GB2213217A

GB2213217A - Planetary gearing for accessory drive

Info

Publication number: GB2213217A
Application number: GB8827300A
Authority: GB
Inventors: Wolfgang Baier
Original assignee: Fichtel and Sachs AG
Current assignee: ZF Sachs AG
Priority date: 1987-11-26
Filing date: 1988-11-23
Publication date: 1989-08-09
Also published as: IT8868049A0; DE3740082C2; IT1223935B; DE3740082A1; FR2623868A1; FR2623868B1; GB8827300D0

Description

0 01 1. 1 " 2 2 13.,- 1 Torque transmission unit

The invention relates to a torque transmission unit of the kind as stated in the opening statement of Claim 1.

The drive of the secondary units of a motor vehicle engine, for example cooling water pump, fan wheel, lubricant pump, oil pump for supplying hydraulic units, airconditioning plant, compressor of an internal combustion engine, in general takes place rigidly, for example through a belt drive system, with a fixed ratio of rotation rates dependent upon the belt pulley transmission ratio. Since the rotation rate range of modern internal combustion engines is becoming ever greater, in the case of rigid drive of the secondary units a large rotation rate range in which they must operate also results for the secondary units.Since in general the secondary units work optimally only in one specific design rnge, in idling or at low engine rotation rate these do not deliver their desired performance, while at high engine rotation rate they run at bursting rotation rate and in any case absolutely in the uneconomical range.

It is already known to couple the secondary units with the internal combustion engine through torque transmission units which permit a variation of the rotation rate ratio between internal combustion engine and secondary units, whether for example in order to limit the maximum rotation rate of the secondary units, to ensure a minimum rotation rate of the secondary units even at low engine rotation rate, or quite generally to operate the secondary units always in a favourable rotation rate range in the cases of different engine rotation rates.

A torque transmission unit of the kind as stated in the opening statement of Claim 1 is known from DE-OS No. 2,303,562. The variation of the rotation rate ratio between the input member and the output member is effected by means of a planet gear in which the torque transmission path is connected from the input member by way of the hollow wheel, which is constantly fixedly connected therewith, optionally by way of the blocking device, directly to the output member or, after release of the blocking device, by way of the planet wheel carrier, which is driven with stepdown ratio, to the output member which is constantly firmly connected with the planet wheel carrier. The blocking device is formed as a mechanical centrifugal clutch which is coupled at low rotation rate, so that it drives the output member, while the free-wheel coupling arranged between the sun wheel and the stationary support member permits entraining of the entire planet gear as a block. After release of the centrifugal coupling the output member, loaded by the secondary units, lags behind so that the planet wheel carrier firmly connected therewith is driven by the hollow wheel; then the planet wheel is supported on the sun wheel, which in turn is hindered from a deviating reaction movement by the free-wheel clutch.

Mechanical blocking devices of the kind as described in DE-OS No. 2,303, 562 are constructionally very expensive. Since the power consumption of the secondary units is very high, especially in high-class modern motor vehicles, and peak moments for example of 50 Nm can occur at lower engine i R rotation rate, the required clutch area is very large, which leads to a large overall diameter or, when multi-disc clutches are used, to a great overall depth, so that in general the torque unit can no longer be arranged in the place usually proposed for it, in extension of the crank shaft of the internal combustion engine. Another disadvantage of a torque transmission unit of the known kind with mechanical blocking device is seen in that mechanical coupling faces are always subject to wear, especially if the torque transmission unit is driven for a long time in the region of the change-over point and therefore has to carry out a large number of change-over operations. Therefore relatively great service expense is necessary for the known torque transmission unit.

breover mechanical couplings also incline to a certain noise generation.

It is an object of the present invention to provide a torque transmission unit which is constructionally simpler and more compact, for a pre-determined transmission performance, than the known torque transmission unit, and in operation works with low and thus little service, and largely noiselessly.

According to the invention there is provided a torque transmission unit for the drive connection of at least one secondary unit with an internal combustion engine, comprising an input member in connection with an output shaft of the internal combustion engine,an output member in connection with the auxiliary unit, a planet gear in the torque transmission path between the input member and the output member, this planet gear formed with a sun wheel, a planet carrier, a hollow wheel and at least one planet wheel mounted on the - f+ - planet carrier and meshing simultaneously with the sun wheel and the hollow wheel, where of each of the parts sun wheel, planet carrier and hollow wheel one is the input member, a further one the output member and a further with a stationary support member transmission path is variable by connected or connectable with is connected or connectable with one is connected or connectable while furthermore the torque the planet gear, the transmission ratio between output member and input member being varied, while a free-wheel coupling is provided between the two parts of at least one first pair of parts from the group of parts: input member, output member, sun wheel, planet carrier, hollow wheel and stationary support member and a blocking device is provided between the two parts of at least one further pair of parts from the group of parts: input member, output member, sun wheel, planet carrier, hollow wheel and support member, characterised in that the blocking device is formed by a pump unit having two mutually relatively rotatable pump sub-units, with suction means and outflow means, the pump sub-units being rotatable in relation to one another, that is the blocking device being released, on opening of the outflow means, and being non-rotatable in relation to one another at least in one direction of rotation, that is the blocking device being blocked, on shutting-off of the outflow means, and shut-off means being provided in the outflow means.

The blocking device is formed by a pump unit having two pump sub-units rotatable in relation to one another and having an inlet and an outlet for the pump medium, where the pump sub-units are rotatable in relation to one another on - c- 8 opening oE the pump outlet and are non-rotatable in relation to one another in at least one direction of rotation on blocking of the outlet. Fundamentally all hydrostatic or volumetric hydraulic pumps come into question as blocking devices. Accordingly when the outlet is open the blocking device is released, when the outlet is closed the blocking device is blocked. Controllable shut-off means are provided in the outlet of the pump unit. Such pump units are very simple in design and construction. Since the power is not transmitted through components situated mechanically in frictional engagement with one another, they are low-wearing and therefore need little or no servicing; furthermore their noise generation is extremely low. The essential advantage of a blocking device formed by a pump unit is seen in that this, for a pre-determined power throughput, has smaller constructional dimensions than the known mechanical solution, so that the torque transmission unit can for example be attached directly to the housing of the internal combustion engine in extension of the crank-shaft.

A device for the limitation of the drive rotation rate of secondary units of a vehicle internal combustion engine is already known from DE-OS No. 2, 938,356, in which a gear pump is used as clutch pump. In this case a slider valve displaceable by centrifugal force against the force of a spring is arranged in a rotating cover part, which valve closes the outlet of the gear pump at low rotation rate of this cover part, so that a driven input member entrains the output member; when a specific rotation rate is reached the slider valve opens and clears the outlet of - the gear pump to - G such extent in each case that a specific maximum rotation rate is not exceeded. The control edges of the slider valve act as a constriction point where the excess pressure energy of the pump medium, which is not to be used for a further increa-se of the rotation rate of the output member, is destroyed. While thus an excess rotation rate of the secondary units can be avoided, a reduction of the energy to be supplied by the internal combustion engine in the case of lower energy requirement of the secondary units is not however achievable therewith.

In further development of the invention it is provided that the shut-off means in the outlet of the pump unit are actuated in dependence-upon an operational condition of the internal combustion engine or a peripheral unit connected with the internal combustion engine. The determining operational conditions of the internal combustion engine are preferably its rotation rate, but secondarily also the rotation rate acceleration and the power demanded from the internal combustion engine at the time; as determining operational conditions of the peripheral units mention may be made for example of the state of charge of the battery and thus the power consumption of a dynamo connected with the internal combustion engine, or the reachi.ng of bursting rotation rate of one of the secondary units.

In one development of the design in accordance with the invention it is provided that the shut-off means are controlled in dependence upon the rotation rate of a rotating part of the internal combustion engine, of the torque transmission unit or of a secondary unit. In the - -7 - torque transmission unit in this case the possibility exists of actuation of the shut-off means by a part rotating with the input rotation rate or a part rotating with the output rotation rate, as will be explained more preci sely by reference to the examples of embodiment.

In another development of the design in accordance with the invention it is provided that the shut-off means are controlled by a control unit arranged outside the torque transmission unit. Such a control unit can for example actuate an electrically actuatable valve arranged in the output of the pump unit, which valve is controlled in dependence upon signals which are issued by measuring sensors arranged on the internal combustion engine, the torque transmission unit or the secondary units for the monitoring of different operational conditions.

