GB2075151A

GB2075151A - Flexible couplings

Info

Publication number: GB2075151A
Application number: GB8113488A
Authority: GB
Original assignee: Koppers Co Inc
Current assignee: Beazer East Inc
Priority date: 1980-05-05
Filing date: 1981-05-01
Publication date: 1981-11-11
Also published as: ZA812205B; IT8148396A0; FR2481769A1; CA1178074A; DE3113813A1; JPS56156524A; IT1142422B; NL8101893A; GB2075151B

Abstract

A flexible coupling for transmitting drive from a driving shaft (14) to a driven hub (10) includes a driving hub (12) which is keyed to the shaft (14) by a key (16). The driving hub (12) has a plurality of blades (20) fixed to its outer circumference, and, disposed between these blades (20) and a plurality of segments (28), are a plurality of cylindrical elements (24) made of elastomeric material. Thus, rotation of the shaft (14) will cause rotation of the driving hub (12) and the blades (20), and torque will be transmitted from the blades (20) to the elastomeric elements (24) and then to the segments (28). The driven hub (10) is fixed relative to the segments (28). The blades (20) may be integral with the hub (12). <IMAGE>

Description

SPECIFICATION Improvements in or relating to flexible couplings This invention relates to flexible couplings and more particularly, is concerned with flexible couplings in which torque is transmitted between two rotatable members by means of elastomeric elements in compression.

Flexible couplings for transmitting torque between misaligned driving.and driven members by means of elastomeric elements in compression are well known, see U.S. Patent Specification No. 28,873,590. Such couplings have demonstrated the ability not only to compensate for misalignment between the driving and driven members but also to protect the driving and driven members from shock loading and vibration. While over the years these couplings have given good service in the field, assembly and disassembly is a difficult problem because the elastomeric elements must be inserted in the cavity formed by the sleeve and hub axially and be precompressed during the process of insertion. This problem of precompression during insertion becomes increasingly severe as the size of the coupling increases.Also, if the coupling must be disassembled, as is the case when the coupled machinery is to be replaced, all the elastomeric elements are normally damaged in the process and must be replaced, thereby increasing the cost of maintenance. Further, the cost of these types of couplings has always been relatively high. For the foregoing reasons these flexible couplings have not achieved the degree of acceptance in industry that the performance and reliability they provide would suggest they should.

According to the present invention, there is provided a flexible coupling suitable for transmitting torque between driving and driven members, comprising (a) a plurality of elastomeric elements; (b) first hub means adapted to be mounted on one of said driving and driven members, said first hub means having a plurality of blade means engaging said elastomeric elements; (c) sleeve means comprising a plurality of segments, each of said segments being adapted to maintain a plurality of said elastomeric elements in engagement with a blade means of said first hub means; (d) retainer means adapted to engage said segments of said sleeve means; and (e) second hub means adapted to be mounted on the other of said driving and driven members, said second hub means being adapted to engage said segments of said sleeve means and being fixed to said retainer means whereby rotation of said hub means mounted on said driving member will cause rotation of the other hub means through said elastomeric elements.

The present invention also provides a flexible coupling suitable for transmitting torque between driving and' driven members, comprising (a) a plurality of elastomeric elements; (b) first hub means adapted to be mounted on one of said driving and driven members, said first hub means having a plurality of blade means engaging said elastomeric elements; (c) first sleeve means comprising a plurality of segments, each of said segments being adapted to maintain a plurality of said elastomeric elements in engagement with a blade means of said first hub means; (d) first retainer means adapted to engage said segments of said first sleeve means; (e) second hub means adapted to be mounted on the other of said driving and driven members, said second hub means having a plurality of blade means adapted to engage said elastomeric elements; (f) second sleeve means comprising a plurality of segments, each of said segments being adapted to maintain a plurality of said elastomeric elements in engagement with a blade means of said second hub means; (g) second retainer means adapte.d to engage said segments of said second sleeve means; and (h) plate means adapted to engage said segments of said first and second sleeve means and being fixed to said first and second retainer means, whereby rotation of said hub means mounted on said driving member will cause rotation of the other hub means through said elastomeric elements.

