PILLOW BLOCK ASSEMBLY

Abstract

A pillow block assembly is for supporting a shaft for rotating about an axis of rotation, the pillow block assembly including a bearing housing, having an interior accommodating a shaft bearing, and a seal assembly. The bearing housing is split along a first plane accommodating the axis of rotation into a first bearing housing half and a second bearing housing half. The seal assembly includes at least one radial shaft seal with at least one seal lip, preferably having a spring adapted to bias the seal lip, and a spacer adapted to be fitted around the shaft and adapted to rotate with the shaft, the spacer having a radially outwardly directed first sealing surface. The seal assembly further includes a cover at least partially surrounding the first sealing surface of the spacer, the cover being reversibly secured to the housing. The radial shaft seal is arranged to seal between the cover and the first sealing surface of the spacer.

Claims

1. A pillow block assembly for supporting a shaft rotatable about an axis of rotation, the pillow block assembly comprising: a bearing housing, having an interior accommodating a shaft bearing, the bearing housing being split along a first plane accommodating the axis of rotation into a first bearing housing half and a second bearing housing half; and a seal assembly including at least one radial shaft seal with at least one seal lip a spacer adapted to be fitted around the shaft and adapted to rotate with the shaft, the spacer having a radially outwardly directed first sealing surface, and a cover at least partially surrounding the first sealing surface of the spacer, the cover being reversibly secured to the housing, the radial shaft seal being arranged to seal between the cover and the first sealing surface of the spacer and surface formations are arranged on the spacer towards the interior of the housing and are adapted to serve as oil flingers.

2. The pillow block assembly according to claim 1, wherein the radial shaft seal is arranged on the cover, and the seal lip is biased towards the spacer to seal between the cover and the first sealing surface of the spacer.

3. The pillow block assembly according to claim 1, wherein the seal assembly further includes a gap seal arranged between the cover and the spacer on a side of the radial shaft seal facing towards the interior of the housing.

4. The pillow block assembly according to claim 1, wherein an axial labyrinth seal is arranged between the cover and the spacer on a side of the radial shaft seal facing away from the interior of the housing.

5. The pillow block assembly according to claim 1, wherein a contact leap seal is arranged between the cover and the spacer between the radial shaft seal and the axial labyrinth seal.

6. The pillow block assembly according to claim 5, wherein the contact lip seal is arranged on the cover and is adapted to seal between the cover and the first sealing surface of the spacer.

7. (canceled)

8. The pillow block assembly according to claim 1, wherein the at least one radial shaft seal includes at least two radial shaft seals each having at least one seal lip.

9. The pillow block assembly according to claim 1, wherein each of the at least one radial shaft seal includes two or more seal lips.

10. The pillow block assembly according claim 1, wherein the interior of the bearing housing accommodates a shaft bearing and two seal assemblies each arranged on a separate side of the interior.

11. The pillow block assembly according to claim 1, wherein the seal assembly further includes a spring adapted to bias the at least one seal lip and/or the surface formations on the spacer are in the form of machined grooves.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The various aspects of the invention, including its particular features and advantages, will be readily understood from the following illustrative and nonlimiting detailed description of an exemplary embodiment of the present invention, wherein:

[0021] FIG. 1 shows a schematic view of a pillow block assembly according to an example embodiment of the present invention;

[0022] FIG. 2 shows a partially cut-out view of the pillow block assembly of FIG. 1 along the line A-A shown in FIG. 1;

[0023] FIG. 3 shows an enlarged portion of the cut-out view of FIG. 2, marked with the circle B, depicting a portion of a first example embodiment of the seal assembly comprising one radial shaft seal;

[0024] FIG. 4 shows an enlarged portion of the cut-out view of FIG. 2, marked with the circle B, depicting a portion of a second example embodiment of the seal assembly comprising a radial shaft seal and a contact lip seal.