The shut-off means can also be controlled in accordance with the invention by a control unit accommodated within the torque transmission unit. Such a control unit preferably uses a centrifugally actuated valve arrangement which opens or closes the outlet of the pump unit according to choice. Thus it is possible to build a very compact unit completely enclosed to the exterior, the change-over point of which depends upon the input rot4tion rate or the-output rotation rate of the torque transmission unit, or upon an intermediate rotation rate.

According to the present invention the shut-off means can be controlled in such a way that at low rotation rates of the input member the ratio of the rotation rate of the output member to therotation rate of the input member has a first greater value, and that at higher rotation rates of the input member the ratio of the rotation rate of the output member to the rotation rate of the input member has a second lower value. At low engine rotation rates there is accordingly -a greater transmission ratio to the secondary units, at greater engine rotation rate a smaller transmission ratio. Without consideration of the additionally provided belt pulley transmission ratio the design can for example be made such that in the torque transmission unit at low input rotation rate there is a step-up transmission, at greater input rotation rate there is a 1: 1 coupling, or that at low input rotation rate ther'e'is a 1: 1 coupling and at high input rotation rate a step-down takes place. The invention also renders an arrangement possible in which at low input rotation rate there is a step-up transmission, at medium rotation rate a 1' : 1 coupling and at high rotation rate a step-down takes place, as will be explained by reference to the examples of embodiment.

In further development of the invention it is provided that the shut-off means are controlled in dependence upon the variation of the operational state in such a way that on variation of the operational state in a first. dir'ection they respond at a first operational state value and on variation of the operational state in a sedond direction they respond at a second operational state value. The shut-off means are preferably controlled in dependence upon the rotation rate of a rotating part in such a way that on increase of the rotation rate of the rotating part they respond at a first - q - rotation rate value and on reduction of the rotation rate of this rotating part they respond at a second rotation rate value, the second rotation rate value being lower than the first rotation rate value. By this hysteresis effect it is possible to avoid the torque transmission unit constantly switching to and fro when the rotation rate of the rotating part remains over a lengthy period in the region of a change- over rotation rate.

In a further development of the invention a delay device is provided which delays the start-up of the torque transmission unit in relation to the start-up of the internal combustion engine. In this way it is possible to achieve the object that at a low engine rotation rate the torque transmission unit absorbs no power at all, so tha t the power to be supplied by the starter in the starting of the internal combustion engine for example is less.

The inlet or the suction means and the outlet or outflow means of the pump unit are connected, in preferred development of the inyention, with an internal fluid supply within the torque transmission unit, which supply is independent of external fluid supply.

In the case of an arrangement in which the blocking device is blocked at low ro.tation rate, in accordance with the present invention the suction means can be connected with a fluid supply in such a way that filling of the pump occurs with delay in relation to the start-up of the input member. This measure too serves to delay the full power take-up of the torque transmission unit in the start-up of the internal combustion engine until the latter makes an 1 adequate power available.

For this purpose the suction means and the outflow means are connected for example with an internal fluid supply within the torque transmission unit, which is housed in a rotating container within the torque transmission unit and on reaching of a pre-determined rotation rate of this container forms a fluid ring, the connection of the suction means with the fluid supply being brought about only after the formation of this fluid ring. Since a closed fluid ring, formed in the upper part of the container too, forms only at a specific minimum rate of rotation, the possibility exists of placing the suction opening of a conduit connected with the suction means into this upper region of the container, in order to achieve the desired delay in the pump filling.

In order at all costs to prevent damage to the secondary units as a result of exceeding of a maximum rotation rate, in the case of failure of the control means as described, in accordance with the invention furthermore an additional safety valve is arranged in the outflow means, which valve opens the outflow means at a predetermined maximum rotation rate, independently of the controlling by other control means.

In further development of the invention it is provided that the shut-off means are controllable in dependence upon the acceleration of the internal combustion engine. In the acceleration of a motor vehicle as far as possible the maximum power of the internal combustion engine should be available. The acceleration-dependent controlling-of the t X - I k shut-off means is intended to have the effect that at a specific acceleration of the internal-combustion engine the secondary units are in every case driven with their minimum rotation rate at which their power consumption and thus the loss of engine power are at the minimum.

In further development of the invention it is provided that the shut-off means are controlled in dependence upon the state of charge of a battery which is charged by a generator driven through the drive unit. Thus by way of example in the case of a poor state of charge of the battery the generator can be operated at high rotation rate, irrespective of the rotation rate of the internal combustion engine, until the state of charge of the battery is satisfactory.

In accordance with the invention the pump unit is for example a gear pump. Gear pumps are ordinary commercial appliances which with small overall dimensions can transmit a relatively high power, and which moreover require little maintenance and are reasonably priced. The gear pump is preferably an internal-rotor gear pump with a pump housing, an internally toothed gear ring mounted rotatably in the pump housing eccentrically of the housing axis and an externally toothed gear wheel rotating coaxially with the housing axis about the gear axis, the external toothing of which rolls on the internal toothing of the gear ring. The blocking device formed as gear pump has two operational conditions, namely blocked or released. On account of the incompressibility of the pump medium, when the outflow means are closed expulsion of the pump medium is prevented, so that rolling of the inter-engaging toothings on one another is not possible and the components provided with the toothings block in the housing. When the shut-off means are opened the gear pump delivers more or less without power in closed circuit operation.

The input member of the torque transmission unit can be arranged coaxially with an output shaft of the internal combustion engine or offset axially parallel therewith and connected by torque -transmission means with this output shaft. Thus there is great freedom of action for the designer.

In another example of embodiment the torque transmission unit comprises a frame which is stationary in relation to the internal combustion engine and on which a plurality of auxiliary units is fixedly arranged which are in drive connection with the output member. This solution renders it possible in one single working action to fit the torque transmission unit and all secondary units on the internal combustion engine, or to dismantle them therefrom.

For the arrangement of the free-wheel coupling, the blocking device and the shut-off valve arrangement, for the case where the latter is centrifugally controlled, various possibilities exist which are to be explained by reference to various examples of embodiment. Several examples of embodiment of the invention are desc ribed in greater detail hereinafter and illustrated in the drawing, wherein: - FIGURE 1 shows diagrammatically a torque transmission unit in which the input member is connected with the planet wheel carrier and the output member is connected with the 4 i - 12, hollow wheel and where the drive proceeds according to choice from the input member through the free-wheel coupling directly in the ratio 1: 1 or stepped up through the planet carrier to the first output member; in the first mode the blocking device arranged between sun wheel and support member is released, in the second mode it is blocked; the shut-off means for the blocking device are controlled by a control unit arranged outside the torque transmission unit; FIGURE 2 shows diagrammatically- a blocking device according to Figure 1 in a front elevation; FIGURE 3 shows a torque transmission unit approximately according to Figure I in an island arrangement offset axially parallel in relation to the crank-shaft of the internal combustion engine; FIGURE 4 shows a torque transmission unit somewhat according to Figure 1 in cassette arrangement connected with the secondary units through a common carrier to form a module; FIGURE 5 shows a torque transmission unit somewhat according to Figure 1, but in which the shut-off means of the blocking device are controlled by a control unit arranged within the torque transmission unit; FIGURE 5a shows in enlarged representation a modified control unit for use in Figure 5; FIGURE 6 shows a diagram of the rotation rate course of the output member over the rotation rate of the input member, without hysteresis; FIGURE 7 shows a diagram somewhat according to Figure 6, but with hysteresis;, - 1 L - FIGURE 8 shows a modification of Figure 1, in which the blocking device is arranged between input member and planet carrier;.

