GB1583615A - Shaft coupling - Google Patents

Description

(54) SHAFT COU PLING (71) We, RINGFEDER GmbH, of D-41 50 Krefeld-Uerdingen Duisburgerstrasse 45, Federal Republic of Germany, a German Company, 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 an improvement in the coupling disclosed in British Patent Application 10604/77 (Serial No. 1528894) which concerns a non-positive, rigidly acting shaft coupling with a sleeve which extends over facing shaft ends and can be upset thereon. Compression rings, which are axially slidable by means of oppositely directed stressing screws and have conical surfaces, are provided for upsetting the sleeve onto the shafts, and each side of the sleeve is provided with a conical surface, each conical surface being constructed to receive a compression ring which has a correspondingly constructed conical surface. The sleeve is provided in its middle region with a collar having tapped bores and in which the stressing screws for each of the compression rings are retained.

Often the slipping of the shafts cannot be prevented in the event of incorrect use of the shaft coupling, for example, due to faulty installation or overloading in operation. Relative motion in the axial direction can occur between a respective shaft and the sleeve on the slipping side of the join; in an extreme case of shafting comprising a plurality of vertically arranged shafts it is even possible for the shafting situated below the slipping place to wind itself out of the coupling by virtue of its own dead weight.

It is therefore an object of the invention and its embodiments to provide a shaft coupling which allows axial fixing of the sleeve and the two shafts to counteract the effects of slipping.

The present invention provides a shaft coupling which comprises a cylindrical sleeve for receiving two shaft ends and having two coaxial frusto-conical radially outer surfaces and an axially central flanged portion, the two frusto-conical surfaces tapering from said central flange portion; each frustoconical outer surface being provided with as associated compression ring having a radially inner frusto-conical surface complementary to the associated frusto-conical radially outer surface; each compression ring being provided with one, two or more stressing screws, said central flanged portion being adapted for screw-threaded engagement with said one, two or more stressing screws for urging said each compression ring towards the central flanged portion in use of the coupling and thereby stressing the sleeve onto the shaft ends, and a connecting socket adapted to be secured against axial movement to the inside of the sleeve for holding together the shaft ends.

To enable the connecting socket to be secured easily on the sleeve side, one embodiment of the invention provides that the collar i.e. the central flanged portion contains at least one radially oriented tapped bore into which a screwthreaded stud is inserted to cooperate with the connecting socket. Preferably the connecting socket is split into two halfshells. In order to fix the half-shells to the sleeve, the connecting socket is provided with a circumferential groove in the interests of simplicity of manufacture and it is recommended to provide the collar with three screw which are circumferentially offset by 1200 relative to each other. This also ensures that at least one screw engages with each halfshell at a place outside the joints.

According to another feature of the invention the connecting socket can be readily attached to both shaft ends by providing each axial end of the connecting socket with a circumferentially extending lip which engages in a groove formed in the end of a respective shaft.

In another embodiment of the invention the width of the collar of the sleeve and the width of the connecting socket are so dimensioned in relation to each other that the sleeve is stressed onto the shaft in a region outside the respective grooves, so that the whole cross-section of such grooved shafts can be utilized for transmitting power from one shaft to the other. Thus, the presence of the connecting socket does not detract from the load transmission capacity of the coupling.

Thus, the invention advantageously provides a shaft coupling which prevents axial relative motion between the sleeve and the two shafts in the event of slipping, so that substantially improved operational reliability is obtained.

An embodiment of the invention is described hereinbelow with reference to the accompanying drawing. The illustration shows an axial section through a shaft coupling having a sleeve 1 and two compression rings 2 whose conical surfaces 2a are stressed to bear against the corresponding conical surfaces la of the sleeve 1, so that corresponding regions of the internal wall lf of the sleeve 1 are pressed against the shafts 6, 6a for the purpose of transmitting power. Stressing is achieved by means of screws (not shown) which extend through bores in the compression rings 2 and are retained in screwedthreaded engagement in collar 1c of the sleeve 1.

A connecting socket 7 comprising two half-shells is provided in the region of the collar lc of the sleeve 1 and is secured thereon by three screwed studs 8 uniformly distributed around the circumference of the sleeve and extending into a groove 7a of the socket 7.

Each side of the connecting socket 7 is provided with a circumferential lip 7b which engages in a groove 9 formed on a respective shaft end. Since the grooves 9 are situated in the region below the collar lc, i.e. outside those regions of the sleeve which are deformed for the purpose of transmitting torque it follows that the full shaft crosssections are available for transmitting power from one shaft to the other.

