GB2078908A - Torque transmitting device - Google Patents

Abstract

An inertia member (28) is rotated, by a drive element 11 with a fluid-filled housing 13 about the axis of rotation of the element. Depending on the centrifugal force acting on the member (28), the rotary movement of drive element (13) is transmitted to a driven element (12). In order to permit a slip of 0% to 100% between these two elements, (12, 13), member (28) is coupled to a crankpin (27) or eccentric connected to driven element (12) and non-return valve 20, port 24 with member 28 and passage 29 are provided to prevent the centrifugal force (31) acting on rotating inertia member (28) at least partially from exerting a torque on driven element (12) through the crankpin (27) or the eccentric, in a predetermined component range of the relative torsional position between elements (12, 13). <IMAGE>

Description

SPECIFICATION Torque transmitting device The invention relates to a device for transmitting a torque from a drive element turning about an axis of rotation to a rotatable driven element, having at least one inertia member which is associated with the drive element and which is driven by the drive element to rotate about the said axis of rotation.

A classical example of known devices of this kind are the so-called centrifugal clutches. In these centrifugal clutches, the centrifugal force acting on the inertia member increases or reduces a frictional connection between the drive and driven elements depending on the speed of rotation of the inertia member or the speed of rotation of the drive element. In certain centrifugal clutches, the centrifugal force acting on the inertia member even causes a positive connection between drive element and driven element as soon as synchronism is at least approximately reached between these elements.

An important disadvantage of centrifugal clutches is the fact that the transmission of torque generally comes about through a frictional connection. With slip between drive element and driven element, considerable frictional heat is generated with accompanying wear. In addition, centrifugal clutches are not able to produce an amplification, depending on the speed of rotation of the drive element, of the torque transmitted to the driven element or taken therefrom.

It is an object of the present invention to obviate or mitigate these disadvantages.

The present invention is a torque transmitting device comprising a rotary torque input element adapted to be drivably connected with motor means, a rotary torque output element adapted to be drivably connected with driven means to which at least a part of the torque of the input element is to be transmitted, an inertia member operatively associated with said input element for revolving in common with and about the axis of rotation of same and for generally radial displacement relative to the axis of rotation of said input element, crank pin means generally parallel with the axis of rotation of said output element and secured to said output element for revolving in common with same about the axis of rotation of said output element and at a radial spacing from same, connection means having a first section operatively secured to said inertia member, and a second section connected to said crank pin means, the inertia member, the crank pin means and the connection means being so arranged and disposed as to allow rotation of the input element relative to the output element and to transmit onto said crank pin means a portion of centrifugal force acting on said inertia member as it revolves about the axis of rotation of said input element.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which Figure 1 shows a diagrammatic cross-section through a first embodiment on the line I - I of Figure 2, Figure 2 shows an axial section on the line Il-Il of Figure 1, Figure 3 shows a diagrammatic cross-section through a second modified embodiment with three inertia members, derived from the form of embodiment of Figure 1, Figure 4 shows an axial section substantially on the line IV-IV of Figure 3, Figure 5 shows a diagrammatic cross-section through a third modified embodiment, Figure 6shows a simplified section on the line VI-VI of Figure 5, Figure 7 shows a part of a cross-section similar two Figure 5 but in another relative torsional position between drive element and driven element, Figure 8 shows a diagrammatic cross-section through the form of embodiment of Figure 5 but in which the relative position between drive element and driven element is turned through 1800 in comparison with Figure 5, Figure 9 shows a diagrammatic axial section through a fourth embodiment, Figure 10 shows part of a section on the line X-X of Figure 9, Figure 11 shows a section similar to Figure 10 but with another relative torsional position between drive element and driven element.

Figure 12 shows a greatly simplified axial section through a fifth embodiment but in which several components are omitted for the sake of greater clarity, Figure 13 likewise shows a simplified axial section through a sixth modified embodiment, Figure 14 shows a section substantially on the line XIV-XIV of Figure 12, Figure 15 shows, very diagrammatically, the embodiment of Figure 12 seen in the axial direction, Figure 16 shows a diagrammatic cross-section through a seventh form of embodiment on the line XVI-XVI of Figure 17, and Figure 17 shows a section on the line XVII-XVII of Figure 16.

Reference will first be made to Figures 1 and 2.

The device 10 illustrated in these Figures 1 and 2 has a drive shaft 11 as a drive element and a coaxial driven shaft 12 as a driven element. Rigidly connected to the drive shaft 11 is a housing 13 in the form of a shallow, cylindrical box. Secured to the driven shaft 12 is a round crank disc 14 on the outer periphery of which is the housing portion 15.

