Page 318 - needle bearings

One-way clutches
NTN

One-way Clutches

This is a compact and roller type one-way clutch which
formed a cam face on its outer ring. (Available shaft
diameter range: 6 to 35 mm) When the outer ring is
going to rotate counterclockwise against shaft rotation
(arrow ˠ direction on outer ring widthay surface), the
rollers advance to the position of engagement with the
outer ring cam face by spring action and drive the shaft
by acting as a wedge between the outer ring cam face
and the shaft. (See Fig. 1) When the outer ring rotates
Fig. 1 Fig. 2
clockwise against the shaft, the shaft rotates One-way clutch in engagement One-way clutch in idling
counterclockwise relatively to the outer ring and, as the
result, the rollers get away from the outer ring cam face
and simultaneously the outer ring idles against the shaft.
(See Fig. 2)

Applied shaft Composition of
Type Remarks
diameter (mm) nominal clutch number
Type HF

HF 10 12 One-way clutch HF composed of an outer ring drawn from
a thin steel plate by precision drawing has the clutching
Width
function only.
П6ʙП35 Bore diameter This one-way clutch must be provided with a bearing
Type code at its both sides to support radial load acting thereon
and to ensure smooth rotating motion.

Type HFL

HFL 10 22 One-way clutch HFL has an outer ring drawn from thin
steel plate by precision drawing, a clutching function, and
Width
an integral needle roller and cage assembly capable of
П8ʙП35 Bore diameter
supporting radial load at its both ends respectively.
Type code Thus, this HFL can function as clutch and, in addition,
support radial load.

Both of Type HF and HFL use a polyamide resin cage specified value or more. Table 2 shows the
and press the needle rollers to a wedge, which is formed recommended value.
between the outer ring cam face and the shaft, by action
of a plate spring supported with the cage.
Table 1 Clutch fits
Clutch fit Type Shaft Housing
Iron series Light metal alloy
Table 1 shows the one-way clutch fits on shaft and in
housing. Both of Type HF and HFL are only press-fitted in HF
h5 (h6) N6 (N7) R6 (R7)
a housing, needing no axial fixing by use of a snap ring, HFL
etc.
However, due to the outer ring drawn from thin steel by
precision drawing, the performance of the both is directly Table 2 Recommended housing wall thickness
affected by the dimensional and profile deviations of the Housing material Housing wall thickness
shaft/housing. To avoid such an inverse affect, shaft and Steel, cast iron 0.75 DʵFw and over
housing accuracy must be controlled with good care. Any
Light metal alloy 1.5 DʵFw and over
housing is required to have the wall thickness of a

B-256