Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P7/00—Controlling of coolant flow
  • F01P7/02—Controlling of coolant flow the coolant being cooling-air
  • F01P7/04—Controlling of coolant flow the coolant being cooling-air by varying pump speed, e.g. by changing pump-drive gear ratio
  • F01P7/046—Controlling of coolant flow the coolant being cooling-air by varying pump speed, e.g. by changing pump-drive gear ratio using mechanical drives
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P7/00—Controlling of coolant flow
  • F01P7/02—Controlling of coolant flow the coolant being cooling-air
  • F01P7/04—Controlling of coolant flow the coolant being cooling-air by varying pump speed, e.g. by changing pump-drive gear ratio
  • F01P7/042—Controlling of coolant flow the coolant being cooling-air by varying pump speed, e.g. by changing pump-drive gear ratio using fluid couplings

Definitions

• the invention relates generally to a device for driving an auxiliary unit of a motor vehicle and in particular to a device for driving a radiator fan of an internal combustion engine.
• auxiliary units driven by the internal combustion engine are usually provided in a motor vehicle, such as, for example, an electrical generator, oil pumps, compressors for compressed air or air conditioning units, or a cooler fan or cooler fan.
• Auxiliary units of this type are often driven from the internal combustion engine via a belt transmission.
• the belt transmission which can be a transmission gear or a reduction gear, adjusts the speed of the internal combustion engine to the operating speed of the auxiliary unit.
• Radiator fans are usually operated using liquid Controlled friction clutches depending on the temperature, as described for example in DE-A-38 07 109.
• the fluid friction clutch turns the radiator fan off at low temperatures and on at high temperatures.
• the cooling capacity requirement also depends on the driving speed and the resulting cooling of the wind.
• the power that can be transferred from the fluid friction clutch to the radiator fan is also dependent on the engine speed. In order to be able to transmit a sufficiently large torque via the clutch at a low engine speed, it is often necessary to rapidly translate the engine speed for driving the radiator fan. On the other hand, it is desirable to reduce the speed at high speeds in order to save power.
• the object of the invention is to provide a drive device for a radiator fan of a motor vehicle, the speed of which can be adapted better than before to the cooling requirements of the internal combustion engine of the motor vehicle.
• the invention is based on a device for driving a radiator fan of an internal combustion engine of a motor vehicle, comprising: a transmission in the drive path of the radiator fan and a fluid friction clutch connected to the transmission for, in particular, temperature-dependent control of the operation of the radiator fan.
• the device according to the invention is characterized in that a planetary gear is mounted on a central shaft and has three gear components which can be rotated relative to one another about a common axis of rotation, of which a first gear component is a sun gear, a second gear component has a ring gear enclosing the sun gear and a third gear component has a planet gear carrier with at least one planet gear meshing with both the sun gear and the ring gear such that controllable brake means are assigned to one of the gear components, in particular the first gear component this gear component exerts a changeable braking torque and that the internal combustion engine and the radiator fan are each connected to one of the two other gear components, in particular the internal combustion engine with the third gear component and the radiator fan with the second gear component.
• the combination of the fluid friction clutch with a gearbox with changeable speed ratio allows the cooling capacity of the radiator fan to be better adapted to the current operating conditions of the motor vehicle, in particular its driving speed and engine speed, than before.
• the fluid friction clutch is expediently controlled as a function of temperature, as was previously the case, the braking device can be controlled as a function of an engine speed threshold and / or a driving speed threshold by means of an electrical control, for example.
• the coaxial structure of both the fluid friction clutch and the planetary gear allows both components to be arranged coaxially and, if necessary, to be connected directly to an output end of the crankshaft of the internal combustion engine.
• the planetary gear can, however, also be offset against the crankshaft axis and can optionally be connected to the crankshaft via a belt transmission.
• the braking means are designed as a controllable clutch, in particular as an electromagnetic clutch, by means of which the first transmission component can be blocked relative to a component that is stationary relative to the internal combustion engine.
• the second gear component is connected to the third gear component via a one-way clutch and to the radiator fan via the fluid friction clutch.
• a transmission gear can be built up with a sufficiently small installation space, which translates rapidly when the clutch is switched on, but allows the radiator fan to be driven directly at the engine speed when the clutch is in the open state via the additional one-way clutch. At low engine speeds, the fan speed can be increased in this way without having to accept increased drive losses.
• the second gear component comprising the ring gear is preferably firmly connected to the fluid friction clutch. This applies in particular if the drive from the internal combustion engine is via the third gear component, i.e. the planet carrier.