Located in the housing 13, which is filled with a hydraulic fluid, are two separating or guide walls 16, 17 which are parallel to one another and lead from the peripheral outer wall 15' almost to the periphery of the crank disc 14. These separating or guide walls 16, 17 separate the interior 18 of the housing portion 13 from a displacement chamber 19. This displacement chamber 19 is connected to the interior 18 via a non-return valve 20 which is only indicated diagrammatically and which is constructed in the separating wall 16 (or 17) this non-return valve 20 opening towards the displacement chamber 19.

Mounted for displacement between the separating or guide walls 16 and 17 and the plane ends 21, 22 of the housing 13, that is to say in the displacement chamber 19, is a displacement member 23 constructed in the manner of a piston with an external cross-section in mirror image.

The displacement member 23, which is hollow, has a port 24 in its end and is coupled to a connecting rod 26 through a gudgeon pin 25 at its end opposite to the port 24. The other end of the connecting rod 26 is mounted on a crankpin 27 which extends from the flat side of the crank disc 14 adjacent to the interior 18 inwards parallel to the driven shaft 12.

Captive in the interior of the displacement member 23 is an inertia member 28 which is capable of limited displacement in relation to the displacement member 23 and at the same time forms a closing member for the port 24. The member 28 may have a certain lateral clearance with respect to the inner wall of the displacement member 23 or it may - as indicated - have a passage 29 with a small throughput capacity constructed in its wall surface.

In order to describe the mode of operation, reference should be made in particular to Figure 1 in which various relative torsional positions of the parts turning or rotating with the housing portiop 13 in relation to the driven shaft 12 which is assumed to be locked, are illustrated in broken lines. It is assumed that the drive shaft 11 and hence the housing 13 are rotating in the direction of the arrow 30, at a speed n. It is further assumed that the mass of the displacement member 23 and that of the connecting rod 26 are negligibly in comparison with that of the inertia member 28.

As a result of the rotation of the housing 13, the displacement member 23 and with it the member 28 are caused to rotate about the axis of rotation of the drive shaft 11. As a result, the member 28 is always exposed to a centrifugal force which is proportional to the square of the speed of rotation n and to the distance of the centre of gravity of the member 28 from the axis of the drive shaft 11. This centrifugal force is always directed radially with respect to the axis of the drive shaft 11.

In the relative position illustrated in full lines in Figure 1, this centrifugal force merely causes the member 28 to hold the port 24 closed with a relatively high closing force. The centrifugal force acting on the member 28 is taken up by the displacement member 23 and transmitted in full to the connecting rod 26 which in turn is radially directed. in this relative torsional position, therefore, no torque is yet exerted on the driven shaft 12 by the connecting rod 26 via the crankpin 27. The displacement member is in its outermost dead centre position.

If the next following relative torsional position between drive shaft 11 and driven shaft 12 in clockwise direction in Figure 1 is considered, then it will be seen that the crankpin 27 (assumed to be stationary) through the connecting rod 26 has caused the displacement member 23 and the member 28 captive therein, to be displaced radially inwards in the displacement chamber 19. This is easily possible thanks to the non-return valve 20 opening towards the displacement chamber 19. The centrifugal force (here designated by the arrow 31 ) still acts on the member 28 so that it continues to hold the port 24 closed and so transmits this centrifugal force to the displacement member 23.

The connecting rod 26, on the other hand, is no longer radially directed. It can onlytake up that component of the centrifugal force 31 which is directed in the same direction as itself and is designated by the arrow 32. The separating or guide walls 16,17 on the other hand take up the component 33 of the centrifugal force 31 at right angles thereto.

Since the connecting rod 26 is no longer directed radially, it has a spacing from the axis of the driven shaft 12 designated by r. Therefore, in this relative torsional position, the centrifugal force 31 acting on the member 28 has the effect that a torque is exerted on the driven shaft 12 via the crankpin 27, which torque is equal to the product of rwith the component 32 which in turn depends on the mass of the member 28 and on the speed of rotation of the drive shaft.

Such a torque arises (depending on the relative torsional position) until the displacement member 23 has reached its innermost dead centre position, as illustrated in broken lines facing downwards in Figure 1. The displacement chamber 19 has now reached its maximum volume and is filled with hydraulic fluid which has flowed through the (open) non-return valve 20. The connecting rod is again directed radially but inwards. In this torsional position, again no torque is exerted on the driven shaft 12.

