WO2015024947A2

WO2015024947A2 - Method and apparatus for aligning engine and transmission

Info

Publication number: WO2015024947A2
Application number: PCT/EP2014/067683
Authority: WO
Inventors: John HOGLEY
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2013-08-19
Filing date: 2014-08-19
Publication date: 2015-02-26
Anticipated expiration: 2016-02-19
Also published as: GB2517429A; GB201314796D0; WO2015024947A3; GB2517429B

Abstract

A torque converter has an external engine facing pocket for engagement by an alignment tool, for restraining the torque converter against rotation within a transmission housing. The tool is arranged for removal through the usual starter motor aperture so as not to obstruct connection to the transmission of the engine.

Description

Method and Apparatus for Aligning Engine and Transmission

TECHNICAL FIELD

This invention concerns alignment of an engine and transmission during connection thereof, in particular for permitting relative rotation for engagement of drive and/or coupling elements.

BACKGROUND TO THE INVENTION

Engines and transmissions, in particular of vehicles, usually comprise discrete complex assemblies which are required to be coupled together, both to transmit drive from the engine to the transmission and to form a unitary component.

The rotatable connection generally comprises a rotatable output drive member of the engine and a rotatable input drive member of the transmission, and during assembly relative rotation thereof is required in order to align these components for transmitting torque therebetween.

In the case of an automatic transmission having a torque converter, the engine drive member is typically a flex plate of corresponding diameter. The torque converter includes a circular array of axially projecting studs to engage within corresponding holes of the flex plate.

During assembly thereof, the engine crankshaft is generally rotated to align the flex plate and torque converter, so that the studs will smoothly enter the corresponding holes, but in practice the flex plate will tend to drag the torque converter in rotation as the components first touch, thus preventing proper alignment of the studs and holes. The circumferentially extending housings for the flex plate and torque converter typically prevent access for a restraining tool. The torque converter may be fitted to the transmission from the front, with a transit strap to restrain relative rotational alignment with the transmission housing, but this strap must necessarily be removed prior to connection of the engine and transmission. What is required is a means and method of facilitating precise alignment, and which permits relative rotation of the engine crankshaft/drive member without risk of dragging the input member of the transmission in rotation. SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a torque converter for a vehicle transmission and adapted for rotational coupling to a vehicle engine, said torque converter having a rotational axis and comprising a shell having an engine side, a transmission side and a substantially cylindrical portion at the outer periphery thereof, an alignment feature being provided on said portion, said alignment feature comprising an open mouthed pocket facing in the direction of said axis toward the engine side.

In an embodiment, the pocket comprises a somewhat straight sided slot, open at the radially outer side, and may be constituted by a "C" shaped component attached to the torque converter shell by, for example, spot welding. The component may include an upstanding wall around the inner periphery of the slot, and in one embodiment comprises a steel pressing of substantially constant wall thickness. Such a torque converter is adapted to receive an alignment tool which in use is rotationally fixed relative to a transmission housing, and is adapted for withdrawal in the direction of the coupling axis on the transmission, typically through a starter motor aperture, after connection of an engine and transmission. Several such pockets may be provided about the torque converter shell so as to minimise relative rotation of the torque converter to an alignment location and to ensure balance of the torque converter upon rotation in use.

According to a second aspect of the invention there is provided an alignment tool for a torque converter rotatable about a rotational axis of a transmission housing, said tool comprising a body movable on an attachment axis parallel to said input axis between disengaged and engaged conditions; in the engaged condition said tool being restrained against movement relative to said transmission housing save on said attachment axis in a disengaging direction, said tool including a foot engageable upon movement in an engaging direction to the engaged condition in a pocket of the torque converter thereby to restrain rotational movement of the torque converter relative to said transmission housing, and said tool being disengageable by movement in a disengaging direction via an aperture for a starter motor.

A feature of the invention is that the tool is in sliding engagement in the pocket, in the direction of connection of engine and transmission, but does not obstruct engagement of the mating flanges of engine and transmission; the tool is typically located in the vicinity of the usual aperture for a starter motor, and is removed through this aperture after the connection of the engine and transmission is made. Typically the tool is engaged prior to connection of the engine and transmission and just prior to removal of the usual transit strap.