• the transmission ratio achievable in this configuration with a stationary sun gear is particularly well adapted to the operating speed range of the internal combustion engine on the one hand and of the radiator fan on the other hand.
• the fluid friction clutch can be particularly easily with the second one that forms the ring gear.
• Gear components are connected to a structural unit.
• the central shaft can in particular also be connected coaxially and permanently directly to the crankshaft.
• Planetary gears mounted directly on the crankshaft are exposed to comparatively high mechanical loads due to the irregularity of the crankshaft rotation. Last but not least, vibrations occur on the crankshaft both radially and axially, since the crankshaft is generally floating in slide bearings.
• the electromagnetic clutch comprises an axially movable armature unit which is connected to the first gear component in a rotationally fixed manner and a magnetic winding unit which surrounds the central shaft in a ring shape and which directly or indirectly radially via at least one roller bearing on the central shaft is performed and a both axially and radially elastic Drehmo ⁇ management support on a component of the internal combustion engine " loft ⁇ out firmly.
• the magnetic coil assembly can be followed in this way the axial and radial Schwingungsbewegun- gene of the crank shaft, yet is non-rotatably held on the internal combustion engine.
• the torque arm is expediently a sheet metal part which is rigid in the circumferential direction and extends in a first section in the direction normal to the axis of rotation and in a second section in the direction of the axis of rotation.
• the armature unit comprises at least one armature plate which is axially movably connected to the first gear component, for example riveted, by means of an axially elastic leaf spring arrangement. It has been shown that such a suspension of the anchor plate wears out little even with large vibrations of irregularity.
• the fluid friction clutch also forms the controllable one Brake means and exerts a braking torque of variable magnitude on one of the transmission components.
• the clutch torque of the fluid friction clutch allows not only to control the performance of the radiator fan, but also its drive speed.
• the control is conventionally carried out by changing the degree of fluid filling in the shear slots of the fluid friction clutch, but preferably by means of external control means, such as pumps or valves, in order to be able to specify a certain temperature characteristic of the clutch operation, or additionally or alternatively the clutch operation to be able to vary depending on the engine speed or the driving speed.
• the fluid friction clutch can be combined with the planetary gear in the manner explained above for an electromagnetic clutch, so that stationary feed lines can be used for the feed of the shear fluid.
• the radiator fan is expediently in turn rotatably connected to the second gear component forming the ring gear, while the fluid friction clutch, depending on the gear component used for the drive, is connected to one of the two other gear components, but in particular to the first gear component forming the sun gear. connected is.
• the fluid friction clutch which in this embodiment acts as a "fluid friction brake”
• the fluid friction clutch can also exert its braking action between two of the transmission components, in order to block the planetary transmission as a whole and to provide a 1: 1 drive for the cooler. to reach lüfers.
• the fluid friction clutch is preferably connected to a stationary component of the internal combustion engine in a rotational test.
• a speed switch Stable planetary gear on an extension of the crankshaft of an internal combustion engine and use for the speed adjustment of an auxiliary unit of the motor vehicle.
• the planetary gear is designed as a reduction gear and drives the sun gear ending in a pulley via its planet gear carrier, which is connected in a rotationally fixed manner to the extension of the crankshaft.
• the ring gear of the planetary gear which meshes with the planet gears as well as the sun gear, can be blocked relative to the stationary motor housing via an electromagnetic clutch.
• a one-way clutch connects the planet carrier with the ring gear for direct drive.
• the ring gear and the sun gear are mounted on each other and on the extension of the crankshaft via conventional deep groove ball bearings.
• the belt pulley forming the output element of the planetary gear mechanism simultaneously forms a housing enclosing the planetary gear mechanism and is filled with lubricant in order to be able to keep wear low even with a comparatively high drive power to be transmitted.
• the housing Since the transmission rotates together with the crankshaft, the lubricant filling is exposed to centrifugal forces. In order to be able to reliably lubricate all ball bearings and the gears of the planetary gear, the housing would have to be completely filled with lubricant. This is undesirable in itself, since it increases the weight of the planetary gear and even small lubricant losses during operation lead to the dry running of the ball bearings arranged essentially radially on the inside in the housing.
• the conveying device can be a pump or a scoop pipe, which is driven by the relative movement of the gear components of the planetary gear after the gears of the planetary gear only roll against one another in the reduction or step-up mode.
