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Selection Guide

1. Checking required specifications

Confirm your desired specifications that are based on manufacturing machines.

1.Work
···Check the transfer load, distance and takt time of the workpiece.
2.Space
···Confirm the machine or unit size (width, height and depth).
3.Surroundings
···Check the temperature, humidity and environmental conditions.
4.Others
···Check other conditions (durability, unit service life, etc.).

2.Selecting the transmission method

Decide on an efficient driver such as hydraulics, pneumatics, electric drive, engine, etc. Confirm the structure and the control suited for achieving the required accuracy.


3.Selecting the driver (in case of motor)

Torque

Calculate the generated torque by motor torque line and RPM when you set the motor capacity, with or without reduction gear, and its reduction rate.  If there is no manufacturer’s information for the motor, then please use the standard formula below.

Torque

Safety factor    K
Load condition K
Small inertia Under 60% of motor rated torque 1.5 - 2.0
Medium inertia In case acceleration/deceleration time is long and reverse motion is not frequent 2.0 - 3.0
Large inertia In case of rapid deceleration, impact and frequent reversing 3.0 - 5.0
Input torque value of Mecha-lock : Tmax < Maximum allowable torque capacity


Thrust

Input thrust load < Maximum allowable thrust load


Torque & Thrust

Calculate by using standard formula below when there is a torque and thrust combined load, and compare with maximum allowable torque capacity of Mecha-lock.

Torque & Thrust

Input combined load of Mecha-lock : Ts < Maximum allowable torque capacity


Torque up

  1. Use several Mecha-locks (only for MT, MKT)
    Mecha-lock can increase the transmission torque capacity by increasing quantity. (Hub outer diameters will be different if several Mecha-lock units are used.)
         (Examples) 2 pcs → 2 times 3 pcs→ 3 times
    2 pcs can be installed in opposite positions for the MA, MSA, MKA, MR, MSR, MKR. In this case, uninstallation could be difficult.
  2. Remove grease on the bore of Mecha-lock and the shaft surface.
    10 to 20% of transmission torque can be increased.
    Note) Taper surface and outer ring of Mecha-lock should not be degreased.
  3. Customized Mecha-lock
    Please contact us for customized products. ISEL designs and manufactures suitable specifications.


Torque Down

  1. If shaft has a key seat, torque will be reduced by area of non-contact surface between shaft and Mecha-lock bore.
  2. If Mecha-lock has been fully degreased, the screw axis force could be extremely reduced with more than 30% of transmission torque down from the catalog specifications.
    Please be aware that Mecha-lock stainless types such as MSA and MSR can seize.
  3. Oil and grease which include additives to reduce friction could decrease over 50% of transmission torque compared to the catalog figures if they have been applied to the bore of Mecha-lock and the shaft surface.

4.Checking shaft and hub specifications

Shaft

  1. Shaft fit tolerance and surface roughness
    Shaft fit tolerance and surface roughness
    • The recommended shaft fit tolerance is +0.010 for φ35 only.
      (Except for MN, MKN, MT, MKT and MC)
    For minimizing off-centering, h6 is recommended.
  2. Shaft material
    Select material having shaft contact surface pressure number greater than 1.2 times the yield point stress figure specified in the Mecha-lock catalog.

    ※Select material over 1.4 times yield point stress for MT and MR series.

  3. The maximum hollow shaft bore size
    Calculate the maximum bore size by the following formula if a hollow shaft is chosen for Mecha-lock installation.
    The maximum hollow shaft bore size

Hub

  1. Hub material

    Select material having hub contact surface pressure number greater than 1.2 times the yield point stress figure specified in the Mecha-lock catalog.

    ※Select material over 1.4 times yield point stress for MT and MR series.

    Mecha-lock’s high contact surface pressure could enlarge the hub or crack it in case the hub material is aluminum or cast iron and is thin, or of low strength.
    Cast iron — material over 249MPa tensile strength recommended.
    Aluminum — material over 245MPa tensile strength recommended.
    Aluminum or cast iron material is not suitable for MB series because of its high contact surface pressure.

    Select a hub material which has a stronger yield strength and tensile strength than in the table below in case of using aluminum and cast iron hub FCD450.
    New MC series are recommended for aluminum hub.
  2. Hub installation tolerance and surface roughness.
    Hub installation tolerance and surface roughness.

    For minimizing off-centering, H6 is recommended.
  3. Standard design for the smallest outer diameter of hub. (Standard yield stress point)
    Check the table of yield stress point of hub material and the smallest diameter on each page of Mecha-lock to confirm. If the material is not on table then calculate and judge from yield stress point. Especially be careful with cast iron and aluminum. Contact us if you are not sure about the selection.
  4. If hub outer diameter is small and not suitable.
    Number of screws can be decreased to reduce the pressure if there is enough torque. Remove screws in even locations and use the comparison calculation to find the correct torque and surface pressure.
  5. Design and processing of hub.
    Concerning the design and processing of hub, please refer to the following "Note for the hub processing of single taper Mecha-lock series.", "Note for the hub processing of MT and MKT series." & "Note for design of MN and MKN series if space is not enough for hub width.".

