SLS bearing

Explanation for Needle Retainer Assembly

NEEDLE RETAINER ASSEMBLY
Needle retainer assembly is a kind of independent bearing unit
with high load capacity and rigidity especially applicable for the
tray of shaft and seat holes with the unit which is limited in ra-
dical dimension.
Each needle have excellent operative characteristic due to
each needle exactly guided and kept by the retainer.

Structure

K	Needle retainer assembly
K...ZW	Double row needle retainer assembly

Needle retainer assembly is divided into two series:single row and double row.In the case of crank shaft where difficulty

of using and mounting occur , SLS will supply the divided structure . In general case , M type punched retainer is used,

besides, there are metal solid retainer,fiber glass reinforced nylon 66 retainer. The latter can work under the temperature

of 120^oC for a long period while it can even operate under 150^oC for short time.

Precision

Table 1 needle diameter tolerance
Precision grade	Needle diameter tolerance
G2	0~-2	-2~-4	-4~-6
G3	0~-3	-3~-6	-6~-9

The dimensional tolerances of needle retainer are listed in

Table 1.When bearings of more than two types are used in

parallel on a same shaft , the needles must belong to the

sub group with same value.The retainer width tolerance Bcis -0.2/-0.55mm.

Combination

The radical gap ofneedle retainer assembly depends on the machined precision of the inner and outer trays and the

needles. Table 2 shows the combination recommended as per the different operational conditions.

Table 2 the recommended shaft tolerances of the casing when machined as per G6
Nominal shaft diameter Operational conditions	Recommended shaft tolerance
	≤80	>80
High speed, high precision	j5	h5
General operational condition	h5	g5
High temperature or greatmounting tolerance	g6	f6

When the needles are running directly in the shaft or in outer case , to make the needle retainer assembly reach its fully

load capacity , the hardness of the inner and outer tray surface must reach 58-62HRC and theroughness must not gr-

eater than 0.32μm.The surface quality must be the same of rolling bearing tray.

Assembling and relative dimensions

Figure 2, Figure 3 show the relative dimensions of the needle retainer assembly.The axial fixed way used in bearing as-

sembling is show in Fig 4 and 6.When used for high speed,a heat treated washer should be added between the retainer

and the axial limit so that direct contact of retainer and limit can be avoided