• the invention is based on a device for driving an auxiliary unit of a motor vehicle, which comprises: a planetary gear held on a central shaft with three gear components rotatable relative to one another about a common axis of rotation, of which a first gear component is a sun gear, one a second gear component has a ring gear enclosing the sun gear and a third gear component has a planet gear carrier with at least one planet gear meshing with both the sun gear and the ring gear, controllable braking means being assigned to one of the gear components, which exert a changeable braking torque on this gear component and the internal combustion engine and the auxiliary unit are each connected to one of the two other gear components, and at least one of the gear components is mounted on at least one roller bearing, the roller body of which lies between a radially inner raceway and the like nd
• the planetary gear has a lubricant chamber which is partially filled with lubricant and sealed to the outside and which encloses at least the sun gear, the ring gear and each planet gear, but within the lubricant chamber there is at least one that is only open radially inwards, but otherwise closed, ring-shaped lubricant pocket is divided, in which the outer and inner raceways of at least one roller bearing are essentially completely accommodated and that the planetary gear has a lubricant delivery device which moves the lubricant from a radially outer region of the lubricant chamber to a region radially inside the sun gear and each lubricant pocket.
• the lubricant conveying device conveys the lubricant, which is expediently liquid lubricant, such as oil or the like, during the reduction or translation operation of the planetary gear in the region of the central shaft, from where it is by centrifugal force distributed over the surfaces to be lubricated. If necessary, additional channels are provided so that the lubricant can be distributed in a targeted manner.
• the roller bearings run in a lubricant bath within the lubricant pockets.
• the lubricant pockets which can partially empty when the transmission is at a standstill after they are open radially inwards, are filled with the first transmission or reduction operating phase of the planetary gear following the standstill. If necessary, provision can be made for the planetary gear to be switched on in certain operating situations, for example when the internal combustion engine is started, for example for a short period of time. In any case, however, the raceways of the rolling bearing are subsequently prevented from running dry and wearing out.
• the second aspect of the invention is independent of this and for driving other auxiliary units, such as Example of an electrical generator, a pump of a hydraulic or pneumatic system, an air conditioner or the like is suitable.
• the device according to the invention is This is particularly advantageous if the planetary gear is coupled directly to the crankshaft, ie is not driven from the crankshaft via a vibration-damping belt drive. However, drive via a belt drive is also possible.
• separate lubricant pockets can be assigned to the individual roller bearings. However, more or less closely adjacent bearings or other components subject to wear can also be accommodated in a common lubricant pocket.
• all of the rolling bearings provided for the storage of the individual gear components relative to one another are accommodated in lubricant pockets of the type described.
• the lubricant pockets can be realized in a particularly simple manner in that a first component forming the outer raceway is firmly, in particular integrally, connected axially on one side of the rolling elements to an annular shoulder, which extends radially inward beyond the smallest diameter of that on a second Component provided inner race extends out.
• These components can be bearing rings of conventional roller bearings, but the raceways are expediently integrally formed in components that are otherwise necessary for the function of the planetary gear, in order to provide space and additional means for fixing the Saving stock.
• the annular shoulder and the first component forming the outer raceway can be connected to one another in one piece, but it can also be two separate but firmly connected parts, for example in a press fit.
• the ring shoulder is preferred on that of the planet gears axially facing side of the outer raceway is provided, wherein the first component on the side axially facing away from the planet gears is either sealed with a sealing ring against the second component or is rotatably and tightly connected to a side wall of the lubricant chamber.
• this type of sealing offers particular advantages if, as will be explained in more detail below, the construction is such that the rolling bearings provided for mounting the gear components are clamped axially to compensate for play.
• the surfaces to be lubricated cover the annular shoulder in the direction of installation.
• the annular shoulder has an annular flange made of elastic material, which protrudes radially inwards and engages in a peripheral recess of the second component.
• Such an elastic ring flange can also be installed across undercuts. This is particularly advantageous when raceways or the like are to be integrally formed on the second component.
• crankshaft of the internal combustion engine are exposed to particularly high vibrations and irregularities in the rotary movement. Since the crankshaft is normally mounted in plain bearings, ie "floats" on an oil film, this is due to the order of ignition. Non-uniformity or torsional vibration superimposed both radial and axial vibrations. This is especially true for diesel engines and here especially diesel engines for trucks.