If the housing portion 13 now runs faster than the driven shaft 12, a relative torsional position is reached as illustrated, for example in Figure 1 facing downwards on the left. The connecting rod 26, articulated on the crankpin 27 (assumed to the stationary) now displaces the displacement member 23 radially outwards in the displacement chamber 19. The non-return valve 20, which is now closed, does not allow the hydraulic fluid to escape from the displacement chamber 19. The decreasing pressure acts on the member 28 through the port 24, in precisely the opposite direction to the centrifugal force.As a result, the member 28 is lifted from the port 24 so that the hydraulic fluid has the possibility of flowing through the port 24 and past the member 28 (passage 29) out of the displacement chamber 19 back into the interior 18 (arrow 34), and does so until the displacement member 23 has again reached its outermost dead centre position. Naturally, the said pressure building up in the displacement chamber 19 contributes to producing a torque on the driven shaft 12 in the same direction as the direction of rotation 30. If the effect of this developing pressure is ignored, however, it can be shown that in the relative torsional positions in which the drive shaft 11 leads the driven shaft 12 by between 0 and 1800, a torque which can be taken off at the driven shaft 12 is produced by the centrifugal force 31 or by its component 32 alone, which torque increases from 0 (lead angle 0 ) to a maximum to drop to 0 again from the lead angle 1800.

Thus in the embodiment of Figure 1 - so long as no synchronism is reached between drive shaft and driven shaft - a torque is exerted intermittently on the latter, the frequency of these "torque shocks" being proportional to the difference in speed of rotation between drive shaft and driven shaft.

In order to mitigate this intermittent transmission or production of torque, the solution illustrated in Figures 3 and 4 can be selected for example. Here three displacement chambers 19,19', 19" are provided distributed in the housing portion 13 at uniform angular distances apart of 1200 round the axis of the drive shaft, and each containing a displacement member 23, 23', 23" with inertia members "captive" therein. The connecting rods 26,26', 26" articulated on the displacement members 23, 23', 23" are all articulated on the same crankpin 27 of the crank disc 14.

As a result of this arrangement, at least one of the displacement members with its inertia member is always sure to be in a position with respect to the crank disc 14 which can be designated as leading the driven shaft 12 between 0 and 1800, that is to say in such a position that the centrifugal force acting on the inertia member in question exerts a torque directly on the driven shaft 12. While an embodiment is shown in Figures 3 and 4 in which three displace mentchambers each with a displacement member and a mass member, are provided, it is obvious that four or more displacement chambers of like construction may be disposed in one and the same housing portion.

The embodiment of Figures 5,6,7 and 8 is based on the endeavour firstly to increase the mass of the inertia member, thus increasing the centrifugal force, and secondly to increase the length both of the crank arm of the crankpin 27 (distance of the axis of the crankpin from the axis of the driven shaft 12) and also the length of the connecting rod 26, with substantially the same external dimensions of the housing portion 13.

As distinct from the embodiments in Figures 1,2 and 3, 4, in the embodiment of Figures 5 - 8, the member 28 is rigidly connected to the displacement member 23 which is solid in construction. The displacement chamber 19 is disposed at the opposite side of the mass member 28 - in relation to the axis of the drive shaft 11. Accordingly, the nonreturn valve 20 is constructed so that it closes towards the displacement chamber 19. The closing member 35 of the non-return valve 20 also comprises a port 36 with a small throughput capacity, the purpose of which is to allow a throttled stream of the hydraulic fluid from the interior 18 into the displacement chamber 19, while the flow out of the displacement chamber 19 can take place practically unhindered.

In the embodiment of Figures 5 - 8, the member 28 is not only guided for displacement through the displacement member 23 rigidly connected thereto and the guide walls 16, 17 but also through two lateral tongues 37, 38 formed thereon which can slide along plane outside wall portions 39,40 of the housing portion 13 and also contribute to the mass of the member 28.

Consider now the operation of the embodiment of Figures 5 - 8: In Figure 5, the device is shown in the position in which the housing portion 13 and hence the mass member 18, and the displacement chamber 19 with the displacement member 23 do not lead the crankpin 27 or the driven shaft 12 (lead angle 0 ).

The connecting rod 26 is directed like a radius extending from the axis of the driven shaft 12. The centrifugal force to which the member 28 is exposed, since it is directed in the same way as the said radius, does not exert any torque on the driven shaft 12. The member 28 is in its outermost dead centre position whereas the displacement member 23 is in its innermost dead centre position.

