SMC Networks MY3A Series User manual

Doc. no. MY*A-OM0002H-D
PRODUCT NAME
Mechanically Jointed Rodless Cylinder
Basic short type
Basic standard type
Slide bearing type
MODEL/ Series
MY3A/3B/3M Series

Contents
Safety Instructions・・・・・・・・・・・・・・・・・・・・Ｐ．３～９
１．Mounting
１．１ Cylinder mounting face・・・・・・・・・・・・・・Ｐ．１０
１．２ How to mount・・・・・・・・・・・・・・・・・・・Ｐ．１０～１１
１．３ Piping・・・・・・・・・・・・・・・・・・・・・・Ｐ．１１
１．４ Cautions in mounting・・・・・・・・・・・・・・・Ｐ．１２～１３
１．５ How to mount a switch ・・・・・・・・・・・・・・Ｐ．１４
１．６ Auto Switch mounting positions・・・・・・・・・・Ｐ．１５～１６
２．How to select of cylinder・・・・・・・・・・・・・・・Ｐ．１７～２９
３．Replaceable parts and inspection, maintenance
３．１ Replaceable parts・・・・・・・・・・・・・・・・Ｐ．２９
３．２ Inspection, maintenance・ ・ ・・・・・・・・・・Ｐ．２９
４．Precautions
４．１ Operating environment・・・・・・・・・・・・・・Ｐ．２９
４．２ Intermediate stop・・・・・・・・・・・・・・・・Ｐ．３０
４．３ Use a cylinder with external guides・・・・・・・Ｐ．３０～３１
４．４ Parallel operation of cylinders・・・・・・・・・Ｐ．３１
４．５ Air leakage caused by detachment of seal belt・・Ｐ．３２
４．６ About rubber bumper displacement ・・・・・・・・Ｐ．３３
４．７ Air cushion adjustment ・・・・・・・・・・・・・Ｐ．３４
４．８ Stroke adjusting unit・・・・・・・・・・・・・・Ｐ．３４
５．Technical date
Applicable grease ・・・・・・・・・・・・・・・・・・・Ｐ．３５
Guide for replacement of MY3A/B Sliding bearing ・・・・Ｐ．３６
Guide for replacement of MY3A/B seal belt・・・・・・・・Ｐ．３７
Guide for replacement of MY3A/B dust seal band ・・・・・Ｐ．３８
Adjusting procedure of MY3M slide bearing ・・・・・・・Ｐ．３９
Disassembly/Assembly procedure of MY3M ・・・・・・・・・Ｐ．４０～４１
-2-

Operation manual of MY3A/3B/3M Series
Safety Instructions
These safety instructions are intended to prevent a hazardous situation and/or
equipment damage. These instructions indicate the level of potential hazard by a
label of “Caution”, “Warning”. To ensure safety, be sure to observe ISO4414(Note
1), JIS B 8370(Note 2) and other safety practices.
！ Warning Operator error could result in serious injury or loss of life.
！ Caution Operator error could result in injury or equipment damage.
(Note 1) ISO4414: Pneumatic fluid power - General rules relating to systems
(Note 2) JIS B 8370: General Rules for Pneumatic Equipment
Explanation of Graphical symbol
Graphical
symbol Meaning of graphical symbol
Prohibition
“ ”shows the prohibition (Do not do). A concrete content of the
prohibition is in the chart sign and directed by the picture and sentences
to be near.
Instruction
“ ”shows the compulsion of the directed act (Do). A concrete content
is in the chart sign and directed by the picture and sentences to be near.
-3-

