Cover assembly for bearing

A bearing cover assembly can be assembled to a bearing housing in which a rolling element bearing is accommodated. The bearing housing assembly includes an annular adapter and an end cap that can be mated together. The annular adapter can have a tapered inner annular surface and can be inserted into the housing bore of the bearing housing. The end cap can have a corresponding outer tapered surface. When the end cap is inserted into the adapter hole defined by the annular adapter, the sliding contact between the tapered inner annular surface and the outer surface radially expands the annular adapter inside the housing bore creating a positive engagement retaining the bearing cover assembly to the bearing housing.

BACKGROUND

Rolling element bearings are anti-friction devices used to rotatably support shafts in industrial settings and mechanical equipment. Rolling element bearings include a plurality of rolling elements such as spherical balls or cylindrical rollers that are located between inner and outer bearing rings, referred to as races, and the rolling elements are arranged so that they can roll along the inner and outer circumferences of the respective inner and outer bearing races. The rolling elements enable the inner and outer bearing races to rotate with respect to each other. A rotating shaft that is fixedly mounted to the inner bearing race can thus rotate with respect to the outer bearing race that may be fixedly mounted to a stationary supporting structure.

The rolling element bearings may be supported in a bearing housing such as, for example, a pillow block housing or a flange housing that mounts the bearing to the supporting structure. The bearing housing may be made of cast iron or a similar structural material to rigidly support the bearing and transfer loads from the shaft to the supporting structure. The bearing housing includes a housing bore disposed through the structure in which the rolling element bearing is located. The shaft can extend into the housing bore from either side of the housing structure. In some embodiments, the axial end of the shaft may be located in the bearing housing such that the shaft is anchored by the rolling element bearing mounted therein, while in other embodiments the shaft may extend through the bearing housing.

To cover the housing bore, for example, to prevent unintended contact with the rotating shaft therein and to prevent contamination and debris from interfering with the bearing, bearing covers may be attached to the bearing housing. Common attachment mechanisms include using bolts or set screws to fasten the bearing cover to the housing or press-fitting a polymer cap into the housing bore. Such attachments methods, however, require that machining processes be undertaken or the cover may unintentionally dislodge due to incidental contact. These attachment methods may further require compatibility between the style and/or dimension of the bearing housing and the corresponding bearing cover. The present disclosure is directed to an improved bearing cover assembly to facilitate attachment to a bearing housing.

BRIEF SUMMARY

The disclosure describes a bearing cover assembly for enclosing the housing bore of a bearing housing accommodating a rolling element bearing that may be used to support a rotating shaft. The bearing cover assembly includes an annular adapter and an end cap that can be mated together. The annular adapter may be inserted into the housing bore of the bearing housing and includes a tapered inner annular surface that defines an adapter hole. The end cap can include a tapered outer surface that may generally correspond in dimension to the tapered annular inner surface of the annular adapter. When the end cap is inserted into the annular adapter, sliding contact between the tapered inner annular surface and the tapered outer surface radially expands the annular adapter in the housing bore, thereby positively retaining the bearing cover assembly to the bearing housing through a mechanical engagement. The annular adapter may include axially extending first and second latch arms that can extend around the end cap and that can be received in corresponding recesses disposed on the end cap. A radially inward barb on the distal end of the latch arms can catch on the recesses to secure the annular adapter and end cap together.

A possible advantage of the disclosure is that the bearing cover assembly is securely and positively engaged to the bearing housing so as to prevent unintentional dislodgement of the bearing cover assembly. Another possible advantage is that the ability of the annular adapter to radial expand or contract with respect to the housing bore enables the bearing cover assembly to possibly fit a variety of bearing housings. These and other possible advantages and features will be apparent from the following detailed description and accompanying drawings.

DETAILED DESCRIPTION

Now referring generally toFIGS. 1-4where, whenever possible, like reference numbers will refer to like elements, there is illustrated a bearing cover assembly100configured for attachment to a bearing housing102which defines a circular housing bore104disposed through it and in which a rolling element bearing106can be accommodated. The housing bore104and rolling element bearing106define an axis line108extending there through. In addition to being used on a bearing housing, in various applications the cover assembly can be used on an enclosed gear box. When a rotating shaft is supported in the bearing housing102, it can align and rotate with respect to the axis line108. The bearing housing102may be configured as a pillow block as illustrated that can mount to a supporting structure that supports the loads transmitted from the shaft. The bearing housing102can be made of cast iron or a similar rigid material of suitable strength and may include lubrication ports or grease fasteners to receive lubrication for the rolling element bearing106. In accordance with the disclosure, however, the bearing housing106may have other suitable configurations and be made of other materials.