The present invention further provides a flexible coupling suitable for transmitting torque from a flywheel to a driven shaft, comprising (a) a plurality of elastomeric elements; (b) first hub means adapted to be fixed to the driven shaft, said first hub having a plurality of blade means adapted to engage said elastomeric elements; (c) sleeve means comprising a plurality of segments, each of said segments being adapted to maintain a plurality of said elastomeric elements in engagement with a blade means of said first hub means; (d) retainer means adapted to engage said segments of said sleeve; and (e) adaptor means adapted to be fixed to said flywheel, said adaptor means being adapted to engage said segments of said sleeve means and being fixed to said retainer means whereby rotation of said flywheel will cause rotation of said shaft through said elastomeric elements.

The present invention further provides a flexible coupling suitable for transmitting torque between a driving and driven shaft by means of elastomeric elements in precompression, comprising a sleeve means for retaining said elastomeric elements in contact with a hub means comprising (a) a central core adapted to be fixed to one of said shafts, and (b) blade means comprising segments fixed to outer surface of said central core.

The present invention further provides a flexible coupling suitable for transmitting torque between a driving and driven shaft by means of elastomeric elements in precompression, comprising a hub means having a plurality of blade means and a sleeve means comprising a plurality of segments adapted to maintain a plurality of said elastomeric elements in contact with a blade means of said hub means.

For a better understanding of the invention, and to show more clearly how the same may be carried out, reference will now be made, by way of example, to the accompanying drawings in which.

Figure 1 is an isometric view of a coupling of the present invention in the process of being assembled; Figure 2 is a fragmentary end view, in section, of the coupling of Fig. 1; Figure 3 is a fragmentary side view, in section, of the coupling of Fig. 1; Figure 4 is a fragmentary side view, in section, of another coupling of the present invention; Figure 5 is a fragmentary side view, in section, of another coupling of the present invention, and Figure 6 is a fragmentary end view, in section, of another coupling of the present invention.

Referring to Figs. 1 to 3, the coupling shown, generally designated 10, includes a hub 12 which is made of steel and is keyed to a shaft 14 by means of a key 16. Fixed to the hub 12, each by a weld 18, are a plurality of blades 20. (It is to be understood that a cast hub can be used in place of this fabricated hub.) In the illustrated embodiment, the hub 12 has five blades 20, but the hub 12 may have fewer or more blades. Each blade 20 is adapted to abut the adjoining blade 20 at an interface 2; and each blade 20 is of like length and width.

The coupling 10 further comprises a sleeve element comprising a plurality of cylindrical segments 28. Cylindrical segments 28 have a section formed of three arcs and two lines. In the illustrated embodiment, since the hub 12 has five blades 20, the sleeve element comprises five cylindrical metallic segments 28.

The cylindrical segments 28 have the same axial length as each other, which axial length is at least as great as that of blades 20. End faces 33 and 34 of segments 28 must be parallel to each other and perpendicular to the outer periphery 35 thereof. Each of the segments 28 is placed around the blades 20 of the hub 12 as shown in Fig. 1. The segments 28 are constructed so that the angle between straight portions 29 thereof is slightly less than 360 divided by 5, it being understood that if more or less than five segments are used then the angle between the straight portions will be slightly less than 3603 divided by the number of elements.This will ensure that when the segments 28 and the blades 20 are assembled around the hub 12 as described below, the segments 28 will contact in the area of tips 31 thereof, but when the coupling is finally assembled the straight portions 29 will mate and form an interface 30 of significant area.

The coupling 10 further comprises a plurality of elastomeric elements 24 which, in the illustrated embodiment, are solid cylinders of an elastomeric material, such as rubber. When a pair of elastomeric elements 24 is inserted in each segment 28, and the segments 28 are placed around the blades 20 of the hub 12, a small amount of precompression is created in each element 24. After assembling the segments 28 and elastomeric elements 24 around the blades 20, the assembled hub member is placed between a retainer ring 26 and a rigid hub 36. However, the retainer ring 26 is independent of the hub 12 and the shaft 14. The rigid hub 36 is mounted on a driven shaft 46. The assembled hub member is now clamped between the retainer ring 26 and the rigid hub 36 by means of bolts 40 which extend through openings 42 in the rigid hub 36 and openings 44 in a retainer ring 26.In the illustrated embodiment, five bolts are used for symmetry with the blades 20 of the hub 12 and the segments 28.