! Warning
1. The compatibility of pneumatic equipment is the responsibility of the
person who designs the pneumatic system or decides its
specifications.
Since the products specified here are used in various operating conditions, their
compatibility for the specific pneumatic system must be based on specifications or after
analysis and/or tests to meet your specific requirements. Please examine all content
of the specification according to a product catalog and material which is hereafter the
latest, and compose the system in consideration of the situation of the possibility of
the breakdown of the equipment.
2. Only trained personnel should operate pneumatically operated machinery and
equipment.
Compressed air can be dangerous if handled incorrectly. Assembly, handling or repair
of pneumatic systems should be performed by trained and experienced operators.
3. Do not service machinery/equipment or attempt to remove components until safety
is confirmed.
1. Inspection and maintenance of machinery/equipment should only be performed after
confirmation of safe locked-out control positions.
2. When equipment is to be removed, confirm the safety process as mentioned above. Cut
the supply pressure for this equipment and exhaust all residual compressed air in the
system.
3. Before machinery/equipment is restarted, take measures to prevent shooting-out of
cylinder piston rod, etc. (Bleed air into the system gradually to create back
pressure.)
4. Contact SMC if the product is to be used in any of the following conditions:
1. Conditions and environments beyond the given specifications, or if product is used
outdoors.
2. Installation on equipment in conjunction with atomic energy, railway, air navigation,
vehicles, medical equipment, food and beverages, recreation equipment, emergency stop
circuits, press applications, or safety equipment.
3. An application which has the possibility of having negative effects on people, property,
or animals, requiring special safety analysis.
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5. There is a danger of sudden action by air cylinders if sliding parts of machinery
are twisted, etc., and changes in forces occur.
In such cases, human injury may occur; e.g., by catching hands or feet in the machinery,
or damage to the machinery itself may occur.
Therefore, the machine should be designed to avoid such dangers.
6. Install a protective cover when there is a risk of human injury.
If a driven object and moving parts of a cylinder pose a danger of human injury, design
the structure to avoid contact with the human body.
7. Securely tighten all mounting parts and connecting parts so that they will not
become loose.
Especially when a cylinder operates with high frequency or is installed where there
is a lot of vibration, ensure that all parts remain secure.
8. A deceleration circuit or shock absorber, etc., may be required.
When a driven object is operated at high speed or the load is heavy, a cylinder’s cushion
will not be sufficient to absorb the impact. Install a deceleration circuit to reduce
the speed before cushioning, or install an external shock absorber to relieve the impact.
In this case, the rigidity of the machinery should also be examined.
9. Consider a possible drop in operating pressure due to a power outage, etc.
When a cylinder is used in a clamping mechanism, there is a danger of work pieces dropping
if there is a decrease in clamping force due to a drop in circuit pressure caused by
a power outage, etc. Therefore, safety equipment should be installed to prevent damage
to machinery and/or human injury. Suspension mechanisms and lifting devices also
require consideration for drop prevention.
10. Consider a possible loss of power source.
Measures should be taken to protect against human injury and equipment damage in the
event that there is a loss of power to equipment controlled by air pressure, electricity
or hydraulics, etc.
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11. Design circuitry to prevent sudden lurching of driven objects.
When a cylinder is driven by an exhaust center type directional control valve or when
starting up after residual pressure is exhausted from the circuit, etc., the piston
and its driven object will lurch at high speed if pressure is applied to one side of
the cylinder because of the absence of air pressure inside the cylinder. Therefore,
equipment should be selected and circuits designed to prevent sudden lurching because,
there is a danger of human injury and/or damage to equipment when this occurs.
12. Consider emergency stops.
Design so that human injury and/or damage to machinery and equipment will not be caused
when machinery is stopped by a safety device under abnormal conditions, a power outage
or a manual emergency stop.
13. Consider the action when operation is restarted after an emergency stop or
abnormal stop.
Design the machinery so that human injury or equipment damage will not occur upon restart
of operation. When the cylinder has to be reset at the starting position, install safe
manual control equipment.
14. Confirm the specifications.
The products advertised are designed according to use in industrial compressed air
systems. If the products are used in conditions where pressure, temperature, etc., are
out of specification, damage and/or malfunction may be cause. Do not use in these
condition. (Refer to specifications)
Consult SMC if you use a fluid other than compressed air.
15. Use clean air.
Does not use compressed air which includes chemicals, synthetic oils containing organic
solvents, salt or corrosive gas, etc., as it can cause damage or malfunction.
16. Do not use in environments where there is a danger of corrosion.
Refer to the construction drawings regarding cylinder materials.
