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NEEDLE RETAINER ASSEMBLY

RTL 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 radical 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

                  RTL 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 ,  RTL  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℃ for 
             a long period while it can even operate under 150℃ for short time.

Precision

                 The dimensional tolerances of RTL 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 Bc is -0.2/-0.55mm.

Table 1 needle diameter tolerance

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

Combination

    The radical gap of  RTL needle 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

Operational conditions	Recommended shaft tolerance
Operational conditions	≤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 the
 roughness must not greater 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 assembling 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

图1

图2

图3

图4

图5