GB1573780A

GB1573780A - Universal coupling

Info

Publication number: GB1573780A
Application number: GB4673077A
Authority: GB
Original assignee: Voith Transmit GmbH
Current assignee: Voith Transmit GmbH
Priority date: 1976-11-15
Filing date: 1977-11-09
Publication date: 1980-08-28
Also published as: IT1091045B; DE2652024C3; DE2652024B2; BE860796A; DE2652024A1

Description

(54) UNIVERSAL COUPLING (71) We, VOITH TRANSMIT GMBH of Viktoriastrasse 16-18 D-43 30 Mülheim/Ruhr, West Germany a Company of the German Federal Republic, do hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to a method for installing a bearing in a universal coupling of the so-called "Hooke's Joint" type. The invention also relates to couplings assembled by this method.

In particular, the Hooke's Joint couplings envisaged here are of the heaviest type of construction, such as are used to drive rolling mills for example, and whose greatest extemal diameter, known as the diameter of rotation, can amount to more than one metre.

In known Hooke's Joint couplings of this kind (see, for example, the Publication Antriebstechnik 1974, pp. 94 to 100) the coupling forks are invariably made in more than one piece i.e. each fork eye is divided across a diametre so that one half of the fork eye can be removed from the coupling fork like a bearing cap. This means that the assembly of the Hooke's Joint coupling can be effected by first mounting the complete bearing assemblies (bearing sleeves with the rolling elements, generally rollers, located in them) on the pins of the crosspiece, and then inserting the crosspiece, together with the bearings, successively into the two coupling forks, after which each of the fork-eye halves are bolted to the coupling fork. The installation of the bearings and the assembly of the coupling is thus a relatively simple operation in this case. It is also possible to replace a bearing, for example, at the site where the coupling is used, without the entire coupling shaft having to be removed from the drive line.

However, a particular disadvantage of known Hooke's Joint couplings lies in the fact that the coupling forks lose much of their rigidity by being made in more than one piece, so that there is always a danger that where large torques are being transmitted, the coupling forks will be deformed, and with them the bearing housings as well, resulting in a consequent reduction in the working life of the bearings.

For this reason, attempts have been made to construct Hooke's Joint couplings, even of the largest size, with one-piece coupling forks.

In this case, however, the installation of the bearings and the assembly of the coupling must be carried out by radically different means than is the case with Hooke's Joint couplings with split coupling forks. Thus, it is first necessary to insert the crosspiece into one of the coupling forks without the bearings, and then the bearings are pressed in and simultaneously pushed onto the crosspiece from the outside, in a direction parallel to the axis of the bearing. It is already known (from German Patent Specification No. 15 27 557) for a special pressing-in device to be used for inserting the bearings into the fork eyes. However, the known pressing-in device is unsuitable for couplings of the largest size, since the dimensions of the pressing-in device are considerably greater than those of the Hooke's Joint coupling. Naturally, it would also be possible to produce a pressing-in device of this kind for Hooke's Joint couplings of the larger sizes. However, such a device would then have the disadvantage, apart from the expense of construction, that it could only be used on the production site for the assembly of Hooke's Joint couplings, but not to replace a bearing at the site where the Hooke's Joint coupling was in service. Since such a device would be extremely large and heavy it would be impracticable to transport it to the site of the Hooke's Joint coupling installation.

The invention therefore seeks to devise a method ob installing a bearing in Hooke's Joint couplings of the larger sizes, which have one-piece coupling forks, using easily transportable equipment.

According to one aspect of this invention, a method for assembling a universal coupling of the Hooke's Joint type, said method serving to mount two opposing pins of a crosspiece having four pins, into the two fork eyes of a one-piece coupling fork, and to mount a bearing having a bearing sleeve and serving for pivotably supporting one of the pins in the respective fork eye, is characterised in that a tie rod is inserted in a bore which is situated in the crosspiece and extends along the axes of the opposing pins, said tie rod passing through a central bore in the bearing sleeve which appertains to the cne fork eye and being supported on the other fork eye, after which the bearing sleeve is pressed into the fork eye appertaining to it with the aid of a pressing device attached to the tie rod.

Such a method can be used both for replacing a single bearing and for assembling the Hooke's Joint coupling from its separate component parts. A requirement for the ap plication of the method according to the in vention is that the crosspiece should have two bores extending along the axes of the pins, and also that each bearing sleeve should have a central bore. A Hooke's Joint coupling with these features is already known from German Gebrauchsmuster Specification No. 69 08 115.

However, in that instance, these bores are used only for holding or topping-up lubricant.

The essence of the present invention con sists in giving the known lubrication bores an additional function, and in modifying them in such a way that they can be used for the introduction of a tie rod. For this purpose, the small diameter of the existing bores must be increased. Initially, there were doubts about this, since the pins in the crosspiece are subjected to a high level of bending stress.

However, the cross-section of the pin is only weakened in the vicinity of the neutral axis when the bore diameter is increased, so that its bending strength is only slightly reduced.

