Ogura MSU Quick guide

Ogura Industrial Corp, Somerset, NJ, USA www.ogura-clutch.com
MSU / MSCP
Installation and Instruction Manual
The Ogura model MSU is an inline shaft unit in which the MSC type clutch and MSB
type brake are accurately centered and set in a light alloy housing, and is ideal for repeated
start and stop. The MSCP type has only the clutch set in the same way as the MSU type. All of
them are stationary type and have input / output shafts, so they can be easily connected
directly by coupling or driven by belt pulleys. In addition, it has a large heat dissipation capacity,
can withstand high frequency use, and the gap is kept constant by the auto gap device only by
applying the exciting voltage, so no adjustment is required after installation.

Ogura Industrial Corp, Somerset, NJ, USA www.ogura-clutch.com
Table of Contents
1. Safety Precautions << Be sure to read before use >>
1-1 Precautions for Installation
1-2 Handling Precautions
1-3 Precautions for Installation
1-4 Precautions Before Operating
1-5 Precautions While Operating
1-6 Precautions for Maintenance and Inspection
2. Function - Performance
2-1. Specifications
2-2. Structure and Operation
3. Precautions –Practical Use
3-1. Handling Precautions
3-2. Precautions for Installation
3-3. Confirmation During Operation
3-4. Maintenance and Inspection
4. Troubleshooting
Please refer to the product catalog and technical data for detailed product dimensions and
characteristics.
■When using the unit, please read the "Safety Precautions" in Section 1 of this instruction
manual first, and then read the functions and below in Section 2.
■If you maintain the product based on this instruction manual and perform regular
inspections, you can use it with peace of mind for longer performance.
■Please follow this instruction manual in the handling, maintenance and inspection of the unit
in your machine / equipment.
■Please keep this instruction manual in a safe place so that you can take it out and read it
when necessary, and be sure to deliver it to the final customer.

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1. Safety Precautions << Be sure to read before use >>
When using the product, please read this instruction manual, product specifications, and other
technical documents carefully, and pay sufficient attention to safety when handling the product
correctly.
DANGER and CAUTION:
It is assumed that the user may be killed or seriously injured if mishandled.
There is a risk of injury to the user due to when mishandling, and property damage is expected
to occur.
Although every effort has been made to ensure quality control, in the unlikely event that the
clutch does not disengage and the machine rotates continuously, the brakes do not work and
the machine coasts, or if the vibration becomes large, it may be damaged. It is expected. Please
pay sufficient attention to safety measures on the machine side in case of these failures.
1-1. Precautions for Installation
Do not use in an atmosphere where there is a risk of ignition or explosion.
Never use it in a flammable gas atmosphere where there is a risk of ignition or
explosion. Also, if there is a flammable material such as cloth nearby, seal the main
body. Please note that the allowable work load will decrease if it is sealed.

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When shutting off DC, use a protective element in parallel with the clutch / brake coil.
A counter electromotive voltage (back electromotive force) is generated when the
switch is turned off, so if it is used as it is, it may cause deterioration of switch contacts,
deterioration of coil insulation and burning, and cause adverse effects on peripheral
devices. It is necessary to connect appropriate protection elements to form a discharge
circuit.
Be sure to install the safety cover
Since there is a rotating body, touching the product with your hands or fingers may
cause injury. To prevent danger, be sure to use a well-ventilated safety cover to prevent
your body from touching it. Also, install a safety mechanism so that the rotating body
suddenly stops when the cover is opened.
This product is a product in which the clutch and brake are engaged when the coil is energized.
Make sure that it is suitable for the intended use and purpose of use, and then install it
in the machine.
Do not use in places exposed to dust, high temperature, condensation, wind and rain.
Also, do not install it directly in a place subject to vibration or shock.
If used in the above-mentioned surrounding environment, it may cause damage to the
product, malfunction, or deterioration of performance.