• the gear components on both sides of the area in which each planet gear rotates around the sun gear are rotatably mounted on roller bearings whose components forming the raceways together with components of at least one of the gear components in a common support force path between two in are axially spaced opposite stop members of the central shaft axially substantially free of play. It is hereby achieved that the gear components mounted on the roller bearings are essentially axially free of play with respect to one another and accordingly there is no impact load on the roller bearings due to the gear components moving axially or radially relative to one another. Preferably, all of the roller bearings involved in the mounting of the gear components are included in the common support path.
• roller bearings are preferably shoulder bearings or angular contact bearings, ie roller bearings with at least one raceway which generally runs at an angle to the axis of rotation.
• the advantage of these roller bearings is that their raceways, which run obliquely anyway, can be used to form the lubricant pocket.
• the central shaft supporting the planetary gear can be a stationary shaft, in particular if the planetary gear is arranged separately from the crankshaft and is driven, for example, by a belt drive or the like.
• the central shaft is arranged so as to be rotatable about the axis of rotation and that one of the gear components is connected via connecting means. tel, which allow axial movement, is non-rotatably connected to the central shaft, while the other two transmission components via roller bearings, the inner and outer raceways of which permit axial movement relative to one another, are rotatably guided relative to one another and to the central shaft, in the supporting force path.
• the transmission components are in and of themselves loosely guided on the central shaft, and axial play is only compensated for by the axial support in the support force path.
• a particularly simple variant for a translating planetary gear of the latter type is obtained when the third gear component is seated on the central shaft in a rotationally fixed manner and the first gear component is mounted on the central shaft with a first of the roller bearings, the second gear component being supported by a second one of the roller bearings the third gear component and a third of the roller bearings on the first gear component.
• Such an embodiment is compact, can be easily installed and can be sealed without problems.
• the lubricant delivery device can operate in the manner of a gear pump, the stator and rotor of which are each connected to different gear components, so that they rotate relative to one another in the gear unit's transmission mode.
• the first gear component comprising the sun gear preferably carries the pump device so as to bring the lubricant particularly close to the central shaft.
• the pump device can be, for example, a radially extending scoop tube, which skims the lubricant from the radially outer region during the relative rotation of the sun gear and the ring gear and conveys it radially inwards.
• an axially extending lubricant channel for example in the form of an annular gap or at least one axially extending groove, is provided, which distributes the lubricant in the axial direction in the area of the individual lubrication points.
• the axial lubricant channel expediently ends at one end in the lubricant pocket of the first rolling bearing.
• the other end of the axial lubricant channel can be connected to an annular lubricant pocket of the third gear component which is closed radially outward and from which a radial channel leads radially within the region of each planet gear to the bearing of the planet gear.
• the lubricant emerging from the axial lubricant duct can be distributed uniformly in the circumferential direction in a simple manner, while the radial ducts emanating from the lubricant pocket ensure targeted lubrication of the planet gear bearings.
• Figure 1 is a partial representation of an axial longitudinal section of a drive assembly for a radiator fan of an internal combustion engine.
• Fig. 2 is a schematic representation of the assembly
• FIG. 3 shows a diagram showing the dependence of the drive power P of the radiator fan on the speed n of the radiator fan;
• Fig. 4 is a schematic representation of a variant of a drive assembly for a radiator fan
• FIG. 5 shows a partial illustration of an axial longitudinal section of a still further variant of a drive unit for a radiator fan.
• 1 shows a drive unit for a radiator fan or radiator fan 1 of an internal combustion engine of a motor vehicle (not shown in more detail).
• the cooler fan 1 is seated in a manner known per se on a housing 3 of a liquid friction clutch of a conventional type, generally designated 5, as will be explained in more detail with reference to FIG. 5.
• the housing 3 is rotatably mounted on a pin 7 and, together with an armature disk 9 firmly held on the pin 7, forms shear gaps 11 which, when they are filled with a viscous shear fluid, on the Drive pin 7 acting drive torque transmitted to the housing 3 and thus the radiator fan 1.
• the filling level in the shear gaps 11 determines the transmissible torque and is controlled in a temperature-dependent manner by a mechanical temperature control 13, for example a bimetal control, via a valve arrangement (not shown in more detail), as is described, for example, in DE-A-38 07 109.
• a mechanical temperature control 13 for example a bimetal control
• a valve arrangement (not shown in more detail), as is described, for example, in DE-A-38 07 109.
• the shear fluid is dynamically pumped out of the shear gaps 11 due to the relative rotation between the rotor disk 9 and the housing 3, with which the cooler fan 1 is uncoupled from the driven pin 7, while the shear gap 11 is filled at high temperatures and the cooler fan 1 therewith is switched on.