If the housing 13 now leads the driven shaft 12, for example by 90 , the situation illustrated in Figure 7 results. The connecting rod 26 has caused the member 28 to approach the axis and at the same time to introduce the displacement member 23 further into the displacement chamber 19. This occurs practically without resistance because the non-return valve 20, which is now open, permits the hydraulic fluid to flow out. Acting on the mass member 28 is the centrifugal force 31 of which the component 32 exerts a corresponding torque on the driven shaft 12 through the lever arm r, while the component 33 is taken up by the side wall portion 40 or the guide wall 17.

This effect, namely the exertion of a torque on the driven shaft 12 continues until shortly before a lead angle of 1800 is reached between housing 13 and driven shaft 12. This situation is illustrated in Figure 8. The member 28 has reached its innermost dead centre position and the displacement member 23 has reached its outermost dead centre position and the connecting rod 26 faces radially inwards, starting from the crankpin 27. The displacement chamber 19 has its smallest volume and the non-return valve 20 is now closed. The displacement chamber 19 only remains in communication with the interior 18 through the port 36.

If, starting from the position illustrated in Figure 8, the housing 13 leads the driven shaft 12 further, then the connecting rod again displaces the member 28 outwards and so forces the displacement member 23 out of the displacement chamber 19. As a result, a reduced pressure develops in the latter (depending on the throughput capacity of the port 36) which counteracts the centrifugal force to which the mass member 28 is exposed. On the one hand, this reduced pressure contributes, if only to a small extent, to the fact that a torque in the same direction is exerted on the driven shaft 12 and on the other hand that the resulting force acting radially on the member 28 is considerably smaller than the pure centrifugal force. Thus in the region of the lead angle 1800 - 360 , the torque originating from this resulting force and acting in the opposite direction on the driven shaft 12 is in any case smaller than that in the range of the lead angle 0 - 180". Thus the integral found over the whole lead angle range 0 - 360" of the torques exerted instantaneously on the driven shaft 12, remains positive, that is to say the same as the direction of rotation 30.

The embodiment in Figures 9 - 11 is derived from the embodiment of Figures 5 - 8. Here the member 28 is not rigidly connected to the displacement member 23 but is displaceable to a limited extent in relation to the latter (comparable with the embodiment in Figure 1).

For this purpose, the displacement member 23, which is here provided with a through bore 41, comprises two laterally projecting wings 42,43 on its end remote from the displacement chamber 19 (Figure 10). Immediately preceding these wings, the displacement member 23 comprises a transverse bore 44 originating from the bore 41 and having a restricted throughput capacity. The wings 42,43 are disposed in a recess 45 formed in the member 28 and itself so dimensioned and shaped that the member 28 can be displaced to a limited extent in its longitudinal direction with respect to the displacement member. The two wings 42,43 are each engaged under by an extension 46 or 47 formed on the member (Figure 10), a further port 48 with a limited throughput capacity, leading from the recess 45 to the interior 18 being formed in the extension 46.

It can further be seen from Figure 10 that the non-return valve 20 likewise closes towards the displacement chamber 19 but the closing member 35 is not provided with any port. The connecting rod 26 (as in Figure 1) is articulated on the displacement member 23 through the gudgeon pin 25 which is here of bent construction. (Figure 9).

From what has been said it follows that in this embodiment the mass member 28 or its extension 46 acts as a "closing member" which frees or prevents the communication between the transverse bore 44 and the port 48 - according to the relative torsional position between drive shaft and driven shaft.

Apart from this the construction of the embodiment in Figures 9 - 11 corresponds largely to that of Figures 5 - 8.

The operation of this embodiment likewise corresponds largely to that of Figures 5 - 8, with the difference that in the lead angle range 1800 - 360" (for example illustrated in Figure 11) the flow of hydraulic fluid out of the interior 18 into the displacement chamber 19 does not take place through a restrictor in the region of the non-return valve 20 but through the port 48, the transverse bore 44 and the bore 41. In the course of this, the communication between transverse bore 44 and the port 48 is freed, constricted more or less according to the pressure drop between the pressure prevailing in the interior 18 and the reduced pressure developing in the displacement chamber 19.

In Figures 12, 14and 15a practical embodiment with a total of 8 inertia bodies is illustrated very diagrammatically, associated with each of which is a two part displacement member in a displacement chamber which is likewise in two parts.