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1-2. Handling Precautions
Do not allow water or oils to adhere (do not apply).
Since the clutch and brake are for dry type, the torque will drop significantly if oils
adhere to the friction surface. Therefore, the machine may coast or run away, causing
an accident or injury.
Do not hang the product with lead wires.
Do not pull or bend the lead wire protruding from the terminal block at an acute angle.
In particular, if you hang the product by holding the lead wire, the unit may fall on your
leg and cause an accident or injury. Be sure to carry the product itself when handling it.
Please be careful about the weight when installing / removing / transporting.
If you have a heavy product, you may get injured due to back pain or falling. Please be
careful when installing, removing, and transporting. Especially for products with
eyebolts, use a hoist etc. for work.
1-3. Precautions for Installation
Use a wire size that matches the power capacity.
If an electric wire with a small current capacity is used, the insulation film will melt and
insulation will be poor, which may cause electric shock and leakage, as well as cause a
fire.
Be sure to control the tightening torque of the bolts and prevent them from loosening.

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Depending on how tight the bolts are, they may be in a very dangerous state such as
shearing and breakage. Be sure to use the specified tightening torque and bolt material,
tighten it securely so that it will not loosen due to machine vibration, etc., and use
adhesive, spring washers, etc. to prevent it from loosening.
Do not allow water or oils to adhere (do not apply).
Since the clutch and brake are for dry type, the torque will drop significantly if oils
adhere to the friction surface. Therefore, the machine may coast or run away, causing
an accident or injury. Please attach a protective cover when using in a place where oil or
water easily enters.
1-4. Precautions Before Operating
Do not use in an atmosphere where there is a risk of ignition or explosion.
Never use it in a flammable gas atmosphere where there is a risk of ignition or
explosion. Also, if there is a flammable material such as cloth nearby, seal the main
body. Please note that the allowable work load will decrease if it is sealed.
Please operate within the allowable work load.
If you operate more than the allowable amount of work, heat generation may increase
and the operating surface may become very hot and cause a fire. In addition, the
specified performance will not be obtained, so please use within the allowable work
load.

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The surface may become hot just by energizing. Do not touch the product while the power is
on.
The surface temperature of the main body rises due to the heat generated by the coil
even when the power is turned on. Please note that touching it may cause burns. The
temperature does not drop immediately after use. Make sure that the temperature has
dropped sufficiently before working, not only during operation, but also when touching
the product for maintenance or inspection.
1-5. Precautions While Operating
Do not increase the rotation beyond the permissible rotation speed.
If it is used above the permissible rotation speed, vibration will increase, and in some
cases it may be damaged or scattered, resulting in a very dangerous condition. Be sure
to use it at the allowable rotation speed or less and install a protective cover.
Do not touch the product while operating.
The rotating part is exposed to the outside, and touching the product with your hands or
fingers may cause injury. Never touch the product while operating.
The surface temperature of the product may rise to about 90 to 100 ° C due to slip heat
and heat generated by the built-in coil. Never touch the product while operating, as you
will get burned if you touch it. The temperature does not drop immediately after the
operation is stopped. Make sure that the temperature has dropped sufficiently before
working, not only during operation, but also when touching the product for
maintenance or inspection.

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Keep voltage fluctuations within ± 10%.
If a voltage outside the specified range is applied, problems such as performance
degradation and burning may occur.
If abnormal noise or vibration is generated during operation, there is a possibility that the
product may not be installed properly, and if left unattended, the device itself may be
damaged.
Immediately stop operation and inspect.
1-6. Precautions for Maintenance and Inspection
Never disassemble the product.
Please note that we are not responsible for any damages caused by repairs, disassembly
and modifications made by any party.
Do not allow water or oils to adhere (do not apply).
Since the clutch and brake are for dry type, the torque will drop significantly if oils
adhere to the friction surface. Therefore, the machine may coast or run away, causing
an accident or injury. If you use it in a place where oil or water can easily enter, attach a
protective cover.
Do not touch the power supply.
Since the power supply unit is exposed to the outside, there is a risk of electric shock if
you touch it with your hands or fingers. Do not touch it directly during operation as well

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as during maintenance and inspection, and be sure to turn off the power before starting
work.
2. Function - Performance
2-1. Specifications
Table 1 Performance
Note: MSU type indicates clutch / brake, and MSCP type indicates clutch only.

