WO2013141691A1

WO2013141691A1 - An alignment device

Info

Publication number: WO2013141691A1
Application number: PCT/MY2013/000035
Authority: WO
Inventors: Syed Salim SYED ALI; Azali AWALUDIN
Original assignee: Felda Agricultural Services Sdn. Bhd.
Priority date: 2012-03-19
Filing date: 2013-02-27
Publication date: 2013-09-26
Also published as: MY160693A

Abstract

The present invention relates to an alignment device (100, 101). The alignment device (100, 101) comprises a moving member (20), a guiding member (30) for guiding the moving member (20); and a plurality of balancing members (60) for moving the moving member (20) to an aligned position.

Description

AN ALIGNMENT DEVICE

FIELD OF THE INVENTION The present invention relates to an alignment device. BACKGROUND ART

In machinery, a shaft rotating or reciprocating about a rigid guide bushing is often seen. Due to the rotating or reciprocating movement of the shaft, there is always the presence of lateral loads on the shaft.

As such, the shaft is always prone to bending under the lateral load. If the bending persists, misalignment of the shaft may happen. This may also lead to bending stresses, which may be in the form of alternating or fluctuating fatigue stresses. In this connection, if the misalignment is not taken into account during the shaft design stage, the possibility of fatigue failure can become real.

In addition, misalignment may also generate severe contact stresses on the guide bushing. This may further cause rapid wear on the bushing, the shaft, or both too should lubrication fails. Furthermore, excessive contact stresses may lead to surface fatigue failure particularly when the load is alternating and fluctuating.

In light of the above, several machine designs have been introduced to alleviate this issue. One of the easiest methods is to provide enough radial clearance between the shaft and the bushing. However, this is not encouraged because if the clearance is allowed to be large, noise and vibration may prevail. Usually, such issues are followed by wear. Apart from the above, other method has also been provided to tolerate misalignment of the shaft. There are designed proprietary ball and roller bearings that tolerate misalignment for rotating shafts. There are also proprietary linear bearings designed for tolerating misalignment for reciprocating shafts. However, these bearings have been known to be expensive, and limited in design applications since only a limited set of physical dimensions exist for these bearings.

In light of the above, an alignment device that can eliminate the above-mentioned drawbacks is therefore very much in need.

SUMMARY OF THE INVENTION

According to the present invention, there is provided an alignment device. The alignment device comprises a moving member, a guiding member for guiding the moving member; and a plurality of balancing members for moving the moving member to an aligned position.

It is an object of the present invention to provide an alignment device for preventing a shaft misalignment due to a lateral load. The guiding member, for example a bushing, is allowed to rotate in order to reduce or eliminate the bending of the moving member, for example a rotating or reciprocating shaft, extended through the guiding member due to a lateral load. Specifically, substantially a small degree of rotation in one plane is allowed for the guiding member. The plane of rotation takes place at the plane where the lateral load is acting. In order to achieve this, the guiding member is supported by the balancing members. The balancing members assist the guiding member to rotate to the aligned position in the presence of the lateral load. Optionally, the guiding member is allowed rotates on a housing of the device about a pivot formed on the guiding member. It is also an object of the present invention to provide an alignment device that prevents bending stresses, which may be in the form of alternating or fluctuating fatigue stresses, as a result of that the moving member or the shaft is prone to bending when it is subjected to the lateral loads.

It is further an object of the present invention to provide an alignment device that prevents rapid wear of the guiding member and lead surface fatigue failure caused by excessive contact stresses due to the misalignment of the moving member or the shaft.

It is also an object of the present invention to provide an alignment device that eliminates the problem of noise and vibration, as well as wear of the guiding member that may appear due to the sufficient provision of clearance between the moving member and the guiding member for addressing the issue of the misalignment of the moving member.

It is a final object to provide an alignment device for tolerating misalignment of the shaft that is flexible and cost-effective unlike those proprietary ball and roller bearings for tolerating misalignment of rotating shaft only, and those proprietary linear bearings for tolerating misalignment for reciprocating shaft only that are expensive and limited in terms of design applications due to the existence of a limited set of physical dimensions only.

The present invention consists of certain novel features and a combination of parts hereinafter fully described and illustrated in the accompanying drawings and particularly pointed out in the appended claims; it being understood that various changes in the details may be without departing from the scope of the invention or sacrificing any of the advantages of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawings the preferred embodiments from an inspection of which when considered in connection with the following description, the invention, its construction and operation and many of its advantages would be readily understood and appreciated.

FIG. 1 shows a cross-sectional view of a shaft rotating or reciprocating about a bushing of one of the preferred embodiments of the present invention.

