Technical Data  Clutches  Selection

To view selection procedures and precautions, please proceed to the following.

Click here to narrow down the product series or to make a tentative selection.

To selection guide

Selection Method

Clarify the mode of cam clutch (overrunning, indexing, backstopping). Since the selection method differs for each mode, follow the respective procedure to select a cam clutch. In the case of the following model numbers, please contact us.

  • (1)Cam Clutch Boxes
  • (2)Clutch for feed with stopper (indexing)

1.Overrunning

  • (1)Calculate the torque on the Cam Clutch according to the formula below.

    Torque formula

    SI Unit T = 60000 × kW 2π × N × S.f(N・m)

    {Gravity unit } T = 974 × kW N × S.f{kgf・m}

    		T Loaded torque on Cam Clutch (N・m)
    kW Transmitted power (kW)
    N Speed of Cam Clutch shaft rotation (r/min)
    S.f Service factor (Table on the right )

    Service factor table

    Conditions S.f
    No shock load 1～1.5
    Moderate shock load 1.5～2.5
    Shock load 2～3
    Heavy shock load 4～6
  • (2)Maximum Overrunning Speed
  • (3)Shaft Bore Diameter
  • (4)Installation method
  • (5)others (Atmosphere conditions, maintenance, etc. )

Select a clutch that satisfies the above conditions from the clutches for overrunning (see the list of applicable series by mode and their respective pages).

◎……Most suitable 　○……Suitable
Series
Application MZ
MZ-G		 BB PB 200 LD ML MG MI MX MI-S BS BR
BR(P)		 MG-R MA MR Cam Clutch Boxes MZ-C MG-C
Dual Drive
・
Two Speed Drive 		high speed disengaged; high-speed engaged ○ ◎ ○
High speed disengaged; low-mid speed engaged ◎ ◎ ◎
high speed disengaged; low speed engaged ◎ ◎ ◎ ◎
low-mid speed disengaged; low-mid speed engaged ◎ ○ ○ ○ ○ ○ ○ ◎ ○
engage in one-way direction, overrun in reverse direction ◎ ○ ○ ○ ○ ○ ○ ○ ◎ ○
free wheeling ◎ ○ ○ ○ ○ ○ ○ ◎ ◎ ○
manual drive ○ ○ ○ ◎ ◎ ○

If the service factor (S.f.) is unknown, use the following procedure.

S.f = Starting torque of mover % × Shock factor (Maximum 2.5)

Shock factor is,
Inertia ratio = Load inertia on clutch shaft
(Clutch shaft conversion ) Input inertia on clutch shaft
(Clutch shaft conversion )
should be calculated from the figure below.

Shock factor

Shock factor

2.Indexing

2.1 Cam clutch for indexing feed

  • (1)Calculate the torque applied to the cam clutch using formula A or B.
    Note) The above formula is not applicable to indexing not by crank mechanism.

    Formula A

    T = I・θ・N2 101750 + TB

    		T Loaded torque on Cam Clutch  N・m
    I Inertia of load on Cam Clutch shaft (Can clutch shaft conversion ) kg・m2
    θ Feeding angle (Can clutch shaft conversion )
    N Indexing cycles per minute
    TB Brake torque calculated on Cam Clutch shaft  N・m(Can clutch shaft conversion )

    Formula B

    T = 60000 × P 2π × n ・ ℓ2 ℓ1 × 2.5

    		T Loaded torque on Cam Clutch  N・m
    P Power transmission  kW
    n Speed of crank shaft  r/min
    ℓ1 Length of crank  m
    ℓ2 Length of lever on Cam Clutch  m
    2.5 Factor
  • (2)Maximum indexing cycles
  • (3)Feeding angle (θ) 90° or less except for MI-S series
  • (4)N × θ ≦ 20000(high-mid speed; small feed angle )
    N × θ ≦ 50000(low speed; large feed angle )
  • (5)Expected accuracy
    Use the MX series, especially when high accuracy feed is expected.
    In addition, use high accuracy backstopping clutches and brakes.
  • (6)Shaft Bore Diameter
  • (7)Installation method
  • (8)others (Life, maintenance, etc. )

Select a clutch that satisfies the above conditions from the clutches for indexing (see the list of applicable series by mode and their respective pages).