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2-2. Structure and Operation
The MSU type has the structure shown in Fig. 1, and the MSCP type has the structure shown in
Fig. 2.
③ ⑧ Clutch / brake field with built-in coil (clutch field ② for MSCP type) is fixed to the inner
surface of the casing, respectively, ④ input shaft (⑥ for MSCP type) and ⑨ output shaft (⑪
for MSCP type). Is supported by ②⑤ ball bearings (MSCP type ③⑦⑩).
For the MSU type, the brake disc assembly is screwed to the brake field. The ⑦ rotor assembly
is fixed to the input shaft by the ⑥ parallel key, and the ⑪ armature hub (⑫ for the MSCP
type) is fixed to the output shaft by the ⑩ parallel key (⑨ for the MSCP type).
⑬ Clutch armature (MSCP type is ⑧) and ⑫ Brake armature are attached to the spline part
of the armature hub via a guide.
When the clutch side coil is energized, magnetic flux flows between the clutch field, rotor, and
clutch armature, the armature is attracted to the rotor, the clutch is engaged, and the rotation
of the input shaft is transmitted to the output shaft.
The auto-gap device keeps the air gap constant even if the friction surface wears.

Ogura Industrial Corp, Somerset, NJ, USA www.ogura-clutch.com
Fig 1. MSU type
MSU type clutch / brake component names
①Casing ②Ball bearing ③Clutch field
④Input axis ⑤Ball bearing ⑥Parallel key
⑦Rotor assembly ⑧Brake field ⑨Output shaft
⑩Parallel key ⑪Armature hub ⑫Brake armature
⑬Clutch armature ⑭Parallel key ⑮Terminal block

Ogura Industrial Corp, Somerset, NJ, USA www.ogura-clutch.com
Fig 2. MSCP type
MSCP type clutch component names
①Casing ②Clutch field ③Ball bearing
④Rotor assembly ⑤Parallel key ⑥Input axis
⑦Ball bearing ⑧Clutch armature ⑨Parallel key
⑩Ball bearing ⑪Output shaft ⑫Armature hub
⑬Flange ⑭Terminal block

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3. Precautions –Practical Use
3-1. Handling Precautions
Do not hit, drop, or apply excessive force to the product.
Electromagnetic clutches and brakes use a lot of soft materials. Please note that if you
hit or drop it or apply excessive force, it may cause dents or deformation, which may
cause malfunction or insufficient torque.
Do not allow water or oils to adhere (do not apply).
Since the clutch and brake are for dry type, if oils adhere to the friction surface, the
torque will be significantly reduced and the function of the product will be impaired, so
please avoid water and oils. Also, be aware that if oil gets on the auto-gap device or the
armature hub, the auto-gap function cannot be maintained. If you use it in a place
where oil or water can easily get in, attach a protective cover.
Do not hang the product with lead wires.
Do not pull or bend the lead wire coming out of the product at an acute angle. In
particular, if you place an object on the lead wire or hang the product by holding the
lead wire, the lead wire will be crushed, damaged or broken, and you will not be able to
use it. Be sure to carry the product itself when handling it.
Be careful not to damage the clutch or brake when handling.
When installing, removing, and transporting, be careful when handling the clutch and
brake so that there is no impact or collision.

Ogura Industrial Corp, Somerset, NJ, USA www.ogura-clutch.com
3-2. Precautions for Installation
When installing, pay attention to the following points:
Fig 3. An example in which the MSU type is installed between the motor and the reducer to
start and stop the load.
Do not allow water or oils to adhere (do not apply).
Since the clutch and brake are for dry type, if oils adhere to the friction surface, the
torque will be significantly reduced and the function of the product will be impaired, so
please avoid it. If you use it in a place where oil or water can easily get in, attach a
protective cover.
Securely mount the installation on a solid flat surface.
For the casing installation surface, securely tighten the bolts to the specified torque on a
solid machined flat surface, and take measures to prevent loosening with adhesive,
spring washers, etc.

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Install so that there is no misalignment.
When connecting by coupling etc., install so that there is no misalignment (axial
displacement, deviation, declination).
Do not give an impact to the input shaft and output shaft.
If an impact is applied to the input shaft / output shaft, the auto gap device will not
operate normally. Therefore, when inserting a coupling etc. into the shaft, use the
center tap at the end of the input shaft / output shaft.
Set the inner diameter tolerance of the coupling etc. to H7.
The input shaft and output shaft are processed to h7. Set JIS H7 and h7 for the drive side
and the driven side.
Connect the wiring to the clutch and brake as shown in the figure.
Connect the accessory back surge absorption protection element (varistor) to each of
the clutch and brake in parallel. At that time, the lead wires and protective elements of
the clutch and brake have no polarity.