FIG. 2 shows a cross-sectional view of a shaft rotating or reciprocating about a bushing of another preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to an alignment device (100, 101). Hereinafter, the alignment device (100, 101 ) shall be described according to the preferred embodiments of the present invention and by referring to the accompanying description and drawings. However, it is to be understood that limiting the description to the preferred embodiments of the invention and to the drawings is merely to facilitate discussion of the present invention and it is envisioned that those skilled in the art may devise various modifications without departing from the scope of the appended claim.

Referring to FIG. 1 , the alignment device (100, 101 ) of the present invention comprises a moving member (20), a guiding member (30), and a plurality of balancing members (60). The guiding member (30) is adapted for guiding the moving member (20). The balancing members (30) are adapted for moving the moving member (20) to an aligned position.

The device (100, 101 ) is mounted on a housing (10). The moving member (20) is a shaft (20). Optionally, the moving member (20) is an elongate shaft (20). The moving member (20) is also allowed to be a beam, a hollow shaft, or in any other form provided that it is able to substantially perform like the moving member (20).

Specifically, the alignment device (100, 101 ) is adapted for preventing the shaft (20) from misaligning due to a lateral load. The bushing (30) is allowed to rotates such that the shaft (20), the bushing (30), or both (20 & 30) are able to rotate to the aligned position in the presence of the lateral load.

The balancing members (60) are equally distributed around the bushing (30). The balancing members (60) equalize with one another around the bushing (30). In the presence of the lateral load, a portion of the balancing members (60) compresses whilst the other portion of the balancing members (60) extends such that the bushing (30) is able to rotate. The bushing (30) rotates, for example at an arbitrary angle Θ/2, as shown in FIG. 1 . In the absence of the lateral load, the balancing members (60) equalize around the bushing (30) such that the balancing members (60) rotate the bushing (30) to the aligned position.

The balancing members (60) each comprise a plurality of washers (80), and a fastener (70). The fastener (70) is extended through the washers (80), and a fastener (70). In other words, the washers (80) are guided by the fastener (70). The washers (80) are intended to act as compression springs. In effect, it is allowed that the washers (80) optionally suspend the bushing (30) as shown in FIG. 1 & 2. The fastener (70) is therefore adapted for connecting the bushing (30) to the housing (10). It is allowed that the washers (80) each are a Belleville washer. The washers (80) are also allowed in other forms substantially as long as the balancing members (60) are able to perform their functions.

The alignment device (100, 101 ) further comprises a plurality of clearances (90) formed on the housing (10) or positioned between the housing (10) and the bushing (30). These clearances (90) allow the bushing (30) to rotate. The clearances (90) consist of angular clearances, radial clearances, or both. It is also allowed that the clearances (90) assume other forms substantially as long as the clearances (90) are able to perform their above-mentioned functions. The shaft (20) or the bushing (30) is allowed to rotate in one plane. The alignment device (100) of the present invention uses the balancing members (60) i.e. each a combination of washers (80), fastener (70) and optionally, appropriate features on the housing (10) and bushing (30) to allow substantially a small degree of rotation in one plane. The plane of rotation is the plane where the lateral load is acting. The bushing (30) is allowed to rotate such that the bending of the shaft (20) is reduced or eliminated.

Optionally, with reference to FIG. 2, the alignment device (101 ) is allowed to further comprise a tilting member (50). The tilting member (50) is adapted for tilting the moving member (20) substantially about an axis substantially perpendicular to the lengthwise extent of the moving member (20).

It is allowed that the tilting member (50) is a pivot (50) as shown in FIG. 2. Nevertheless, the tilting member (50) is not limited to the pivot (50) as the tilting member (50) is allowed to assume any other forms as long as the tilting member (50) is able to perform its above-mentioned functions. The pivot (50) is formed on the bushing (30). The bushing (30) is allowed to rotate about the pivot (50) on the housing (10). The bushing (30) rotates about the pivot (50) such that the shaft (20), the bushing (30), or both are able to rotate to the aligned position in the presence of the lateral load.

The balancing members (60) are equally distributed on the both sides of the pivot (50). In other words, equal number of the washers (80) is installed on the both sides of the pivot (50). One side of the pivot (50) of the preload of the balancing members (60) is adapted to equalize the other side of the pivot (50) of the preload of the balancing members (60). In the presence of the lateral load, one side of the pivot (50) of the balancing members (60) compresses whilst the other side of the pivot (50) of the balancing members (60) extends such that the bushing (30) is able to rotate about the pivot (50). The bushing (30) rotates about the pivot (50) for example at an arbitrary angle Θ/2 in the form of a knife-edge bearing as shown in FIG. 2. In the absence of the lateral load, the balancing members (60) equalize on the both sides of the pivot (50) such that the balancing members (60) rotate the bushing (30) to the aligned position. While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.

Claims

1 . An alignment device (100, 101 ) comprising:

a moving member (20);

a guiding member (30) for guiding the moving member (20); and

a plurality of balancing members (60) for moving the moving member (20) to an aligned position.

2. An alignment device (100, 101 ) as claimed in Claim 1 wherein the alignment device (100, 101 ) is mounted in a housing (10).