With the aid of the tie rod the pressing-in of the bearing housing can be accomplished in a simple manner, for example, by using a normal commercial hydraulic press or merely by using a nut screwed onto the tie rod.

A tie rod of this type must extend right through the entire Hooke's Joint coupling.

However, since it is only subject to pure tension during the pressing-in operation, its cross-section need not be very large. This means that the tie rod will be light in weight and thus easily transportable, whereas, if an assembly tool with two or three gripping arms to grip the coupling forks round the outside were to be used, (thus, the said bores would not be required), such gripping arms would be loaded in the bending direction and thus would have to be of such heavy construction that the assembly tool could only be trans ported to the installation site with difficulty and used there with the aid of a hoist.

According to another aspect of this in vention, a universal coupling of the Hooke's Joint type assembled according to the method of the said one aspect of the invention, said coupling having two one-piece coupling forks and a crosspiece with four pins, which is pivotably mounted by means of a bearing with a bearing sleeve in each of the fork eyes of the coupling forks, the crosspiece having two bores extending along the axes of the pins, and the base of each bearing sleeve having a central bore, is characterised in that the diameter of the bores in the crosspiece amounts to around 0.25 times to 0.4 times the external diameter of the pins.

In order that the invention may be readily understood and further features made apparent the assembly of a Hooke's Joint coupling will now be described, by way of example, with reference to the accompanying drawing which shows a longitudinal crosssection of the coupling, one of the two coupling forks being omitted from the drawing for clarity.

The coupling fork which is shown is given the reference numeral 10, its fork eyes are 11 and 12, and the crosspiece is 13. Three of the four cross pins of the crosspiece 13 are shown and are designated 14, 15 and 16. The crosspiece 13, previously inserted in the coupling fork 10, rests temporarily in a guide sleeve 17 inserted in the (lower) fork eye 12, in order thus to centre the crosspiece 13. For this, a two-part spacer ring 19 can be provided between a collar 18 on the guide sleeve 17 and the fork eye 12. The thickness of this ring can be chosen so that the crosspiece 13 is arranged initially a little off-centre (relative to the axis of rotation 7), being nearer to the lower fork eye 12 by an amount a.

For mounting the cross pin 14 in the (upper) fork eye 11 there is a multi-row roller bearing with a bearing sleeve 20, shown in the drawing being pressed into the fork eye. For this purpose, a pressure plate 21 is placed on the bearing sleeve 20 with the cylinder 22 of a so-called trunk piston press resting on it. Its piston 23 is hollow, i.e.

it has a central bore into which a tie rod 24 is inserted. In the drawing this tie rod has previously passed through a threaded bore 9 in the bearing sleeve 20 (this bore is sealed off when assembly has been completed) and through a bore 25 in the crosspiece 13, and is screwed into the guide sleeve 17. The guide sleeve thus also serves to support the tie rod 24 against the lower fork eye 12 of the coupling fork 10. The piston 23 is supported on the tie rod 24 via a nut 26. To enable the tie rod 24 to be inserted, the diameter d of the bore 25 and of the threaded bore 9 is greater than in previously known Hooke's Joint couplings; it amounts to around 0.25 times to 0.4 times the external diameter D of the cross pins 14, 15, 16.

When the cylinder 22 is supplied with pressure, the piston 23 moves upwards relative to the cylinder, pressing the bearing sleeve 20 in until it rests on the cross pin 14. To secure the bearing sleeve 20 in the fork eye 11 a circlip can be inserted in an annular groove 27. In this case it is advisable, after the spacer ring 19 has been removed and with the cylinder supported directly on the fork eye 11, to press the bearing sleeve 20, together with the crosspiece 13, against the circlip by loading the piston 23 in the reverse direction. After this, the press 21 to 23, the tie rod 24 and the sleeve 17 are removed.

When the other bearing sleeve is installed in the fork eye 12, the crosspiece 13 has already been centred by the previously inserted bearing. For this reason, the guide sleeve 17 is now inserted in the coupling fork upside down, i.e. by its seat 17a, since it only serves now to support the tie rod 24 against the coupling fork.

After this, the crosspiece 13 and the other coupling fork (not shown in the drawing) are assembled together in the same way as described above.

Dismantling of a bearing can also be carried out with the aid of the trunk piston press 22, 23, and with a tie rod screwed into the threaded bore 9 in the bearing sleeve 20. For this purpose, the base 8 of the bearing sleeve is made with considerably thicker walls than in previously known Hooke's Joint couplings so that as the bearing sleeve is drawn out it is not permanently deformed by the tension exerted by the tie rod. Preferably, the wall thickness of the base 8 will amount to around 1/10 of the external diameter of the bearing sleeve 20.

WHAT WE CLAIM IS:- 1. A method for assembling a universal coupling of the Hooke's Joint type, said method serving to mount two opposing pins of a crosspiece having four pins, into the two fork eyes of a one-piece coupling fork, and to mount a bearing having a bearing sleeve and serving for pivotably supporting one of the pins in the respective fork eye, characterised in that a tie rod is inserted in a bore which is situated in the crosspiece and extends along the axes of the opposing pins, said tie rod passing through a central bore in the bearing sleeve which appertains to the one fork eye and being supported on the other fork eye, after which the bearing sleeve is pressed into the fork eye appertaining to it with the aid of a pressing device attached to the tie rod.