FIGURE 9 shows shut-off means and control unit for a torque transmission unit according to Figure 8;- FIGURE 10 shows a torque transmission unit somewhat according to Figure 8, where the shut-off means are controlled by a control unit arranged within the torque transmission unit; FIGURE 11 shows a modification of Figure 10, with a control unit arranged and formed differently therefrom; FIGURE 12 shows a modification of Figure 1 in which the blocking device is arranged between hollow wheel and output member, with a control unit arranged outside the torque transmission unit; FIGURE 13 shows a torque transmission unit somewhat according to Figure 12, with a control unit arranged within it; FIGURE 14 shows a torque transmission unit in which the input member is connected with the hollow wheel and the output member with the planet carrier while the drive proceeds according to choice from the input member through the blocking device directly in the ratio 1: I or stepped down by the hollow wheel and the planet carrier to the output member; in the former mode the free-wheel coupling arranged between sun 'wheel and support member permits a rotation of the sun wheel, in the second mode the sun wheel is hindered from a rotation; FIGURE 15 shows a torque transmission unit somewhat - is- according to Figure 14, where the control unit is arranged within the torque transmission unit; FIGURE 16 shows a torque transmission unit in which the input member is connected with the planet carrier and the output member with the sun wheel while the drive proceeds according to choice from the input member through the freewheel coupling directly in the ratio 1: 1 or, stepped up through the planet carrier, to the sun wheel; in the former mode the blocking device arranged between the hollow wheel and the support member is released, in the second mode it is blocked; FIGURES 17 to 19 show a torque transmission unit in which three different transmission ratios are possible; FIGURE 20 shows a diagram for the rotation rate course of the ou.tput member over the rotation rate of the input member in the torque transmission unit according to Figure 19; FIGURE 21 shows a longitudinal section through a torque transmission unit approximately according to Figure 1.

The torque transmission unit as represented in Figure 1 and designated as a whole by 2 comprises an input member 4 in connection with the output shaft 6 of an internal combustion engine, an output member 8 which can be connected with one or more auxiliary units, and a planet gear in the torque transmission path between the input member 4 and the output member 8. The planet gear for its part comprises a sun wheel 10, a planet carrier 12, on which at least one planet wheel 14 is mounted, and a hollow wheel 16. The hollow wheel 16 is integrated into one construc'tion group - 16, with a gear box 18 and the output member 8. For reasons of improved clarity only the parts arranged above the line of symmetry 20, of each of the planet carrier 12, the hollow wheel 16, the gear box 18 and the output member 8 are represented; the parts which are not illustrated are symmetrical with these and therefore dispensable to the description.

Between the sun wheel 10 and a stationary support member 22 a blocking device 24 is arranged, which in a released operational state permits a free rotation of the sun wheel 10, but in a blocked operational state connects the sun wheel fast in rotation with the support member 22. Between the input member 4 and the gear box 18 a free-wheel coupling 26 is arranged which permits a relative rotation of the gear box 18 in relation to the input member 4 in one direction, but blocks it in the other direction.

The function of the torque transmission unit 2 is as follows: With the blocking device 24 blocked, the sun wheel 10 is connected fast in rotation with the support member 22. On rotation of the input member 4 the planet carrier 12 firmly connected therewith is likewise rotated. The planet wheel 14 mounted on the planet carrier 12 rolls on the sun wheel 10 and drives the hollow wheel 16, and the output member 8 connected therewith, faster in relation to the rotation rate of the input member 4. The free-wheel coupling 26 permits the gear box 18, which likewise is revolving with stepped-up ratio, to overtake the input member 4 in the drive direction of rotation.

After release of the blocking device 24 the planet - I'l - wheel 14 can no longer support itself on the sun wheel 10 and therefore can no longer transmit drive power to the hollow wheel 16. On account of the loading by the secondary units the construction unit 8, 16, 18 retards until it is in synchronism with the input member 4, the free- wheel coupling 26 coupling the gear box 18 directly with the input member, so that the output member 8 connected with the gear box 18 rotates in the ratio I: 1 with the input member 4. Since the hollow wheel 16 connected with the gear box and the planet carrier 12 connected with the input member rotate at the same speed in the same direction of rotation, the planet wheel 14 does not roll, but entrains the sun wheel 10 likewise in the same direction of rotation and with the same speed of rotation; the planet gear rotates as a block.

The blocking device 24 is formed as a rotating hydrostatic pump unit with an inlet or suction means 28 and an outlet or outflow means 30 for the hydraulic pump medium, preferably oil. In the outflow means, in the outlet conduit 32 in the present example, shut-off means 34 are provided with which the outlet 30 can be shut off. When the outlet 30 is shut-off the blocking device 24 is blocked and the sun wheel 10 is connected fast in rotation with the support member 22, as has already been stated.

The outlet conduit 32 is guided in the present example of embodiment to outside the torque transmission unit, so that the shut-off means 34 can likewise be arranged outside the torque transmission unit. As represented diagrammatically, the shut-off Means 34 comprise for example a shut-off slider 38 actuated by a solenoid drive 36. The - I's - solenoid drive is actuated by a control unit 40 to which in turn signals are supplied through signal conductors 42, 44 which characterise an operational state of the internal combustion engine or of a peripheral unit connected with the internal combustion engine.

One of the signal conductors 42 is connected to a tacho-generator T which detects the rotation rate of the crank-shaf t 6. At low crank-shaft rotation rate the shutoff slider 38 is closed, so that the output member 8 is driven with stepped-up ratio and accordingly the secondary unit to be driven receives an adequate power supply, despite the low rotation rate of the crank-shaft 6. At high rotation rate of the crank-shaft 6 the shut-off slider 38 is open, so that the blocking device 24 is released and the output member 8 rotates with the same rotation rate as the crankshaft 6, so that despite the high rotation rate of the crank-shaft 6, over-high rotation rates of the secondary unit are avoided.

Since the blocking device 24 either runs completely freely, namely with open shut-off slider 38, or is completely blocked, in no operational condition is substantial power consumed in the blocking device 24 or on the shut-off slider. The shut-off means 34, just like the electrically actuated shut-off means

as described by ref erence to the further examples of embodiment, are preferably formed so that in the absence of current supply the secondary units are driven with a low transmission ratio, so that even at high engine rotation rate they do not reach their break-down - ic - rotation rate.. In the example according to Figure 1 accordingly the shut- off means 34 are open without current.

A diagrammatically represented device, designated as a whole by 46, is connected with -the input member 4, for the recording of the rotational acceleration of this input member 4, the electrical output value of which device, which characterises this rotational acceleration is fed by way of the signal conductor 44 to the control unit 40. The device 46 for rotational acceleration recordal has the task of opening the shut-off means, irrespective of other operational states, whenever the internal combustion engine must provide a high acceleration; when the shut-off means 34 are opened the blocking device 24 is released, so that the output member 8 is coupled-in the ratio I: 1 with the input member 4 in the manner as already described, so that the secondary units take up less power than in the case of a step-up transmission ratio of the output member 8. here it is advantageous that the pump unit forming the blocking device delivers largely- without power when the blocking device is released, so that the maximum possible power is available for the acceleration of the internal combustion engine.

Between the input member 4 and the output shaf t 6 of the internal combustion engine a centrifugal clutch 48 is arranged which is disengaged below a specific coupling rotation rate and engages automatically at this coupling rotation rate. The purpose of this centrifugal clutch is to separate the internal combustion engine entirely from the torque transmission unit 2 in the lower rotation rate range -.1 4z, - of the internal combustion engine, for example in order not to load the starter, in the starting of the internal combustion engine, with the torque transmission unit and the secondary units driven by it.

The outlet conduit 32 pertaining to the outflow means 30 has a branch 50 in which there is arranged a safety valve 52 acting in parallel with the shut-off means 34. This safety valve 52 comprises a valve housing, arranged on the planet carrier-12, with a valve body 56 which is loaded by a spring 58 in the closing direction and by centrifugal force in the opening direction against the force of the spring 58, which centrifugal force acts upon the valve body 56 when the planet carrier 12 is rotating. The saf ety va lve 52 is designed so that the blocking device 24 is released at a pre-determined maximum rotation ' rate independently of control by other control means, so that the torque transmission unit is shifted into the mode in which the secondary units have their lower rotation rate.

Figure 2 shows, in highly diagrammatic representation, a blocking device 24 formed as rotating hydrostatic pump unit. It comprises essentially a first pump sub-unit 60 formed by a housing and a second pump sub-unit. 62'rotatable in relation thereto, which in turn comprises an internally toothed ring 64 arranged eccentrically in relation to the housing and rotatable therein and an externally toothed gear 66 concentric with the housing. The housing 60 is Ponnected in Figure 1 with the stationary support member 22, while the gear wheel 66 is connected with the sun wheel 10. In the case of rotation of the second pump sub-unit 62 in the direction of the arrow 68 and with inlet means 28 and outlet means 30 opened, that is to say with shut-off slider 38 opened, the pump sucks in a fluid from the fluid reserve 19 (Figure 1) through the inlet means 28, transports it to the outlet means 30 whence - with the shut-off slider 38 opened - it is fed, without power, to the fluid reserve 19 again.