3. An alignment device (100, 101 ) as claimed in Claim 2 wherein the moving member (20) is a shaft (20), and the guiding member (30) is a bushing (30) having a bore (40); the shaft (20) is mounted through the housing (10) and the guiding member (30); and the shaft (20) rotates or reciprocates about the bore (40).

4. An alignment device (100, 101) as claimed in Claim 3 wherein the alignment device (100, 101 ) is for preventing the shaft (20) from misaligning due to a lateral load.

5. An alignment device (100, 101 ) as claimed in Claim 4 wherein the bushing (30) rotates such that the shaft (20), the bushing (30), or both (20 & 30) are able to rotate to the aligned position in the presence of the lateral load. '

6. An alignment device (100, 101 ) as claimed in Claim 5 wherein the balancing members (60) are equally distributed around the bushing (30).

7. An alignment device (100, 101 ) as claimed in Claim 6 wherein the balancing members (60) equalize with one another around the bushing (30); in the presence of the lateral load, a portion of the balancing members (60) compresses whilst the other portion of the balancing members (60) extends such that the bushing (30) is able to rotate; and in the absence of the lateral load, the balancing members (60) equalize around the bushing (30) such that the balancing members (60) rotate the bushing (30) to the aligned position.

8. An alignment device (100, 101 ) as claimed in Claim 7 wherein the balancing members (60) each comprise a plurality of washers (80), and a fastener (70) extended through the washers (80); and the fastener (70) is for connecting the bushing (30) to the housing (10).

9. An alignment device (100, 101 ) as claimed in Claim 8 further comprising a plurality of clearances (90) formed on the housing (10) or positioned between the housing (10) and the bushing (30) for allowing the bushing (30) to rotate.

10. An alignment device (100, 101 ) as claimed in Claim 9 wherein the washers (80) each are a Belleville washer.

1 1. An alignment device (100, 101 ) as claimed in Claim 10 wherein the clearances (90) are selected in a group consisting of angular clearances, radial clearances, and both.

12. An alignment device (100, 101 ) as claimed in Claim 1 1 wherein the shaft (20) or the bushing (30) is allowed to rotate in one plane, the plane of rotation is the plane where the lateral load is acting, and the bushing (30) is allowed to rotate such that the bending of the shaft (20) is reduced or eliminated.

13. An alignment device (100, 101 ) as claimed in Claim 2 further comprising a tilting member (50) for tilting the moving member (20) about an axis perpendicular to the lengthwise extent of the moving member (20).

14. An alignment device (100, 101 ) as claimed in Claim 13 wherein the tilting member (50) is a pivot (50) formed on the bushing (30); and the bushing (30) rotates about the pivot (50) on the housing (10).

15. An alignment device (100, 101 ) as claimed in Claim 14 wherein the bushing (30) rotates about the pivot (50) such that the shaft (20), the bushing (30), or both are able to rotate to the aligned position in the presence of the lateral load.

16. An alignment device ( 00, 101 ) as claimed in Claim 15 wherein the balancing members (60) are equally distributed on the both sides of the pivot (50).

17. An alignment device (100, 101 ) as claimed in Claim 16 wherein one side of the pivot (50) of the preload of the balancing members (60) equalizes the other side of the pivot (50) of the preload of the balancing members (60); in the presence of the lateral load, one side of the pivot (50) of the balancing members (60) compresses whilst the other side of the pivot (50) of the balancing members (60) extends such that the bushing (30) is able to rotate about the pivot (50); and in the absence of the lateral load, the balancing members (60) equalize on the both sides of the pivot (50) such that the balancing members (60) rotate the bushing (30) to the aligned position.

18. An alignment device (100, 101 ) as claimed in Claim 17 wherein the balancing members (60) comprise a plurality of washers (80), and a fastener (70) extended through the washers (80); and the fastener (70) is for connecting the bushing (30) to the housing (10).

19. An alignment device (100, 101 ) as claimed in Claim 18 further comprising a plurality of clearances (90) formed on the housing (10) or positioned between the housing (10) and the bushing (30) for allowing the bushing (30) to rotate.

20. An alignment device (100, 101 ) as claimed in Claim 19 wherein the washers (80) each are a Belleville washer.

21 . An alignment device (100, 101 ) as claimed in Claim 20 wherein the clearances (90) are selected in a group consisting of angular clearances, radial clearances, and both.

22. An alignment device (100, 101 ) as claimed in Claim 21 wherein the bushing (30) rotates about the pivot (50) in such a manner that is similar to a knife-edge bearing.

23. An alignment device (100) as claimed in Claim 22 wherein the shaft (20) or the bushing (30) is allowed to rotate in one plane, the plane of rotation is the plane where the lateral load is acting, and the bushing (30) is allowed to rotate such that the bending of the shaft (20) is reduced or eliminated.