17. Please follow the manual of auto switch for the handling of auto switch.
-6-
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! Caution
1. Operate the piston within a range such that collision damage will not occur at
the stroke end.
Operate within a range such that damage will not occur when the piston having inertial
force stops by striking the cover at the stroke end. Refer to the cylinder model
selection procedure for the range within which damage will not occur.
2. Use a speed controller to adjust the cylinder drive speed, gradually increasing
from a low speed to the desired speed setting.
3. Provide intermediate supports for long stroke cylinders.
Provide intermediate supports for cylinders with long strokes to prevent bending of
the tube, and deflection due to vibration and external loads, etc.
4. Do not apply strong impacts or excessive moment to the slide table (slider).
The slide table (slider) is supported by precision bearings or resin bearings. Therefore,
do not apply strong impacts or excessive moment, etc., when mounting work pieces.
5. Do not scratch or gouge the cylinder tube by striking or grasping it with other
objects.
Cylinder bores are manufactured to precise tolerances, so that even a slight deformation
may cause malfunction.
6. Readjust with the cushion needle.
The cushion is adjusted before shipment from the factory, but the cushion needle located
on the cover should be readjusted before operation according to the load and operating
speed, etc. Turning the cushion needle clockwise closes the restriction and increases
the strength of the cushion.
7. Do not operate with the cushion needle completely closed.
This can cause damage to seals.
-7-
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8. Be careful not to get hands caught in the unit.
When using a product with stroke adjusting unit, the space between the slide table
(slider) and the stroke adjusting unit becomes narrow, causing a danger of hands getting
caught. Install a protective cover to prevent direct contact with the human body.
9. Do not use until you can verify that equipment can operate properly.
Verify correct mounting by suitable function and leakage inspections after compressed
air and power are connected following mounting, maintenance or conversions.
10. Preparation before piping
Before piping is connected, it should be thoroughly blown out with air (flushing) or
washed to remove chips, cutting oil and other debris from inside the pipe.
11. Wrapping of pipe tape
When screwing together pipes and fittings, etc., be certain that chips from the pipe
threads and sealing material do not get inside the piping.
Also, when pipe tape is used, leave 1.5 to 2 thread ridges exposed at the end of the
threads.
12. Lubrication of non-lube type cylinder
The cylinder is lubricated at the factory and can be used without any further lubrication.
However, in the event that it will be lubricated, use class 1 turbine oil (without
additives) ISO VG32.
Stopping lubrication later may lead to malfunction due to the loss of the original
lubricant. Therefore, lubrication must be continued once it has been started.
13. Install air filters.
Install air filters at the upstream side of valves. The filtration degree should be 5
μm or finer.
14. Install an after cooler, air dryer or water separator, etc.
Air that includes excessive drainage may cause malfunction of valves and other
pneumatic equipment. To prevent this, install an after cooler, air dryer or water
separator, etc.
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15. Use the product within the specified range of fluid and ambient temperature.
Take measures to prevent freezing, since moisture in circuits can be frozen under 5℃,
and this may cause damage to seals and lead to malfunction.
16. Drain flushing
Remove drainage from air filters regularly.
17. Piston speed
As for mechanically jointed rodless cylinder, the fluctuation of the piston speed might
become large compared with the standard air cylinder.
Please consult us if considering it is used in the application for which the definite
speed is necessary.
-9-
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F
１．Mounting
１．１ Cylinder mounting face
While a high level of flatness is desired for the surface on which the cylinder
is to be mounted, if sufficient flatness cannot be attained, use shims to adjust
the mounting of the cylinder so that the slide table can be operated throughout
its stroke under the minimum operating pressure (0.15MPa).
１．２ How to mount
[１] Mount the main body at the head cover parts on both ends. The mounting face
that is at the bottom of the tube more than 5mm is necessary for the cylinder
both ends fixed part.
（Refer to Fig.-1）
ig.-1
Fig-1
[２] When a cylinder is mounted on the ceiling or the wall, support a cylinder tube
both ends part by the side supports in addition to the fixed bolt of the head
cover port.（Refer to Fig.-2）
Fig.-2 Fig-2
[３] Avoid mounting at slide table.(Refer to Fig.-3) It means the excessive load
on the bearing part and it causes mal function.
-10-
5mm or over 5mm or over
Side support Side support
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[４] Also, consult with us in the case of overhang mounting.(Refer to Fig.-4) It
may cause malfunction due to be deflected of tube.
Fig.-3 Mounting at Slide table Fig.-4 Overhang mounting
〈Forbidden〉 〈Contact SMC〉
１－３ Piping
The piping connection of head cover is selected according to the situation.
Referring to the port variation (Figure-5) ,select the most suitable piping
connection ●○ . (Applicable fitting for ports with * in drawing is limited when
stroke adjusting unit is used)
Port variations
Fig.-5
-11-
Slide table
Head cover
Cylinder tube
Head cover
Slide table
Cylinder tube
Ｌ
Ｌ
Slide table operating direction
Ｒ
Ｒ
Ｒ Ｌ
Ｌ
Ｒ
Ｒ Ｌ
Ｒ
Ｌ
Ｒ
Ｌ
ＲＬ
Ｒ
Ｌ
* *
*
*
ＲL