To enclose the exposed aperture of the housing bore104on either side of the bearing housing102, the bearing cover assembly100can have a two-piece construction configured to be assembled to and engage the housing. The bearing cover assembly100can include an annular adapter110that may be partially inserted into the housing bore104and an end cap112that can be mated with the annular adapter in a manner that expands the bearing cover assembly to positively engage the housing bore104. The annular adapter110and the end cap112can be made from a molded thermoplastic material or steel having a resilient or flexible characteristic that enables the annular adapter to radially expand within the housing bore and secure the bearing cover assembly to the bearing housing.

Referring toFIGS. 2 and 3, to mate with the end cap112, the annular adapter110can be an annular, ring-like structure that, when assembled to the bearing housing102, extends circumferentially about and is concentrically aligned with the axis line108. The annular adapter110can include an intermediate shoulder flange120that may be sized and dimensioned slightly larger than the housing bore104and configured to axially abut against the face of the bearing housing102into which the housing bore104is disposed. For axial insertion into the housing bore104, the annular adapter110includes an annular, ring-like adapter sleeve122that extends axially rearward from the intermediate shoulder flange120and that is sized smaller in diameter than the intermediate shoulder flange. The rolling element bearing106may be set back into the housing bore104to provide a stepped clearance to accommodate the adapter sleeve122. The intersection between the intermediate shoulder flange120and the adapter sleeve122provides an annular shoulder that can be dimensioned and shaped to abut against the corresponding intersection between the face of the bearing housing102and the bearing bore104and that may limit the axial insertion of the adapter sleeve into the housing bore.

To facilitate alignment and sliding contact with the end cap112when mated, the annular adapter110can include a tapered inner annular surface124that is radially oriented towards and circumferentially extends about the axis line108. The tapered inner annular surface124may taper radially inward towards the axis line108as the inner surface of the annular adapter110extends rearward. As illustrated, the tapered inner annular surface124may be associated with the inner surfaces of the intermediate shoulder flange120and the adapter sleeve122, although in other instances the tapered inner annular surface124may only extend over a portion of the axial length of those parts of the annular adapter110. The outer annular surface126of the adapter sleeve122may have a similar taper such that the two surfaces are parallel, although in other instances the outer annular surface may instead extend parallel with the axis line108.

To enable the annular adapter110to radially contract and expand, the annular adapter can be formed with a split cut128disposed through it and which splits the circular structure of the annular adapter. The split cut128, which may be formed by cutting the annular adapter110over its axial length, enables the circumference of the annular adapter to contract radially inwardly under radially applied compressive force and can expand radially outwardly when the force is removed due to a resilient characteristic of the material of the annular adapter. The split cut128may be parallel to the axis line108or may be disposed at an approximate angle to the axis line.

To mate with the end cap112, the annular adapter110can include at least one latch arm, and may include a first latch arm130and a second latch arm132, which extend axially forward of the intermediate flange120and which may be positioned at directly opposing locations along the circumference of the annular adapter110. The first and second latch arms130,132can be curved to correspond with the circular shape of the annular adapter110and may be formed as arcs that curve only partially around the axis line108. For example, the arc length of each of the first and second latch arms130,132may be less than a quarter of the 360° circumference of the annular adapter110. The latch arms130,132may be each located at approximately 90° on opposite sides with respect to the location of the split cut128in the annular adapter110. To hook or grasp the end cap112, the first and second latch arms130,132can have formed at their axially forward, distal ends a radially inwardly directed catch or radially inward directed barb134that protrudes slightly towards the axis line. The radially inward directed barb134may be coextensive with the arc length of the first and second latch arms130,132or may extend only over a portion of the arc length of the latch arms.

The end cap112can be a cup-shaped structure including an axial face panel140oriented normal to the axis line108and a rearward extending tapered insert142that projects axially rearward from the axial face panel140. The tapered insert142can be an annular structure, as indicated inFIG. 4, and extends around the axis line108such that the interior of the end cap112is hollow. The tapered insert142can include an annular circumferential wall144that that may have an outer diameter that corresponds to the inner diameter defined by the annular adapter110. Moreover, the circumferential wall144can have a tapered outer surface146that tapers radially inwardly as the circumferential wall extends rearward from the axial face panel140. The tapered outer surface146can be the same or similar to that of the tapered inner annular surface124of the annular adapter110.

