A high load capacity bearing that includes a cylindrical outer sleeve that fits around a separable cylindrical outer race assembly. The outer race assembly includes a set of non-helical grooves formed on its inside surface that mesh and engage teeth formed on the outside surface of a plurality of rotating rollers that are longitudinally and axially aligned inside the outer race assembly. The rollers are longitudinally aligned and evenly space apart and rotated as a unit inside the outer race assembly. Located inside the rollers is an inner race with non-helical grooves formed on its outside surface that mesh and engage the teeth on the rollers. The inner race includes a smooth inside bore that fits around the support surface on a shaft.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to bearings and more particularly bearings specifically designed for high loads.

2. Description of the Related Art

Bearings5found in the prior art shown inFIGS. 1 and 2commonly consist of stacked pairs of ball bearings6mounted on a support shaft7. The bearing may mount or attached to a cavity or support surface formed on a part9. The load capacity of the ball bearings6is dependent on the number of ball bearings6stacked together, and the size and number of balls8. Generally, the larger number of ball bearings6stacked together, and the larger the size and number of balls8used, the larger is the load capacity of the bearing5. Unfortunately, in environments where large load capacity is needed, the bearing5must be relative large and the shaft and housing must be relatively large.

The load capacity of a bearing5is determined by the size and number of contact points11,12between the balls8and the bearing's inside and outside races9and10, respectively. The size and number of balls8and the sizes of the races9,10are often limited by the environment or machine where the bearing5is used. In environments where the load capacity is near or slightly lower than the maximum load capacity of the bearing5, the bearings5frequently wear out and must be replaced.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a bearing that has a relatively high load capacity.

It is an object of the present invention to provide a bearing that is relatively small and compact and has a relatively long life span.

It is another object of the present invention to provide such a bearing that can be used in place of a single or multiple bearings used in the prior art.

Disclosed herein is a compact bearing with increased contact areas between opposing structures located inside the bearing that substantially increases the bearing's load capacity and increases the bearing's life span. The bearing is specifically designed so that it may be easily assembled.

More specifically, the bearing includes a plurality of small diameter rollers axially and radially aligned therein. The rollers include a plurality of non-helical teeth that simultaneously engage compatible-shaped, non-helical grooves formed on the inside surface of an outer race assembly. In the embodiment presented herein, the outer race assembly is a cylindrical structure made of two half cylindrical sections that are joined together. When the two half cylindrical sections are joined to form a complete cylindrical structure, a cylindrical outer sleeve is positioned around the two half cylindrical sections to hold them tightly together. The two half sections include non-helical grooves that when tightly joined together, form continuous, circular aligned non-helical grooves on the inside surface of the outer race assembly.

The rollers are part of a roller assembly portioned longitudinally inside the bearing. The roller assembly includes a means for holding a plurality of longitudinally and axially aligned rollers inside the outer race assembly. Each roller includes a plurality of non-helical teeth configured to mesh and engage the non-helical grooves formed on the outer race assembly. The roller assembly includes a rotating support structure that holds the rollers longitudinally in a fixed position inside the bearing and hold the rollers in an equally spaced, radially aligned position. The rotating support structure may be two alignment rings or a cylindrical cage.

In one embodiment, a cylindrical inner race is disposed over the shaft and inside the roller assembly. The inner race includes a plurality of non-helical grooves configured to engage the teeth on the rollers. During assembly, the inner race is mounted and locked in position on a bearing support surface on the shaft.

The roller assembly is disposed inside a gap formed between the outer race assembly and an inner race or the shaft. The inner race is a cylindrical with a smooth center bore and a plurality of non-helical grooves designed to mesh with the teeth on the rollers. The rollers are circumferentially aligned around the inner race and fit inside the raceway and against the inner race and the outer race assembly. Each roller has a sufficient diameter and length so that the non-helical teeth simultaneously mesh with the non-helical grooves formed on the outer race assembly and the inner race.

After assembly, the bearing is placed on the bearing support surface on the shaft. In one embodiment, the shaft includes an abutment surface and external threads that extend outside the bearing. A nut is attached to the threads on the shaft which squeezes the inner race against the abutment surface to fix the inner race onto the shaft. Also during assembly, the outer sleeve and outer race assembly are mounted on a fixed location on a support surface or cavity located on a desired part. The rotation of the roller assembly and the rotation of the individual rollers between the outer race assembly and the inner race, the enable shaft and part to rotate and transfer load forces therebetween.

