center of gravity.
Calculation of Guide Load Factor
1.
Maximum load weight (1), static moment (2), and dynamic moment (3) (at the time of impact with stopper) must be examined for the selection calculations.
∗To evaluate, use υa (average speed) for (1) and (2), and υ(impact speed υ= 1.4υa) for (3). Calculate m max for (2) from the maximum allowable load graph (m1, m2, m3 )
and Mmax for (2) and (3) from the maximum allowable moment graph (M1, M2, M3).
2. Reference formulas [Dynamic moment at impact]
Use the following formulas to calculate dynamic moment when taking stopper impact into consideration.
m:Load weight (kg)
F:Load (N)
FE:
Load equivalent to impact (at impact with stopper) (N)
υa: Average speed (mm/s)
M:Static moment (N •m)
υ= 1.4υa (mm/s) FE= 1.4υa x δx m •g
1
ME=
—
•FE•L1= 4.57υaδm L1 (N •m)
3
Note 4) 1.4υaδ is a dimension less coefficient for calculating impact force.
Note 5) Average load coefficient = :
This coefficient is for averaging the maximum load moment at the time of stopper impact according to service life calculations.
3. For detailed selection procedure, please refer to pages 2, 3, 18, 19.
Coordinates and Moments
z
y
M3: Yawing
xM2: Rolling
M1: Pitching
Horizontal
mounting
Wall
mounting
Ceiling
mounting
m3x g
x
M2
z
M3
X
Z
y
m1x g
M1
X
x
M2
Yy
m2x g
M1
X
x
M2
Y
Vertical
mounting
g: Gravitational acceleration
M1
Z
M3
zy
Y
Note)
m
4
is a mass movable by thrust. Use 0.3 to 0.7 times the thrust
(differs depending on the operating speed) as a guide for actual use.
Mounting direction
Static load m
Horizontal
m1
Ceiling
m2
Wall
m3
M1
M2
M3
m1x gx X
m1x gx Y
—
m2x gx X
m2x gx Y
—
—
m3x gx Z
m3x gx X
m4x gx Z
—
m4x gx Y
Vertical
m4
M1
FE
M3
Y
υa
Mounting direction
Dynamic load
FE
Horizontal Ceiling Wall Vertical
Note) Regardless of the mounting orientation, dynamic moment is
calculated with the formulae above.
Dynamic moment M2E will not be generated.
1.4υax δx mnx g
x FEx Z
1
3
x FEx Y
1
3
M1E
M2E
M3E
Load Weight and Static Moment
g: Gravitational acceleration
υa: Average speed
δ: Bumper coefficient
Note 1) Moment caused by the load, etc., with cylinder in resting condition.
Note 2) Moment caused by the impact load equivalent at the stroke end (at the time of impact with stopper).
Note 3) Depending on the shape of the work piece, multiple moments may occur. When this happens, the sum of the load factors (Σα) is the total of all such moments.
FE
ME
m
L
1
υ
Z
FE
M1E
υa
M3E
Dynamic Moment
mnx g
mnx g
m4x g
Static
moment
Dynamic
moment
Note)
Σα=+ + <1
=
Load weight
[
m
]
Maximum load weight
[
m max
]
Static moment
[
M
]
Allowable static moment
[
Mmax
]
Sum of guide
load factors
Note 1) Dynamic moment [M
E
]
Allowable dynamic moment
[
M
E
max
]
Note 2)
Note 5)
Note 4)
1
3
•
••
υ: Impact speed (mm/s)
L1: Distance to the load’s center of gravity (m)
ME: Dynamic moment (N •m)
δ: Bumper coefficient
With rubber bumper = 4/100
With air cushion = 1/100
With shock absorber = 1/100
g:Gravitational acceleration (9.8 m/s2)
()
MY3A3B.qxd 06.2.17 9:13 AM Page 6
