GB1592489A

GB1592489A - Torque convertors

Info

Publication number: GB1592489A
Application number: GB4955877A
Authority: GB
Original assignee: Brockhouse Transmissions Ltd
Current assignee: Brockhouse Transmissions Ltd
Priority date: 1977-11-29
Filing date: 1977-11-29
Publication date: 1981-07-08
Also published as: DE2850577A1

Description

(54) IMPROVEMENTS RELATING TO TORQUE CONVERTORS (71) We, BROCKHOUSE TRANSMISSIONS LIMITED, a British Company of Howard Street, Hill Top, West Bromwich, West Midlands, 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: This invention relates to a hydrodynamic transmission comprising an engine and a torque convertor having an impellor and a turbine, the impellor being drivably connected to the engine.

The term "torque convertor as hereinbefore defined" is used herein to include not only a "torque convertor proper" having a fixed reaction member but also a "free-wheel" torque convertor having a reaction member permitted to rotate in one direction as well as a fluid coupling having no reaction member.

The torque convertor has to be axially located and if this is done by means of a rigid connection of the impellor to the crankshaft of the engine either directly or by interposed stiff plates the crankshaft has end loads, resulting from internal hydraulic forces in the torque convertor, applied to it. Such end loads are undesirable as they impose excessive end loads on the axial locating washers of the engine crank-shaft.

In an attempt to avoid the imposition of such end loads on the engine crankshaft hitherto the torque convertor has been located axially independently of the crankshaft by axially connecting the turbine to the torque convertor housing through the turbine shaft with an axially flexible connection between the crankshaft and the impellor to accommodate slight axial movement of the impellor permitted by clearances in the torque convertor.

Alternatively the torque convertor has been located directly to the housing by fitting a ball bearing in the impellor hub i.e. fixing the convertor axially relative to the reaction sleeve and hence to the housing.

In order to permit of a connection between the turbine and the turbine shaft it has hitherto been necessary to provide in the driving shell of the torque convertor an end cap of relatively large diameter to permit access to be gained to the connection between the turbine hub and the turbine shaft such connection conventionally comprising a pair of circlips engaged in circumferential grooves in the turbine shaft and abutting opposite sides of the turbine hub.

It is an object of the invention to provide a hy.drodynamic transmission whereby the abovementioned problems are overcome or are reduced.

According to the invention we provide a hydrodynamic transmission comprising an engine and a torque convertor as hereinbefore defined having a housing containing an impellor and a turbine, the impellor being drivably connected to the engine, wherein the turbine is splined to a turbine shaft rotatably mounted and axially located within the torque convertor housing, the turbine is axially located on the turbine shaft by means of a locating element in abutting relationship with an abutment means of the turbine, and the locating element extends transversely outwardly of the turbine shaft through a transverse passage which communicates with an axial passage formed in the turbine shaft and extending to the end thereof adjacent the engine.

The locating element may be spring biased transversely outwardly of the turbine shaft.

The locating element may be provided on a spring received in the axial passage and acting to bias the locating element transversly outwardly of the turbine shaft.

The spring may be of generally V-shape, the ends of the limbs having out-turned parts one, of which forms the locating element and the other of which forms a second such locating element which extends through a second transverse passage, the two transverse passages being diametrically opposite to one another.

The spring may comprise two generally Lr shaped strips, the shorter limbs of the constituting the out-turned parts and the longer limbs of the L being joined together at their free ends to provide the generally*V-shaped spring.

The spring may alternatively be formed as a one piece component, being bent back on itself instead of being rivetted at the free end.

The locating element or elements may be received in a circumferential groove formed in an aperture of the turbine the wall of said aperture being in splined connection with the turbine shaft.

By providing the locating element or elements in a transverse passage formed in the turbine shaft and communicating with an axial passage access may be gained to the locating elements at their inner ends and hence means may be provided to bias the locating elements outwardly, such as by means of the generally Vshaped springs hereinbefore described, although it should be appreciated that if desired any other form of biasing means may be provided including a positive biasing means such as a suitable cam shaped element received within the axial passage and in engagement with the inner ends of the locating elements.

The invention will now be described in more detail by way of example with reference to the accompanying drawing which is a diagrammatic longitudinal cross-sectional view through part of a hydrodynamic transmission embodying the invention.

