Special Issue; Products for Industrial Machinery - NTN

NTN TECHNICAL REVIEW No.742006
2.3.1 Compact design
The structure of the old TDL28 is characterized in
that the roller at each end of the spring is forced to the
cam surface. In contrast, the TDL16 has a novel
structure in which multiple rollers at each end of the
spring are forced to the cam surface. Because of this
arrangement, the outer diameter of the TDL16 is
smaller than that of the TDL28 though both designs
have the same number of rollers. Thus, the TDL16
has succeeded in minimizing the loss of load bearing
capacity on the clutch.
In Table 2, the dimensions and limiting torque of the
TDL16 are compared with those of the TDL28.
2.3.2 Lightweight design
By incorporating the resin components (output
shaft, housing, lid) shown in Fig. 8, the authors’
TDL16 compact, lightweight torque diode achieved
weight reduction of 50% relative to the TDL28 (Fig. 9).
Table 2 Size and limiting torque of TDL16 and TDL28
2.3.3 Durability
Under the test conditions summarized in Table 3,
the TDL16 has successfully endured 300,000 cycles
of load applications.
Running speed
Load torque
One cycle
Table 3 Test condition of endurance test
3. Conclusion
250min -1
0.5 N-m (constant loading in one direction)
Forward rotation for 2.5 sec.standstill for 10 sec.
reverse rotation for 2.5 sec.standstill for 10 sec.
NTN believes that their NTB14 ultra-compact torque
limiter unit and TDL16 compact, lightweight torque
diode positively contribute to space and energy
conservation in photocopying machines and printers.
NTN will further develop unit products to satisfy future
market needs.
Shape
TDL16
25 OD x 35.8 L (mm)
(Note that the shape of the
resin housing can be altered
upon customer request.)
TDL28
30 OD x 38.2 L (mm)
Limiting torque 2)
2.5Nm
4.9Nm
Note 2) These limiting torque values have been calculated based on the maximum
surface pressures occurring on the cam surfaces. The useful operating life
of a torque diode can vary depending on operating conditions.
Weight g
70
60
50
40
30
20
10
0
TDL16
TDL28
Fig. 9 Weight of TDL16 and TDL28
Photos of authors
Shoji ITOMI
Industrial Engineering Dept.
Industrial Sales headquarters
Atsushi MOROOKA
Industrial Engineering Dept.
Industrial Sales headquarters
-72-