１－４ Cautions in mounting
！ Caution
①Be careful not to give a strong impact or an excessive moment to the slider.
②Align carefully when connecting to a load having an external guide mechanism.
③Before mounting, the connection piping needs to be flushed sufficiently so that
any dust or chips should not enter the cylinder.
(Any chips, seal tape or dust in piping operation cause the malfunction such as
air leakage.)
④Be careful to avoid flaws or cracks on the peripheral surface of the cylinder
tube. They lead the damage of Bearing or Scraper and cause the malfunction.
⑤When the cylinder is unavoidably operated in an atmosphere with chips or dust
(like paper powder or waste thread) and cutting oil (like light oil or water),
consider the cover setting.
⑥When mounting the load, settle with 4 set screws on top surface of the slide
table. Otherwise, the slide table and set screws are damaged.
⑦For MY3A/3B series When the amount of looseness of slide table becomes larger
during using by reason of wearing out the slide bearing, replace the bearing
according to "Guide for Replacement of MY3A/3B Sliding bearing ".
Initial situation of use can be obtained by replacement of bearing.
Although the slide table of MY3M series is adjusted when shipped out, please
adjust or replace according to attached “Adjusting procedure of MY3M slide
bearing ”, and “Disassembly/Assembly procedure of MY3M” when the deflection
amount becomes large during operation.
If the amount of looseness becomes larger in a short period, or a large looseness
exists even after replacement, check the operation conditions for use again and
consult with us.
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⑧When the cylinder with long stroke is used, it may have deflection due to self-weight
or load. In that case, use the cylinder by supporting the intermediate position
with the side support so that the supporting interval (=L) shown Fig.-6 in the
following is less than the value of graph (Fig.-7)
Note) However, if accuracy of mounting surface of the cylinder tube is unknown, the
side support may lead malfunction. So, when you mount, adjust the accuracy level.
Fig.-7
-13-
Instruction
ｍ
L
ｍ
L
ｍ
L L
Fig.-6