Referring to the Figure, an engine crankshaft is indicated generally at 10 and is connected by a star formation flexible driving disc 11 having, for example, four equi-angularly spaced limbs the outer ends of which are bolted as indicated at 12 to a ring 13 carrying a starter gear 14 and welded to the torque convertor shell outer wall as indicated at 15. The external configuration of the torque convertor shell is indicated at 16 and it will be seen that an impellor hub 17 is welded to the shell as indicated at 18 as is a nose piece 19 as indicated at 20.

A bearing bush 21 is received in a recess 22 formed in the shell 16 and a nose piece 19 and provides a bearing for one end of a turbine or output shaft 23.

Surrounding the turbine shaft 23 is a reaction member sleeve 24 which has a reaction member 25 splined thereto as indicated at 26.

Also within the torque convertor shell 16 is a turbine hub 27 having a central aperture 28 which provides a splined connection 28a with the turbine shaft 23. A circumferential groove 29 is formed in the wall of the aperture 28 and a blind passage 30 is formed in the turbine shaft 23 extending from the end 31 thereof adjacent the engine.

A pair of diametrically opposite radial passages 32 are formed in the turbine shaft and communicate with the axial passage 30 and are aligned with the groove 29.

Received within the passages 32 are locating elements 33 the ends of which are received in the groove 29 and thus provide an axial location between the turbine shaft and the turbine.

The locating elements 33 are each formed by a shorter limb of a generally L shaped spring 34 the longer limbs of which are of curved configuration and are riveted together as indicated at 35 to provide a generally V-shaped spring thus serving to bias the locating elements 33 radially outwardly into engagement with the groove 29.

The nose piece 19 is formed with a bore 36 part of which is formed with a thread 36a to receive a closure plug 37.

The nosepiece 19 and plug 37 are shaped so as to be received in a recess 38 in the end of the crankshaft.

In use, when the torque convertor is assembled a suitable tool is engaged with the limbs 34 of the spring to move them together and thus withdraw the locating elements 33 so that they are of a diameter not greater than the diameter of the passage 30 nor greater than the diameter of the bore of nosepiece 19 so that the spring can be passed through the nose piece 19 and into the passage 30. The tool is then removed from the spring so the spring biasing action urges the locating elements 33 outwardly through the radial passages 32 and hence into axial locating engagement with the groove 29. The plug 37 is then screwed into the end of the end of the nose piece 19.

If it is desired to disassemble the torque convertor the reverse sequence of operations is performed.

It will be seen therefore that the invention provides a simple and effective way of connecting the turbine to the turbine shaft and locating these elements axially without the need to provide a relatively large diameter end cap for the torque convertor shell.

Although in this example the torque convertor has a fixed reaction member, if desired the invention may be applied to a "free wheel" torque convertor or to a fluid coupling having no reaction member.

WHAT WE CLAIM IS: 1. A hydrodynamic transmission comprising an engine and a torque convertor as herein before defined having a housing containing an impellor and a turbine the impellor being drivably connected to the engine, wherein the turbine is splined to a turbine shaft rotatably mounted and axially located within the torque convertor housing, the turbine is axially located on the turbine shaft by means of a locating element in abutting relationship with an abutment means of the turbine, and the locating element transversely outwardly of the turbine shaft through a transverse passage which communicates with an axial passage formed in the turbine shaft and extending to the end thereof adjacent the engine 2. A transmission according to Claim 1 wherein the locating element is spring biased transversely outwardly of the turbine shaft.

3. A transmission according to Claim 2 wherein the locating element is provided on a spring received in the axial passage and acting to bias the locating element transversely outwardly of the turbine shaft.

4. A transmission according to Claim 3 wherein the spring is of generally V-shape, the ends of the limbs having out-turned parts one

