Type WKB is a non bearing supported sprag typefreewheel. The sprags run directly on the shaftprovided by the user. Bearings are required to support axial and radial loads. Lubrication and sealing must also be provided by the installation. A typical arrangement is to install this type alongside a bearing as shown on the following page.The housing bore to receive the outer race will be machined with a H7 tolerance. A key will transmit the torque. The shaft on which the sprags run must have a surface hardness of HRc 60 to 62 for a finished depth of 0,6 mm minimum. Core hardness should be HRc 35 to 45. Surface roughness must not exceed 22 CLA. Maximum shaft taper 0,01 mm per 50 mm length.Concentricity between shaft and housing bore should be maintained within TIR 0,05 mm. The preferred lubrication is oil. The Stieber design allows the use of most of the common lubricants used in power transmission including gear oils with EP additives. When necessary grease lubrication is also possible.
Note:More powerful spring type "WKB-ss" is also available,When you need the inner race,please order "WKB-IR".
The shaft which is Cooperating with the clutch should be Quenching axis，Hardness should reach HRC56-60. Mounting shaft tolerance h7，Cylindrical 0.01mm.
Use 2 # lithium grease 30% + Engine oil 70% ,Stirring evenly. The grease required temperature range -40 ℃ ～ + 150 ℃. Plus grease once for every month.