Note for the hub processing of single taper Mecha-lock series.

Note for hub processing

Note for the hub processing of single taper Mecha-lock series.Machine simultaneously in order to achieve squareness between hub edge and bore and concentricity between bores. This angle affects centering accuracy of Mecha-lock. (Fig.1) Hub edge should be processed C 0.5 to avoid contact with the radiused part between the flange and counter lock. (Fig.2)

MC series of fig.2 has a straight through-hole shape.


Note for the hub processing of MT and MKT series.

The MT and MKT series require a guiding part as there is no centering function. Hub processing should be carried out following the steps shown in Fig. 4 below. Be sure that a guiding part is made.

※The same installation for 2 Mecha-locks application.

Note for the hub processing of MT and MKT series.

※The minimum hub diameter to withstand surface pressure generated inside the hub mainly depends if the guiding part (should be equal to or more than 1/2 of the shaft diameter) for centering use is provided.
If the required guiding part length cannot be achieved, ISEL must be contacted.


Note for design of MN and MKN series if space is not enough for hub width.

Note for design of MN and MKN series if space is not enough for hub width.

Hub width should be 1/2 or more of Mecha-lock MN and MKN L1 size. (Fig.5)

※Hub width capacity should be over B=L1/2.

※Mecha-lock can be used if hub surface pressure L1/B<hub surface pressure 196MPa (20Kgf/mm2).

※Hub location should be center of L1 or nut side if hub width is shorter than Mecha-lock L1.

Note) If the hub width is less than L1, they cannot be used (except MN and MKN series).

5.Selecting of Mecha-lock series

Select the suitable Mecha-lock considering the application, space, operation, specification, etc. with lineup page. (P9−P10) (The features of each Mecha-lock are at top of each page.)
Electroless nickel plating and stainless types are added. Also aluminum Mecha-lock for aluminum pulley has been introduced.

Contact us for oil cleaning, vacuum grease of standard parts with extra charge.

6.Checking the load

  1. Bend moment to Mecha-lock.

    Basically Mecha-lock cannot withstand a bend moment. However Mecha-lock can be used by changing the load receiving location or design of hub.

    Bend moment to Mecha-lock.If radial direction load is not on the outer diameter of Mecha-lock (Fig.6), a bend moment is created on Mecha-lock due to the increased contact area between hub and shaft, resulting in shaft slippage or shaft/Mecha-lock damage. So move the Mecha-lock connection location to a position capable of withstanding radial direction load. Also enlarge the hub guide section in contact with the shaft to withstand bend moment (Fig.7).

  2. Radial load to Mecha-lock.

    Radial load to Mecha-lock.Calculate the capacity with the formula below if a radial load is placed on to Mecha-lock.
    Radial road can be received if shaft surface pressure Pir and Hub surface pressure Por by radial load R are less than 20% of normal connection surface pressure (P) (catalog value).


7.Final Check

Check and confirm the Mecha-lock selection and specifications.

Please check step 1 to 6 to confirm suitability.
If there are no problems, then please check the following points.


Installation depth of shaft and hub

It is recommended that the shaft goes through the Mecha-lock. But please confirm that the shaft reaches the taper point (point where the flange or nut reaches the shaft edge). If it does not, the Mecha-lock can deform and be unsuitable for reuse.
Decide the shaft installation amount to hub considering the moment capacity and installation process (for example processing to hide the screw head from the hub edge and use the Mecha-lock in the center of the radial load).

※For the MR and MN series, shaft insertion should be longer than the inner ring length.



Balance

Mecha-lock is basically not balanced as it cannot be used by itself. Our recommendation for the customer is to balance the unit after assembling the hub, shaft and Mecha-lock. For an application greater than minimum 6000rpm high speed rotation, it is probable that the transmission force will be reduced.


Environmental temperature

Mecha-lock should be used in environments of -40 to +150°C.

※MC series should be used in environments of -40 to +80°C.
(If temperature rises, transmission torque reduction will probably occur.)


Reuse

A Mecha-lock may be used more than 30 times provided it has been correctly installed and used in normal operation conditions. Screws and surfaces do become scratched so that shaft specs may slowly deteriorate after being reused twice so that replacement of screws are recommended to maintain 100% performance.

※Use the screw specified by ISEL.


8.Check the purchasing price

Mecha-lock design is as simple as possible to reduce costs. We maintain high quality and accuracy standards with our original processing to produce high-performance units. Please ask your closest distributor for a quotation.


9.Precautions on use of Mecha-lock

Introduction

Mecha-lock is a friction fastener to fasten a shaft and hub with no key. Tolerance of installation surface, surface roughness and proper assembly are very important in obtaining the predetermined performance.


Use of torque wrench / understanding of specified torque

Make sure to use a calibrated torque wrench with a torque adjustment scale to tighten the lock bolts to the recommended tightening torque value (confirm according to the specification table of the respective series and the included Instruction Manual). Because the plate type torque wrench specified toque is difficult to check, this may result in trouble such as slip and deformation.


