DE10235721B4 - Adjustable coolant pump - Google Patents

Abstract

A controllable coolant pump with a belt pulley (4) and a magnetic coupling connecting said belt pulley (4) in dependence on the operating temperature of the coolant in connection with a frictional pairing with a vane wheel (27), with a vane wheel side a running region (5) of a shaft in the region of Coil receiving (7) arranged adjacent, provided with a two-blade or a wedge or tooth profile driving portion (10) of the shaft, on the one hand a support sleeve (11) and on the other hand, a sliding bush (12) in bores with each of the driving area (10 are arranged with a rigidly connected to the slide bushing (12) friction disc (13), wherein on a driving area (10) adjacent the impeller side impeller region (26) of the shaft is a rotatably mounted impeller (27) which by means of a on the free end of Flügelradlaufbereiches (26) arranged Stützr inges (35) is limited axially, characterized
- That on the slide bushing (12) in the magnetic field of the magnetic coil (8) with a spring chamber (15) versehener plunger armature ...

Description

The Invention relates to a a pulley driven variable coolant pump for internal combustion engines, in which the impeller switchable driven in conjunction with a friction pair of the pump shaft can be.

in the The prior art are coolant pumps for internal combustion engines prescribed above a Pulley driven by the crankshaft of the internal combustion engine be and where the impeller switchable in conjunction with a friction pairing of the pump shaft is driven.

By those with such coolant pumps Two-point control that can be implemented can control the cooling capacity as well as the drive power the coolant pump optimized become.

These Control of coolant pumps for motor vehicles allows Among other things, that one Immediately upon starting the engine incipient forced cooling avoided which allows the warm-up phase of the engine with all the in this phase, such as increased friction losses, increased Emission levels and increased Fuel consumption can be significantly reduced.

For example, describes the DE 197 52 372 A1 a directly driven by the crankshaft controllable coolant pump in which the impeller is freely rotatably mounted on the shaft and is taken on reaching the operating temperature by the contact force of a thermocouple of the drive shaft. However, since the thermocouples used for the speed control always produce a dependent of the respective coolant temperature frictional force occurs between the pump shaft and the impeller not only a brief slip, which then inevitably contributes to increased wear of the torque transmitting surfaces.

In order among other things also to eliminate this disadvantage was in the DE 100 57 098 C1 a controllable coolant pump presented in the stationarily in the pump housing, a magnetic coil is arranged, which arranged with a rotatably, but spring loaded slidably disposed on the drive shaft, the impeller side with a friction lining armature disc can enter into operative connection that when the magnetic field due to the spring pressure on the rotatable the drive shaft arranged impeller is taken from the armature disk.

One significant disadvantage of this design is that the driving torque through the available standing magnetic space is severely limited.

The is called, that at low available Space, depending on the magnet used, even relatively small Anpressfederkräfte for decoupling the impeller overcome by the drive shaft can be.

Of the Invention is therefore the object of a cost and production-technically simple manufacturable, driven by a pulley, adjustable coolant pump for combustion engines, at the wheel switchable in conjunction with a friction pair driven by the pump shaft can be developed at the time of the friction of the Magnetic coupling on the impeller to be transferred Antriebsreibmoment be increased significantly with minimal space should.

According to the invention this Task by a controllable coolant pump solved with the features of claim 1.

essential to the invention is that on the sliding bush connected to the friction disc in the Magnetic field of the magnetic coil provided with a spring chamber Plunger armature is arranged, wherein in the spring chamber a compression spring is arranged which is supported against the support sleeve.

On Reason this ertindungsgemäßen arrangement can the solenoid plunger in the magnetic field of the solenoid on the outer jacket the slide bushing translate the spring force of the compression spring be moved.

characteristic is also that on the outer jacket the slide bushing in the working area of the compression spring a circlip which is arranged with a at the inner end of the spring chamber Stop collar can enter into operative connection.

By the interaction of stop collar and circlip is the Stroke of the plunger anchor in the return path limited.

in the Working distance is the maximum stroke of the plunger armature through the stop the face of the plunger anchor to the friction disc rigidly connected to the sliding bushing limited.

The advantageously provided on the impeller side with a preferably annular friction lining friction is according to the invention in the contact area with the end face of the plunger anchor with Overflow openings provided which diving anchor side are preferably connected to each other by means of an annular groove.