C51 By shutting off the outlet means 30 by means of the shut-off slider 38 in the manner as described above the fluid cannot be expelled through the outlet means 30, so that the rolling movement of the gear 66 in relation to the toothed ring 64 is not possible and thus the rotation of the gear 66 in relation to the pump housing 60 is blocked.

The fluid reserve 19 is accommodated within the gear box 18 and on rotation of the gear box 18 forms a fluid ring. Theupwardly directed suction conduit 29 connected to the inlet means 28 dips into this fluid ring so that the pump 24 is filled with fluid and thus can be effective as blocking device only when the fluid ring 19 has developed. This has the consequence that the step-up transmission occurs only when the input member 4 has already reached a certain minimum rotation rate. This ensures a low loading of the internal combustion engine in starting.

Figure 3 shows the transmission unit 2 according to Figure 1 (the nonobligatory device 46 for rotational acceleration recording having been omitted). In contrast to the arrangement according. to Figure 1, in Figure 3 the torque transmission unit 2 is not arranged coaxially with the output shaft 6 of theAnternal combustion engine, but is offset axially parallel therewith. The torque transmission unit 2 comprises an input shaft 70 which is connected through the centrifugal clutch 43 with the input member 4 of the torque transmission unit 2, as has already been described. On the input shaft 70 a belt pulley 72 is secured which is connected through a drive belt 74 with a belt pulley 76 arranged on the output shaft 6.

In Figure -4 again the torque transmission unit 2 according to Figures 1 and 3 is represented, the input member 4 again being arranged coaxially with the output shaft 6 of the internal combustion engine and connected therewith through a centrifugal clutch 48. The entire torque transmission unit 2 is arranged on a stationary frame 82 connected with the housing 80 of the internal combustion engine for example through connection means 78, which frame also carries the various secondary units 84. The respective input shafts of the secondary units 84 are connected for example through a chain 86 with the output member 8, which then is formed as chain wheel. The frame 82 can be formed preferably as a closed cassette. This arrangement according to Figure 4 renders it possible in one single action to fit the torque transmission unit with all attached secondary units on the internal combustion engine.

Figure 5 shows a torque transmission unit 502 which corresponds in its essential parts, for example the arrangement of the planet gear, of the free-wheel coupling 526 and the blocking device 524, to the torque transmission units as described with reference to Figures 1, 3 and 4. The shut-off means 534 comprise a centrifugally controlled valve arrangement, arranged on the input member 504, with a valve housing 553 and a valve body 555 radially displaceably arranged therein, which is loaded in the closing direction by a spring 557 and in the opening direction by the centrifugal force acting upon the valve body 555 when the input member 504 is rotating. The valve arrangement forming the shut-off means 534 is arranged in the outlet conduit 532 of the blocking device 524. Below a specific change-over rotation rate of the input member 504 or the internal combustion engine coupled therewith the valve body 555 closes the outlet conduit 532 and blocks the blocking device 524; when the change-over rotation rate is reached the valve body 555 is pressed radially outwards against the force of the spring 557 and liberates the outlet conduit 532, so that the blocking device 524 is released.

In the simplest case the rotation rate of the secondary units - taking into consideration any step-up or step-down between the torque transmission unit and the secondary units - follows a course as represented in solid lines in Figure 6. In the start-up of the internal combustion blocking device is blocked, the secondary units are driven with step-up transmission so that the rotation rate ratio between the secondary units and the internal combustion engine corresponds to the line A. At a specific change-over rotation rate nS of the internal combustion engine the blocking device is released, the output member 508 loaded by the secondary units retards more or less suddenly along the curve B and at the point C is coupled by the free-wheel 526 with the input member 504, so that the rotation rate of the secondary units on further acceleration follows the 1: 1 engine the A - Z4line D. On decrease of the rotation rate nMOT OE internal combustion engine the rotation rate nNA of the secondary units -likewise follows the continuous line D, B, A. As shown especially by Figure 1, the suction means 28 are connected through an inlet conduit 29 with an oil ring 19 developed in the gear box 18. Since this oil ring 19 develops only at a specific rotation rate of the gear box 18, the blocking device 24 is initially out of action at low engine rotation rates, so that the rotation rate of the secondary units initially follows the line D, which is relevant for the released blocking device, or its chain line prolongation F. only after the development of the oil ring 19 does the pump unit. which forms the blocking device, fill with the oil and, since the shut-off means 534 are closed, block the sun wheel 510 in relation to the support member 522, so that the rotation rate nNA from the origin 0 firstly follows the chain line E valid for the direct coupling and then merges by way of the dot-and-dash transition line F into the line A. This effect is desired, since thus the start-up of the secondary units is delayed in comparison with the start-up of the internal combustion engine, so that in the low rotation rate range the maximum possible power is not taken up from the internal combustion engine by the secondary units. The dot-and-dash line G describes the case where a centrifugal clutch 48 is arranged between the input member 4 in Figure 1 and the output shaft 6. This centrifugal clutch 48 has the effect that below a coupling rotation. rate nK the torque transmission unit and thus the secondary units are not driven at all; only at the rotation k k -2-Srate nK is the torque transmission unit driven, more or less suddenly, and are the secondary units accelerated initially to the line E characteristic of direct coupling, whereupon the rotation rate of the secondary units then follows the line F and passes over into the line A, in the -manner as already described.

In the case where the internal combustion engine is running for a lengthy time in the region of the rotation rate nSj in order to prevent the torque transmission unit from constantly switching to and fro between the lines A and D, shut-off means according to Figure 5a are used in place of the simple shut-off means 534. In the valve housing 753 a valve body 755 is arranged displaceably in the radial direction in relation to the input member 504. The valve body 755 is loaded-in the closing direction by a spring 757 and in the opening direction by centrifugal force. The valve body 755 is seated not directly in the valve housing 753, but in a valve bush 759 which is radially outwardly open and radially inwardly closed by a bottom 761. The bottom 761 is pierced by a compensating bore 763. The valve bush 759 is likewise radially displaceable and loaded in the radially outward direction by a spring 765. The inlet opening 767 of the valve housing 753 has opposite to the outlet bore 769 a radially inwardly offset lower edge. The valve bush 759 likewise has an inlet bore 771 and an outlet bore 773 which, in the position of the valve bush 759 as illustrated, are aligned with the inlet bore 767 and the outlet bore 769 rdspectively. The function of the shu't-off means 734 is as follows: - at low rotation rate of the - 9L6 - input mlember 504 the shut-off means 734 assume the mutual position as represented in Figure 5a. With increasing rotation rate the valve body 755 is displaced outwards against the force of the spring 757- until the lower edge of the valve body 755 lies at the level of the lower edges of the bores 767 and 771. Then below the valve body 755 an oil pressure builds up as a result of the constriction action of the compensating bore 763, which has the -consequence of a rapid and complete displacement of valve body 755 radially outwards and a displacement of valve bush 759 radially inwards. The shut-off means 734 suddenly opened at the change- over rotation rate, the blocking device 724 is released. Then the valve bush 759 returns into its position according to Figure 5a, because the oil pressure collapses on opening of the bores 773, 769.

With decreasing rotation rate of the input member 504 the centrifugal force acting upon the valve body 755 decreases, this body shifts radially inwards until its lower edge comes into the region of the lower edge of the outlet opening 773, so that the outflow of the pressure oil is throttled. Therefore a pressure builds up below the valve body 755, which has the consequence that the valve bush 759 shifts downwards against the force of the sprng 765, until it rests on the lower stop 775. Only thereafter can the valve body 755 completely close the connection between the bores 767 and 769 and thus block the blocking device 724, by further radially inward movement.

Figure 7 shows a diagram which shows the rotation rate course of the secondary units when using shut-off means the the are _Xlaccording to Figure Sa. The continuous line A again characterises the state with the blocking device 724 blocked, in which the secondary units are driven with stepup transmission (the delay effects characterised by the lines F, G in Figure 6 have been omitted in Figure 7). At the upper change-over point nSO the blocking device 724 is released and the output member 508 is coupled directly with the input member 504, so that the rotation rate of the secondary units follows the line D from the point C onwards. On reduction of the rotation rate of the input member 504 or the internal combustion engine coupled therewith, the rotation rate of the secondary units follows the line D downwards past the point C to the point H, which corresponds to a lower change-over rotation rate nSU. At this rotation rate nsu the blocking device 724 is again blocked, the output member 508 is again stepped up in relation to the input member 504. so that the rotation rate of the secondary units springs back from the point H' along the line B' to the line A' and on further reduction of rotation rate of the internal combustion engine follows the line A' as far as the origin 0. Typical values for the lower and upper changeover rotation rates are nSU = 1875 r.p.m. and nSO = 300O r.p.m., if the transmission ratio i is equal to 16.