Precautions on assembly / design

Precautions on assembly/designPrecautions on assembly of MA series (MA, MSA, MKA, MB) and MR series (MR, MSR, MKR)

If there is any positioning step on the back face of the hub, take 1mm or more of interval () between the Mecha-lock back face and the step. (If they are in close contact with each other, a large force is required for disassembly, and Mecha-lock may not be removed or reused.) Also, eliminate clearance between the flange part () of Mecha-lock and the hub. If there is any clearance, the flange part may be deformed, resulting in trouble.

※There are some products such as the MC series and MN series of which structures differ slightly. Check them with the catalogs and Instruction Manuals.


Precautions on assembly / assembling procedure

  1. Confirm that the shaft and hub are completely inserted while referring to the above drawing. If tightened with the shaft not completely inserted, the Mecha-lock will be plastically deformed and it will be impossible to insert it into the shaft/hub making it impossible to reuse.
  2. Tighten the lock bolt after positioning. First tighten the lock bolt slightly (about 1/4 of the predetermined tightening torque) in diagonal order, and gradually increase the tightening force (about 1/2 of the predetermined tightening torque), then tighten to the predetermined torque. Tighten sequentially in the circumferential direction at the end, and repeat several times. Confirm that the lock bolts are tightened to the predetermined torque, and none of the lock bolts have forgotten to be tightened.
Tightening procedure
  1. Tighten diagonally to approximately 1/4 of the predetermined torque.
  2. Tighten diagonally to approximately 1/2 of the predetermined torque.
  3. Tighten diagonally to the predetermined torque.
  4. Tighten sequentially in the circumferential direction to the predetermined torque several times.
  5. Confirm that none of the lock bolts have forgotten to be tightened.

When tightening stainless steel bolts for stainless steel specification (MSA, MSR), slowly rotate them. Quick tightening may result in galling or seizure of the bolts.

Hub movement amount of MN and MKN series / precautions on installation

Hub movement amount of MN and MKN series/precautions on installation

※The hub moves by tightening the nut in Mecha-lock MN and MKN series due to how they are constructed. Refer to the movement amount in the table below.

Hub movement amount of MN and MKN series/precautions on installation

Check that the hub edge 
achieves perfect contact.After installing Mecha-lock, confirm the hub edge is perfectly attached to the nut and the shaft goes through the Mecha-lock. (Fig.13). Adjust the location and tighten gently by hand,
tighten the nut lightly after positioning. And tighten again with a torque wrench with the specified torque. Finally, confirm that nut does not rotate after tightening.

※If installation is difficult when rotating together with the shaft, fix the hub side first, then turn the nut by hand so there is no gap. Finally start tightening with torque wrench.



Uninstallation

The hub and nut connection can be unlocked by loosening 2 nuts. Outer ring will move to the nut and the connection of the outer and inner ring will separate.


Cleaning of shaft and hub / application of oil

Completely wipe away rust, dust and dirt on the surface of the shaft and hub bore with thinner and lightly apply oil or grease. Since it is unnecessary to apply oil or grease to some products, see the following table and diagram for proper use.
Tightening efficiency is enhanced on some products (MSA, MSR series) according to type of grease, and surface pressure on the shaft and hub may exceed the yield point, therefore, it is recommended to conduct an evaluation test.

Mecha-lock oil/grease application list

※Do not apply grease to shaft and bore for MSA and MSR series.


Type A Oil/grease application locations
Type B Oil/grease application locations


[WARNING!] Never use molybdenum or an extreme-pressure additive containing oil and grease. Significant reduction in allowable torque and slippage may result.

Other precautions

  • If the shaft has key seats, it can be used in a case where the seat width is nearly equivalent to the JIS standard, however, the allowable torque will be reduced by 15% to 20%. Use it after removing burrs on the key seats.
  • For a hollow shaft (pipe), sufficient surface pressure may not be obtained depending on the wall thickness. Contact us in such a case.
  • Never use unauthorized bolts. Breakage of bolts, and related accidents may result.
  • Confirm that the product is as you ordered, and there is no damage. Use of a product different from an ordered product or damaged product may result in injury to operators or breakage of equipment.
  • When reusing the product, confirm that there is no deformation or missing component to the product.
  • Products of special specifications may differ slightly from what the catalog and Instruction Manual describe. Contact your distributor or our company.

Removal

Screw hole for removal
  • Confirm safety before removal and start operation.
    1. Turn off the power source (power supply), and confirm that torque and thrust force are not applied to the Mecha-lock and there is no risk of dropping.
    2. Loosen the lock bolts sequentially and gradually. Insert the loosened bolts into all of the screw holes for removal, and tighten gradually with uniform force in diagonal order, and then the Mecha-lock can be disassembled.

    ※Do not loosen the lock bolts quickly and do not remove all of the bolts. Some bolts may fly out, which may be dangerous.

  • Apply lubricant to the removed bolts.
  • When removing the Mecha-lock, make sure to use all of the screw holes for removal, and tighten it gradually several times. If only some of the screw holes are used, the inner ring may be deformed resulting in being unable to be reused.