These inventive arrangement allows that all overflow openings as well as the ring groove by means of the magnetic field is under the spring force of the compression spring pressed end face of the Dive anchors are sealed tight.

According to the invention is Pump housing the friction disk outstanding, in the pump housing close Area with oblong holes provided outer tube arranged, which is arranged by a likewise on the pump housing Filter screen covered becomes.

About these slots allows the inventive arrangement the inflow or outflow of coolant from the pressure chamber into the coupling space.

The on the circumference of the outer tube arranged filter screen prevents the entry of particles from the pressure chamber into the coupling space. Is essential to the invention continue that on the entrainment area flow side adjacent, provided with a recess Flügelradlaufbereich the shaft a running in the outer tube with its edge impeller is arranged.

The Gap width between the edge of the impeller and the adjacent thereto Ring edge of the outer tube is so close according to the invention measured that due to the very small gap width available there in connection with the additional gap resistance building up with a rotating impeller the entire replacement of coolant takes place from the pressure chamber into the coupling space via the elongated holes.

characteristic is also that on Impeller on the friction wheel side and / or on the friction disk on the impeller side inside an inflow ring, in the middle an outflow ring and outside a friction ring provided with or without friction lining is arranged.

Of the on the outer edge ensured lying friction ring that the due to the contact force over the frictional friction generated friction always a maximum drive torque transfers to the impeller.

A particularly advantageous embodiment the solution according to the invention is characterized characterized by the fact that am outer edge both wing-side at the. Friction disc as well as Reibscheibenseitig on the impeller respectively a friction ring with a repeating for example after 180 ° on the circumference, for Example statistical distribution of different sized friction surfaces with intervening tooth pockets is arranged such that the distribution the friction surfaces and the tooth pockets on the friction disc and the impeller are complementary to each other.

These inventive arrangement causes in the "start-up" the cooling medium can escape from the chambers between the friction disc and the impeller and at the same time a high driving torque is generated.

Advantageous the recess serves in the Flügelradlaufbereich the wave of reducing the friction torque at the Flügelradlaufbereich rotating impeller.

following the invention with reference to an embodiment in conjunction closer with three figures explained become.

there demonstrate

1 : The variable coolant pump according to the invention in section in the side view with coupled impeller;

2 : the cut at AA according to the 1 ;

3 : The inventive, controllable coolant pump in section in the side view with decoupled impeller.

In the 1 is the inventive variable coolant pump in section in the side view with coupled impeller 27 shown.

At the free end of the running area 5 one in a pump housing 1 arranged shaft is in a bearing seat 2 on the pump housing 1 one by means of a ball bearing 3 mounted pulley 4 pressed on the running area of the shaft.

The camp seat 4 Neighboring is in the running area 2 the shaft is a radial shaft seal 6 arranged. This is the housing side in a seal seat of the pump housing 1 attached. The use of this radial shaft seal on the one hand, the manufacturing costs are reduced and at the same time avoiding steam leaks.

In the pump housing 1 is a coil holder 7 with a magnetic coil 8th arranged.

The running area 2 the shaft is in a radial shaft seal 8th adjacent, in the area of the coil receiving 7 arranged plain bearings 9 stored, whereby a simple and inexpensive production is guaranteed. The running area 5 in the flow space on the impeller adjacent driving range 10 the shaft is for example provided with a two-flat or a wedge or tooth profile.

On this driving range 10 are provided in their shaft bores with each of the driving area associated Mitnehmerflächen, on the one hand a support sleeve 11 and on the other hand, a sliding bushing 12 arranged.

On the sliding bush 12 is a friction disc rigidly connected to it 13 arranged.

The support bush 11 and also the sliding bush 12 are therefore both axially displaceable but simultaneously non-rotatably connected to the shaft.

moreover allows the chosen one Design at the same time a production technically simple installation

On the sliding bush 12 is in the magnetic field of the magnetic coil 8th one with a spring chamber 15 provided plunger anchor 14 arranged.

In the spring chamber 15 of the plunger anchor 14 is a compression spring 16 which are arranged against the support bush 11 supported.

Due to this arrangement, the plunger anchor 14 in the magnetic field of the magnetic coil 8th on the outer surface of the sliding bush 12 counteract the spring force of the compression spring 16 be moved in the longitudinal direction.