2. A method according to Claim 1, characterised in that, for the installation of the bearing sleeve, the crosspiece is centred with the other fork eye by temporarily inserting a guide sleeve therein, the guide sleeve serving at the same time to support the tie rod on the coupling fork.

3. A method according to. Claim 2, characterised in that, during its centering in the other fork eye, the cross piece is arranged initially off-centre by a given amount from the axis of rotation of the coupling fork so as to be nearer to the other fork eye, and the bearing sleeve is pressed in deeper by this amount into one fork eye, and in that, after securing the bearing sleeve relative to the axis of rotation of the coupling form, the crosspiece together with the bearing sleeve is brought into the central position by means of the tie rod.

4. A universal coupling of the Hooke's Joint type assembled according to any one of claims 1 to 3, said coupling having two one-piece coupling forks and a crosspiece comprising four pins, each of which is pivotably mounted by means of a bearing with a bearing sleeve in a respective fork eye of a coupling fork, the crosspiece having two bores extending along the axes of opposing pins, and the base of each bearing sleeve having a central bore, characterised in that the diameter of the bores in the crosspiece amounts to around 0.25 times to 0.4 times the external diameter of the pins.

5. A method of assembling a universal coupling of the Hooke's Joint type, substantially as hereinbefore described with reference to the accompanying drawing.

6. A universal coupling of the Hooke's Joint type, constructed and arranged substantially as hereinbefore described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

11 a circlip can be inserted in an annular groove 27. In this case it is advisable, after the spacer ring 19 has been removed and with the cylinder supported directly on the fork eye 11, to press the bearing sleeve 20, together with the crosspiece 13, against the circlip by loading the piston 23 in the reverse direction. After this, the press 21 to 23, the tie rod 24 and the sleeve 17 are removed.

When the other bearing sleeve is installed in the fork eye 12, the crosspiece 13 has already been centred by the previously inserted bearing. For this reason, the guide sleeve 17 is now inserted in the coupling fork upside down, i.e. by its seat 17a, since it only serves now to support the tie rod 24 against the coupling fork.

After this, the crosspiece 13 and the other coupling fork (not shown in the drawing) are assembled together in the same way as described above.

Dismantling of a bearing can also be carried out with the aid of the trunk piston press 22, 23, and with a tie rod screwed into the threaded bore 9 in the bearing sleeve 20. For this purpose, the base 8 of the bearing sleeve is made with considerably thicker walls than in previously known Hooke's Joint couplings so that as the bearing sleeve is drawn out it is not permanently deformed by the tension exerted by the tie rod. Preferably, the wall thickness of the base 8 will amount to around 1/10 of the external diameter of the bearing sleeve 20.

WHAT WE CLAIM IS:- 1. A method for assembling a universal coupling of the Hooke's Joint type, said method serving to mount two opposing pins of a crosspiece having four pins, into the two fork eyes of a one-piece coupling fork, and to mount a bearing having a bearing sleeve and serving for pivotably supporting one of the pins in the respective fork eye, characterised in that a tie rod is inserted in a bore which is situated in the crosspiece and extends along the axes of the opposing pins, said tie rod passing through a central bore in the bearing sleeve which appertains to the one fork eye and being supported on the other fork eye, after which the bearing sleeve is pressed into the fork eye appertaining to it with the aid of a pressing device attached to the tie rod.
2. A method according to Claim 1, characterised in that, for the installation of the bearing sleeve, the crosspiece is centred with the other fork eye by temporarily inserting a guide sleeve therein, the guide sleeve serving at the same time to support the tie rod on the coupling fork.
3. A method according to. Claim 2, characterised in that, during its centering in the other fork eye, the cross piece is arranged initially off-centre by a given amount from the axis of rotation of the coupling fork so as to be nearer to the other fork eye, and the bearing sleeve is pressed in deeper by this amount into one fork eye, and in that, after securing the bearing sleeve relative to the axis of rotation of the coupling form, the crosspiece together with the bearing sleeve is brought into the central position by means of the tie rod.
4. A universal coupling of the Hooke's Joint type assembled according to any one of claims 1 to 3, said coupling having two one-piece coupling forks and a crosspiece comprising four pins, each of which is pivotably mounted by means of a bearing with a bearing sleeve in a respective fork eye of a coupling fork, the crosspiece having two bores extending along the axes of opposing pins, and the base of each bearing sleeve having a central bore, characterised in that the diameter of the bores in the crosspiece amounts to around 0.25 times to 0.4 times the external diameter of the pins.
5. A method of assembling a universal coupling of the Hooke's Joint type, substantially as hereinbefore described with reference to the accompanying drawing.
6. A universal coupling of the Hooke's Joint type, constructed and arranged substantially as hereinbefore described with reference to the accompanying drawing.