In one embodiment, the inner race is eliminated and a modified shaft is used that includes a bearing support surface region with the second set of non-helical grooves that are identical in shape and size to the first set of non-helical grooves formed on the outer race assembly and configured to mesh with the teeth on the rollers. During use, the non-helical teeth on the rollers mesh with the non-helical grooves formed on the outer race assembly and on the shaft. In this embodiment, the abutment edge on the shaft and the nut may be eliminated.

In another embodiment, a modified two part outer sleeve and a modified outer race assembly are used so that forces exerted between the shaft and the outer race assembly do not cause the outer sleeve to be removed from the outer sleeve assembly. The outer sleeve includes two outer sleeve sections that are placed over the opposite ends of the outer race assembly to hold the two outer sleeve sections together. A gap is formed between the two outer sleeve sections. The modified outer race assembly includes an outward extending circular collar that fits into a gap formed between an outer sleeve made up of two outer sleeve sections.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring to theFIG. 3, there is shown a high load capacity bearing15mounted on a shaft60that has greater internally opposing contact areas that substantially increases the bearing's overall capacity and its life span. The increased capacity is created by using intermediate structures inside the bearing15that spread the load over substantially large areas. The structures are also compact enabling the overall size and shape of the bearing15to be relatively small and compact.

Referring toFIG. 4, the bearing15includes an outer race assembly30made of two half cylindrical sections32,36. In the embodiment shown, the half cylindrical sections32,36are identical in shape and size each with two planar, longitudinally aligned abutment edges33,34and37,38, respectively that enable the two half cylindrical sections32,36to be closed tightly to form a complete cylindrical outer race assembly30. During assembly, a cylindrical outer sleeve20slides over the two half cylindrical sections32,36to hold them tightly together. In the embodiment shown, outer sleeve20includes two open ends24,26.

Formed on the inside surface of each half cylindrical section32,36is a plurality of semi-circular non-helical grooves35,39, respectively. When the two sections32,36are joined together to form the cylindrical outer race assembly30, the grooves35,39on the two outer sleeve sections32,36are aligned so that they form a continuous set of non-helical grooves (denoted40) on the inside surface of the outer race assembly30.

In a first embodiment shown inFIGS. 4-5, the bearing15includes a small diameter, cylindrical inner race44is coaxially aligned and located inside the outer race assembly30. As shown inFIG. 6, a circular gap or raceway42is formed between the inside surface of the outer race assembly30and the outside surface of the inner race44. Formed on the outside surface of the inner race44is a second set of non-helical grooves46that are aligned with and compatible in number, size and shape to the first set of non-helical grooves40formed on the outer race assembly30.

Disposed inside the raceway42is a roller assembly that includes a plurality of longitudinally aligned rollers80. The rollers80are circumferentially aligned around the inner race44and fit inside the raceway42and against the grooves formed on outer race assembly30and the inner race44. Each roller80includes a set of non-helical teeth86that are similar in shape and size to the sets of non-helical grooves40,46formed on the outer race assembly30and on the inner race44, respectively. Each roller80has a sufficient diameter and length so that the non-helical teeth86formed thereon simultaneously mesh with the non-helical grooves40,46on the outer race assembly30and the inner race44, respectively. The rollers80are offset so that the tips and valleys of the non-helical teeth86fits within the non-helical grooves40,46formed on the outer race30and the inner race44, respectively.

In the first embodiment, the inner race44mounts to a smooth bearing support area62formed on the shaft60as shown inFIGS. 5 and 6. The shaft60also includes a threaded end section64. Formed or attached to the shaft60adjacent to the bearing support area62is an abutment edge66which prevents longitudinal movement of the bearing15over the shaft60. When the bearing15is attached to the shaft60, the threaded end section64is exposed and receives a threaded nut70that when tightened against the end of the thrust bearing15and presses against the inner race44to hold it in place on the shaft60. It should be understood that the threaded nut70could be replaced with another structure that holds the inner race44in place on the shaft60.

