Bearing Pullers and Tools Information
A bearing puller is a tool used to remove bearing sets from a rotating machine shaft or from a blind bearing hole. The most common application is removing a caged set of ball or tapered bearings from a rotating shaft, such as in a car’s transmission. These tools are made of tool grade steel, so they are harder than the parts they are used on. They are usually hand-powered with a handle on the turn screw, or a male hex end to match a drive socket. Some bearing pullers are hydraulically powered, using a hydraulically powered piston to press against the end of the shaft the bearing is on.
There are also small-sized versions of bearing pullers to remove small millimeter-wide bearings in small fractional horsepower motors and fishing reels. There are arms with extensions that allow the user to pull in the inner race as well. It is preferable to drive from the inner race since it is firmly set on the shaft, while the outer race is not very well secured to the rest of the bearing assembly.
Types of bearing pullers include bearing splitter plates, two and three arm bearing pullers and internal bearing pullers.
Bearing Splitter Plates
Bearing splitter plates are the safest type of bearing pullers to use. Technically these are not pullers, but pushers, since they use wedges to push and pop the bearings off of the shaft. These consist of two half plates held together by two long, wide diameter, heavy duty screws with nuts on all four ends. The plates have a hole in the middle and are ground downwards towards the hole in the center, so as you tighten the two plates together on the outside, the tool wedges into and applies upward thrust on the inner race of the bearing. These work best if there is a gear or hub directly behind the bearing, so that the tool is held in place on one end as the upward thrust pushes on the inner bearing race.
Two and Three Arm Bearing Pullers
These are the most common types of bearing pullers and can be used for pulling gears or bearings. The arms have fingers on the end that bend in to get behind the bearing to its race. The center screw of the puller is torqued so it pushes on the top of the shaft and upward thrust is applied to the bearing’s race. Arms and fingers are interchangeable so the same puller can accommodate a wide variety of bearing and shaft sizes and lengths.
Internal Bearing Puller
Internal bearing pullers are made to extract a bearing set, a bushing, or a simple bronze sleeve from a blind hole. Blind holes preclude using a punch to drive out the sleeve or bearing. Internal bearing pullers usually resemble small dent pullers since they have a slide hammer along the shaft to apply upward thrust and shock to the bearing. The collet, the part that goes into the bearing at the tip of the puller shaft, is expandable. The user can lock the collet inside the bearing or bushing, usually by spinning the collet tighter on the puller shaft. By working the slide hammer away from the bearing and up towards the user, the tool’s hammer will transmit the upward thrust to the bushing and pull it out of its hole.