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. received in a circumferential groove formed in an aperture of the turbine the wall of said aperture being in splined connection with the turbine shaft. By providing the locating element or elements in a transverse passage formed in the turbine shaft and communicating with an axial passage access may be gained to the locating elements at their inner ends and hence means may be provided to bias the locating elements outwardly, such as by means of the generally Vshaped springs hereinbefore described, although it should be appreciated that if desired any other form of biasing means may be provided including a positive biasing means such as a suitable cam shaped element received within the axial passage and in engagement with the inner ends of the locating elements. The invention will now be described in more detail by way of example with reference to the accompanying drawing which is a diagrammatic longitudinal cross-sectional view through part of a hydrodynamic transmission embodying the invention. Referring to the Figure, an engine crankshaft is indicated generally at 10 and is connected by a star formation flexible driving disc 11 having, for example, four equi-angularly spaced limbs the outer ends of which are bolted as indicated at 12 to a ring 13 carrying a starter gear 14 and welded to the torque convertor shell outer wall as indicated at 15. The external configuration of the torque convertor shell is indicated at 16 and it will be seen that an impellor hub 17 is welded to the shell as indicated at 18 as is a nose piece 19 as indicated at 20. A bearing bush 21 is received in a recess 22 formed in the shell 16 and a nose piece 19 and provides a bearing for one end of a turbine or output shaft 23. Surrounding the turbine shaft 23 is a reaction member sleeve 24 which has a reaction member 25 splined thereto as indicated at 26. Also within the torque convertor shell 16 is a turbine hub 27 having a central aperture 28 which provides a splined connection 28a with the turbine shaft 23. A circumferential groove 29 is formed in the wall of the aperture 28 and a blind passage 30 is formed in the turbine shaft 23 extending from the end 31 thereof adjacent the engine. A pair of diametrically opposite radial passages 32 are formed in the turbine shaft and communicate with the axial passage 30 and are aligned with the groove 29. Received within the passages 32 are locating elements 33 the ends of which are received in the groove 29 and thus provide an axial location between the turbine shaft and the turbine. The locating elements 33 are each formed by a shorter limb of a generally L shaped spring 34 the longer limbs of which are of curved configuration and are riveted together as indicated at 35 to provide a generally V-shaped spring thus serving to bias the locating elements 33 radially outwardly into engagement with the groove 29. The nose piece 19 is formed with a bore 36 part of which is formed with a thread 36a to receive a closure plug 37. The nosepiece 19 and plug 37 are shaped so as to be received in a recess 38 in the end of the crankshaft. In use, when the torque convertor is assembled a suitable tool is engaged with the limbs 34 of the spring to move them together and thus withdraw the locating elements 33 so that they are of a diameter not greater than the diameter of the passage 30 nor greater than the diameter of the bore of nosepiece 19 so that the spring can be passed through the nose piece 19 and into the passage 30. The tool is then removed from the spring so the spring biasing action urges the locating elements 33 outwardly through the radial passages 32 and hence into axial locating engagement with the groove 29. The plug 37 is then screwed into the end of the end of the nose piece 19. If it is desired to disassemble the torque convertor the reverse sequence of operations is performed. It will be seen therefore that the invention provides a simple and effective way of connecting the turbine to the turbine shaft and locating these elements axially without the need to provide a relatively large diameter end cap for the torque convertor shell. Although in this example the torque convertor has a fixed reaction member, if desired the invention may be applied to a "free wheel" torque convertor or to a fluid coupling having no reaction member. WHAT WE CLAIM IS:

1. A hydrodynamic transmission comprising an engine and a torque convertor as herein before defined having a housing containing an impellor and a turbine the impellor being drivably connected to the engine, wherein the turbine is splined to a turbine shaft rotatably mounted and axially located within the torque convertor housing, the turbine is axially located on the turbine shaft by means of a locating element in abutting relationship with an abutment means of the turbine, and the locating element transversely outwardly of the turbine shaft through a transverse passage which communicates with an axial passage formed in the turbine shaft and extending to the end thereof adjacent the engine

2. A transmission according to Claim 1 wherein the locating element is spring biased transversely outwardly of the turbine shaft.

of which forms the locating element and the other of which forms a second such locating element which extends through a second transverse passage, the two transverse passages being diametrically opposite to one another.

5. A transmission according to Claim 4 wherein the spring comprises two generally L- shaped strips the shorter limbs of the L constituting the out-turned parts and the longer limbs of the L being joined together at their free ends to provide the generally V-shaped spring.

6. A transmission according to Claim 4 wherein the generally V-shaped spring is formed as a one piece component constituting the out-turned parts.

7. A transmission according to any one of the preceding claims wherein the locating element or elements is or are received in a circumferential groove formed in an aperture of the turbine, the wall of said aperture being in splined connection with the turbine shaft.

8. A transmission according to any one of the preceding claims wherein the axial passage in the turbine shaft is provided with removable closure means at the end thereof adjacent the engine.

9. A transmission substantially as hereinbefore described with reference to and as shown in the accompanying drawing.