• the fluid friction clutch 5 is flanged directly to a crankshaft 17 of the internal combustion engine via a switchable planetary gear 15.
• the planetary gear 15 is designed as a transmission gear and comprises an electromagnetic clutch 19, via which it can be switched on in the drive path between the crankshaft 17 and the drive pin 7 to increase the drive speed or can be bridged for the direct drive with the crankshaft speed .
• the electromagnetic clutch The lung 19 is controlled by a controller 21 (FIG. 2), which in turn responds to further operating parameters of the motor vehicle, in particular the speed of the internal combustion engine detected by a speed sensor 23 and, if appropriate, the driving speed of the motor vehicle detected by a sensor 25 and optimizes the operation of the cooling fan 1 on the basis of these parameters.
• FIG. 3 shows the power requirement P of the cooling fan 1 as a function of the fan speed n with the engine speed assumed to be constant.
• Curve A shows the power requirement of cooler fan 1 alone, ie the drive power required for cooler fan 1 at the outlet of fluid friction clutch 5, while curves B and C show the drive power to be used for this purpose at the input of fluid friction clutch 5 at different output speeds represent.
• Curve B shows the conditions for the direct drive with the engine speed, while curve C represents the conditions for speed transmission by the planetary gear 15.
• the power difference indicated by hatching represents the power loss due to slippage in the fluid friction clutch 5. As shown in FIG.
• the switchover speed n can have a predefined size; however, it can also be varied depending on the driving situation of the motor vehicle, for example depending on its driving speed and the resulting cooling power requirement of the internal combustion engine, for example by increasing the fan speed at a low driving speed and thus low airflow cooling, while reducing it at a high driving speed is gert.
• the planetary gear 15 is guided radially and axially on a central shaft 29 which is coaxial with the axis of rotation 27 of the fluid friction clutch 5 and thus of the radiator fan 1.
• the shaft 29 is coaxial with an end flange 31 and is directly attached to an end face of the crankshaft 17.
• the planetary gear 15 comprises three gear components rotatable relative to one another about the axis of rotation 27, of which a first gear component comprises a sun gear 33 rotatable relative to the shaft 29, a second gear component, a ring gear 35 rotatable both about the shaft 29 and the sun gear 33, and a third Gear component is connected to shaft 29 in a rotationally fixed manner via a toothing 37, generally designated 39
• Planetary carrier comprises, on which several, for example three, planet gears 43 are rotatably mounted axially parallel to the axis of rotation 27 via roller bearings 41. 1 shows, for the sake of simplicity, only one of the planet wheels 43 meshing with both the sun gear 33 and the ring gear 35.
• the sun gear 33 is connected in a rotationally fixed manner to a double cone 47 via a clutch disc 45, which is toothed both radially on the inside and radially on the outside.
• the double-cone 47 is radially mounted inside via a first rolling bearing 49 on the shaft 29 and supports seinerseit 's radially one is ten gehal ⁇ of two housing shells 53, 55, between which the ring gear 35 by screws 57 outside via a second rolling bearing 51st
• the other housing shell 55 is, via a third roller bearing 59, on a ring part 61 of the planet gear carrier 39 which surrounds the shaft 29 and is coupled to the ring part 61 via the toothing 37.
• a further ring part 67 is on the housing half 55 by a cover part 63 coaxial with the ring part 61 held non-rotatably via a toothing 65.
• the ring parts 61, 67 form, on the one hand, the raceways of the roller bearing 59 and, on the other hand, the engagement surfaces of a one-way or freewheeling clutch 69 arranged axially between the roller bearing 59 and the planet gears 43.
• the electromagnetic clutch 19 comprises a magnetic coil unit 71 which is concentric with the axis of rotation 29 and which is guided centered on the shaft 29 via a roller bearing 73.
• a circumferentially rigid reaction torque support 75 for example in the form of a shaped sheet metal part, connects the electromagnet unit 71 in a rotationally fixed manner to a stationary component, for example the engine block of the internal combustion engine.
• the reaction torque arm 75 extends around both axial and radial vibrations of the crankshaft 17
• the electromagnet unit 71 is assigned an armature unit 81, which is held on the double cone 47 in a rotationally fixed but axially movable manner via a toothing 83. In speed-translated operation, the electromagnet unit 71 is excited, whereby the armature unit 81 is attracted and the sun gear 33 is braked against the stationary engine block.
