Integrated Freewheels FXRV with
torque limiting and without release
function
This series of backstops with torque limiting is
the basic version. The design and the available
standard sizes are shown on page 74.

Integrated Freewheels FXRT with
torque limiting and with release
function
This series is designed in the same way as series
FXRV; as an addition, a finely controllable release
function is built in. The design, the description
of the release function and the available stan-
dard sizes are shown on page 75.
The backstops with controllable release func -
tion are used if a controlled relaxing of the belt
or the unit – perhaps in the case of a jam on the
pulley drum – or a limited reverse movement of
the conveyor system is required.

Selection torque
The following determination of the selection
torque applies to multiple-drives installations in
which each drive has the same motor power.
Please contact us in case of different motor
powers.
If the backdriving torque M L per drive is known,
then the selection torque M A for the particular
backstop should be determined as follows:
M A = 1,2 · M L [Nm]
If, however, only the nominal power per drive
P 0 [kW] is known, then this applies:
M A = 1,2 · 9550 · h 2 · P 0 /n SP [Nm]
In these equiations:
M A = Selection torque of the particular back-
stop [Nm]
M L = 9550 · h · P L /n SP [Nm]
= Static backdriving torque of the load
for each drive referring to the particu-
lar backstop shaft [Nm]

Approximate values for h:

In each case, the sum of the slipping torques
of the particular backstops must be 1,2 times
higher than the static backdriving torque of
the installation (also at overload). The torques
specified in the tables are maximum values.
Lower values can be set upon request. If in
doubt, please contact us stating the precise
description of the installation and the oper a-
ting conditions. It is preferable to use the ques-
tionnaire on page 124.

Example
Dual-drive system
Motor power per drive: P 0 = 630 kW
Type of installation:
Conveyor belt with 8° incline => h 2 = 0,61
Speed per backstop shaft:
n SP = 360 min -1
Selection torque of the particular backstop:
M A = 1,2 · 9 550 · 0,61 · 630 / 360 [Nm]
= 12 234 Nm
The following rule applies in all cases:
M R ^ M A
=> FXRT or FXRV 200 - 63 MXare the suitable,
economical backstop sizes.

Freewheel Size

Type

Slipping torque
M_R
Nm

Sprag lift-off at inner
ring speed min^-1

Max. speed
Inner ring  freewheels min^-1

mm

mm

Bore d
Standard
mm       mm

mm

mm

max. mm

A
mm

B
mm

C
mm

D
mm

G**

H
mm

K
mm

L
mm

O
mm

R
mm

S
mm

T
mm

min. mm

U***
max. mm

V
mm

Z**

w
kg

FXRT  85 - 40

MX

1 400

430

6 000

45

50

60

65

65

330

148

6

295

M 12

37

29

60

127

280

110

308

165

215

43

6

60

FXRT 100 - 50

MX

2 300

400

4 500

45

50

55

60

70

75

80*

350

159

6

311

M 12

39

31

70

134

300

125

328

180

240

38

6

66

FXRT 120 - 50

MX

3 400

320

4 000

60

65

70

75

80

95

95

400

159

6

360

M 16

36

31

70

134

340

145

373

200

260

38

6

87

FXRT 140 - 50

MX

4 500

320

3 000

65

90

100

110

110

430

163

6

386

M 16

36

31

70

134

375

165

403

220

280

50

6

104

FXRT 170 - 63

MX

9 000

250

2 700

70

85

90

100

120

130

500

188

6

460

M 16

43

40

80

156

425

196

473

250

340

38

6

166

FXRT 200 - 63

MX

12 500

240

2 100

130

155

555

188

6

516

M 16

49

40

80

156

495

226

528

275

390

38

6

209

FXRT 240 - 63

LX

21 200

220

3 000

185

710

210

8

630

M 20

50

50

90

170

630

290

670

355

455

45

12

355

FXRT 260 - 63

LX

30 000

210

2 500

205

750

223

8

670

M 20

50

50

105

183

670

310

710

375

500

40

12

418

FXRT 290 - 70

LX

42 500

200

2 500

230

850

243

8

755

M 24

52

50

105

190

730

335

800

405

560

48

12

574

FXRT 310 - 96

LX

53 000

195

2 100

240

900

293

10

800

M 24

63

63

120

240

775

355

850

435

600

69

12

805