Here mounted on the drive shaft 11 is a gearwheel 49 which meshes with a gearhweel 51 mounted on a wall entrance of the housing portion 13, constructed in the form of a bearing hub 50. Present in the interior of the housing portion 13 are two groups, disposed axially offset, each with four two-part displacement chambers 19,19', in turn disposed axially offset, (Figure 14), only one of these displacement chambers being shown in Figure 12forthe sake of simplicity. The displacement chambers in each group are disposed turned through 90" in relation to one another, while one group is disposed turned through 45" in relation to the other group.

This can be seen from Figure 15 where the directions of the four displacement chambers of one group is indicated by the broken lines 119 and those of the displacement chambers of the other group by the broken lines 219.

Each part of the two-part displacement member 23, 23' extends into the corresponding part of the two-part displacement chamber 19, 19' and is formed on the side of the mass member 28 (see Figure 14). Each of the eight inertia members is articulately connected to an associated connecting rod 26 through a gudgeon pin 25. The connecting rods 26 of the one group of mass members are coupled, each through a ball bearing 52, to a common crankpin 27 originating from a crank disc 14 (Figure 12, left), the connecting rods of the other group are coupled, likewise each through a ball bearing (not illustrated) to a common crank pin 27' originating from a crank disc 14'.

The two crank discs 14,14' are disposed turned through 1800 in relation to one another. In order to ensure that reference position of the two crank discs 14, 14' turned through 1800 is retained, the two crank discs 14, 14' may be coupled to one another through a gear train originating from their shafts 12, 12' (consisting of gearwheels 53, 54, 55, a shaft 56 and gearwheels 55', 54', 53') or through a crank web 57 secured to the ends of the two crankpins 27, 27'. If the crank web 57 is provided, the need for one of the shafts 12, 12' and the gear train is eliminated so that the remaining shaft 12' or 12 can serve directly as a driven shaft.

The form of construction of each set of mass members 28 with associated displacement members 23, 23' and displacement chambers 19, 19' corresponds in principle to that of Figures 5 - 8 with the difference already mentioned that the displacement members, and so also the displacement chambers, are in two parts, so as to provide the necessary space for the crankpin 27 and the connecting rod 26 between them. These two elements are not disposed axially offset in relation to mass members, displacement members and displacement chambers as in Figures 5 - 8, but practically in the same plane.

Accordingly, there is a recess 58 in the mass member which permits swinging of the connecting rod 26 in relation to the mass member 28.

The two parts 19, 19' of the displacement chambers are each in communication with the interior 18 through a non-return valve 20, 20' closing towards this, and the resiliently prestressed closing member 35 of each of these non-return valves 20, 20' is provided with a port 36 with a restricted throughput capacity as illustrated in Figure 14, bottom left.

From what has been said it follows that the mode of operation of each set of inertia members, displacement members and displacement chambers of the form of embodiment of Figures 12,14,15 corresponds substantially to that of the form of embodiment of Figures 5 - 8. Thus each set exerts a torque component, through the crankpin in question, on the corresponding driven shaft 12, 12' depending on its instantaneous lead angle with respect to this driven shaft. It has already been explained that this torque component has a maximum in the lead angle range between 0" and 180 .

Since, in Figures 13,14, a total of eightsets of inertia members, displacement members and displacement chambers are present, which are each disposed turned through 45 in relation to one another (see Figure 15), one or two of these sets is always in the "most favourable" lead angle range.

Since the torque components originating from the individual sets are superimposed, a practically shock-free torque can be taken off at the driven shaft 12 or 12' of the embodiment of Figures 12, 14, 15 and is the greater the higher the speed of rotation of the drive shaft 11 or of the housing 13.

Finally, Figure 13 shows an embodiment which is derived in principle from that of Figures 9 - 11, and which is particularly suitable for aligning any desired number of sets of mass members, displacement members and displacement chambers axially on the unit construction principle in an optimum relative torsional position.