• the crankshaft 17 drives the planetary gear carrier 39 via the shaft 29, the planetary gears 43 of which are supported on the stationary sun gear 33 and drive the ring gear at the translated speed.
• the fluid friction clutch 5 centrally attached to the cover part 63 with its drive pin 7 is thus driven via the ring gear 35.
• the housing halves 53, 55 form a lubricant chamber 85, which is only partially filled with liquid lubricant, such as lubricating oil.
• liquid lubricant such as lubricating oil.
• the roller bearings 49, 51 arranged axially adjacent to the electromagnetic clutch 19 are sealed by ring seals 87, 89; for sealing on the axially other side of the planetary gear 15, the cover part 63 covers the free end face of the shaft 29.
• a scoop leading from the radially outer region into the radially inner region promotes Pipe 91 the lubricant in the area of the shaft 29.
• the scoop pipe 91 sits on the double cone 47, that is rotatably connected to the sun gear 33, and scoops the lubricant centrifuged into the outer region and rotating with the ring gear 35 or the housing halves 53, 55 relative to the sun gear 33 in the region of the shaft 29, where it is distributed over axial channels (not shown) and is centrifuged back in the area of the rolling bearings and gears.
• FIG. 4 schematically shows a radiator fan 1 a, which in turn is driven from the crankshaft 17 a of the internal combustion engine via a planetary gear 15 a.
• the planetary gear 15a in turn comprises a planet gear carrier 39a, which is non-rotatably connected to a central shaft 29a and has a plurality of planet gears 43a, each of which meshes with a sun gear 33a rotatably enclosing the shaft 29a and a ring gear 35a connected to a unit with housing halves 53a, 55a.
• the radiator fan 1 a is connected in a rotationally fixed manner to the ring gear 35 a, and instead of the electromagnetic clutch 19, the fluid friction clutch 5 a is connected to the sun gear 33 a.
• the fluid friction clutch 5a acts as a "brake", by means of which the sun gear can be braked against the engine block of the internal combustion engine via the reaction torque arm 75a with variable torque.
• the braking torque is determined by the filling state of the shear gap 11a of the fluid friction clutch 5a.
• the fluid friction clutch has a Shear fluid supply line 92 is connected to a fluid source 93 which, controlled by the electrical control 21a, changes the filling state of the shear gaps 11a.
• the controller 21a not only responds to the engine speed and possibly the driving speed of the motor vehicle by means of the sensors 23a, 25a, but also to the coolant water temperature or the ambient temperature of the internal combustion engine by means of a temperature sensor 95.
• An advantage of the variant of the structural unit shown in FIG. 4 is that the speed of the radiator fan 1 a can be varied continuously via the fluid friction clutch 5 a acting as a brake.
• the operation of the radiator fan 1 a can be further optimized by means of suitable speed characteristic curves, for example implemented by characteristic curve fields of the control 21 a.
• the freewheel clutch of the exemplary embodiment in FIGS. 1 and 2 is missing.
• the cooler fan 1 a can be switched off when the shear gaps 11 a are completely empty, since the planet gears 43 a are no longer supported on the sun gear 33 a that then rotates freely can.
• the maximum speed of the cooling fan la is reached at the maximum fill level of the shear gap la and thus essentially completely stationary braked sun gear 33a.
• FIG. 5 shows a further variant of a drive unit for a radiator fan 1b.
• the structural unit corresponds to the principle according to the variant of FIGS. 1 and 2, with the fluid friction clutch 5b being shown in further details.
• FIG. 5 shows that the housing 3b, which is mounted with a bearing 97 on the drive pin 7b, through a partition 99 into a working chamber 101 which contains the rotor disk 9b and together with the rotor disk 9b forms the shear gap 11b
• the partition 99 contains a valve hole 105, which is opened or closed in a temperature-dependent manner by a bimetal 109 controlled by a valve plate 107.
• a valve hole 105 When the valve hole 105 is open, shear fluid flows into the shear gap 11b.
• a pump element 111 which is effective due to the relative rotation between the rotor disk 9b and the housing 3b, pumps the shear fluid back into the reservoir 103 through an opening 113 of the partition 99 to shut off the fluid friction clutch 5b when the valve hole 105 is closed.
• the planetary gear 15b forms a structural unit with the fluid friction clutch 5b and the radiator fan 1b. It is in turn mounted on a central shaft 29b, which is attached via its flange 31b to the crankshaft 17b coaxially with the axis of rotation 27b.