In an embodiment of the invention, the shape and form of the alignment tool depends to some extent upon the nature and position of the starter motor opening. For example some starter motors are fitted axially, and some radially of the drive line axis. The starter motor aperture may be formed wholly in the engine block, or at least partially in the transmission casing. The starter motor may be mounted to the engine block or to the transmission casing.

In one embodiment the tool has rearwardly facing pegs for engagement in corresponding holes of the transmission housing. The pegs may be dowels for close fitting engagement in suitable round holes. Alternatively or additionally the tool may have side faces for abutment in an opening of the transmission housing. The opening may define a somewhat tapered mouth facing the engine, so as to locate the tool without relative circumferential play. The foot may be positioned on a depending leg, which may be cranked away from the engine side.

Typically the straight sided slot of the pocket receives a foot having corresponding planar sides which snugly engage the slot, thereby to substantially eliminate relative movement in rotation.

Aspects of the invention relate to a torque converter transmission to which the tool is fitted, to a connected engine and torque converter transmission in which the tool is fitted, and to a method of connecting an engine and torque converter transmission. Within the scope of this application it is expressly envisaged that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.

BRIEF DESCRIPTION OF DRAWINGS

Other features of the invention will be apparent from the following description of embodiments shown by way of example only in the accompanying drawings in which:-

Fig. 1 is a schematic side elevation of engine and transmission sub-assemblies prior to connection thereof.

Fig. 2 is a corresponding side elevation showing a connected engine and transmission.

Fig. 3 is a schematic rear elevation of an engine, showing a drive member.

Fig. 4. is a schematic front elevation of a transmission, showing a torque converter.

Fig. 5 is partial view from the front of a tool according to an embodiment of the invention mounted to a transmission.

Fig. 6 is a pictorial view from the rear of a tool according to the embodiment of Fig. 5.

Figs. 7-1 1 illustrate in plan, elevation and section, a pressing for use with the tool of Fig. 6, and intended to be fixed to a transmission drive member.

Fig. 12 is a pictorial scrap view from the front of the alignment tool mounted to an engine/transmission assembly, just prior to removal thereof.

Fig. 13 is a pictorial scrap view from the front of an alternative engine/transmission assembly, from which the alignment tool has been removed. Fig. 14 is a rear (radially inward) view of an alignment tool suitable for the embodiment of Fig. 13. DESCRIPTION OF EMBODIMENTS

With reference to the drawings, an engine 10 comprises a cylinder block 1 1 having a peripheral rear flange 12. Within the rear flange is a through aperture 13, and mounted to the flange is a starter motor 14 which projects through the aperture 13 for engagement with a ring gear of a flex plate or the like (52; Figs. 12 and 13). The engine includes a rotatable drive member 15 as drive output.

A transmission 21 also comprises a main housing 22 having a bell or converter housing 24 at the front with a peripheral front flange 23. Within the housing 24 is rotatable a torque converter 25, which comprises the drive input member of the transmission.

During manufacture of a motor vehicle, the engine 10 and transmission 21 are provided as substantially complete sub-assemblies, and are connected along the drive axis by bringing the flanges into contact so as to create a single effective unit. The flanges are coupled by screw fasteners passing through corresponding flange apertures 31 . At the same time the drive plate and torque converter must be coupled for transmission of torque, and for this purpose a circular array of forwardly projecting studs 26 of the torque converter 25 must be engaged in a corresponding circular array of drive apertures 16 of the drive member 15. Other means of transmitting drive are possible, and the invention is not limited to the studs 26 of this embodiment.

It will be understood that the drive member 15 and torque converter 25 are relatively rotatable, and must be brought into register if the engine block and transmission housing are to be successfully coupled.

