NFA series backstopDetailed product description：

NFA series backstop

Specification

dmin

dmax

Smin

Smax

D

L

L0

H

htwo

A

Aone

A0

B

Bone

B0

NFA10 NFA16 NFA25 NFA40 NFA63 NFA80 NFA100 NFA125 NFA160 NFA200 NFA250

thirty-two forty-five fifty sixty seventy eighty ninety one hundred one hundred and ten one hundred and twenty one hundred and thirty

fifty sixty seventy eighty ninety one hundred one hundred and ten one hundred and thirty one hundred and forty one hundred and fifty one hundred and sixty

one hundred and ten one hundred and ten one hundred and fifteen one hundred and twenty one hundred and twenty-five one hundred and thirty one hundred and forty one hundred and sixty one hundred and sixty-five one hundred and seventy-five one hundred and eighty

one hundred and forty-five one hundred and fifty one hundred and fifty-five one hundred and sixty-six one hundred and eighty one hundred and eighty-five two hundred and twenty two hundred and fifty two hundred and sixty two hundred and sixty two hundred and seventy

one hundred and ninety two hundred and eight two hundred and thirty two hundred and forty-five two hundred and sixty-five two hundred and eighty-five three hundred and five three hundred and forty three hundred and seventy four hundred and fifteen four hundred and fifty

one hundred and sixty-two one hundred and sixty-seven one hundred and seventy-two one hundred and eighty-three one hundred and ninety-six two hundred two hundred and thirty-eight two hundred and sixty-two two hundred and seventy-three two hundred and seventy-five two hundred and eighty-five

thirty-six thirty-eight forty-three forty-eight fifty-six fifty-six sixty-eight seventy-six eighty-four eighty-seven ninety-two

two hundred and fifteen two hundred and twenty-five two hundred and fifty two hundred and sixty-five three hundred and thirty three hundred and forty-five three hundred and seventy-five four hundred four hundred and thirty-five four hundred and sixty-five five hundred

twelve twelve sixteen sixteen twenty twenty twenty-two twenty-two twenty-five twenty-five twenty-five

two hundred two hundred two hundred and fifty two hundred and fifty three hundred and eighty three hundred and eighty four hundred four hundred four hundred and fifty four hundred and fifty four hundred and fifty

one hundred and sixty one hundred and sixty two hundred two hundred three hundred and thirty three hundred and thirty three hundred and fifty three hundred and fifty three hundred and eighty three hundred and eighty three hundred and eighty

fourteen fourteen eighteen eighteen twenty-two twenty-two twenty-two twenty-two twenty-six twenty-six twenty-six

ninety-five ninety-five one hundred and twenty one hundred and twenty one hundred and sixty one hundred and sixty one hundred and seventy one hundred and seventy one hundred and eighty one hundred and eighty one hundred and eighty

sixty sixty seventy-five seventy-five one hundred one hundred one hundred and ten one hundred and ten one hundred and twenty-five one hundred and twenty-five one hundred and twenty-five

twenty twenty twenty-five twenty-five thirty-four thirty-four thirty-four thirty-four thirty-six thirty-six thirty-six

Note: "Smin" and "Smax" in the table represent the minimum and maximum lengths required for installing the backstop shaft extension, respectively.
6. Applicable instructions
The non-contact backstop is installed on the high-speed shaft extension or intermediate shaft extension of the reducer. The selection of backstop is related to the required backstop torque, shaft extension speed, and size for its installation shaft.
Taking the belt conveyor as an example, the selection steps are as follows:
6.1 Calculate the required backstop torque M based on the operating conditions, where M should be less than or equal to the rated backstop torque Mn of the backstop.


Where:
Mr. - Calculation of required reverse torque for conveyor (N · m)
I-Transmission ratio of the installation shaft of the backstop extending to the output shaft of the reducer
N - Number of backstops installed on the conveyor drive device
Kj - Bonding coefficient (less than 10 shutdowns per hour, Kj=0; Shutdown more than 10 times per hour, Kj=0.1）
Ku - Temperature coefficient, refer to Table 7 based on ambient temperature

Environmental temperature (℃)	twenty	thirty	forty	fifty	sixty	seventy
Ku	0	zero point one	zero point two	zero point three	zero point four	zero point five

Ks - working time coefficient, refer to Table 8 for daily working hours

Daily working hours (hours)	<2	2~6	7~12	＜12
Ks	0	zero point one	zero point two	zero point three

F-life coefficient, refer to the graph based on the total number of reverse stops of the backstop



The uneven load coefficient is determined based on the layout of the conveyor, with a single drive coefficient of Φ=1; Multiple drivers can be retrieved according to Table 6

Dynamic form	Single drum dual motor	Double drum dual motor	Double drum three motor	Double drum four motor
Φ	one point two five	two	one point five	two

6.2 Verify the non-contact speed Nf of the backstop based on the rotational speed Nd of the shaft extension of the backstop installed on the host, with the requirement that Nd>Nf
6.3 Determine the installation hole diameter of the backstop based on the shaft extension size of the installation backstop.
6.4 Determine the rotation direction of the backstop. Facing the outer end face of the installation shaft extension, the shaft extension rotates clockwise, and the inner ring rotation direction code is "S"; Otherwise, it is' N '.
6.5 Determine the type of backstop based on the reverse torque, installation hole diameter of the backstop, and rotation direction code of the inner ring, using the model representation method described earlier.

NFA series backstop