Figure 8 shows a torque transmission unit 802 in which the input member 804 is connected through the blocking device 824 with the planet carrier 812. The f ree-wheel coupling 826 is again arranged between the input member 804 and the gear box 818. The sun wheel 810 is constantly firmly connected with the support member 822. Below a change-over rotation rate the blocking device 824 is blocked, the drive of the output member 808 takes place through the input member 804, the planet carrier 812 and the planet wheel 814, which is supported on the sun wheel 810, to the hollow wheel-816, which is firmly connected with the output member 808. Accordingly a stepped-up transmission of CD the rotation rate of the output member 808 takes place. When the change- over rotation rate is reached the blocking device 824 is released, the gear box 818 connected with the output member 808 retards until, it is overtaken by the input member 804 and is entrained in the rotation rate ratio 1: 1 through the centrifugal clutch 826. The shut-of f means 834 are again controlled by a control unit 840 which is arranged outside the torque transmission unit 8.02. Since the blocking device 824, rotating with the input member 804, must be controlled by stationary shut-off means 834, a special design is necessary rendering possible the transition from the rotating to the stationary part.

Figure 9 shows such a design. The blocking device 824 comprises a first pump sub-unit 860 formed by a housing, in which there is mounted a second pump sub-unit 862 rotatable in relation thereto (corresponding to the arrangement according to Figure 2). The first pump sub-unit 860 is firmly connected with the planet carrier 812, the second pump sub-unit 862 with the input member -804. The inlet conduit 829 reaching into the oil ring 819 (see Figure 8) feeds the oil to the pump unit, the outlet conduit 832 consisting of an axial and a radial away again. Coaxially with the section conducts the oil first pump sub-unit 860 A -;_R there is provided a bore 833 arranged transversely of the radial section of the outlet conduit 832, in which a valve body 855 is displaceably mounted. The valve body 855 is actuated by a solenoid device 857 in dependence upon operational parameters of the internal combustion engine or peripheral units connected therewith. When the valve body 855 closes the outlet conduit 832, the second pump sub-unit 862 is hindered from a rotation in relation to the first pump sub-unit 860 and entrains the latter, so that the input member 804 is firmly connected with the planet carrier 812. When the valve body 855 is drawn back so far that it liberates the outlet conduit 832, the second pump sub-unit 862 can rotate in relation to the first pump sub-unit 860, so that there is no coupling between the input member 804 and the planet carrier 812.

Figure 10 shows a torque transmission unit 1002 which substantially corresponds to the arrangement according to Figure 8 as regards the arrangement of the planet gear, the blocking device 1024 and the freewheel coupling 1026. In the case of the configuration according to Figure 10 however the shut-off means 1034 are again arranged within the torque transmission unit 1002 and formed as centrifugally actuated valve. The function of the shut-off means 1034 corresponds to that of the shut-off means 534 in Figure 5. The actuation of the shut-off means 1034 takes place in dependence upon the rotation rate of the input member 1004 and the output shaft 1008, coupled therewith, of the internal combustion engine.

Figure 11 shows a torque transmission unit 1102 which - Sc> - differs from the torque transmission unit 1002 according to Figure 10 only in that the shut-off means 1134 are now connected with the planet carrier 1112 and not with the input member 1104. While in the case of Figure 10," where the shut-off means rotate with the input member, a hysteresis effect according to Figure 7 is desired, but is 0 not necessary, in the case of Figure 11, where the shut-off means 1134 rotate with the planet carrier 1112, a hysteresis is necessary as will be explained hereinafter. At a rotation rate below the opening rotation rate of the shutoff means 1134 the blocking device 1124 is blocked, the planet carrier 1112 is firmly connected with the input member 1104 and rotates at the same speed therewith. At the opening rotation rate of the shut-off means 1134 the blocking device 1124 is released, the planet carrier 1112 is driven at stepped-down ratio by the retarding hollow wheel 1116, which is firmly connected with the output member 1108. Thus the rotation rate of the shut-off means 1134 is retarded. Without a hysteresis effect the blocking device would block again and so forth so that it would constantly switch to and fro in a wide rotation rate range of the input member. Figure 11 shows shut-off means 1134 which are formed by two centrifugal valves 1135, 1137 arranged one behind the other in relation to the direction of throughflow of the pump medium. The firgt centrifugal valve 1135, thanks to the reel-shaped configuration of its valve body 1135a, is independent of the pressure in the output conduit 1132, so that it it always sets itself according to an equilibrium between centrifugal force and spring force 1 X_ I- 1135 onens - S\ - 1135b. The second centrifugal valve 1137 is loaded by the pressure of the pump medium in the opening direction, in addition to the centrifugal force and to the spring force 1137b in all positions in which the lower edge of the valve body 1137a stands above the lower edge of the inlet opening 1139 of the valve housing. On increase of the rotation rate of the input member 1104 and of the planet carrier 1112 coupled therewith initially through the blocking device 1124, firstly the valve bodies 1135a, 1137a move against the action of the springs 1135b, 1137b into the position as represented in Figure 11, where the first centrifugal valve 1135 is already opened and the second centrifugal valve 1137 is still closed, that is to say the first centrifugal valve at a lower rotation rate than does the centrifugal valve 1137. On further increase of the rotation rate the lower edge of the valve body 1137a of the centrifugal valve 1137 reaches the lower edge of- the inlet opening 1139, so that it is suddenly loaded by the pressure of the pump medium and displaced in the opening direction. This is the opening rotation rate of the centrifugal valve and at the same time the opening rotation rate of the shutoff means 1134. The blocking device 1124 is released. The rotation rate of the planet carrier 1112 and thus of the shut-off means 1134 thus decreases below the opening rotation rate of the shut-off means 1134, the valve bodies 1135a,- 1137a shifting in the closing direction, while however the centrifugal valve 1135, on account of its lower opening rotation rate, does not return into the closure position and the centrifugal valve 1137, on account of the pressure charging through the opening 1139, cannot return into the closure position. Only at a lower opening rotation rate would the first centrifugal valve 1135 close, so that the second centrifugal valve 1137 would be no longer loaded and would likewise be closed by the associated spring 1137b. The design of the shut-off means 1134 can be made such that the opening rotation rate of the centrifugal valve 1135 lies lower than that rotation rate of the shut-off means 1134 which these receive from the planet carrier, after release of the blocking device 1124, assuming constant rotation rate of the input member 1104, so that the above- described change-over to and fro is avoided.

In the case of a reduction of the rotation rate of the input member 1104 the shut-off means 1134 block only on falling short of the opening rotation rate of the centrifugal valve 1135, Then howev'er the increase of rotation rate due to the renewed coupling of the shut-off means 1134 to the input member 1104 does not suffice to reopen the centrifugal valve 1137, so that there is no fear of changing to and fro even in this phase.

Figure 12 shows a torque transmission unit in which the blocking device 1224 is arranged between the hollow wheel 1216 and the gear box 1218, which is firmly. connected with the output member 1208. The free-wheel coupling 1226 is again arranged between the gear box 1218 and the input member 1204. The planet carrier 1212 is firmly connected with the input member 1 204, the sun wheel 1210 is constantly firmly connected with the stationary support member 1222. Below a change-over rotation rate the blocking device 1224 -S-Sis blocked, so that the drive path extends from the input member 1204 by way of the planet carrier 1212, the planet wheel 1214, the hollow wheel 1216 and the gear box 1218, which is connected therewith by way of the blocking device 1224, to the output member 1208, which accordingly is driven in stepped-up manner. On reaching of the change-over rotation rate the blocking device 1224 is released and the drive path proceeds from the input member 1204 by way of the free-wheel clutch 1226 directly to the gear box 1218 and the output member 1208 connected therewith, which accordingly is driven in relation to the input member in a rotation rate ratio of 1: 1. The shut-off means 1234 again correspond to the shut-off means as described with reference to Figure 1, and therefore do not need to be explained in greater detail.

Figure'13 shows a torque transmission unit 13-02 which corresponds in its essential construction to the torque transmission unit 1202 according to Figure 12. In departure from te latter however the shut-off means 1334 for the blocking device 1324 are formed in conformity with the shutoff means. 1034 as already described by way of example by reference to Figure 10 and are made as a centrifugal valve arranged within the torque transmission unit 1302.