However it will also be appreciated that access to the torque converter and drive plate is not possible at the point of final connection, because the housing 24 is substantially continuous, and apertures therein are not desirable. Furthermore as the drive member 15 is rotated so as to precisely align the studs 26 and apertures 16, it may snag or drag the torque converter so as to cause rotation in common - and in these circumstances alignment is difficult if not impossible to achieve. An embodiment of the invention provides a restraint between the torque converter and the housing 24 which prevents rotation of the torque converter relative to the housing 24 during rotational alignment of the drive member, which permits full engagement of the flanges 12, 23, and which is removable through the starter motor aperture 13. With reference to Figs. 5 and 6, an alignment tool 41 comprises a planar generally semi-circular body 42 having circular rear facing projections 43 for close-fitting engagement in corresponding apertures (not shown) of the transmission mounting flange 23. These apertures may be provided specifically for the tool 41 , or may be pre-existing.

The arcuate outer face of the tool may be within the diameter of the starter motor aperture 13 so that it can be drawn axially therethrough; however, as will be explained below, other mounting arrangements for the starter motor are possible. The planar body 42 includes a depending leg 44, which is cranked rearwardly (with respect to the engine), and includes a precision foot 45 for engagement in a corresponding close-fitting pocket 27 provided on the outer periphery of the torque converter 25. The pocket 27 is forward facing, and in this embodiment is defined by a precision steel pressing 28 (Figs. 7-1 1 ) spot welded to the outer steel casing or shell of the torque converter 25. In order to better define the pocket 27, the pressing includes a continuous upstanding wall 29 which includes parallel portions adjacent the mouth thereof. Corresponding parallel sides 46 are provided on the foot 45, and a sliding fit along an axis parallel to the drive axis is intended, to the intent that relative rotation of the torque converter is obviated.

Suitable welding locations are indicated at 30, and the dimensions of the pocket 28 may be around 15 x 30mm, with a recess having a width of 10mm, a wall height of 5mm and a thickness of 1 .4mm. These dimensions may of course be varied to suit circumstances, but a typical weight may be 5 grams.

Several such pockets may be equispaced about the torque converter shell and diametrically opposed, not only to allow minimal rotation to first engage the tool 41 , but also to maintain rotational balance. In an embodiment, the pocket(s) require to be attached in a pre-determined angular relationship with the drive studs 26, so as to permit fitting of the tool 41 prior to removal of a transit strap. For manufacturing purposes the tool 41 may comprise plate steel to which the foot 44 is located by dowels 47 and a screw 48, and the circular projections 43 are dowels which are a friction fit in precision drilled blind holes.

A peg 49 is provided at the radially outer edge for manipulating the tool by hand; the peg is a press-fit in a through hole and may be secured by welding if necessary. A bayonet fitting 55 is provided for tool removal, as will be explained. Although not clearly illustrated in Figs. 7-1 1 , the base of the pocket 28 may be somewhat arcuate to suit the curvature of the torque converter 25.

Fig. 12 illustrates an embodiment of the invention in which the starter motor aperture of the engine 10 is represented by a cut-away 51 , and the starter motor is instead mounted directly to the forward facing flange 23 of the transmission 21 . Such a construction is possible because the engine and transmission are unitary after connection thereof. In this embodiment the assembly axis of the starter motor is parallel to that of the crank shaft. Fig. 12 shows the alignment tool 41 in place after connection of the engine and transmission, and ready for removal. The usual starter motor ring gear 52 can be seen, as well as the head of a torque converter drive stud 26, to which is attached a threaded nut 53. In use, after relative insertion of the drive studs 26 in the apertures 16, the ring gear 52 is rotated to permit attachment of corresponding nuts 53 one by one through an access opening provided by the cut-away 51 .