[0025] The drawings show diagrammatic exemplifying embodiments off the present invention and are thus not necessarily drawn to scale. It shall be understood that the embodiments shown and described are exemplifying and that the invention is not limited to these embodiments. It should also be noted that some details in the drawings may be exaggerated in order to better describe and illustrate the invention. Throughout the detailed description, like reference numerals refer to like elements, unless explicitly expressed otherwise.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0026] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which a currently preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

[0027] With reference to FIG. 1, a pillow block assembly 10 according to an example embodiment of the present invention is shown in a schematic and perspective view. The pillow block assembly 10 has a bearing housing 20 with a first bearing housing half 22 and a second bearing housing half 24. The bearing housing half 22 and the bearing housing half 24 are secured to each other by fastening means 28, here in the form of bolts 28. The second bearing housing half 24 is furthermore adapted to be secured to a fundament by means of further fastening means 28 also in the form of bolts 28. On top of the pillow block assembly 10 is a lifting means 29 in form of a ringbolt 29 arranged, which allows a simple and secure lifting of the pillow block assembly 10 with the help of commonly known lifting arrangements (not shown) normally provided in the locations where machinery and pillow block assemblies are mounted.

[0028] The bearing housing 20 has a bearing housing interior 26 accommodating a shaft bearing (not shown) and a seal assembly, which is not shown here either, but will be explained later in the following with reference to the FIGS. 2 to 4.

[0029] The pillow block assembly 10 is designed for supporting a shaft (not shown) for rotating about an axis of rotation. To achieve this, a shaft (not shown) is inserted into the pillow block assembly 10 and supported by a shaft bearing (not shown) in the bearing housing interior 26. The shaft bearing (not shown) is lubricated with oil, and to avoid leakage of the oil a seal assembly 30 is provided, preferably on both sides of the pillow block assembly 10. However, depending on the circumstances and design requirements, and especially when a shaft will not completely pass through the pillow block assembly 10, one side of the pillow block assembly 10 could be covered by an appropriate adapted lid or cover and comprise a seal assembly 30 or a different seal assembly.

[0030] Parts of the seal assembly 30 that are visible in this view are described here, the remaining parts of the seal assembly 30 will be described later with reference to FIGS. 2 to 4. A spacer 40 is arranged to be fitted on a shaft (not shown), and in order to seal between the shaft and the spacer 40 to avoid leakage of oil, a seal 44 in form of an O-ring is provided on the inside of the spacer 40 at each end of it. As it will be explained later, it is intended that the spacer 40, once fitted on a shaft, will rotate together with the shaft. To achieve this, the spacer 40 will be reversibly fixed to the shaft with commonly known fixing means not explained or shown here.

[0031] The spacer 40 cooperates with a cover 50, which is reversibly fixed to the bearing housing 20 by means of fastening means 28, here in the form of bolts 28. Outside of the spacer 40 is a support frame 90 arranged, at least partially surrounding the spacer 40 and reversibly fixed to the bearing housing 20 by means of fastening means 28, here in the form of bolts 28. The support frame 90 is an adjustment tool used to place the spacer 40 in the correct position on the shaft (not shown) in relation to the bearing housing 20. Accordingly, the support frame 90 is used only temporarily when mounting the spacer 40 on the shaft (not shown), and not a permanent part of the pillow block assembly according to the invention. However, it is an important part to assure the correct positioning of the spacer 40 on the shaft (not shown) in relation to the bearing housing 20.

[0032] The bearing housing 20 of the pillow block assembly 10 with the support frame (or adjustment tool) 90 is, with other words, shown in the state just after the mounting of the spacer 40 on a shaft (not shown) in the correct position in relation to the shaft (not shown) and the bearing housing 20.

[0033] Referring now to FIG. 2, FIG. 2 depict an enlarged view of a seal assembly 30 in accordance with the invention. This view is a result of a cut through the pillow block assembly 10 of FIG. 1 along the line A-A, looking into the direction of the arrows. The seal assembly 30 is adapted to seal the interior 26 of the pillow block assembly 10 from the exterior. The seal assembly 30 comprises a spacer 40 arranged to be fitted on a shaft (not shown), having a seal 44 in form of an O-ring on the inside at each end. This will avoid leakage of oil between the shaft (not shown) and the spacer 40 when the spacer 40 is fitted on the shaft (not shown). The seal assembly 30 further comprises a cover 50, reversibly fixed to the bearing housing 20, in this view to the first bearing house half 22 of the bearing housing 20. To avoid leakage of oil between the first bearing house half 22 and the cover 50, a seal 44 in form of an O-ring is arranged between the first bearing house half 22 and the cover 50. The seal assembly 30 furthermore comprises a support frame 90, arranged on the outside of the pillow block assembly 10 and reversibly fixed to the bearing housing 20, in this view to the first bearing house half 22 of the bearing housing 20.