On the outer jacket of the sliding bush 12 is located in the working area of the compression spring 16 a circlip 17 , which with one at the inner end of the spring chamber 15 arranged stop collar 18 can come into operative connection.

In the return path, the stroke of the plunger armature 14 through the cooperation of stop collar 18 and circlip 17 limited.

In its maximum working distance is the stroke of the plunger anchor 14 by the stop of the end face of the plunger to the rigid with the sliding bushing 12 connected friction disc 13 limited.

The Flügelradseitig with trained as a friction ring and a special annular friction lining 25 provided friction disc 13 is in contact with the face 19 of the plunger anchor 14 , like out 1 in connection with in the 2 illustrated section through the 1 at AA, with overflow openings 20 provided, which as in the 1 shown, Tauchankerseitig each other by means of an annular groove 21 are connected.

This arrangement allows all the overflow openings 20 as well as the ring groove 21 by means of the magnetic field switched off under the spring force of the compression spring 16 pressed on face 19 of the plunger anchor 14 to the friction disc 13 can be sealed tightly.

At the pump housing 1 is a friction disk 13 outstanding, in the pump housing close area with oblong holes 23 provided outer tube 22 arranged, which also from one on the pump housing 1 arranged filter screen 24 is covered.

This design allows the inflow or outflow of cooling liquid from the pressure chamber into the coupling space via the elongated holes 23 ,

That on the circumference of the outer tube 22 arranged filter screen 24 prevents the entry of particles from the pressure chamber into the coupling space.

On the take-off area 10 adjacent to the flow space, with a recess 34 provided impeller running area 26 the wave is one with its edge 33 in the outer tube 22 running impeller 27 arranged.

The recess 34 in the Flügelradlaufbereich 26 In particular, the shaft serves to reduce the frictional torque in the impeller region 26 rotating impeller 27 ,

The gap width between the edge 33 the impeller 27 and the adjacent ring edge of the outer tube 22 is dimensioned so small that with a rotating impeller 27 in connection with the additional gap resistance which builds up during rotation, the exchange of cooling liquid from the pressure chamber into the coupling space via the oblong holes 23 he follows.

At the impeller 27 is Reibscheibenseitig, as in the 1 and 2 shown, inside a inflow ring 28 , in the middle an outflow ring 29 and outside a friction ring 30 arranged.

The inside slightly deeper inflow ring 28 and between the inflow ring 28 and the friction ring 30 arranged much flatter Ausströmring 29 are used to build a hydrostatic negative pressure at from the end faces 19 of the plunger anchor 14 closed overflow openings 20 ,

In this in the 1 shown operating state in which the magnetic field of the magnet kitchen sink 8th is switched off, closes the end face 19 of the plunger anchor 14 the overflow openings 20 ,

At the same time, the compression spring pushes 16 the rotating friction disc 13 against the back wall of the impeller 27 ,

Like from the 1 in connection with in the 2 illustrated section through the 1 at AA, are on the outer edge both Flügelradseitig on the friction disc 13 as well as the friction wheel on the impeller 27 each a friction ring with a special, after 180 ° on the circumference recurrent distribution of friction surfaces 31 with tooth pockets in between 32 arranged.

The distribution of the friction surfaces 31 and the tooth bags 32 are at Reibscheibe 13 and impeller 27 complementary to each other, so that these opposing surface elements can even engage with each other.

The inventive arrangement causes in the "start-up" the cooling medium can flow optimally between the friction disc and the impeller, while ensuring at the same time is that always a high driving torque is generated.

In the start-up phase will be that between the two discs cooling medium first pressed together between the two discs and displaced to the outside.

The cooling medium initially remaining between the two circular disks during startup is then centrifugally accelerated and thereby thrown outwards. As a result of outward between the friction disc 13 and the friction-side end face of the impeller 27 from the inflow ring 28 via outflow ring 29 up to the friction ring always tapered gap width, a negative pressure is built during the closing process in the start-up phase, which in addition to the spring pressure of the compression spring 16 the generation of Antriebsreibmomentes on the impeller 27 serves.

These two on the friction disk 13 acting, the frictional force generating forces is then at the construction of the discharge pressure in the pressure chamber, over the long holes 23 also in the coupling space on the friction disc 13 fitting, compressive force of the delivery pressure from the pressure chamber superimposed. After the start-up slip has reduced in the start-up phase, and the impeller 27 then almost the speed of the friction disc 13 has reached, due to the above-described, acting jointly on the friction disc forces, in conjunction with in the 2 illustrated inventive arrangement of complementary friction surfaces 31 and tooth pockets 32 both on the impeller 27 as well as the friction disk 13 , these two "surface gears" in engagement.