In use the tool 41 may be removed by pulling it forwardly in a direction along the assembly axis 54 until the location projections 43 are disengaged. The depending 44 leg can be manoeuvred around the starter ring gear 52. In order to facilitate tool removal the peg 49 may include a bayonet fitting attachment 55 for a tubular removal tool; any appropriate disengageable attachment is however suitable, if considered necessary, and the bayonet device illustrated forms no part of the invention, as such. After removal of the tool 41 , the starter motor is attached in a conventional fashion. An alternative embodiment is illustrated in Fig. 13, in which the starter motor is mounted by movement in a radial rather than an axial direction. The mounting aperture 61 for the starter motor is formed partly by the engine cylinder block 1 1 and partly by the converter housing 24; attachment holes 62 are provided on the cylinder block for the starter motor. Through the aperture can be seen the starter motor ring gear 52, a torque converter 25, a torque converter drive stud 26, and the pocket 28 in which an alignment tool is adapted to locate.

Fig. 14 illustrates a tool 71 for use in the arrangement of Fig. 13. This embodiment includes a flat plate part 72 to overlie that part of the opening 61 which is formed by the converter housing 24, a radially inward profile 73 for close fitting engagement in the transmission opening and a lug 74 to fit against the inner surface of the converter housing, for the purposes of restraining the tool 71 in place; the lug 74 is formed on a separate stamping, and may have a slight spring bias so as to perform a gripping function. A foot 75 extends radially inwardly for engagement with the pocket 28, which is substantially identical in form to that illustrated in Figs. 7 to 1 1 .

In use, the tool 71 is engaged by rearward movement parallel to the rotational axis of the transmission, to restrain relative rotation of the torque converter, and foot 75 fits snugly within the pocket 27 of the pressing 28 at the front of the converter housing.

After connection of engine and transmission, the tool is disengaged from the transmission housing by forward movement, and upon disengagement may be removed radially.

The alignment tool of the invention can be made of any suitable material, or combination of materials. Typically it will comprise a steel fabrication, but could if desired be moulded in plastic. The provision of one or more pockets on the torque converter provides an anti- rotation feature which may be used with many different configurations of engine and transmission, yet is accessible via the usual starter motor opening.

It will be understood that the invention is not limited by the foregoing description of preferred embodiments, and that variations are possible within the scope of the claims appended hereto. Certain aspects of the invention are stated in the numbered paragraphs that follow:

1 . A torque converter for a vehicle transmission and adapted for rotational coupling to a vehicle engine, said torque converter having a rotational axis and comprising a shell having an engine side, a transmission side, and a substantially cylindrical portion at the outer periphery thereof, an alignment feature being provided on said portion, said alignment feature comprising an open mouthed pocket facing in the direction of said axis toward the engine side.

2. A torque converter according to aspect 1 wherein said pocket comprises a straight sided slot, open at the radially outer side.

3. A torque converter according to aspect 2 wherein said pocket comprises an upstanding wall around the inner periphery of said slot.

4. A torque converter according to aspect 3 wherein said pocket comprises a pressing of substantially constant wall thickness 5. A torque converter according to aspect 4 wherein said pocket comprises a "C" shaped component attached to said torque converter shell by welding.

6. An alignment tool for a torque converter rotatable about a rotational input axis of a transmission housing, said tool comprising a body movable on an attachment axis parallel to said input axis between disengaged and engaged conditions; in the engaged condition said tool being restrained against movement relative to said transmission housing save on said attachment axis in a disengaging direction, said tool including a foot engageable upon movement in an engaging direction to the engaged condition in a pocket of the torque converter thereby to restrain rotational movement of the torque converter relative to said transmission housing, and said tool being disengageable by movement in said disengaging direction via an aperture for a starter motor.

7. A tool according to aspect 6 wherein said body is substantially planar and orthogonal to said attachment axis, one or more pegs extending therefrom in the engaging direction for engagement in corresponding apertures of said transmission housing.

8. A tool according to aspect 6 and including a leg extending from the body thereof in the engaging direction, said foot being provided at the end thereof.

9. A tool according to aspect 8 wherein said leg is cranked radially inwardly of said body. 10. A tool according to aspect 6 wherein said foot has substantially parallel sides extending in the direction of said attachment axis.

1 1 . A tool according to aspect 6 wherein movement from the disengaged to the engaged condition is in the range 5 to 15mm.