◎……Most suitable 　○……Suitable
Series
Application MZ
MZ-G		 BB PB 200 LD ML MG MI MX MI-S BS BR
BR(P)		 MG-R MA MR Cam Clutch Boxes MZ-C MG-C
high speed; small feed angle ◎
low-mid speed; small feed angle ○ ○ ○ ○ ○ ○ ◎ ○ ○
low speed; large feed angle ◎
backstop device for indexing ○ ○ ○ ○ ○ ○ ◎ ◎ ○
indexing furnished with stopper Contact us for more information.
infinite variable feed ○ ○ ○ ○ ○ ○ ○ ◎

2.2 Backstopping with indexing feed

Use the same model number as the feed cam clutch or one size smaller.

Furthermore, if you are using the MX series, make sure that it is in the lower range of the respective curves in the graph below.

Range of use of the MX series

Range of use of the MX series

[Click to enlarge ]

3.Selection method for backstopping

3.1Torque calculation for cam clutch

(1)Backstopping for belt conveyor

[Steps 1] Calculate the power to move an empty belt and idlers: (P1) P1 = 0.06 × f × W × V × ℓ + ℓ0 367 (kW)

[Steps 2] Calculate the power to move a loaded belt horizontally: (P2) P2 = f × Qt × ℓ + ℓ0 367 (kW)

[Steps 3] Calculate the power to move the load vertically: (P3) P3 = h × Qt 367 (kW)

[Steps 4] Calculate the back stop power: (Pr) Pr = P3 - 0.7(P1 + P2)(kW)

[Steps 5] Calculate the back stop torque: (T) SI Unit T = 60000 × Pr 2π × N × S.f(N・m) {Gravity unit } T = 974 × Pr N × S.f{kgf・m}

  • f = Friction coefficient of rollers
    = 0.03(normally used )
  • W = Weight of moving parts of the conveyor in the unloaded condition {kg/m}
    (Use the values from the table below. )
    Belt width mm 400 450 500 600 750 900 1050 1200 1400 1600 1800 2000
    Mass W 22.4 28 30 35.5 53 63 80 90 112 125 150 160
  • V = Conveying speed m/min
  • Qt = Max. possible load t/h
  • h = Total lift m
  • ℓ = Horizontal distance between head pulley and tail pulley m
  • ℓ0 = Modification coefficient for horizontal distance m
    = 49m(normally used )
  • N = Shaft speed (r/min) on which the clutch is mounted. r/min
  • S.f = Service factor
    (Select service factor from table below: )
    Backstopping: Several times a day 1.5
    Backstopping: More than several times a day 2.0

(2)Backstopping for bucket elevator

[Steps 1] Calculate the back stop torque: (T) SI Unit T = (L + D) × Qt × D × 9800 120 × V
  × S.f(N・m) {Gravity unit } T = (L + D) × Qt × D × 1000 120 × V
  × S.f{kg・m}

[Steps 2] Select a size for which the above back stop torque (T) is within the allowable maximum torque.

  • Note) 1.When calculating the back stop torque, it is recommended that the maximum conveying capacity (Qt) be the largest value that can be considered for the conveyor's capacity. An unexpected reverse of a conveyor often occurs when the conveyor reaches its full load capacity.
  • Note) 2.For conveyors other than those mentioned above, back stop torque should be calculated separately using formulas specific to each conveyor. In this case, too, the calculation should be based on the assumption that the load is applied to the full capacity of the conveyor.
  • L = Total lift m
  • D = Pitch circle dia. of head sprocket m
  • Qt = Max. possible load t/h
  • V = Conveying speed m/min
  • S.f = Service factor
    (Select service factor from table below: )
    Backstopping: Several times a day 1.5
    Backstopping: More than several times a day 2.0
  • T = Motor trip torque
  • kW = Motor Capacity (kW)
  • N = Cam clutch overrun rotation speed r/min
  • S = Motor stall torque %
  • Tmax = Max. allowable torque in catalog

(3)Selection by motor trip

If there is a possibility that the motor may trip and stop due to trouble during conveyance or wiring errors, use the following formula for selection.