However, different numbers of bolts could be used.

The retainer ring 26 and the rigid hub 36 have mirror image chamfers 32 and 38. Because of the chamfers 32 and 38 and the clamping effect caused by the bolts 40, the segments 28 move radially toward the axis of the coupling, so compressing the elastomeric elements 24, in the course of clamping.

Whereas the segments 28 are rigidly clamped between the retainer ring 26 and the rigid hub 36 by reason of the contact with faces 33 and 34, the hub 12 is free to move, within limits, in the axial, radial and angular directions so that the coupling can accommodate misalignment between the driving shaft 14 and the driven shaft 46.

Rotation of the shaft 14 will cause rotation of the hub 1 2 and the blades 20. Torque will be transmitted from the blades 20 to the elastomeric elements 24 and then to the segments 28, which are fixed to the rigid hub 36. The torque will thus cause rotation of the hub 36 and the shaft 46.

An alternative embodiment of the coupling is shown in Fig. 4, wherein two couplings are used to correct relatively large misalignments.

This arrangement is known in the art as "full flex". In this embodiment, a driving hub 12 transmits torque to a driven hub 48 through two coupling as described with reference to Figs. 1 to 3 except that the rigid hub 36 is replaced by a common interconnecting plate 50. The bolts 40 of each coupling are threaded in staggered and tapped holes 52 in the plate 50. The plate 50 has chamfered guide surfaces 54 and 56 on its two sides to radially move the segments as previously described. In order to maintain a reasonable dynamic balance, guide bushings 56 may be used between the retainer rings 26 and the hubs 12 and 48.

Another embodiment of the coupling of the present invention, for use in connection with an internal combustion engine, is shown in Fig. 5. This coupling is mounted on the engine's flywheel 58, and an adaptor 60 is bolted to the flywheel 58 in a conventional manner. The adaptor 60, which acts as a rigid hub, is provided with chamfered guide surfaces 62 and tapped holes 64.-The segments 28 are fitted in the same manner as previously described, using the retainer ring 26 and the bolts 40, which have hexagonal heads 65. The torque from the flywheel is thus transmitted to the shaft 14 through the hub 12.

The coupling of the present invention can be embodied in a configuration other than a circular one. One such configuration is illustrated in Fig. 6.

If desired, in any embodiment of the present invention, a continuous circumferential band 66 can be welded to the outside circumference of the elements 28, as shown typically in Fig. 3. It will be understood, however, that by use of band 66, the advantage of radial assembly of the elastomeric elements is lost, but the cost benefit of the invention is retained.

The present invention, at least in the embodiments described with reference to the drawings and not having band 66, overcomes the foregoing problems of the prior art by providing a flexible coupling in which the elastomeric elements can be assembled into the coupling, or removed therefrom, radially.

The elastomeric elements are inserted into the sleeve segments and assembled radially over a hub blade without the need of the degree of precompression required by the prior art. This minimizes the problem of assembly and disassembly. Also, the cost of the coupling is significantly less. The sleeve element of the coupling is comprised of a plurality of segments adapted to retain the elastomeric elements in operable contact with the coupling hub, which is mounted on the driving or driven shaft. The individual segments of the sleeve are mated to the rigid hub, which is mounted on the driving or driven shaft, by means of a retainer ring. The retainer ring is fixed to the rigid hub by means of fasteners such as bolts.

Claims

1. A flexible coupling suitable for transmitting torque between driving and driven members, comprising (a) a plurality of elastomeric elements; (b) first hub means adapted to be mounted on one of said driving and driven members, said first hub means having a plurality of blade means engaging said elastomeric elements; (c) sleeve means comprising a plurality of segments, each of said segments being adapted to maintain a plurality of said elastomeric elements in engagement with a blade means of said first hub means; (d) retainer means adapted to engage said segments of said sleeve means; and (e) second hub means adapted to be mounted on the other of said driving and driven members, said second hub means being adapted to engage said segments of said sleeve means and being fixed to said retainer means whereby rotation of said hub means mounted on said driving member will cause rotation of the other hub means through said elastomeric elements.