The embodiment illustrated in Figure 13 has a stationary housing 60 constructed, in practice, for example, from a plurality of parts axially flanged together. A driving disc 61 is secured to the drive shaft 11 leading into the housing 60. The driving disc 61 carries external teeth 62 which mesh with a pinion 63 which in turn is mounted on a shaft 64 which is mounted for rotation in the housing 60 and has an axis parallel to that of the drive shaft 11 and which extends through the whole housing 60. Mounted on the shaft 64 is a further pinion 65 which is like the pinion 63, and meshes with external teeth 66 on a second driving disc 67.The two driving discs 61,66 are constructed alike in principle but here (since only two driving discs are present) are disposed turned through 1800. The connection of the two driving discs 61,66 through the pinions 63, 65 and the shaft 64 offers a guarantee that this position turned through 180 is retained. Constructed on each driving disc is a displacement chamber 19 which extends substantially radially to the drive shaft 11. As in Figures 9 - 11, the associated tubular displacement member 23 extends in each displacement chamber 19 and has a mass member 28 coupled to its end remote from the displacement chamber 19. Mounted for rotation in these ends of the displacement members 23 is a pin 27 which is parallel to the drive shaft 11 and which projects in the axial direction from the periphery of an eccentric disc 68.The two eccentric discs 68 are each mounted for rotation in a recess 69 or 70, which in turn is formed eccentrically in a first and second driven disc 71,72 respectively.

The two driven discs 71,72 - like the driving discs 61, 66 - carry external teeth 73 and 74 and are coupled to one another for synchronous running through pinion-shaft-pinion as indicated diagrammatically at 75.

Following on the driven disc 72 is the driven shaft leading out of the housing 60. The eccentric discs 68 in their recesses 69 and 70 here take over the function ofthe connecting rods and crankpins shown in the previous forms of embodiment, the length of the crank arm corresponding to the distance from the centre of the eccentric disc to the axis of the driven shaft 12 (arrow 127) and the length of the connecting rod corresponding to the distance from the middle of the eccentric disc 68 to the axis of the pin 67 (arrow 126).

From what has been said it is clear that the embodiment of Figure 13 is to some extent composed of two "stages" which are frictionally connected in parallel but geometrically axially one behind the other and are disposed turned through 180 in relation to one another, each individual one of which is constructed in principle like the embodiment in Figures 9 - 11 and works accordingly.

In the embodiment in Figures 16 and 17, the drive shaft 11, the driven shaft 12, the housing 13 filled with hydraulic fluid and the inertia member 28 are seen. The interior 18 of the housing 13 is traversed by two guide rods 76,77 on which the member 28 is mounted for displacement. The guide rods 76, 77 thus ensure that the member 28 is caused to rotate about the axis of rotation of the drive shaft 11 or of the housing portion 13. An L-shaped coupling member 78 is mounted for rotation in the member at 81 by its shorter arm 79 parallel to the drive shaft 11.

The other arm 80 of the coupling member 78, which is at right angles to the arm 79 engages telescopically in the manner of a plunger piston in a sleeve member 82 which is open at one end and which contains the displacement chamber 19. Anchored on the sleeve member 82 is the crankpin 27 which is parallel to the drive shaft 11 and which in turn is mounted for rotation in a pin sleeve 83. The pin sleeve 83 is rigidly secured at one end to the crank arm 14' originating from the driven shaft 12 and carries, at the other end, a substantially circular closing disc 84 of which the end face adjacent to the sleeve member 82 comprises two plane surface sections 85,86 of which the surface section 85 bears as closely as possible against the sleeve member 82 while the surface section 86 has spacing from the sleeve member 82.Fundamentally, the closing disc 84 could have only the shape of half a circle which extends only over the surface section 85.

The sleeve member 82, in which the arm 80, which may be provided with seals 87, engages in the manner of a plunger piston, comprises at its end remote from the arm 79 only one port 88 which leads to a passage 89 formed on the sleeve member 82.

This passage 89 leads to an inlet 90 in the region of the closing disc 84. This inlet 90 is closed or at least very greatly constricted by the surface section 85 so long as the inlet 90 sweeps over the surface section 85 in the corresponding relative torsional position between housing portion 13 and driven shaft 12. On the other hand, the inlet 90 is open when it passes the region of the surface section 86.