• the sun gear 33b is connected via the double cone 47b in a rotationally fixed manner to the armature unit 81b of the electromagnetic clutch 19b, the ring-shaped electromagnet 71b surrounding the shaft 29b on the crankshaft side of the planetary gear 15b is guided radially relative to the shaft 29b by means of the ball bearing 73b.
• the ball bearing 73b is not arranged axially next to the roller bearings 49b, 51b, which are arranged essentially radially one above the other, but also approximately radially over these camps. Similar to FIG.
• the electromagnet unit 71b is assigned a reaction torque arm 75b which, in the circumferential direction, non-rotatably connects the electromagnet unit 71b to a stationary component of the internal combustion engine, for example the engine block, and likewise a radially extending, axially elastic section 77b and includes an axially extending, radially elastic portion 79b to accommodate axial and radial vibrations of the crankshaft 17b.
• the electromagnetic clutch is in turn controlled by an electrical controller 21b which responds to the speed of the internal combustion engine by means of a speed sensor 23b and optionally to the driving speed of the motor vehicle with a further sensor 25b.
• the sun gear is not connected to the armature unit 81b via positive toothed clutches or the like, since it has been found that the non-uniformity of the rotational movement of the crankshaft 17b and its axial and radial vibrations lead to excessive wear on the positive toothing to lead.
• the sun gear 33b is therefore either in one piece or, as shown in FIG. 5, connected by a press fit connection 115 to the component passing between the two roller bearings 49b, 51b, here the double cone 47b.
• the armature unit 81b has an annularly closed armature plate 117, which may be composed of several segments, which is fixedly mounted, for example riveted, to the double cone 47b by a leaf spring element 119, which may also be segmented.
• the leaf spring element 119 connects the anchor plate 117 in a rotationally fixed but axially movable manner to the double cone 47b.
• the ring gear 35b is between two according to FIG. 1 Housing halves 53b, 55b inserted and fastened with screws 57b, the housing halves 53b, 55b on the crankshaft side via the bearings 51b, 49b on the shaft 29b and on the side remote from the crankshaft via the bearing 59b on the plane seated on the shaft 29b Support the gear carrier 39b.
• a one-way clutch 69b is again provided between the ring part 61b of the planet gear carrier 39b seated on the shaft 29b and a ring part 67b fastened by screws 121 to the housing half 55b.
• the scoop tube 91b is connected via a radial bore 123 of the sun gear to an axially extending channel 125 formed radially between the sun gear 33b and the shaft 29b.
• the channel 125 distributes the lubricant in the axial direction in the planetary gear 15b and, for this purpose, opens on the crankshaft side in an annular lubricant pocket 129 formed between the double cone 47 and a bearing ring 127 of the radially innermost roller bearing 49b, which is directed outwards through the Ring seal 87b is sealed.
• the radially overlying roller bearing 51b also forms between the double cone 47b and an outer bearing ring 131b of the roller bearing 51b inserted axially from the outside into the housing half 53b, an annular lubricant pocket 133 which is sealed to the outside by the ring seal 89b and which is connected via an outlet 135 in radially inner region of the scoop tube 91b can also be supplied with lubricant.
• the lubricant pockets 129, 133 are sealed radially outward and are only accessible from the radial inside.
• the end of the channel 125 remote from the crankshaft 17b opens into an annular space 137 which serves to distribute the lubricant, from which in the annular part 61b a channel 139 leads into an annular lubricant pocket 141 located between the annular parts 61b, 67b.
• the lubricant pocket contains the roller bearing 59b, including its inner bearing ring 143 placed on the ring 61b, and the one-way clutch 69b, the engagement surfaces of which are formed by regions of the ring parts 61b, 67b lying radially one above the other.
• the lubricant pocket 141 is sealed by a sealing plate 145 held on the ring part 67b by the screws 121, which extends beyond the end of the shaft 29b remote from the crankshaft, but in the region of this end has an assembly and filling opening closed by a cover 147 .
• annular sealing plate 149 is inserted between the ring part 57b and the housing half 55b, which has an annular sealing lip 151 on its inner circumference, which both over the inner ring 143 and over the radially inner engagement surface of the freewheel coupling 69b protrudes radially inwards and engages in a circumferential groove 153 of the ring part 61b, but does not touch it.
• the lubricant pocket 141 divided in this way in the lubricant chamber 85b delimits a lubricant volume in a radially outwardly sealed manner, since all surfaces and components of the roller bearing 59b and the one-way clutch 69b that are at risk of wear are completely immersed. Even if the planetary gear 15b with the electromagnetic clutch 19b open in the
• the roller bearings 49b, 51b are lubricated in an analogous manner even in the direct gear of the planetary gear 15b.