WHAT WE CLAIM IS: 1. A shaft coupling which comprises a cylindrical sleeve for receiving two shaft ends and having two coaxial frusto-conical radially outer surfaces and an axially central flanged portion the two frusto-conical surfaces tapering from said central flange portion; each frusto-conical outer surface being provided with an associated compression ring having a radially inner frustro-conical surface complementary to the associated frustoconical radially outer surface; each compression ring being provided with one, two or more stressing screws, said central flanged portion being adapted for screw-threaded engagement with said one, two or more stressing screws for urging said each compression ring towards the central flanged portion in use of the coupling and thereby stressing the sleeve onto the shaft ends; and a connecting socket adapted to be secured against axial movement to the inside of the sleeve for holding together the shaft ends.

2. A coupling according to claim 1, wherein the central flanged portion has at least one radially oriented tapped bore in which there is a screw stud for securing against axial movement the connecting socket to the sleeve.

3. A coupling according to claim 1 or 2, wherein the connecting socket is provided at each axial end with a circumferentially extending lip for engagement with a groove formed in a respective shaft end; the connecting socket being formed as half-shells to allow engagement of the lip in the respective groove.

4. A coupling according to claim 3, wherein the width of the central flanged portion of the sleeve and the width of the connecting socket are so dimensioned in relation to each other that the sleeve is stressed onto the shaft ends in a respective axially outer region beyond the groove in the shaft end.

5. A non-positive rigidly acting shaft coupling substantially as herein described with reference to the accompanying drawing.

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

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. Thus, the invention advantageously provides a shaft coupling which prevents axial relative motion between the sleeve and the two shafts in the event of slipping, so that substantially improved operational reliability is obtained. An embodiment of the invention is described hereinbelow with reference to the accompanying drawing. The illustration shows an axial section through a shaft coupling having a sleeve 1 and two compression rings 2 whose conical surfaces 2a are stressed to bear against the corresponding conical surfaces la of the sleeve 1, so that corresponding regions of the internal wall lf of the sleeve 1 are pressed against the shafts 6, 6a for the purpose of transmitting power. Stressing is achieved by means of screws (not shown) which extend through bores in the compression rings 2 and are retained in screwedthreaded engagement in collar 1c of the sleeve 1. A connecting socket 7 comprising two half-shells is provided in the region of the collar lc of the sleeve 1 and is secured thereon by three screwed studs 8 uniformly distributed around the circumference of the sleeve and extending into a groove 7a of the socket 7. Each side of the connecting socket 7 is provided with a circumferential lip 7b which engages in a groove 9 formed on a respective shaft end. Since the grooves 9 are situated in the region below the collar lc, i.e. outside those regions of the sleeve which are deformed for the purpose of transmitting torque it follows that the full shaft crosssections are available for transmitting power from one shaft to the other. WHAT WE CLAIM IS:

1. A shaft coupling which comprises a cylindrical sleeve for receiving two shaft ends and having two coaxial frusto-conical radially outer surfaces and an axially central flanged portion the two frusto-conical surfaces tapering from said central flange portion; each frusto-conical outer surface being provided with an associated compression ring having a radially inner frustro-conical surface complementary to the associated frustoconical radially outer surface; each compression ring being provided with one, two or more stressing screws, said central flanged portion being adapted for screw-threaded engagement with said one, two or more stressing screws for urging said each compression ring towards the central flanged portion in use of the coupling and thereby stressing the sleeve onto the shaft ends; and a connecting socket adapted to be secured against axial movement to the inside of the sleeve for holding together the shaft ends.

2. A coupling according to claim 1, wherein the central flanged portion has at least one radially oriented tapped bore in which there is a screw stud for securing against axial movement the connecting socket to the sleeve.

3. A coupling according to claim 1 or 2, wherein the connecting socket is provided at each axial end with a circumferentially extending lip for engagement with a groove formed in a respective shaft end; the connecting socket being formed as half-shells to allow engagement of the lip in the respective groove.

4. A coupling according to claim 3, wherein the width of the central flanged portion of the sleeve and the width of the connecting socket are so dimensioned in relation to each other that the sleeve is stressed onto the shaft ends in a respective axially outer region beyond the groove in the shaft end.

5. A non-positive rigidly acting shaft coupling substantially as herein described with reference to the accompanying drawing.