[0034] The support frame (or adjustment tool) 90 surround the spacer 40, at least partially, and support spacer 40 to assure the correct positioning of the spacer 40 on the shaft (not shown) in relation to the bearing housing 20 and the cover 50, when mounting the spacer 40 in the correct position on the shaft (not shown) in relation to the bearing housing 20. Accordingly, the support frame 90 is used only temporarily when mounting the spacer 40 on the shaft (not shown), and not a permanent part of the pillow block assembly according to the invention. However, it is an important part to assure the correct positioning of the spacer 40 on the shaft (not shown) in relation to the bearing housing 20.

[0035] In order to control and, if necessary, to replace the sealing arrangement B (sealing arrangement B will be described in the following with reference to the FIGS. 3 and 4) fastening means (not shown), fixedly connecting the spacer 40 with the shaft (not shown) to allow the spacer 40 to rotate together with the shaft (not shown), will be removed or unlocked, and the spacer 40 will be pulled away from the bearing housing 20 to allow access to the opening in the bearing housing 20. The mentioned access is possible between the shaft (not shown) and the cover or drip breaker part 50, on which the sealing arrangement B is arranged. The cover 50 is in accordance with the invention fixedly connected with the bearing housing 20 (here shown the first bearing housing half 22) and surrounds the opening in the side of the bearing housing 20.

[0036] In a next step, the sealing arrangement B will be removed with an appropriate tool, for example a hook. The accessible parts of the opening of the bearing housing 20 as well as the shaft (not shown) will be thoroughly cleaned, and the surface condition of visible surfaces will be checked. If the sealing arrangement B is still in a good condition, it will be reassembled. If the sealing arrangement B need to be replaced, a new sealing arrangement B will be mounted after the cleaning process. With the new sealing arrangement B mounted on the cover or drip breaker part 50, the spacer 40 will be put back in place with the help of a support frame or adjustment tool 90, as described. When the spacer 40 is back in place, the spacer 40 will be fixedly connected with the shaft (not shown) by fasting means (not shown) to allow the spacer 40 to rotate together with the shaft (not shown), the support frame or adjustment tool 90 will be removed, and the bearing housing 20 respective the pillow block assembly 10 is ready for operation.

[0037] The seal assembly 30 comprises several sealing arrangements, which will be explained in the following. Starting from the inside, the bearing housing interior 26, there is gap seal 60, sealing between the spacer 40 and the cover 50 towards the interior 26 of the bearing housing 20. After the gap seal 60, counting from the interior 26, are surface formations 80 arranged, here in the form of machined grooves, adapted to serve as oil flingers 80. Since the spacer 40 will rotate with the shaft (not shown) when fitted on the shaft, any oil on the oil flingers 80 will be thrown away due to the rotation of the spacer 40 and collected for reuse. These oil flingers 80 and their function are well known and will therefore not be explained further here.

[0038] After the oil flingers 80, counting from the interior 26, is a sealing arrangement provided, marked with a circle B. This sealing arrangement B will be described in the following with reference to the FIGS. 3 and 4.

[0039] After the sealing arrangement B, counting from the interior 26, an axial labyrinth seal 70 is provided. Axial labyrinth seals are well known and will therefore not be explained further here.

[0040] Turning now to FIGS. 3 and 4, and starting with FIG. 3, here a preferred embodiment of the sealing arrangement B, marked with the circle B in FIG. 2, is shown in an enlarged view. This preferred embodiment comprises a radial shaft seal 32 fixedly arranged in a recess provided in the cover 50. The radial shaft seal 32 comprises a seal lip 34 and a spring means 36, here in the form of a garter spring. The spring 36 bias the seal lip 34 against a first sealing surface 42 arranged on the spacer 40. By means of this arrangement the radial shaft seal 32 prevents the leakage of oil between the cover 50 and the spacer 40.

[0041] FIG. 4 shows a further preferred embodiment of the sealing arrangement B, marked with the circle B in FIG. 2, in an enlarged view. This preferred embodiment comprises a radial shaft seal 32 and a contact lip seal 38, both fixedly arranged beside each other in a recess provided in the cover 50. The radial shaft seal 32 comprises a seal lip 34 and a spring means 36, here in the form of a garter spring. The spring 36 bias the seal lip 34 against a first sealing surface 42 arranged on the spacer 40. The contact lip seal 38 comprises a seal lip 39 biased against the first sealing surface 42. By means of this arrangement the radial shaft seal 32 and the contact lip seal 38 provides a further improved sealing and prevents the leakage of oil between the cover 50 and the spacer 40.