Formed proximate the intersection between the axial face panel140and the tapered insert142can be an enlarged head148that radially protrudes with respect to the circumferential wall144. The enlarged head148can be diametrically coextensive with the axial face panel140and may extend, for example, approximately half the axial length of the end cap112. To accommodate the first and second latch arms130,132projecting axially forward of the annular adapter110, a first cutout150and a second cutout152, corresponding in shape to the latch arms, can be formed in the enlarged head148. The first and second cutouts150,152can be located at directly opposite sides of the circumference of the enlarged head148and are oriented axially rearward so that, when the annular adapter110and end cap112are mated, the first and second latch arms130,132can be received in the respective first and second cutouts150,152.

To engage with the latch arms130,132, a first recess154and a second recess156can be radially disposed into the circumferential wall144without breaking through to the interior of the end cap112; however, in the event the annular adapter includes only a single latch arm, only a single recess may be required. The first and second recesses154,156can be located completely within the cutouts150,152or may axially extend rearward over a part of the tapered outer surface146. The first and second recesses154,156can be generally rectangular in shape and can curve about the curvature of the circumferential wall144such that their arc length corresponds to the arc length of the first and second cutouts150,152.

As illustrated inFIGS. 2 and 4, to assemble the bearing cover assembly100to the bearing housing102, the annular adapter110is axially aligned with the housing bore104and the adapter sleeve122is inserted therein, for example, by pressing the annular adapter rearward into the housing bore. To facilitate insertion, the diameter of the adapter sleeve122can be reduced by radially compressing the annular adapter110via the split cut128. The adapter sleeve122can be accommodated in the stepped clearance provided by offsetting the rolling element bearing106into the housing bore104and the intermediate shoulder flange120can abut against the axial face of the bearing housing102. When the adapter sleeve122is inserted, the tapered inner annular surface124is concentrically disposed around the axis line108.

To radially expand the annular adapter110within the housing bore104and retain the bearing cover assembly100to the bearing housing102, the tapered insert142of the end cap112is axially aligned with and inserted into the adapter hole defined by the tapered inner annular surface124of the adapter sleeve122. Because of the tapered outer surface146, the outer diameter of the tapered insert142varies over its axial length such that the circumferential wall144will initially be spaced from the adapter sleeve122during insertion, then make sliding contact with the tapered inner annular surface124of the annular adapter110. Further axial insertion of the end cap112into the annular adapter110by, for example, pushing results in an interference fit because the diameter of the tapered outer surface146of the circumferential wall144exceeds the relative diameter of the tapered inner annular surface124of the adapter sleeve122. The interference fit causes the tapered insert142to radially displace the adapter sleeve122against the inner surface of the housing bore104. The annular adapter110, end cap112, and housing bore104are radially constrained, mated, and fixed in place with respect to each other and thereby forcibly retained to the bearing housing102. The radial expansions of the annular adapter110against the housing bored104also enables the bearing cover assembly to remain secured to the bearing housing102even if the structures are subject to thermal expansion and contraction due to changes in the operating temperatures.

To prevent the end cap112from axially backing out of the annular adapter110, the first and second latch arms130,132extending axially forward of the intermediate shoulder flange120can align with the respective first and second cutouts150,152and make sliding contact over the circumferential wall144of the tapered insert142. As the first and second latch arms130,132slide over the circumferential wall144, they can be displaced radially outwards in a cantilevered manner by the tapered outer surface146until the radially inward directed barbs134are received in the first and second recesses154,156disposed into the circumferential wall144. The resilient material of the annular adapter110enables the latch arms130,132to radially press the radially inward directed barbs134into the recesses154,156and against the curved surfaces to grip the circumferential wall144. Further, the edges of the recesses154,156can catch the radially inward directed barbs134if they axially slide backwards and thereby positively retain the annular adapter110to the end cap112.

To release the end cap112from the annular adapter110and disassemble the bearing cover assembly100from the bearing housing102, for example, to service the rolling element bearing, the first and second latch arms130,134as illustrated inFIGS. 3 and 5can each include a hole160configured to receive a threaded set screw162. The holes160and set screws162can be directed radially toward the axis line108and can be oriented to radially bear on the first and second recesses154,156of the tapered insert142disposed within the annular adapter110. The holes160and set screws162may be at directly opposite locations with respect to the circumference of the annular adapter110. When the set screws162are tightened radially inward, they can push off and displace the first and second latch arms130,132with respect to the circumferential wall144and release the radially inward directed barbs134from the recesses154,156. That allows the end cap112to be axially removed from the annular adapter110. Thereafter, to remove the annular adapter110from the housing bore104, the annular adapter can be radially compressed, by, for example, radially squeezing the split cut128closed and disengaging the adapter sleeve122from the housing bore. Accordingly, the bearing cover assembly100can be assembled to and removed from a bearing housing102already installed on equipment in the field.