Figure 14 shows a torque transmission unit 1402 in which the input member 1404 is firmly connected with the hollow wheel 1416, the blocking device 1424 is arranged between the hollow wheel 1416 and the planet carrier 1412, and the free- wheel coupling 1426 is arranged between the sun wheel 1410 and the stationary support member 1422. The planet carrier 1412 is integrated into one construction unit :SLr with the gear box 1418 and the output member 1408. At a rotation rate below the change-over rotation rate the blocking device 1424 is blocked and connects the hollow wheel 1416 with the planet carrier 1412, which thereafter rotate in common. The free-wheel coupling 1426 permits accompanying rotation of the sun wheel 1410 in the same direction of rotation. The output member 1408 is thereafter driven in the rotation rate ratio 1: 1 by the input member 1404. After the change-over rotation rate is reached the blocking device 1424 is released, the planet carrier 1412 is driven with step-down by the hollow wheel 1416, the planet wheel 1414 being supported against the sun wheel 1410, which is hindered by the free-wheel coupling 1426 from rotation. In this mode the output member 1408 is driven in step-down ratio in relation to the input member 1404. The shut-off means 1434 are again controlled by a control unit 1440 CD arranged outside the torque transmission unit 1402.

Figure 15 shows a torque transmission unit 1502, which corresponds in its essential assembly to the torque transmission unit 1402 according to Figure 14. In departure therefrom the shut-off means 1534 are again formed by a centrifugally actuated valve which is arranged on the input member 1504 and/ or the hollow wheel 1516 firmly connected therewith.

Figure 16 shows a torque transmission unit 1602, in which the input member 1604' is firmly connected with the planet carrier 1612 and the output member 1608 is firmly connected with the sun wheel 1610. The blocking device 1624 is arranged between the hollow wheel 1616 and the stationary 1 k, - gE; - support member 1622 and the free-wheel coupling is arranged between the sun wheel 1610 and the planet carrier 1612. At a rotation rate below the change-over rotation rate the blocking device 1624 is blocked. The drive path extends from the input member 1604 by way of the planet carrie'r 1612 and the planet wheel 1614 to the sun wheel 1610, the planet wheel 1614 being supported against the hollow wheel 1616, which is connected with the support member 1622. In this mode the sun wheel and the output member 1608 connected therewith are stepped-up in relation to the input member 1604. The free-wheel coupling 1626 here permits the sun wheel 1610 to rotate with faster rotation rate in relation to the planet carrier 1612. On reaching of the change-over rotation rate the blocking device 1624 opens, the support for the planet wheel 1614 and thus the drive of the sun wheel are eliminated, so that the latter slows down as a result of the loading by the secondary units, until it is driven directly in the rotation rate ratio 1: 1 through the free-wheel coupling 1626 by the planet-carrier 1612 or by the input member 1604 firmly connected therewith. In the case of this form of embodiment the transmission ratio interval is greater than in the forms of embodiment as described hitherto.

Figures 17 to 19 show a torque transmission unit 1702 which permits a step-up transmission, a direct coupling and a step-down transmission. The input member 1704 is for the one part connectable through a blocking device 1724 with the planet carrier 1712 and through a free-wheel coupling 1726 with the hollow wheel 1716. The output member, which is firmlyconnected at least with a part 1718 of the gear box, can be connected for one part through a blocking device 1725 with the hollow wheel 1716 and through a fre a-wheel coupling 1727 with the planet carrier 1712. The sun wheel 1710 is constantly firmly connected with the stationary support member 1722.

Below a first change-over rotation rate nS, (Figure 17) the blocking device 1724 is blocked and drives the planet carrier 1712 which. through the planet wheel 1714 supported by the sun wheel 1710, drives th hollow wheel 1716 with stePped-up ratio. The blocking device 1725 is likewise closed and entrains the gear box 1718 and with it the output member 1708. The free-wheel coupling 1726 permits the faster rotation of the hollow wheel 1716 in relation to the input member 1704; the free-wheel coupling 1727 permits the faster rotation of the gear box 1718 in relation to the planet carrier 1712 (see Figure 17).

On reaching of the first change-over rotation rate nS, (Figure 18) the blocking device 1724 is released and thus the drive connection to the planet wheel 1712 is interrupted. As a result of the loading by the secondary units the output member 1708, the gear box 1718 and thus the hollow wheel 1716 connected with the gear box through the blocked blocking device 1725 are retarded until the output member 1708 reaches the speed of rotation of the input member 1704 and is entrained. thereby through the free-wheel coupling 1726. The output member 1708 in this case rotates at the same speed as the input member 1704. The free- wheel coupling 1727 permits the gear box 1718to rotate faster 57 - than the planet carrier 1712 (see Figure 18).

On reaching of a second change-over rotation rate nS2 higher than the first the second blocking device 1725 is Also released (Figure 19). The hollow wheel 1716 is still driven as before through the free-whdel coupling 1726 by the input member 1704 and through the planet wheel 1714 drives the planet carrier'1712 with a stepped-down rotation rate. The planet carrier 1712 entrains the gear box 1718, through the free-wheel coupling 1727, after the gear box has further retarded due to the loading from the secondary unit, so that the output member 1708 is driven in a stepped-down ratio in relation to the input member 1704 (see Figure 19).

Figure 20. shows a diagram which illustrates the rotation rate nNA of the secondary units in dependence upon the rotation rate nMOT of the internal combustion engine. The steepest line K corresponds to the constellation of the torque transmission unit 1702 as represented in Figure 17, where the output member 1708 is driven stepped up in the ratio 1 x i, where i represents the transmission ratio. At the change-over rotation rate nS, the torque transmission unit 1702 is changed into the constellation as represented in Figure 18; in this case the rotation rate nNA follows the line L, until at the point M it meets the line N representing the direct drive of the output member 1708. On further acceleration the internal combustion engine reaches the change-over rotation rate nS2 at which the torque transmission unit 1702 is switched into the constellation as represented in Figure 19. The relative rotation rate of the output member 1708 follows the line 0 as far as the point P, 1 38- where the line 0 meets the line Q, which represents a stepdown of the rotation rate of the output member 1708 in the ratio l/i. The rotation rate of the secondary units follows the line Q up to the maximum - rotation rate of the 1'nternal combustion engine. On retarding of the rotation rate of the internal combustion engine the rotation rate of the output member 1708 follows the same line sequence QONLK in the opposite direction,it obviously being possible to realise a controlling of the torque transmission unit 1702 in which a hysteresis effect is achieved in the manner as described further above.

Figure 21 shows a design development of a torque transmission unit according to Figure 1. Components in Figure 21 which correspond to the individual components of Figure 1 will therefore be characterised with the same reference numbers.

The crank-shaft 6 of an internal combustion engine is firmly connected with the input member 4 through a tie bolt S.This input member 4 is made in one piece with a flange 12a which forms a part of the planet carrier 12. The planet carrier 12 carries several planet wheels 14. The output member 8 integrated with the gear box 18, a belt pulley, is firmly connected with the hollow wheel 16 which meshes with the planet wheels 14. A free-wheel coupling 26 is arranged between an axial continuation 13 of the planet carrier 12 and the gear box 18. Since the planet carrier 12 is firmly connected with the input member 41 as regards function it is immaterial whether the free-wheel coupling 26 is arranged between the gear box 18 and the planet carrier 12 (as in 1 - 2M - Fig ure 21) or between the gear box 18 and the input member 4 (as in Figure 1). The sun wheel 10, which likewise meshes with the planet wheels 14, is part of the blocking device 24, which is assembled somewhat in accordance with Figure 2. The blocking device 24 is formed as rotating hydrostatic pump unit, with a first pump sub-unit 60 connected with a stationary support member 22 and a second pump sub-unit 62 mounted rotatably in relation to the first pump sub-unit. The second pump sub- unit 62 comprises a gear wheel 66 which is firmly connected with the sun wheel 10, and a ring wheel 64 eccentric in relation to the gear wheel 66 and capable of rotating in the first pump sub-unit 60 of housing-type formation. The pump sub-unit 60 consists of two housing parts 60a and 60b. The inlet conduit 29 engages with a radially outwardly open end in a hollow chamber 21, form;i in the gear box 18, in which an oil ring 19 forms on -rotation of the gear box 18. The oil is fed through the inlet conduit 29 to the blocking device 24, which oil, when the outlet conduit 32 is not blocked, is conducted away through the latter and is re-introduced for example along a return conduit 31 into the lower part of the annular chamber 21 again.

