GB2116653A - Torque transmitting unit including planetary gearing and clutch - Google Patents

Abstract

A torque transmitting unit comprises a drive shaft (12) and a co-axial driven shaft (14). A plurality of inertia members or weights (30) carrying respective gearwheels (32) are positioned in angular synchronism for rotation about their respective shafts (28) by a sun gearwheel (36) on the drive shaft (12). Centrifugal forces cause the inertia members (30) to also perform orbiting movement around the drive shaft (12) and transmit a torque to said driven shaft (14) through a clutch (38, 44). A raised cam portion (52) on the clutch drive member (38) is engaged, during operation, by an abutment member (58) on the drive shaft (12) in order to effect disengagement of the clutch as necessary, to ensure unidirectional transmission of the torque. <IMAGE>

Description

SPECIFICATION An improved torque transmitting unit The present invention relates to a torque transmitting unit and is a development of the arrangement disclosed in my co-pending British Patent Application No. 2078908A.

The object of the invention is to provide a compact transmitting unit of reduced dimensions, weight and cost which provides improved torque transmitting flexibility and reduced vehicle fuel consumption.

The present invention consists in a torque transmitting unit comprising a drive shaft and a driven shaft, a plurality of inertia members positioned in angular synchronism for rotation about their respective axes and operatively connected to said drive shaft, said inertia members transmitting torque to said driven shaft through a clutch and means for disengaging said clutch as necessary to ensure uni-directional transmission of the torque.

In the accompanying drawings: Fig. is a cross-section through a torque transmitting unit according to the present invention, Fig. 2 is a cross-section taken along the line 2-2 of Fig.1, Fig. 3 is a perspective view showing a schematic detail of the clutch disengagement means, Fig. 4 is an enlarged sectional detail showing the mounting of the drive and driven shafts, Fig. 5 is a view similar to Fig. 1, but showing only a half-sectional view of a modified arrangement according to the invention, and Fig. 6 is also a view similar to Fig. 1, but showing only a half-sectional view of a further embodiment according to the present invention.

In carrying the invention into effect according to one convenient mode, by way of example, the torque transmitting unit 10 comprises a drive input shaft 12 and driven output shaft 14 coaxial therewith.

A casing 16 having a peripheral wall 18 connected spaced radial walls 20, 22 is mounted on ball bearings 24,26 positioned on the input and output shafts, 12, 14, respectively. The casing wail 20 adjacent the input shaft 12 is provided with four shafts 28 disposed at equi-angular intervals at 90 from each other which extend parallel to the axes of the input and output shafts 12, 14. An inertia member or weight 30 of semi-circular configuration has a gearwheel 32 integral therewith with the diametric axis of the inertia member 30 coincident with the axis of the gearwheel 32. The inertia member and gearwheel assembly is rotatably mounted by means of roller bearings 34 on each of the shafts 28 adjacent the casing wall 20.A gearwheel 36 co-axial with the drive shaft 12 and fixedly connected thereto engages the gearwheels 32 of the four inertia members 30.

A clutch drive member 38 having a frusto-conical peripheral surface 40 is mounted on the ends of the four shafts 28 positioned adjacent the wall 22 of the casing 16. The surface 40 of the clutch member 38 co-acts with a frusto-conical inner surface 42 of a clutch driven member 44 integral with the output shaft 14. The adjacent inner ends of the output shaft 14 and input shaft 12 are provided, respectively, with outwardly extending radial flanges 46 and 48 which are positioned between spaced, inwardly directed flanges 50, 52 integral with the clutch drive member 38.

A coil spring 54 positioned around the output shaft 14 is interposed between the respective flanges 46 and 50 of the output shaft 14 and clutch drive member 38. The spring 54 urges the clutch member 38 into contact with the clutch driven member 44 via the engaging frusto-conical surfaces 40,42. To effect disengagement of the clutch, the inwardly directed flange 52 on the clutch drive member 38 is provided with a semi-circular raised or cam portion 56 of approximately 0.2 m.m. in height which is engaged by an abutment member 58 on the input member flange 48. Thus, for the reason hereinafter explained, during every complete revolution of the input member 12, the clutch drive member 38 is moved slightly away from the clutch driven member 44 for a duration of 180 degrees to effect disengagement of the clutch.Thereafter, for the other 180 the spring 54 re-asserts itself and moves the clutch drive member 38 back into engagement with the clutch driven member 44 and output shaft 14.