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Fig 4. Terminals
To clutch power source To brake power source
Figure 5 Wiring diagram
Check the torque when installing the machine.
This unit is designed to generate the specified torque from the beginning, but if the
friction surface is not sufficiently fitted depending on the mounting condition, the
specified torque may not be generated from the beginning, so be sure to check the
torque sufficiently when installing the machine.

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On the actual machine, make sure that the load can be started within the specified time
and stopped within the specified time and distance.
<<Burnishing of friction surfaces>>
If the specified torque is not output, pay attention to the following points when burnishing the
friction surfaces.
Pay attention to the temperature rise of the casing under the condition of less than half
of the allowable power of the catalog.
Perform break-in operation with a light load.
If the specified torque does not come out even after burnishing, please contact us.
3-3. Confirmation During Operation
1) Be sure to check the following points during trial run or before starting operation.
(a) Is the casing securely tightened?
(b) Is the exciting voltage the rated voltage at the terminal block of the clutch / brake?
(c) Does the armature operate smoothly by turning the switch ON / OFF?
Especially when starting to use after long-term storage, make sure that the output shaft rotates
smoothly when the clutch is turned on and stops when the brake is turned on before starting
operation.
2) Check the following points during the test run.
(a) Does the clutch work and the load is connected smoothly?
(b) Does the brake work and the load stops smoothly?

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(c) Is there any abnormal noise or overheating?
If you continue to operate and the casing temperature rises too high, check that the load is
below the allowable power in the catalog.
3-4. Maintenance and Inspection
In order to keep the clutch and brake in a normal state at all times, perform the following
maintenance and inspection regarding the clutch and brake.
1) Protection
Do not allow water or oils to adhere (do not apply).
Since this clutch / brake is for dry type, if oils adhere to the friction surface, the torque
will be significantly reduced and the function of the product will be impaired. Therefore,
never use water or oils. If you use it in a place where oil or water can easily get in, attach
a protective cover.
Make sure to supply the specified voltage.
The engagement time and torque of clutches and brakes change depending on the
exciting voltage. Also, if the exciting voltage is too low, the clutch and brake will not be
able to engage, so be sure to supply the specified voltage. Even if the power supply
voltage is as specified, if the circuit is long, the voltage will drop due to line resistance,
so check the voltage at the clutch / brake terminal when the power is on.

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Check the ambient temperature
The operating atmosphere temperature should be in the range of -10 to 40◦C. If used
at high temperatures, the frictional heat generated during clutching and braking cannot be
dissipated, and the coil and friction parts may be damaged. Also, please note that when used
at low temperatures, moisture will adhere due to condensation.
Be careful of rust.
Make sure that the clutch and brake are free of rust. Especially when used in areas with
high salt content such as beach areas, the installation environment may promote the
generation of rust. In this case, please consider implementing rust prevention measures.
2) Point Inspection
If you inspect this clutch / brake regularly, you will be able to demonstrate its performance for a
longer period of time. The inspection period varies depending on the specific usage conditions
of the customer, so please contact us.
Is there any foreign matter or water or oil on the friction surface or rotating parts?
The clutch and brake are for dry use, so make sure that oil, water or dust does not get
into the friction surface. If foreign matter gets into the friction surface or rotating parts,
the performance of the clutch / brake may deteriorate.

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Is a large amount of dust or abrasion powder accumulated?
If a large amount of dust or abrasion powder collects in the gaps or sliding parts of the
clutch / brake, it may cause malfunction.
Is there rust?
Make sure that the clutch and brake are free of rust. Especially when used in areas with
high salt content such as beach areas, rusting may be promoted depending on the
installation environment. In this case, please consider implementing rust prevention
measures.
Is there any abnormality in the operation?
When the clutch is ON, check that the input shaft and output shaft rotate smoothly in
the connected state, and when the brake is ON, check that the output shaft is in the
stopped state and the input shaft rotates smoothly.
Is the exciting voltage normal?
For clutches and brakes, the engagement time and torque change when the exciting
voltage fluctuates. Also, if the exciting voltage falls below the specified value, the clutch
and brake will not be able to attract, so be sure to supply the specified voltage. Even if
the power supply voltage is as specified, if the circuit is long, the voltage will drop due to
line resistance, so check the voltage at the clutch / brake terminal when the power is on.