• the lubricant pockets 129 and 133 are delimited on their sides adjacent to the planet gears 43b by ring shoulders which extend radially inward to the smallest diameter of the inner raceways of the roller bearings 49b, 51b. After initial filling, the lubricant pockets 129 and 133 thus store lubricant which cannot be centrifuged off even in the direct gear of the planetary gear 15b. In this way, running of the roller bearings 49b, 51b and 59b and the one-way clutch 69b is definitely avoided.
• the controller 21b is assigned a timing element 155, which controls the planetary gear 15b either periodically or for certain operating situations of the motor vehicle, for example when starting the internal combustion engine, for a predetermined period of time independently shifts the cooling requirements into the gear in which lubricant is conveyed by the scoop pipe 91b.
• the annular shoulders provided to form the lubricant pockets 129, 133 can, similar to the lubricant pocket 141, realized by additional sealing components; however, they can also be realized by end faces of components which are present anyway, such as an end face 157 of the sun gear in the case of the lubricant pocket 129 or by an annular shoulder 159 integrally formed on the bearing ring 131.
• the needle bearings 41b of the planet gears 43b are also lubricated.
• an inner circumferential groove 163 adjoins the distribution annular space 137 via an annular gap 161, from which a radial channel 165 leading to the needle bearing 41b branches off in the region of each planet gear 43b.
• the sun gear 33b is lubricated through openings on the radially inner foot of the scoop tube 91b.
• the ring gear 35b is immersed in the lubricant sump that collects during rotation in the radially outer region of the lubricant chambers 85b.
• the bearing arrangement of the planetary gear 15b is such that all the gear components of the planetary gear 15b against each other and the shaft 29b bearing bearings 49b, 51b and 59b in a common supporting force path between a support shoulder 167 provided on the shaft 29b and a central one the end of the shaft 29b screwed on fastening nut 169 are arranged free of play.
• the roller bearings 49b, 51b and 59b are all designed as shoulder bearings or inclined bearings, that is to say they generally have raceways which run at an angle to the axis of rotation 27b.
• the supporting force path of the roller bearings 49b, 51b and 59b leads from the bearing ring 127 via the roller bearing 49b, the double cone 47b, the roller bearing 51b, the outer ring 131, the housing half 53b, the ring gear 35b, the housing half 55b, the ring part 67b, the roller bearing 59b, the inner ring 143 to form a support ring 171, which can be screwed against the annular shoulder 167 by means of the fastening nut 169.
• the generally obliquely running raceways of the roller bearings 49b, 51b, 59b here extend axially on both sides of the revolving area of the planetary gear 43b obliquely outwards in order to be able to form the lubricant pockets 129, 133 and 141 explained above.
• the planetary gear T5b shown in FIG. 5 forms, together with the fluid friction clutch 5b and the radiator fan, a structural unit which is mounted directly on the crankshaft 17b. It goes without saying that only the planetary gear 15b can be mounted on the crankshaft 17b, while the fluid friction clutch 5b including the radiator fan 1b can be arranged at another location.
• the ring gear 35b can be connected to a separate output element, for example a pulley 173.
• a separate belt drive can optionally also be provided between the shaft 29b and the crankshaft 17b.
• the planetary gear 15b can also be used to drive other auxiliary units of a motor vehicle independently of a fluid friction clutch.
• the planetary gear of FIG. 5 can also the electromagnetic clutch 19b is replaced by a fluid friction clutch.
• the one-way clutch 69b may also be omitted.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• General Details Of Gearings (AREA)
• Structure Of Transmissions (AREA)
• Retarders (AREA)

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Citations (5)

• 1992
  • 1992-08-26 DE DE9211473U patent/DE9211473U1/de not_active Expired - Lifetime
• 1993
  • 1993-08-26 EP EP93919186A patent/EP0656990B1/de not_active Expired - Lifetime
  • 1993-08-26 WO PCT/EP1993/002305 patent/WO1994004801A2/de active IP Right Grant
  • 1993-08-26 ES ES93919186T patent/ES2097535T3/es not_active Expired - Lifetime
  • 1993-08-26 DE DE59304694T patent/DE59304694D1/de not_active Expired - Fee Related
  • 1993-08-26 BR BR9306958A patent/BR9306958A/pt unknown

Patent Citations (5)

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