Bearing dust shields have been available almost as long as ball bearing itself. The main impetus towards shielded bearings comes from the growing use of “sealed-for-life” bearings in items such as white goods, cars and power tools. Shields are needed to stop the grease lubrication used in these bearings from leaking out. This is particularly important in applications where grease leakage may contaminate the product.
In most operating environments though, the requirement is twofold: to keep the lubricant in the bearing, while stopping moisture, debris and other contaminants from getting in. Of course, while the shields are providing their protective functions, the ball bearing is spinning, often at high speed. If its operating life is to be maximized, one factor that needs to be considered is the frictional effect of the shield on the bearing starting and running torques.
Essentially, shields are non-contact metallic (carbon or stainless steel) devices which allow high-speed operation but offer limited protection against the ingress of moisture and dirt. Shields have no contact with the bearing inner ring, hence their low torque qualities. Shields are better than seals at resisting damage from solid airborne contaminants, such as small flying stones. Bearings with shields are primarily intended for applications where the inner ring rotates. Shields are fitted in the outer ring and do not make contact with the inner ring, but form a narrow gap with it. Depending on the bearing design, series and size, MANU supplies shields in different designs.
Notch type shields are often used in bearings to protect them from foreign particles and dust. As the name suggest, they have a large number of ‘notches’ on their periphery. Various categories of notch type shields manufactured by us include:
The ‘Z’ type shield is a metal shield that typically is non-removable after installation as is it pressed in. There is a small gap about .005 inches between the shield and inner race. There is no contact so obtainable speeds and torque are not effected as in a contact type seal. Lubricant leakage can occur and contamination can enter through this gap. They have fair dust resistance and poor water resistance. Shields are good to around 3500F.
MANU is the single largest source for bearing shields to various customers. Also, MANU works closely in development of ‘New Generation’ shields with its customers which are having very close tolerances. These shields have helped in increasing the bearing life by reducing grease leakages.
Size Range: 10 mm to 220 mm Minimum Order Quantity: 10,000 pieces