12. A tool according to aspect 6 and restrained in the engaged condition by circumferential abutment with said transmission housing.

13. A tool according to aspect 6 and adapted for engagement in a radial opening in a transmission bell housing, said opening being open in the disengaging direction to receive said tool in use.

14. In combination a tool according to aspect 6 and a torque converter transmission including a torque converter.

15. The combination of aspect 14 wherein the tool is engaged with a flange of said transmission housing, said flange facing in the disengaging direction.

16. The combination of aspect 14 wherein said tool is engaged in an opening of the transmission housing, said opening comprising a "C" shaped cut-out of a said housing.

17. The combination of aspect 14 wherein said tool is engageable in a mounting aperture for a starter motor. 18. A method of rotationally restraining a torque converter according to aspect 1 with respect to a transmission housing during connection to an engine, the method comprising:

engaging the alignment tool to said transmission whilst relatively rotating the torque converter to align a pocket thereof with a foot of said tool;

moving said engine and transmission together along a rotational axis thereof, whilst rotating a crankshaft of said engine to align an engine coupling to said torque converter;

rotationally coupling said engine and transmission as the respective connection flanges thereof engage; and

removing said alignment tool via a starter motor aperture.

Claims

2. A torque converter according to claim 1 wherein said pocket comprises a straight sided slot, open at the radially outer side.

3. A torque converter according to claim 2 wherein said pocket comprises an upstanding wall around the inner periphery of said slot.

4. A torque converter according to claim 3 wherein said pocket comprises a pressing of substantially constant wall thickness

5. A torque converter according to claim 4 wherein said pocket comprises a "C" shaped component attached to said torque converter shell by welding.

7. A tool according to claim 6 wherein said body is substantially planar and orthogonal to said attachment axis, one or more pegs extending therefrom in the engaging direction for engagement in corresponding apertures of said transmission housing.

8. A tool according to claim 6 or claim 7 and including a leg extending from the body thereof in the engaging direction, said foot being provided at the end thereof.

9. A tool according to claim 8 wherein said leg is cranked radially inwardly of said body.

10. A tool according to any of claims 6 to 9 wherein said foot has substantially parallel sides extending in the direction of said attachment axis.

1 1 . A tool according to any of claims 6 to 10 wherein movement from the disengaged to the engaged condition is in the range 5 to 15mm.

12. A tool according to any of claims 6 to 1 1 and restrained in the engaged condition by circumferential abutment with said transmission housing.

13. A tool according to any of claims 6 to 12 and adapted for engagement in a radial opening in a transmission bell housing, said opening being open in the disengaging direction to receive said tool in use.

14. In combination a tool according to any of claims 6 to 13 and a torque converter transmission including a torque converter according to any of claims 1 to 5, said tool being engaged with said housing and the pocket of said torque converter to prevent relative rotation of the torque converter.

15. The combination of claim 14 wherein the tool is engaged with a flange of said transmission housing, said flange facing in the disengaging direction.

16. The combination of claim 14 or claim 15, wherein said tool is engaged in an opening of the transmission housing, said opening comprising a "C" shaped cut-out of a said housing.

17. The combination of any of claims 14 to 16 wherein said tool is engageable in a mounting aperture for a starter motor.

18. A method of rotationally restraining a torque converter according to any of claims 1 to 5 with respect to a transmission housing during connection to an engine, the method comprising:

engaging the alignment tool of any of claims 6 to 13 to said transmission whilst relatively rotating the torque converter to align a pocket thereof with the foot of said tool;

removing said alignment tool via a starter motor aperture.

19. A torque converter substantially as described herein with reference to the accompanying drawings.

20. An alignment tool substantially as described herein with reference to the accompanying drawings.

21 . In combination an alignment tool and torque converter transmission, substantially as described herein with reference to the accompanying drawings.

22. An assembly of an engine and torque converter transmission defining an open aperture for a starter motor adjacent the connection plane thereof, having a torque converter substantially as described herein with reference to the accompanying drawings, and having within said aperture an alignment tool, substantially as described herein with reference to the accompanying drawings.