BEARING SEAL

Abstract

A bearing seal includes a radially split stator and a rotor. The rotor is enclosed within the stator along the internal length of the rotor. The rotor may, optionally, also be radially split.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

In the accompanying drawing, wherein similar reference numerals denote similar features throughout the several views:

FIG. 1 is a longitudinal section of one-half of a bearing seal of the invention; and,

FIG. 2 is a similar longitudinal section of the bearing seal of FIG. 1, but with the components in their separated condition.

DETAILED DESCRIPTION OF THE DRAWING FIGURES AND PREFERRED EMBODIMENTS

The invention will now be further described, by way of example only, with reference to the accompanying drawings.

Referring to FIGS. 1 and 2 of the accompanying drawings, there is illustrated a bearing seal 1 mounted on a drive shaft 3 and comprising a stator 4, attached directly or indirectly to the bearing housing and a rotor 7 secured to drive shaft 3 for rotation therewith.

The seal 1 is in the form of a non-contacting labyrinth seal and, in the “in use” condition, shown in FIG. 1, the rotor 7 lies wholly within the stator 5.

The stator 5 is sealed to the bearing housing, or another part connected to the bearing housing, by means of a sealing ring and the rotor 7 is attached and sealed to shaft 3 by means of sealing rings 11 and 13.

Rotor 7 includes a recess 15 which extends longitudinally from one end of rotor 7 about a third of the way longitudinally into said rotor. Mounted within recess 15 is a first sealing ring 17 which is located adjacent to the mouth of recess 15 and, between sealing ring 17 and the blind end of recess 15, a second smaller diameter sealing member 19 which bears against the end wall of recess 15 and also against the larger sealing ring 17.

Sealing ring 17 also bears against a protuberance which extends from inner radial surface 23 into the mouth of recess 15. The end surface of protuberance 21 includes a radial portion and an inner inclined portion, at least the latter bearing against sealing ring 17 while the equipment is stationary. When the equipment is rotating, centrifugal force acting on ring 19 causes it to expand radially outwardly and allow sealing ring 17 to move longitudinally out of engagement with protuberance 21 of stator 5. This opens up a tortuous path which extends from the bearing cavity between the stator 5 and the drive shaft 3 and then all the way round the rotor and within the stator to the exterior (right hand side as seen in FIG. 1) of the bearing seal 1. This tortuous path is defined at least partly by a radially extending protuberance 23 which forms an integral part of rotor 7 and which extends into and is accommodated by a large recess 25 formed within stator 5. The tortuous flow extends further around a flange-like member 27 which extends radially outwardly from a circumferential surface 29 of rotor 7 and is accommodated within a relatively small recess 31 of stator 5.

Both the stator 5 and the rotor 7 are radially split into two halves. In order to assemble the seal while on the drive shaft 3, the two halves of the rotor 7 are first brought together round the drive shaft 3. They are fastened together by means of a nut and bolt arrangement 31 extending through the mating protuberances 23 of the rotor 7. Then the two halves of the stator 5 are brought together around drive shaft 3 at a position, relative to rotor 7, as illustrated in FIG. 2. Accordingly, the protuberance 21 lies, in this position, outside the mouth of recess 15, thereby enabling the two halves of stator to be brought together. They interconnect by means of integral dowels in one or both halves engaging in corresponding recesses in the other half. Once this has been done, the seal may be pushed along the drive shaft until the stator 5 engages with the bearing housing as illustrated in FIG. 1. The rotor 7 is in turn pushed from the position shown in FIG. 2 to that shown in FIG. 1 so that the sealing ring 17 engages the protuberance 21.

The stator 5 may optionally be provided with location pegs and corresponding recesses, indicated at 33, which aid proper alignment of the stator halves during assembly. Alternatively or in addition, the stator may be provided with screw or bolt assemblies for fastening the two halves of the stator together.

While only several embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that many modifications may be made to the present invention without departing from the spirit and scope thereof.

Claims

1. A bearing seal, comprising: a radially split stator; and,a rotor enclosed within said radially split stator along an entire length of said rotor.

2. The bearing seal according to claim 1 wherein a tortuous path is defined between said radially split stator and said rotor.

3. The bearing seal according to claim 1, wherein said rotor is radially split.

4. The bearing seal according to claim 1, further comprising a stator shut-off device.

5. The bearing seal according to claim 4, wherein said stator shut-off device includes an annular sealing member located in a recess of one of said radially split stator and said rotor, and bearing against an integral ring on the other of said radially split stator and said rotor, said integral ring extending into said recess.

6. The bearing seal according to claim 5, wherein said annular sealing member is movable from a first position engaging said integral ring to a second position spaced from said integral ring.

7. The bearing seal according to claim 6, wherein a further annular member is located in the recess, said further annular member being radially expandable when the rotor is rotated for allowing movement of said annular sealing member to said second position.

8. The bearing seal according to claim 6, wherein a tortuous path is defined between said radially split stator and said rotor, said tortuous path extending passed said annual sealing member, when said annual sealing member is in said second position, and around a radial protuberance of said rotor.