１－５ How to mount a switch
①Pick up the switch spacer by fingers, push it into the groove and confirm or
correct the mounting direction.
②Slide the auto switch and lap it over the switch spacer.
③Tighten the switch mounting screw of accessory
by flat head watchmakers screw driver.
Switch spacer model （㎜）
Applicable bore size
（㎜） 16 20 25 40 50 63
Switch spacer model BMY3-016
Note) When tightening the mounting screw
(included with the auto switch), use a
watchmakers screw driver with a handle 5 to
6mm in diameter. The tightening torque
should be 0.05 to 0.1N･m. Rough standard is
to rotate from the position at which you
feel tight by 90°
Fig.-8
-14-
Switch spacer
watchmaker's screw driver
（ＢＭＹ３－０１６）
Switch mounting screw
（Ｍ２．５×４l）
Accessory
①
②
③

１－６ Auto Switch mounting positions
Fig.-9
ＭＹ３Ａ
D-A9, D-A9□V (mm) D-M9□ (mm)
Bore size A B Operating range Bore size A B Operating range
16 22 88 6.5 16 26 84 3.5
20 22 106 9.5 20 26 102 6
25 29 121 10.5 25 33 117 6
32 36.5 156.5 12 32 40.5 152.5 5.5
40 42.5 197.5 15 40 46.5 193.5 8
50 42.5 231.5 13.5 50 46.5 227.5 9.5
63 53.5 266.5 14 63 57.5 262.5 8
ＭＹ３Ｂ/３Ｍ
D-A9, D-A9□V (mm) D-M9□ (mm)
Bore size A B Operating range Bore size A B Operating range
16 28 94 6.5 16 32 90 3.5
20 32 116 9.5 20 36 112 6
25 43 135 10.5 25 47 131 6
32 52.5 172.5 12 32 56.5 168.5 5.5
40 60.5 215.5 15 40 64.5 211.5 8
50 60.5 249.5 13.5 50 64.5 245.5 9.5
63 71.5 284.5 14 63 75.5 280.5 8
Note) The operating range is a guide including hysteresis, but is not guaranteed. They
may be large variations (as such as ±30%) depending on the ambient environment.
-15-
ＡＢ

！ Caution
①Do not drop, bump or apply excessive impacts while handling.
②Avoid repeatedly bending or stretching lead wires.
③Do not use in strong magnetic field.
④Auto switch can be placed at an intermediate position. However, it should be
adjusted so that the cylinder speed is detected with in 300mm/sec considering
the response time of load relay.
⑤When multiple auto switch cylinders are used in close proximity, maintain a
minimum cylinder separation of 40mm. (Refer to Fig.-10)
Fig.-10
-16-
４０㎜ or over
Prohibition
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２ How to select of cylinder
A general selection process to select MY3 series best suited to your application
is introduced with the following flow.
As for MY3A and MY3B series, how to select it varies according to an external
guide’s presence
As for guide selection to use a cylinder with external guides, please examine it
by the guide manufacturer's materials for selection.
Even if a cylinder is operated without external guides, it can be gave a load
directly within range of the capacity of the built-in guide. Allowable load varies
according to the drive speed and the mounting direction of the cylinder. You refer
to the following flow, and select MY3 series.
(Refer to detailed selection flow of the following from ① to ⑥)
-17-
Fig-11.Selection flow
ＭＹ３Ａ：Basic short type
ＭＹ３Ｂ：Basic type
ＭＹ３Ｍ：Slide bearing type
Operating conditions
ｍ：Load（㎏） mounting orientation：
Ｖ：Speed（㎜/ｓ）
Ｐ：Operating pressure（ＭＰａ）
Reexamine operating conditions
②Determine
an allowable load and
moment
⑥Examine external
shock absorber
Examine auto switch mounting (model)
Model determination
ＮＧ
ＯＫ
ＯＫ
Stroke adjusting unit
Built-in cushion
④⑤Examine cushion at the end of stroke
① Determine a temporary model of
cylinder(P.16)
①
)
③External guides selection
※Consult with the info from the
guide manufacturer
ＮＧ
Only case of MY3A and
MY3B
Size ＵＰ
Change the
guide model
Fig-11.Selection flow

① Temporarily determine a model of cylinder
First of all, you temporarily determine a model of cylinder. According to the
operating purpose (a stroke accuracy, installing the stroke adjusting unit or not,
operating speed), refer to Table-1, and do a temporary selection of cylinder model.
Table -1. Standards for model selectionⅠ
Cylinder
model no.
Stroke
accuracy
Applicability
of external
guide
Direct
loading
(Horizontal)
Table
accuracy
(Note 1)
Direct
loading
(Wall)
Load
resistance
Moment
resistance
Comment
MY3A △ ◎ △ △ △ △
Mainly combined with separate guide and reduce the full length
t
he minimum.
MY3B ◎ ◎ ○ △ △ △
Mainly combined with separate guide and require the accuracy.
MY3M ◎ × ◎ ○ ○ ○
Directly place the work load, and require the stroke accuracy.
Note 1) Table accuracy indicates the table deflection when the moment is applied.
Table -2. Standards for model selectionⅡ
Note）Max. operating speed when MY3B16,MY3B20 L unit is used is 800mm/s when the stroke is within the range of fine adjustment.
500mm/s when the stroke is out of fine adjustment range.
-18-
Stroke positioning
Loading style Cushion Max speed
Direct
loading
Cylinder stroke end
Stroke adjusting unit
(Option: L, H unit)
External stopper
Cylinder stroke end
Stroke adjusting unit
(Option:L,H unit)
External stopper
Using external
guide
Rubber Bumper
Air Cushion
Shock Absorber
External
Shock Absorber
Rubber Bumper
Air Cushion
Shock Absorber
External
Shock Absorber
With –X416,-X417 holder mounting bracket
With –X416,-X417 holder mounting bracket