With regard to the operation of the embodiment in Figures 16,17, it is again assumed that the drive shaft 11 and hence the housing 13 with the guide rods 76,77 is turning the direction of the arrow 30 while the driven shaft 12 and hence the crank arm 14' with the pin sleeve 83 is stationary. In Figure 1 the starting position is illustrated in which the angle by which the housing 13 leads the crank arm 14' amounts to 0 . With the pin sleeve 83 stationary and the housing 13 rotating, the arm 80 and the sleeve member 82 can only turn about the axis of the crankpin 27 designated by 91 (Figure 17). As a result however, the inlet 90 is immediately closed by the surface section 85 as a result of which hydraulic fluid is prevented from flowing from the interior 18 into the interior of the sleeve portion 82.Thus the coupling member 78 together with the sleeve member 82 behaves like a connecting rod which is not variable in length, between pin sleeve 83 and member 28. With an increasing lead angle therefore, the member 28 is increasingly caused to be displaced along the guide rods 76,77 towards the axis of the drive shaft 11, while at the same time the arm 80 and the sleeve member 82 are no longer in alignment with the crank arm 14'. Since a centrifugal force directed radially away from the axis of the drive shaft 11 always acts on the inertia member 28, however, - because of the bent position between arm 80, sleeve member 82 on the one hand and crank arm 14' on the other hand, a torque directed in the same direction as the direction of rotation 30 is exerted on the driven shaft 12 through the crank arm 14', somewhat as explained with reference to Figure 1.

As soon as the angle by which the housing 13 leads the driven shaft 12 has reached about 180 , however, the inlet 90 is freed so that only hydraulic fluid from the interior 18 can flow through the passage 89 into the interior of the sleeve member 82, that is to say into the displacement chamber 19. The "connecting rod" formed by this and the coupling member 78 can thus increase its length according to the amount of hydraulic fluid flowing in through the inlet 90, and the member 28 (which reached its position closest to the axis shortly before the lead angle 180 ) can again be displaced into its position furthest away from the axis of the drive shaft 11, under the action of the centrifugal force, without a torque being exerted on the driven shaft 12 through the crank arm 14' as a result.This state continues until the lead angle amounts to 360 or again 0 , that is to say until the reference position illustrated in Figure 16 is reached again.

The devices described are intended to be used as a power transmission unit for engine-driven craft (on land and on water), although other possible uses are perfectly conceivable. The device described can be used in motor car construction. There it can replace the conventional clutches (or torque converters), gears and even the differential gear according to where and how many devices are used. The reduction which can be achieved in net weight (and also in production costs) is as obvious as the improvement which can be achieved in the power transmission characteristic. With this application, a simple transmission stage may appropriately be provided between the engine shaft and the drive element of the device, increasing the speed of the latter, and a reduction stage may follow the driven element. This is because the centrifugal force acting on the mass member or members 28 increases with the square of the speed of rotation so that - with constant torque requirements - the mass of the inertia member and hence the dimensions of the device can be reduced accordingly. In the device described, no friction occurs in the whole slip range between drive element and driven element - apart from bearing friction - and in addition even with slip of 0% it cannot be said that there is a positive connection between drive element and driven element.

Claims (26)

1. A torque transmitting device comprising a rotary torque input element adapted to be drivably connected with motor means, a rotary torque output element adapted to be drivably connected with driven means to which at least a part of the torque of the input element is to be transmitted, an inertia member operatively associated with said input element for revolving in common with and about the axis of rotation of same and for generally radial displacement relative to the axis of rotation of said input element, crank pin means generally parallel with the axis of rotation of said output element and secured to said output element for revolving in common with same about the axis of rotation of said output element and at a radial spacing from same, connection means having a first section operatively secured to said inertia member, and a second section connected to said crank pin means, the inertia member, the crank pin means and the connection means being so arranged and disposed as to allow rotation of the input element relative to the output element and to transmit onto said crank pin means a portion of centrifugal force acting on said inertia member as it revolves about the axis of rotation of said input element.

2. A device as claimed in claim 1, wherein the inertia member is slidably guided by guide means secured to said input element for revolving in common with same and adapted to guide the inertia member along a displacement line generally perpendicularto the axis of rotation ofthe input element.

3. A device as claimed in claim 2, wherein the inertia member is coupled with a displacement member arranged for revolving in common with said inertia member and for sliding within a displacement chamber along said displacement line, said device comprising motion retarding means for retarding the movement of said displacement member relative to said displacement chamber in one direction of said displacement line.

4. A device as claimed in claim 3, wherein walls of said displacement chamber form said guide means.

5. A device as claimed in claim 3 or 4, wherein said connection means is a connecting rod coupling said displacement member with said crank pin means.

6. A device as claimed in claim 3 or 4, wherein said displacement chamber includes hydraulic fluid communication means for communicating said chamber with a hydraulic fluid storage means.

7. A device as claimed in claim 6, wherein said storage means is a part of a casing portion surrounding said displacement chamber and integral with said input element.