FIGS. 7 and 8show a second embodiment of the bearing, denoted15′, in which the inner race44used in the first embodiment is eliminated and a modified shaft60′ is used in place of the first shaft60. The modified shaft60′ includes a bearing support region62′ with the second set of non-helical grooves65formed thereon that are compatible in shaped and size to the set of non-helical grooves40formed on the outer race assembly30. During use, the non-helical teeth86on the rollers80mesh with the non-helical grooves40,65formed on the outer race assembly30and on the shaft60′, respectively. Because a set of non-helical grooves65are formed on the shaft60′, the abutment edge66and the locking nut70shown inFIGS. 5 and 6may be eliminated.

Each roller80has a sufficient diameter and length so that the non-helical teeth86formed thereon simultaneously mesh with the non-helical grooves40,46, or65on the outer race30, the inner race44or the shaft60, respectively. Extending around the shaft60and positioned inside each end of the outer sleeve assembly30are two alignment rings100,110. The alignment rings100,110fits into are restrained by grooves102,112formed on the inside surface of the outer race assembly30. The grooves102,112prevent longitudinal movement of the alignment rings100,110and hold them circumferentially and coaxially over the shaft. The grooves102,112also allow the alignment rings100,110to rotate freely therein. During operation, the alignment rings100,110rotate which allows the rollers80together as a single unit. Each roller80includes two longitudinal aligned arms82,84that during assembly, are inserted into compatible holes104,114, formed on the two alignment rings100,110, respectively, that allows the rollers80to independently rotated on the alignment rings100,110.

During operation, the bearing15or15′ may be attached or coupled to a moving or stationary structure and the shaft60or60′ may rotate freely and continuously inside the thrust bearing15,15′. The load exerted from the structure to the shaft60is spread across all of the contact surfaces between the roller teeth and the race grooves thereby enabling the thrust bearing to be used with greater loads.

FIGS. 9 and 10are sectional, perspective views of another embodiment of the bearing15″ showing the two alignment rings being replaced by a single cylindrical cage140. The cylindrical cage140includes a plurality of axially aligned slots142configured to hold a longitudinally aligned roller80therein.

FIG. 11is a perspective view of another embodiment of the bearing15″′ that includes an outer race assembly made of two outer race sections each with an outward extending, semi-circular collar. When assembled, the two collars form a circular collar that fits into a gap formed between two shorter outer sleeve sections that after assembly form the outer sleeve. The reason for forming a circular collar that fits into a gap formed between the two outer sleeves is to transfer the longitudinal forces exerted by the rollers on the outer sleeve onto one of the outer sleeves. When used with different mating parts, the abutment edges on the mating part may very. By using the collar and gap and the two outer sleeves, that longitudinal forces exerted by the rollers may be transferred to the lateral edges of the outer sleeve.

FIG. 12is an exploded, perspective view of the embodiment of the bearing15′ shown inFIG. 11.

In another embodiment, shown inFIG. 13, a modified two part outer sleeve and a modified outer race assembly are used so that forces exerted between the shaft and the outer race assembly do not cause the outer sleeve to be removed from the outer sleeve assembly. The outer sleeve160includes two outer sleeve sections162,164that are placed over the opposite ends of the outer race assembly170to hold the two outer sleeve sections162,164together. A gap166is formed between the two outer sleeve sections162,164. The modified outer race assembly170includes an outward extending circular collar180that fits into a gap166formed between an outer sleeve sections162,164.

FIG. 14is an illustration showing how the net thrust force f(1) exerted on the shaft creates a force f(2) that is exerted against the end of the inner race. The forces f(3) on the inner race are then transferred from the non-helical grooves on the inner race to the lower teeth on the roller. The force f(4) is then exerted from the upper teeth of the roller to the outer race assembly. The collar then exerts a force f(5) against the edge of the outer sleeve which in turn exerts a force against an abutment edge on the part. The forces f(6) on the part are then exerted on the machinery or ground.

INDUSTRIAL APPLICABILITY

This invention is useful in industries that use bearings that are carry high capacity loads that susceptible wear or breakage.

In compliance with the statute, the invention described herein has been described in language more or less specific as to structural features. It should be understood, however, that the invention is not limited to the specific features shown, since the means and construction shown is comprised only of the preferred embodiments for putting the invention into effect. The invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the amended claims, appropriately interpreted in accordance with the doctrine of equivalents.