The end cap of the bearing cover assembly can have other configurations and features to facilitate access to the rolling element bearing and/or the shaft supported therein. For example, referring toFIG. 6, the end cap200can have a multi-part construction and can include a first semicircular part202and a second semicircular part204. The first and second semicircular parts202,204can be identical in shape, complementary to each other, and, when arranged in mirrored opposition, can be clamped together to produce the end cap200. The first and second semicircular parts202can each include structures that correspond to the axial face panel206and the rearward extending tapered insert208, which may have the same configuration generally described above.

To clamp the first and second semicircular parts202,204together, they can include a clamp210located on one interfacing surface212and a tongue214located on a second interfacing surface216. The clamp210can be a bifurcated structure that is adapted to receive and lock down on the tongue214when the first and second interfacing surfaces212,216are positioned against each other. The clamp210and tongue214therefore hold the end cap200together.

To enable access to the rolling element bearing and/or the shaft, the axial face panel206can be configured with a central aperture220disposed there through. The central aperture220can be produced by two semi-apertures222disposed in the first and second semicircular parts202,204and can be concentrically aligned with the axis line of the bearing housing. The central aperture220can accommodate instruments such as, for example, purge valves for re-lubricating the bearing, speed sensors for measuring the speed of the rotating shaft, and other functions. In another example, the rotating shaft may extend through the central aperture220to protrude from the end cap200.

Referring toFIG. 7, there is illustrated a version of the end cap300configured to form a snap-fit when mated with the annular adapter of the type described above. Similar to the end caps described above, the end cap300includes an axial face panel302and a tapered insert304extending axially rearward from the axial face panel302with respect to an axis line306. To radially expand the annular adapter, the tapered insert304includes a circumferential wall308with a tapered outer surface310. The circumferential wall308can have a smaller, tapering diameter than the enlarged head312associated with the axial face panel302. The enlarged head312includes cutouts314to accept the latch arms extending forwardly from the annular adapter. To form the snap-fit, the circumferential wall308of the tapered insert304can include first and second recesses316on opposite sides of the circumference of the tapered insert and which may have a rectangular outline. The recesses316can be located in the cutouts314disposed partially into the circumferential wall308. Located in the recesses316can be a radial ledge318rising outwardly in the recesses. The radial ledge318can follow the circumferential curve of the circumferential wall308about the axis line306and can be located approximately axial mid-width of the rectangular recesses316. When the end cap300is inserted into the annular adapter, the radially inward directed barbs on the latch arms can slide along the circumferential wall304, be received in the recesses316, and deflect over the radial ledge318to interlock the end cap300and annular adapter together. The radial ledge318catches the radially inward directed barbs and thereafter can prevent the annular adapter from axially backing off the end cap300.

Referring toFIG. 8, there is illustrated a version of the end cap400configured to form a bayonet mount with the annular adapter of the type described above. The end cap400again includes an axial face panel402and a tapered insert404axially extending from the axial face panel with respect to an axis line406. The tapered insert404also includes a circumferential wall408with a tapered outer surface410to radially expand the annular adapter. Disposed in the enlarged head412on circumferential opposite sides of the end cap400can be first and second cutouts414or recesses to accommodate the latch arms extending forwardly on the annular adapter. Disposed into the cutouts414and radially into the material of the end cap400can be a respective bayonet slot418which is configured to form a twist lock with the radially inward directed barb on the latch arm of the annular adapter. The bayonet slot418follows the circumferential curve of the end cap400and extends as an arc partially about the axis line406. The bayonet slot418can have a first axial width420and a second axial width422that is of a smaller dimension than the first axial width420as measured with respect to the axis line406. Further, the smaller second axial width422can be axially offset with respect to the first axial width420.

To assemble the end cap400to the annular adapter, that latch arms on the annular adapter can be inserted into the cutouts414so that the radially inward directed barbs are received in the wider first axial width420of the bayonet slot418. Subsequently twisting the end cap400with respect to the annular adapter will direct the radially inward directed barb to the smaller second axial width422which can serve to axially position the end cap400with respect to the annular adapter in a manner that can control the degrees of radial expansion of the bearing cover assembly.