The outlet conduit 32 can be opened or cl.osed according to choice by means of the shut-off device 34 in dependence upon specific operational states of the internal combustion engine or peripheral units connected therewith. With the outlet conduit 32 closed the pump medium is caught in the blocking device 24 so that the second pump sub-unit 62 can no longer rotate in relation to the first pump sub-unit 60; - 4.0 -the sun wheel 10 is then blocked in relation to the fixed support member 22, as was already described in detail by reference to Figures 1 and 2. In the case of drive of the planet carrier 12 through the input member 4 then the'-planet wheels 14 roll on the stationary sun wheel 10 and drive the hollow wheel 16. the gear box 18 connected therewithand the output member 8 with stepped-up ratio. When the blocking device 24 is released the drive through the planet carrier 12 to the hollow wheel 16 is interrupted, the output member 8 is retarded as a result of the loading by the secondary units, until it reaches the speed of the planet carrier 12. Then the hollow wheel 16 is entrained by the planet carrier 12, through the free-wheel coupling 26, directly in the ratio 1: 1, the hollow wheel 16, the planet wheels 14, the planet carrier 12 and the sun wheel 10 rotating in a block with the same rotation rate and the same direction of rotation.

The housing 18 is mounted by a bearing 18a on the part 13 of the planet wheel carrier 12. 18b and 18c designate seals.. A torsional vibration damper is designated by 6a.

1 - ki -

Claims

CLAIMS:

l.) Torque transmission unit for the drive co'nnection of at least one secondary unit with an internal combustion engine, comprising an input member (4) in connection with an output shaft (6) of the internal combustion engine, an output member (8) in connection with the auxiliary unit, a planet gear (10 to 16) in the torque transmission path between the input member (4) and the output member (8), this planet gear formed with a sun wheel (10), a planet carrier (12), a hollow wheel and at least one planet wheel (14) mounted on the planet carrier (12) and meshing simultaneously with the sun wheel (10) and the hollow wheel (16), where of each of the parts sun wheel (10), planet carrier (12) and hollow wheel (16) one (12) is connected or connectable with the input member (4), a further one (16) is connected or connectable with the output member (8) and a further one (10) is connected or connectable with a stationary support member (22), while fur'thermore the torque transmission path is variable by the planet gear (10 to 16), the transmission ratio between output member (8) and input member (4) being varied, while a free-whqel coupling is provided between the two parts (4, 16) of at least one first pair of parts (4, 16) from the group of parts input member (4), output member (8), sun wheel (10), planet carrier (12), hollow wheel (16) and stationary support member (22) and a blocking device is provided between the two parts (810, 22) of at least one further pa.ir of parts 1 (10y 22) from the group of parts: input member (4), output member (8), sun wheel (10), planet carrier (12), hollow wheel (16) and support member (22), characterised in that the blocking device (24) is formed by a pump unit having two mutually relatively rotatable pump sub-units (60, 62), with suction means (28. 29) and outflow means (30, 32), the pump sub- units (60, 62) being rotatable in relation -to one another, that is the blocking device (24) being released, on opening of the outflow means (30, 32), and being nonrotatable in relation to one another at least in one direction of rotation, that is the blocking device (24) being blocked, on shutting-off of the outflow means (30, 32), and shut-off means (34) being provided in the outflow means (30, 32).
2.) Torque transmission unit according to Claim 1, characterised in that the shut-off means (34) are actuated in dependence upon an operational state of the internal combustion engine or of a peripheral unit connected with the internal combustion engine.
3.) Torque transmission unit according to Claims 1 and 2, characterised in that the shut-off means (34) are controlled in dependence upon the rotation rate of a rotating part (6) of the internal combustion engine or of a rotating part (4, 12) of the torque transmission unit (2) or of a rotating part of the secondary unit.
4.) Torque transmission unit according to one of Claims 1 to 3, characterised in that the shut-off means (34) are controlled by a control unit (40) arranged outside the torque transmission unit (2).

1 v 1 lk k21 -
5.) Torque transmission unit according to one of Claims 1 to 3, characterised in that the shut-off means (534) are controlled by a control unit (534) accommodated within the torque transmission unit (502).
6.) Torque transmission unit according to Cl-aim Sy characterised in that the control unit (534) accommodated within the torque transmission unit (502) comprises a valve arrangement (553, 555) actuated by centrifugal force.
7.) Torque transmission unit according to one of Claims 1 to 6, characterised in that the shut-off means (34) are controlled in such a way that at low rotation rates of the input member (4) the ratio of the rotation rate of the output member (8) to the rotation rate of the input member (4) has a first, greater value and at higher rotation rates of the input member (4) the ratio of the rotation rate of the output member (8) to the rotation rate of the input member (4) has a second lower value.
8.) Torque transmission unit according to one of Claims 1 to 7, characterised in that the shut-off means (34) are controlled in dependence upon the variation of the operational state in such a way that on variation of the operational state in a first direction they respond at a first operational state value (nSO) and on variation of the operational state in a second direction they respond at a second operational state value (nSu).
g.) Torque transmission unit according to Claim 8, characterised in that the shut-off means (534) are controlled in dependence upon the rotation rate of a rotating part (504) in such a way that i.n the case of - k k_ increase of the rotation rate of the rotating part (504) they respond at a first rotation rate value (nSO) and in the case of reduction of the rotation rate of this rotating part (504) they respond at a second rotation rate value (nSu)y the s.econd rotation rate value (nsu) being less than the first rotation rate value (nSO).
10.) Torque transmission unit according to one of Claims 1 to 9, characterised in that a delay device (48) is provided which delays the start-up of the torque transmission unit (2) in relation to the start-up of the internal combustion engine.
ll.) Torque transmission unit according to one of Claims 1 to 10, characterised in that the suction means (28, 29) and the outflow means (30, 32) of the pump unit are connected with an internal fluid reserve (19) within the torque transmission unit (2), which is independent of external fluid supply.
12.) Torque transmission unit according to one of Claims 1 to 11, characterised in that the suction means (28, 29) are-connected with a fluid reserve (19) in such a way that filling of the pump unit takes place with delay in relation to the start-up of the input member (4).
13.) Torque transmission unit accor ' ding to one of Claims 1 to 12, characterised in that the suction means (28, 29) and the outflow means (30, 32) are connected with an internal fluid reserve within the torque transmission unit (2), which reserve is accommodated in a rotating container (18) within the torque transmission unit (2) and on reaching of a pre-determined rotation rate of this container (18) 1 1 i 1 - W5 - forms a fluid ring (19), while the connection of the suction means (28, 29) with the fluid reserve comes about only after formation of this fluid ring (19).
14.) Torque transmission unit according to one of Claims 1 to 13, characterised in that in the outflow means a safety valve (52) is arranged which opens the outflow means (30, 32) at a pre-determined maximum rotation rate. independently of the controlling by other control means.
IS.) Torque transmission unit according to one of Claims 1 to 14, characterised in that the shut-off means (34) are controllable in dependence upon the acceleration of the internal combustion engine.
16.) Torque transmission unit according to one of Claims 1 to 15, characterised in that the shut-off means (34) are controlled in dependence upon the state of charge of a battery which is charged by a generator driven through the torque transmission unit (2).
17.) Torque transmission unit according to one of Claims 1 to 16, characterised in that the pump unit is a gear pump (64, 66).
18.) Torque transmission unit according to Claim 17, characterised in that the pump unit is an internal rotor gear pump having a pump housing (60), an intrnally toothed ring (64) mounted in the pump housing (60) eccentrically rotatably in relation to the housing axis and an externally toothed gear wheel (66) rotating about the gear axis coaxially with the housing axis, the external toothing of which gear rolls on the internal toothing of the toothed ring.