2. A flexible coupling as claimed in claim 1, wherein said segments of said sleeve means are cylindrical in shape.

3. A flexible coupling as claimed in claim 1 or 2, wherein said retainer means and said second hub means have chamfered guide means for facilitating the compression of said elastomeric elements.

4. A flexible coupling as claimed in claim 1, 2 or 3, wherein the outside circumferences of said segments are operably connected.

5. A flexible coupling suitable for transmitting torque between driving and driven members, comprising (a) a plurality of elastomeric elements; (b) first hub means adapted to be mounted on one of said driving and driven members, said first hub means having a plurality of blade means engaging said elastomeric elements; (c) first sleeve means comprising a plurality of segments, each of said segments being adapted to maintain a plurality of said elastomeric elements in engagement with a blade means of said first hub means; (d) first retainer means adapted to engage said segments of said first sleeve means; (e) second hub means adapted to be mounted on the other of said driving and driven members, said second hub means having a plurality of blade means adapted to engage said elastomeric elements; (f) second sleeve means comprising a plurality of segments, each of said segments being adapted to maintain a plurality of said elastomeric elements in engagement with a blade means of said second hub means; (g) second retainer means adapted to engage said segments of said second sleeve means; and (h) plate means adapted to engage said segments of said first and second sleeve means and being fixed to said first and second retainer means, whereby rotation of said hub means mounted on said driving member will cause rotation of the other hub means through said elastomeric elements.

6. A flexible coupling as claimed in claim 5, wherein said segments of said first and second sleeve means are cylindrical in shape.

7. A flexible coupling as claimed in claim 5 or 6, wherein said first retainer means, said second retainer means and said plate means each have chamfered guide means for facilitating the compression of said elastomeric elements.

8. A flexible coupling as claimed in claim 7, wherein the outside circumferences of said segments of said first sleeve means are interconnected, and wherein the outside circumferences of said segments of said second sleeve means are interconnected.

9. A flexible coupling suitable for transmitting torque from a flywheel to a driven shaft, comprising (a) a plurality of elastomeric elements; (b) first hub means adapted to be fixed to the driven shaft, said first hub having a plurality of blade means adapted to engage said elastomeric elements; (c) sleeve means comprising a plurality of segments, each of said segments being adapted to maintain a plurality of said elastomeric elements in engagement with a blade means of said first hub means; (d) retainer means adapted to engage said segments of said sleeve; and (e) adaptor means adapted to be fixed to said flywheel, said adaptor means being adapted to engage said segments of said sleeve means and being fixed to said retainer means whereby rotation of said flywheel will cause rotation of said shaft through said elastomeric elements.

10. A flexible coupling as claimed in claim 9, wherein said segments of said sleeve means are cylindrical in shape.

11. A flexible coupling as claimed in claim 9 or 10, wherein said retainer means and said adaptor means have chamfered guide means for facilitating the compression of said elastomeric elements.

1 2. A flexible coupling as claimed in claim 9, 10 or 11, wherein the outside circumferences of said segments are operably connected.

1 3. A flexible coupling suitable for transmitting torque between a driving and driven shaft by means of elastomeric elements in precompression, comprising a sleeve means for retaining said elastomeric elements in contact with a hub means comprising (a) a central core adapted to be fixed to one of said shafts, and (b) blade means comprising segments fixed-to outer surface of said central core.

14. A flexible coupling suitable for transmitting torque between a driving and driven shaft by means of elastomeric elements in precompression, comprising a hub means having a plurality of blade means and a sleeve means comprising a plurality of segments adapted to maintain a plurality of said elastomeric elements in contact with a blade means of said hub means.

1 5. A flexible coupling substantially as hereinbefore described with reference to, and as shown in, Figs. 1, 2 and 3, or Fig. 4, or Fig. 5, or Fig. 6, of the accompanying drawings.