8. A device as claimed in claim 3 or 5, wherein the displacement member is a piston-like element arranged for reciprocating movement within said displacement chamber and having a passage for hydraulic fluid, said device comprising passage control means for controlling the rate of flow of hydraulic fluid through said passage, in dependence on an instant angular displacement of the input element relative to the output element, by the movement of the piston-like element.

9. A device as claimed in claim 8, wherein said inertia member is arranged for reciprocating motion relative to said piston-like element, said inertia member including a closure section forming said passage control means.

10. A device as claimed in claim 9, wherein said closure section is a part of the inertia member disposed inside the piston-like element and adapted to engage an end wall of said piston-like element, said passage being provided in said end wall.

11. A device as claimed in claim 9, wherein said piston-like element is a tubular element whose one end protrudes out of said displacement chamber, said inertia member being engaged with said one end by way of an engagement member being engaged with said one end by way of an engagement allowing axial play of the inertia member relative to said one end, said closure section being actuated by axial movement of the inertia member relative to said one end.

12. A device as claimed in claim 6, wherein the displacement chamber, the displacement member and the inertia member are all at the same side radially of the axis of rotation of said input element, said displacement chamber being provided with a non-return valve allowing passage of hydraulic fluid only into the displacement chamber to thus communicate the displacement chamber with said part of the casing portion.

13. A device as claimed in claim 6, wherein the displacement chamber and displacement member are arranged on one side radially of the axis of rotation of said input element, while the inertia member is disposed on generally diametrically opposite side radially of the axis of rotation of said input element, said displacement chamber being provided with a non-return valve allowing passage of hydraulic fluid only out of the displacement chamber to thus communicate the displacement chamber with said part of the casing portion.

14. A device as claimed in claim 13, wherein said inertia member is fixedly secured to each other to form an integral part connected by a connecting rod with said crank pin means.

15. A device as claimed in claim 14, wherein said device further comprises fluid flow throttling means for throttling the flow of hydraulic fluid from the displacement chamber when the valve is closed.

16. A device as claimed in claim 15, wherein said throttling means is formed in a closing member of said valve.

17. A device as claimed in claim 2, comprising two or more of said inertia members each having a respective guide means, the guide means extending at a uniform angular spacing from each other, generally radially away from the axis of rotation of said input element.

18. A device as'claimed in claim 17, wherein said crank pin means is a single means and is connected to all of said inertia members.

19. A device as claimed in claim 17, wherein a number of said inertia members is coupled, by said connection means, with a respective crank pin means, and wherein at least two crank pin means is provided, said crank pin means defining crank arms disposed radially with respect to the axis of rotation of said output element and being disposed at a uniform angular spacing from each other relative to the axis of the output element.

20. A device as claimed in any of claims 1,2,3 or 6, wherein said connection means includes two telescoping members being disposed between the first section and the second section of the connection means, whereby the length of said connection means from said connection means from said displacement member and said crank pin means is variable.

21. A device as claimed in claim 20, wherein said telescoping members include a first telescoping member and a second telescoping member, said firsttelescoping member being an L-shaped member having a first shank generally parallel with the axis of rotation of said input element and mounted for pivoting relative to said inertia member, and a second shank perpendicular to the first shank and engaging in a plunger-like fashion one end of a sleeve member forming said second telescoping member, the other end of said sleeve member forming said displacement chamber, whereby said second shank forms in effect said displacement member.

22. A device as claimed in claim 21, wherein the other end of said sleeve member is provided with a passage communicating the displacement chamber with a channel terminating at a port disposed in proximity to said crank pin means and controlled by a closing plate fixedly secured to a pivot sleeve at a free end of a crank arm fixed to the output element and adapted to pivotally receive a follower fixedly secured to said sleeve member, to combine therewith in forming said crank pin means.

23. A device as claimed in claim 2, wherein said crank pin means is formed by a follower fixedly secured to the inertia member and adapted to engage a cam-shaped coulisse having a generally semicircular shape eccentric with respect to the axis of rotation of the output element, said coulisse being fixedly secured to said output element.

24. A device as claimed in claim 1, wherein the inertia member is swingable about a pivot pin generally parallel with the axis of rotation of the input element and eccentric with respect to same.

25. A device as claimed in claim 24, wherein the inertia member comprises a follower adapted to engage a generally semicircular cam or coulisse disposed eccentrically with respect to the axis of rotation of said output element and fixedly secured to the output element, whereby the cam or coulisse and the follower combine to form said crank pin means and a part of said connection means.

26. Atorquetransmitting device substantially as hereinbefore described, with reference to and as shown in the accompanying drawings.