）
≦１
② A cylinder individual operating selection (When you choose "Without
external guides")
②－１ Examine allowable load and moment
Static load (①maximum loading mass and ②static moment) and dynamic load (③
dynamic moment : at the time of collision) must be examined for calculation of
allowable load.
Also total factor should not exceed 1(Σαｎ≦1).
In case of (∑αn>1 , increase the bore size, change the cylinder model or select
the other guide）
*To evaluate ,use Va(average speed) for static load (①, ②), V(impact speed
V=1.4Va) for load (③) ,calculate mmax for ① from the maximum allowable load
graph(m1,m2,m3) and Mmax for ②,③ from the maximum allowable moment graph(M1,M2,M3).
Note 1） Depending on the shape of the work piece, multiple moments may occur. When this
happens, the sum of the load factors (∑α) is the total of all such moments.
Note 2) Moment generated by the load, etc., with cylinder in resting condition.
Note 3） Moment by load equivalent to impact generated at the stroke end (at the time
of collision).
-19-
Load mass（ｍ） Static moment Dynamic moment
Maximum allowable load Allowable static moment Allowable dynamic moment
（ｍmax） （Ｍmax） （ＭＥmax
Sum of load factors Σα＝ ＋ ＋
（Note１） （Note３）
（Note２）

Reference formulae [Dynamic moment at impact]
Use the following formulae to calculate dynamic moment when shock for stopper collision
is taken into consideration.
ｍ：Mass（ｋｇ） Ｖ：Collision speed（ｍｍ／ｓ）
Ｆ：Load（Ｎ） Ｌ１：Distance up to center of
ＦＥ：Load equivalent to impact（Ｎ） gravity of mass（ｍｍ）
Ｖａ：Average speed（ｍｍ／ｓ） ＭＥ：Dynamic moment（Ｎ・ｍ）
Ｍ：Static moment（Ｎ・ｍ） ｇ：Gravitational acceleration（９．８ｍ／ｓ）
σ :coefficient of cushion (Rubber bumper:4/100,air cushion:1/100,shock
absorber:1/100)
Reference formulae [Dynamic moment at impact]
Use the following formulae to calculate dynamic moment when shock for stopper collision
is taken into consideration.
ｍ：Mass（ｋｇ） Ｖ：Collision speed（ｍｍ／ｓ）
Ｆ：Load（Ｎ） Ｌ１：Distance up to center of
ＦＥ：Load equivalent to impact（Ｎ） gravity of mass（ｍｍ）
Ｖａ：Average speed（ｍｍ／ｓ） ＭＥ：Dynamic moment（Ｎ・ｍ）
Ｍ：Static moment（Ｎ・ｍ） ｇ：Gravitational acceleration（９．８ｍ／ｓ）
σ :coefficient of cushion (Rubber bumper:4/100,air cushion:1/100,shock
absorber:1/100)
（Note 4） Average load coefficient (This coefficient is average for the maximum load moment
at the time of collision according to expected life.)
Limit value of maximum allowable load and allowable moment depends on mounting orientation,
piston speed, etc. Please confirm with the graph of each series.
③ Select external guides (In the case of MY3A/3B)
Select external guides by the guide manufacturer materials.
！ Caution
When a cylinder is operated with external guides, support all loads with external
guides and it is operated as actuating purpose only.
If floating connection doesn't function fully, it gives the cylinder excessive
power. Therefore, the cylinder may be damaged.
-20-
Instruction
・ Ｌ
１ (Ｎ・ｍ)
１
∴ Ｍ
Ｅ＝ ・ Ｆ
Ｅ
１．４
ＦＥ＝ Ｖａ ・ ｇ ・ ｍ
１．４Ｖａ (ｍｍ/ｓ)
Ｖ ＝
Note 4）
３
１００