- 1Q0
19.) Torque transmission unit according to one of Claims 1 to 18, characterised in that the input member (4) is arranged coaxially with an output shaft (6) of the internal combustion engine.
20.) Torque transmission unit according to one of Claims 1 to 18, characterised in that the input member (4) is offset axially parallel in relation to an output shaft (6), which drives it, o the internal combustion engine, and is connected with the output shaft (6) through torque transmission means (72, 74, 76).
21.) Torque transmission unit according to one of Claims 1 to 20, characterised in that it comprises a frame (82) stationary in relation to the internal combustion engine, on which frame a plurality of secondary units (84) is arranged which are in drive connection with the output member (8).
22.) Torque transmission unit according to one of Claims 1 to 21, characterised in that the sun wheel (10) is connected by the blocking device (24) with the stationary support member (22), in that the output shaft (6) of the internal combustion engine is connected with the input member (4) and the latter is connected with the planet carrier (12), in that the hollow wheel (16) is connected with the output member 8) and in that the free-wheel coupling (26) is provided between the input member (4) or the planet carrier (12) for the one part and the hollow wheel (16) for the other part, while when the blocking device (24) is blocked the free-wheel coupling (26) permits the hollow wheel (16) to run faster than the planet carrier -1 1 1 - 4.9 - (12) and when the blocking device (24) is released the planet carrier (12) drives the hollow wheel (16) through the free-wheel coupling (26).
23.) Torque transmission unit according to Claim 22, characterised in that a centrifugally controlled shut-off valve arrangement (534) is arranged on the input member (504) or on the planet carrier (512).
24.) Torque transmission unit according to one of Claims 1 to 21, characterised in that the sun wheel (810) is constantly connected fast in rotation with the stationary support member (822), in that the input member (804) is connected with the planet carrier (812) through the blocking device (824) and in that the free-wheel coupling (826) is provided between the input member (804) and the hollow wheel (816), while when the blocking device (824) is blocked the free-wheel coupling (826) permits the hollow wheel (816) to run faster than the input member (804) and when the blocking device (824) is released the input member (804) drives the hollow wheel (816) through the free-wheel coupling (826).
25.) Torque transmission unit according to Claim 24, characterised in that a centrifugally controlled shut-off valve arrangement (1034) is arranged on the input member (1004).
26.) Torque transmission unit according to Claim 24, characterised in that a centrifugally controlled shut-off valve arrangement (1134) is arranged on the planet carrier (1112).
27.) Torque transmission unit according to one of Claims 1 to 21, characterised in that the sun wheel (1210) - 48 is constantly connected with the stationary support member (1222), in that the blocking device (1224) is provided between the hollow wheel (1216) and the output member (1208) and in that the input member (1204) is constantly connected with the planet carrier (1212) and in that the free-wheel coupling (1226) is provided between the input member (1204) or the planet carrier (1212) for the one part and the output member (1208) for the other part, while when the blocking device (12.24) is blocked the free-wheel coupling (1226) permits the output member (1208) to run faster than the input member (1204) and when the blocking device (1224) is released the input member (1204) drives the output member(1208) through the free-wheel coupling (1226).
28.) Torque transmission unit according to Claim 27, characterised in that a centrifugally controlled shut-off valve arrangement (1334) is arranged on the input member (1304) or the planet carrier (1312).
29.) Torque transmission unit according to one of Claims 1 to 21, characterised in that the free-wheel coupling (1426) is arranged between the sun wheel (1410) and the stationary support member (1422), in that the output member (1408) is constantly connected with the planet carrier (1412): in that the input member (1404) is constantly connected with the hollow wheel (1416) and in that the blocking device (1424) is provided between the hollow wheel (1416) and the input member (1404) for the one part and the planet carrier (1412) and the output member (1408) for the other part, while when the blocking device (1424) is blocked the freewheel coupling (1426) permits 1 - 4A - rotation of the sun wheel (1410) in relation to the stationary support member (1422) and when the blocking device (1424) is released the sun wheel (1410) is supported on the stationary support member (1422) through the freewheel coupling (1426).
30.) Torque transmission unit according to Claim 29, characterised in that the centrifugally controlled shut-off valve arrangement (1534) is arranged on the input member (1504) or the hollow wheel (1516).
31.) Torque transmission unit according to one of Claims 1 to 21, characterised in that the output member (1608) is constantly firmly connected with the sun wheel (1610)7 in that the free-wheel coupling (1626) is arranged between the sun wheel (1610) and the planet carrier (1612), in that the input member (1604) is constantly connected with the planet carrier (1612) and in that the hollow wheel (1616) is connected through the blocking device (1624) with the stationary support member (1622), while when the blocking device (1624) is blocked the free-wheel coupling (1626) permits the sun wheel (1610) to run fasterthan the planet carrier (1612) and when the blocking device (1624) is released the planet carrier (1612) drives the sun wheel (1610) through the free-wheel coupling (1626).
32.) Torque transmission unit according to one of Claims 1 to 21, characterised in that the sun wheel (1710) is constantly firmly connected with the stationary support member (1722), in that the input member (1704) is connected through a first blocking device (1724) with the planet carrier (1712), in that a first free-wheel coupling (1726) -.To- is arranged between the input member (1704) and the hollow wheel (1716), in that a second blocking device (1725) is provided between the hollow wheel (1716) and the output (1708) and in that a second free-wheel coupling is provided betwegn the planet carrier (1712) and the member (1708), while when both blocking devices member (1727) output (1724, 1725) are blocked the input member (1704) drives the planet carrier (1712) the hollow wheel (1716) drives the output member (1708) through the second blocking device (1725), the first free-wheel coupling (1726) permits the hollow wheel (1716) to run faster than the input member (1704) and the second free-wheel coupling (1727) permits the output member (1708) to run faster than the planet carrier (1712), while furthermore on blocking of the second blocking device (1725) and release of the first blocking device (1724) the input member (1704) drives the hollow wheel (1716) through the first free-wheel coupling (1726), the hollow wheel (1716) drives the output member (1708) through the second blocking device (1725) and the second free-wheel coupling (1727) permits the output member (1708) to run faster than the planet carrier (1712) and, on release of both blocking devices (1724, 1725) the input member (1704) drives the hollow wheel (1716) through the first free-wheel coupling (1726) and the planet carrier (1712) drives the output member (1708) through the second free-wheel coupling (1727).
33.) Torque transmission unit according to one of Claims 1 - 21, characterised in that an input shaft (4) acting as input member (4) of the torque_ transmission unit zk (2) is mounted fast in rotation on the end section, placed outside an internal combustion engine housing, of an output shaft (6) of the internal combustion engine, in that this input shaft (4) carries, adjacent to its end facing the engine housing, a radial flange (12a) forming a part of the planet carrier (12), in that at least one planet wheel (14) is mounted on this radial flange (12a) on its side remote from the engine housing, in that the sun wheel (10) is rotatably mounted on the input shaft (4), adjoining the side of the radial flange (12a) remote from the internal combustion engine, in that this sun wheel (10) is connected fast in rotation with a pump sub-unit (62) formed as pump rotor, which sub-unit is arranged on the side of the sun wheel (10) remote from the radial flange (12a), in that a further pump sub-unit (60) formed as pump stator is rotatably mounted on the input shaft (4) in the axial direction beside the sun wheel (10) on its side remote from the engine housing, in that this pump stator (60) is supported through a torque support (22) against twisting on the housing of the internal combustion engine, in that a gear box part (18) serving as output member (8) is rotatably mounted on the input shaft (4) or the planet wheel carrier (12) in the axial region of the pump sub-unit (60)9 which gear box part is connected fast in rotation with the hollow wheel, in that the free-wheel coupling (26) is arranged between the planet wheel carrier (12) and the gear box part (18), in that an annular chamber (21) for the formation of an oil ring (19) within the gear box part (18) is formed on the side of the housing part mounting (18a) remote from the _!0__ engine housing, in that the suction means (28, 29) are arranged on the pump stator (60) and comprise a conduit section (29) leading into the annular chamber (21), and in that the oiitflow means (30, 32) are likewise arranged on the pump stator (60) and are connected through a further conduit section (32, 31) with the annular chamber (21) and in that the shut-off means (34) are arranged in this further conduit section (32, 31).
34.) Torque transmission unit according to Claim 33, characterised in that the pump stator (60) comprises a pump housing (60) in which an internally toothed ring (64) is rotatably mounted eccentrically in relation to the input shaft (4), in that the pump rotor (62) comprises an externally toothed gear (66) arranged concentrically with the input shaft (4) and in that this externally toothed gear (66) is arranged fast in rotation on the continuation (9) of the sun wheel (10).
35.) Torque transmission unit substantially as described with reference to the accompanying drawings.

Published 1989 at The Patent Office. State House, 66771 High Holborn, London WCIR 4TR Further copies maybe obtained from The Patentoince. Wes Branch. St Mary Cray, Orpington. Rent BRS 3RD. Printed by MWtiplex tecluuques ltd, St Mary Cray, Rent, Con- 1/87 l