Referring now to Fig. 4which shows details of the mounting arrangement of the shafts, the end of the drive shaft 12 is rotatably mounted in the end of the driven shaft 14 by means of a spigot roller bearing 66. The radial flange 48 of the drive shaft 12 is stepped and an axial thrust roller bearing 68 is interposed between the flange 48 and the flange 46 of the driven shaft 14. Afurther axial thrust roller bearing 70 is interposed between the flange 50 of the clutch drive member 38 and the spring 54.

Fig. 5 shows a torque transmitting unit similar to that shown in Fig. 1, but having a higher torque capacity. The parts are arranged in an identical manner to the arrangement shown in Fig. 4 and are identified by the same reference numerals. The basic differences are the increased size of the inertia members 30 and the increased size and diameter of the shafts which are subjected to the increased torque.

Referring now to Fig. 2, it can be seen that the inertia members or weights 30 are symmetrically arranged to act in unison and during rotation of the unit, in addition to rotating or orbiting about the axis of the drive shaft 12, also rotate about the axis of their respective shafts 28. The reference numeral 60 indicates a radially directed centrifugal force passing through the axes of the drive shaft 12 and the inertia member shaft 28, whilst the reference numeral 62 indicates the centre of gravity of the weight 30.

When in the position shown with the centre of gravity at its maximum distance from the line of action of the centrifugal force 60, the maximum torque for any given speed of rotation is exerted on the clutch drive member 38 and thus through the The drawings originally filed were informal and the print here reproduced is taken from a later filed formal copy.

clutch driven member44tothe output shaft 14.

When the centre of gravity 62 is displaced through 90 in either direction from the point shown in Fig. 2, it lies on the line of action of the centrifugal force 60 and the torque is zero. Furthermore, when the centre of gravity 62 of the wieght is displaced through 180 from the point shown in Fig. 2, the torque is again maximum, but acting against the direction of rotation. For convenience this will be termed "negative torque".

Thus, in operation, the torque transmitted by the four weights 30 to the clutch drive member 38 rises from zero to maximum after rotation through 90" and then returns to zero after a further 90 rotation.

During the following 1800 of rotation the abutment 58 on the drive shaft 12 engages the raised or cam portion 56 on the clutch member 38 to disengage the clutch for the duration of the "negative tomue".

Clearly it is advantageous to provide an arrangement whereby a "positive torque" is transmitted to the clutch driven member 44 and output shaft 14 during the period the clutch is disengaged and with this in view the embodiment shown in Fig. 6 has been developed.

Fig. 6 discloses a double our tandem arrangement of the torque transmitting unit shown and described with reference to Figs. 1 to 4 and therefore a detailed description of each unit is deemed to be unnecessary. For convenience, where possible the same reference numerals have been used to identify similar parts with the suffix "a" indicating similar parts of the second unit.

In this embodiment the casing 16 has been omitted and the four shafts 28 and 28a of the respective units are fixedly mounted in spaced annular plates 80,82, and 80a, 82a rotatably mounted on the drive shaft 12 on ball bearings 84.

The four shafts 28 and 28a of each unit are directed inwardly towards each other and have, respectively, the clutch driving member 38, 38a, inertia members 30, 30a and gearwheels 32, 32a mounted thereon as described above with reference to Figs. 1 and 2. The important point is that the inertia members 30a are all angularly displaced 180" from the positions of the inertia members 30.

The drive shaft 12 is provided with longitudinally spaced gearwheels 36 and 36a which engage, respectively, the four gear wheels 32 and 32a of the units.

