Patent Application
20180015935
In a railway freight car truck, two axles are held in a pair of laterally spaced sideframes, with a bolster extending laterally between and supported on each sideframe. The wheels are press fit on the axles, with the ends of the axles also fitted with a roller bearing assembly. The roller bearing assembly itself is fit into a bearing adapter that is fit into a pedestal jaw opening at the longitudinal end of each sideframe. The ends of the bolsters are themselves supported on spring groups, which are supported on the lower portion of the center openings of the sideframes.
The bearing adapter, which is itself fit on top of the roller bearing assembly, is usually comprised of a unitary cast steel piece. An elastomeric adapter pad is fitted on top of the bearing adapter. The adapter pad itself is usually comprised of an injection molded polymer or a castable polyurethane. The adapter pad usually includes four depending legs, two each of which extend from opposite longitudinal edges of the adapter pad. The depending legs are spaced laterally at each longitudinal edge of the adapter pad such that the depending legs are received in openings between laterally spaced shoulders of the bearing adapter. To avoid the build up of static electricity between the axle rotating within the roller bearing assembly and the railway freight car truck, it is desirable to have an electrical connection between the bearing adapter and the sideframe pedestal jaw.
Accordingly, it is an object of the present invention to provide an improved bearing adapter and pad assembly that provides an improved electrical connection between the bearing adapter and the sideframe pedestal jaw.
A railway freight car truck of the so-called three piece standard design, is comprised of two laterally spaced, sideframes usually of a unitary cast steel structure, and a laterally extending bolster, also usually of a unitary cast steel structure. The ends of the bolster are received and supported on spring groups that themselves are supported on the bottom section of a bolster opening in each sideframe.
The wheel axle assemblies themselves are received in openings, commonly referred to as pedestal jaw openings, at longitudinal ends of each sideframe. The wheel axle assemblies themselves extend laterally between the sideframes, and hence, also laterally between the two spaced railway tracks. For improved performance of the railway freight car truck, it is desirable to receive the roller bearing assemblies press fit on each axle end beneath a bearing adapter assembly. The bearing adapter assembly of the present invention is comprised of a cast steel, unitary bearing adapter. This bearing adapter includes lateral edges themselves having arcuate cutouts to be placed over the bearing assembly. The bearing adapter further comprises depending shoulders that extend from each longitudinal edge of the bearing adapter. The shoulders at each longitudinal edge of the bearing adapter themselves are laterally spaced to form an opening there between. It should be understood that the top section of such bearing adapter is generally rectangular in structure.
The improved bearing adapter pad in accordance with the present invention is comprised of an improved elastomer or polymer, usually a polyurethane. Such improved bearing adapter pad is usually formed in a casting operation, although recent improvements have allowed the improved adapter pad to also be formed in an injection molding operation. The bearing adapter pad itself is seen to be comprised of a generally rectangular main section, with two depending legs extending from each longitudinal edge thereof The depending legs are spaced laterally on each longitudinal edge. Such depending legs are fit downwardly into the opening in the bearing adapter and abut the shoulders of the bearing adapter to provide lateral support for the adapter pad.
The bearing adapter pad inherently provides undesirable electrical insulation between the sideframe pedestal jaw and the bearing adapter that allows static electricity to build up between the sideframe and the bearing adapter. The elastomer pad in accordance with the present invention however includes a generally flat, generally rectangular main section, the elastomeric pad having a first opening in the main section, the first opening extending from a top surface of the main section, and a second opening in the main section, the second opening extending from a bottom surface of the main section, and a first electrical contact fitted into the first opening in the top surface of the main section, and a second electrical contact fitted into the second opening in the bottom surface of the main section, and a conductor extending from the first electrical contact to the second electrical contact.
With the proper relationship between cross section and hardness of the material of the elastomeric pad, a spring rate is designed into the elastomeric bearing adapter pad to assure electrical contact between the bearing adapter and the sideframe pedestal jaw.
In the drawings,
Referring now to
Bearing adapter 30, which is seen to be a generally rectangular unitary structure having four depending legs extending therefrom. Bearing adapter 30 is usually comprised of a unitary cast steel structure. Bearing adapter pad 32 is also seen to be a generally rectangular structure with four depending legs extending therefrom. Bearing adapter pad 32 is usually comprised of a cast or injection molded polymer or elastomer.
Bearing adapter 30 is seen to be comprised of a unitary, cast steel structure that is generally rectangular in shape. Bearing adapter 30 is comprised of a generally rectangular top section 36, which is seen to be generally flat. Two raised edge supports 38 are seen to extend upwardly from the lateral edges of bearing adapter 30, as are similar raised edge supports 40 from the opposite lateral edge of bearing adapter 30. The combined raised edge supports 38 and 40 form a receiving surface and pocket for bearing adapter pad 32. Bearing adapter 30 is also seen to comprise an arcuate opening 42 on each lower lateral edge; this arcuate opening 42 is adapted to seat against a bearing, which is not shown in this view. Bearing adapter 30 is also seen to comprise four depending shoulders, of which 44 and 46 are shown in this view. Depending shoulders 44 and 46 are seen to be laterally spaced, forming an opening for bearing adapter pad 32.
Bearing adapter pad 32 is usually comprised of a cast polymer or elastomeric material and is of unitary structure. It is also possible to construct adapter pad 32 with an injection method. Bearing adapter pad 32 is comprised of a generally rectangular and flat main section 50, with lateral edges, of which lateral edge 52 is shown. Four depending legs, of which depending leg 54 and 56 are shown in this view, are seen to extend downwardly, and form a thrust lug opening 58 there between. A similar thrust lug opening is formed on the other longitudinal edge of adapter pad 32. In assembling bearing adapter pad 32 onto the top of bearing adapter 30, it can be seen that depending legs 54 and 56 project downwardly and are supported laterally against depending shoulders 44 and 46, respectively, of bearing adapter 30.
Referring now to
Referring now to
Bearing adapter pad 32 is also seen to comprise a centrally located opening 60 that extends through main section 50, extending through from top surface 70 of main section 50 through to bottom surface 72 of main section 50. Bearing adapter pad 32 is also seen to comprise a partial opening 62 that extends into top surface 70 of main section 50, but usually does not extend through to bottom surface 72 of main section 50. Bearing adapter pad 32 is also seen to comprise a partial opening 64 that extends into bottom surface 72 of main section 50, but usually does not extend through to top surface 70 of main section 50. An electrically conductive button or cap 68 is fitted into opening 62 in top surface 70 of main section 50. An electrically conductive button or cap 66 is fitted into opening 64 in bottom surface 72 of main section 50. An electrical conductor 70, usually comprised of an electrically conductive wire, connects electrically conductive button 68 to electrically conductive button 66 by passing through opening 60 in main section 50.
Adapter pad 32 is comprised of a cast elastomer of a durometer hardness between 90A and 58D. It should be understood that it is preferred to have adapter pad 32 formed in a casting operation to obtain the desired hardness ratings, but other forming operations are possible so long as the preferred hardness ratings of adapter pad 32 are provided. The spring compressive nature of bearing adapter pad 32 assures that electrical contact is maintained between bearing adapter 30 and sideframe 14 through electrically conductive button 66, conductor 70 and electrically conductive button 68.
