Description
Internal Freewheels FXN
for press fit on the outer ring
with sprag lift-off X
Features
Internal Freewheels FXN are sprag freewheels without bearing support and with sprag lift-off
X. The sprag lift-off X ensures a wear-free free - wheeling operation when the inner ring rotates
at high speed. The outer ring is pressed into the customer hous ing. This makes compact, space-saving fitting solutions possible. The freewheels FXN are used as:
Backstops
Overrunning Clutches
for applications with high speed freewheeling operation and when used as an overrunning
clutch with low speed driving operation. Nominal torques up to 20 500 Nm. The torque is
transmitted on the outer ring by press fit. Bores up to 130 mm. Many standard bores are
available.
Sprag lift-off X
Internal Freewheels FXN are equipped with sprag lift-off X. The sprag lift-off X is used for
backstops and overrunning clutches, provided that in freewheeling operation the inner ring is
rotating at high speed and providing with overrunning clutches that the driving operation
is conducted at low speed. In freewheeling operation, the centrifugal force FC causes the
sprag to lift off from the outer track. In this operating state, the freewheel works wear-free,
i.e. with unlimited service life.
The Figure shows a freewheel with sprag liftoff X in freewheeling operation. The sprags,
which are supported in a cage connected with the inner ring, rotate with the inner ring. The
centrifugal force FC that is applied in the center of gravity S of the sprag turns the sprag counterclockwise and rests against the support ring of the cage. This results in the gap a between the sprag and the outer track; the freewheel works with out contact. If the inner ring speed decreases to such an extent that the effect of the centrifugal force on the sprag is less than that of the spring force FF , the sprag again rests on the outer ring and the freewheel is ready to lock. If used as an overrunning clutch, the driving speed must not exceed 40% of the lift-off speed.
Freewheel size
mm
mm
Bore d
mm
mm
max. mm
B
D mm
F
J
K min. mm
L
Weight
kg
Standard
mm
mm
mm
mm
mm mm
FXN31 - 17/60
20*
20*
25
60 P6
55
31
85
24
0,3
FXN31 - 17/62
20*
20*
25
62 P6
55
31
85
24
0,4
FXN38 - 17/70
25*
25*
25
70 P6
62
38
90
24
0,4
FXN46 - 25/80
25
30
35
80 P6
70
46
95
35
0,8
FXN51 - 25/85
25
30
35
36
35
85 P6
75
51
105
35
0,8
FXN56 - 25/90
35
40
35
90 P6
80
56
110
35
0,9
FXN61 - 19/95
30
35
40
45*
26
95 P6
85
61
120
25
0,8
FXN61 - 19/106
30
35
40
45*
25
106 H7
85
61
120
25
1,2
FXN66 - 25/100
35
40
45
48*
30
100 P6
90
66
132
35
1,1
FXN66 - 25/110
35
40
45
48*
40
110 P6
90
66
132
35
1,8
FXN76 - 25/115
45
55
60*
40
115 P6
100
76
140
35
1,7
FXN76 - 25/120
45
55
60*
32
120 J6
100
76
140
35
1,8
FXN86 - 25/125
40
45
50
60
65
70*
40
125 P6
110
86
150
40
2,3
FXN86 - 25/130
40
45
50
60
65
70*
40
130 P6
110
86
150
40
2,6
FXN 101 - 25/140
55
70
75
45
140 P6
125
101
175
50
3,1
FXN 101 - 25/149
70
75
62
149 H6
125
101
175
62
4,2
FXN 101 - 25/150
55
70
75
45
150 P6
125
101
175
50
3,6
FXN 85 - 40/140
45
50
60
65
65
45
140 P6
125
85
175
60
3,2
FXN 85 - 40/150
45
50
60
65
65
45
150 P6
125
85
175
60
4,2
FXN 100 - 40/160
45
50
55
60
70
75
75
50
160 P6
140
100
190
60
5,1
FXN 105 - 50/165
80
80
62
165 P6
145
105
195
62
5,8
FXN 120 - 50/19
Complaint