SI Unit T = 60000 × kW 2π × N × S 100 ≦ Tmax(N・m)

{Gravity unit } T = 974 × kW N × S 100 ≦ Tmax{kgf・m}

Note) The above selection formula is for BS series. For other series, please contact us.

(4)Backstop with repetitive impact load (Tennis machines, pitching machines, etc. )

Required torque calculation

T = F × ℓ × 3.0

  • T：Torque on cam clutch (N・m)
  • F：Maximum spring pull tension (N)
  • ℓ：Eccentricity (Load )
  • 3.0：Factor

3.2 Overrun rotation speed

3.3 Shaft Bore Diameter

3.4 Installation method

Tennis machines, pitching machines, etc.

Reference Table of backstopping torque/rotating speeds

(MG-R r/min is for continuous overrun )

Reference Table of backstopping torque/rotating speeds

[Click to enlarge ]

Select a clutch that satisfies the above conditions from the clutches for backstopping (see the list of applicable series by mode and their respective pages).

◎……Most suitable 　○……Suitable
Series
Application MZ
MZ-G		 BB PB 200 LD ML MG MI MX MI-S BS BR
BR(P)		 MG-R MA MR Cam Clutch Boxes MZ-C MG-C
low speed overrun ○ ○ ○ ○ ○ ○ ○ ◎ ○
medium speed overrun ○ ○ ○ ○ ○ ○ ◎
high speed overrun ○ ◎ ◎ ○
Backstopping due to reciprocating shock loads ◎
×
(Drag to move. )

Classification of overruning applications

Application Package
Dual Drive
・
Two Speed Drive 		high speed disengaged; high-speed engaged Overrunning speed = 700 r/min and up, engaging speed = 700 r/min and up
High speed disengaged; low-mid speed engaged Overrunning speed = 700 r/min and up, engaging speed = Up to 700 r/min
high speed disengaged; low speed engaged Overrunning speed = 700 r/min and up, engaging speed = Up to 200 r/min
low-mid speed disengaged; low-mid speed engaged Overrunning speed = Up to 700 r/min, engaging speed = Up to 700 r/min
engage in one-way direction, overrun in reverse direction Input force is put into normal rotation for engagement and reverse rotation for overrunning. Speed = Up to 700 r/min
free wheeling Overrunning starts when the rotating speed of the driven side becomes faster than the driving side. Speed = Up to 700 r/min
manual drive Continuous overrunning, manual engagement
×
(Drag to move. )

Classification of indexing applications

Application Package
(1)high speed; small feed angle Frequency (number of rotations) = 300/min. and above. Feed angle (θ) : Up to 90°
(2)low-mid speed; small feed angle Frequency (number of rotations) = 300/min. or less. Feed angle (θ) : Up to 90°
(3)low speed; large feed angle Frequency (number of rotations) = 150/min. or less. Feed angle (θ) : 90° and up
(4)backstop device for indexing Frequency and feed angle are the same as those of Cam Clutches for feeding.
(5)indexing furnished with stopper Application method is the same as (2) except that material is stopped by force during feeding.
(6)infinite variable feed Application method is the same as (2) except that the rotating speed is changed by steplessly changing the feed angle (θ) during operation.
×
(Drag to move. )

Classification of backstopping applications

※There is a range of rotation speeds depending on the model number.
Application Overrunning speed Engagement Main purpose(s)
low speed overrun ※Continuous overrunning at 150 r/min or less Irregular, low-frequency engagement For backstopping of conveyor shafts, pumps, etc.
medium speed overrun ※Continuous overrunning at 150 to 700 r/min For backstopping of intermediate shafts of conveyor-drive reduction gears.
high speed overrun Continuous overrunning at 700 to 3600 r/min For backstopping of high-speed rotating shafts in conveyor-drive machines, pumps, etc.
Repetitive impact load Indexing overrun and engagement are repeated at high frequency. Tennis machines, batting machines, etc.