A clutch driven member 88 includes a boss 90 having radially directed flanges 46, 46a at the respective ends thereof and is rotatably mounted on the drive shaft 12 by means of a roller bearing 92. A radially directed, central web 94 is disposed between the clutch driving members 38, 38a and connects the boss 90 to an outer tubular driven clutch member 96 having oppositely directed frusto-conical inner surfaces 42, 42a respectively engaging similar peripheral al surfaces 40, 40a on the clutch driving members 38, 38a.

The clutch driven member 96 has a peripheral flange 98 at one end connected by bolts 100 to a clutch casing 102 which houses the shafts 28a and associated inertia members 30a and gearwheels 32a.

The clutch casing 102 is fixedly connected by bolts 104to aflange 106 on the driven shaft 14, the end of the latter being rotatably mounted in the end of the drive shaft 12 by means of a spigot roller bearing 108.

A coil spring 54a is interposed between the flanges 46a and 50a of the boss 90 and clutch drive member 38a, respectively, which urges the latter into contact with the clutch driven member 96 via the engaging frusto-conical surfaces 40a, 42a. Again, to effect disengagement of this second clutch, the inwardly directed flange 52a on the clutch drive member 38a is provided with a semi-circular raised or cam portion 56a of approximately 0.2 m.m. in height which is engaged by an abutment member 58a on the input drive member flange 48a. An important point is that the cam portion 56a is displaced 1800 from the cam portion 56 of the other clutch.

Thus, although the two clutch assemblies operate in an identical manner as described above, in operation, during the 180 period of engagement of the frusto-conical surfaces 40,42, of the first clutch assembly, the frusto-conical surfaces 40a, 42a of the second clutch assembly are disengaged and vice versa during the next 180 of rotation. In this manner the "positive torque" transmitted to the output shaft 14 is doubled compared with the embodiment shown in Figs. 1 to 4.

It will be appreciated that more then two torque transmitting units, suitably phased, can be provided if required.

The units described above are particularly, although not exclusively, intended for use as a power transmission unit for engine-driven vehicles.

In the motor vehicle field it can replace conventional clutches, or torque converters, or gears depending on the position and number of units used.

Claims (8)

1. Atorquetransmitting unit comprising a drive shaft and a driven shaft, a plurality of inertia members positioned in angular synchronism for rotation about their respective axes and operatively connected to said drive shaft, said inertia members transmitting torque to said driven shaftthrough a clutch and means for disengaging said clutch as necessary to ensure uni-directional transmission of the torque.

2. A torque transmitting unit as claimed in claim 1, wherein each inertia member is rotatably mounted on a shaft, one end of each shaft being mounted in a member rotatably mounted on said drive shaft, whilst the other end of each shaft is mounted in the clutch driving member, the arrange ment enabling the inertia members to orbit or rotate around the axis of the drive shaft.

3. Atorque transmitting unit as claimed in claim 1 or 2, wherein each inertia member is of semi-circu lar shape and has its diametric axis coincident with the axis of a gearwheel integral with said inertia member, said drive shaft having a coaxial gearwheel fixedly connected thereto which engages the respective gearwheels of the inertia members and drives them in unison for rotation about their respective axes.

4. A torque transmitting unit as claimed in any of claims 1 to 3, wherein the clutch driving member has a peripheral frusto-conical surface which is spring -urged into engagement with a frusto-conical surface of the clutch driven member, the latter being connected to the driven shaft.

5. A torque transmitting unit as claimed in any of the preceding claims, wherein the clutch disengagement means comprises a raised, or cam, portion formed on the clutch drive member which is engaged by an abutment member associated with the drive shaft.

6. Atorquetransmitting assembly comprising a pair of units each as claimed in any of the preceding claims, wherein the plurality of inertia members of one unit are angularly displaced through 180" from the plurality of inertia members of the other unit.

7. A torque transmitting assembly as claimed in claim 6, wherein the clutch driving member of each unit drives a common clutch driven member having oppositely directed frusto-conical inner surfaces.

8. A torque transmitting unit substantially as described with reference to Figs. 1 to 4, or Fig. 6, of the accompanying drawings.