As a result, the initially frictional torque transmission from the friction disk in the start-up state is eliminated 13 on the impeller 27 then in a positive torque transmission over.

The at the outer edge of the impeller 27 arranged friction ring 30 always ensures that the attacking on the outer edge radial drive force due to its large lever arm always a maximum drive torque to the impeller 27 transfers.

Axial becomes the impeller 27 by means of a on the free end of Flügelradlaufbereiches 26 arranged support ring 35 position limits.

In the 3 is the inventive, controllable coolant pump in the side view in section now shown with decoupled impeller.

For the transition from the in the 1 shown operating state in the operating state according to 3 the magnetic field of the solenoid is turned on.

When the magnetic field is switched on, the plunger armature is first activated 14 against the spring force of the compression spring 16 until the stop of his stroke alliance 18 to the on the sliding bush 12 arranged circlip 17 withdrawn.

The one in between the impeller 27 and the friction disc 13 arranged chambers initially existing vacuum sucks cooling medium through the overflow from the clutch chamber.

Due to the presence of the annular groove according to the invention 21 the adhesion in this area is reduced.

The cooling medium flowing into the chambers between the friction disk and the impeller is in turn radially accelerated between these two adjacent disks and, when flowing over, builds up between the friction disk 13 and the outer tube 22 a dynamic pressure between the impeller 27 and the friction disc 13 on, which is reinforced by an arranged in this area on the inner edge of the outer tube annular bead.

As a result of this dynamic pressure is the sliding bush 12 contrary to the end position position on the plunger anchor 14 acting spring force of the compression spring 16 until it stops against the support bush 11 moved up.

That in the outer tube 22 revolving impeller 27 is due to the gap resistance in the narrow annular gap between the edge 33 the impeller 27 and the adjacent ring edge of the outer tube 22 slowed down and comes to a halt.

Claims (4)

Adjustable coolant pump with a pulley ( 4 ) and a pulley ( 4 ) in dependence on the operating temperature of the coolant in conjunction with a friction pair switchable with an impeller ( 27 ) magnetic coupling, with a Flügelradseitig a running range ( 5 ) a shaft in the region of a coil receiving ( 7 ) arranged adjacent, provided with a two-flat or a wedge or tooth profile driving range ( 10 ) of the shaft, on the one hand a support bush ( 11 ) and on the other hand a sliding bush ( 12 ), which are bored in each of the driveways ( 10 ) associated Mitnehmerflächen are provided with a rigid with the sliding bush ( 12 ) connected friction disc ( 13 ) is arranged, wherein on a the entrainment area ( 10 ) impeller wheel region ( 26 ) of the shaft a rotatably mounted impeller ( 27 ), which by means of a on the free end of Flügelradlaufbereiches ( 26 ) arranged support ring ( 35 ) is axially limited in position, characterized in that - on the slide bushing ( 12 ) in the magnetic field of the magnetic coil ( 8th ) with a spring chamber ( 15 ) provided plunger anchor ( 14 ) is arranged, wherein in the spring chamber ( 15 ) of this plunger anchor ( 14 ) a compression spring ( 16 ), which against the support bush ( 11 ) is supported, and wherein on the outer surface of the sliding bush ( 12 ) in the working area of the compression spring ( 16 ) a retaining ring ( 17 ), which serves as a stop for one at the inner end of the spring chamber ( 15 ) of the plunger anchor ( 14 ) arranged stop collar ( 18 ), - that the friction disc ( 13 ) in the area of contact with an end face ( 19 ) of the plunger anchor ( 14 ) with overflow openings ( 20 ), that - on the pump housing ( 1 ) the friction disc ( 13 ) outstanding, close to the pump housing area with slots ( 23 ) provided outer tube ( 22 ) is arranged, which of a likewise on the pump housing ( 1 ) arranged filter screen ( 24 ) is covered, which on the Flügelradlaufbereich ( 26 ) of the shaft rotatably mounted impeller ( 27 ) with a border ( 33 ) with a small gap width in the outer tube ( 22 ) runs, and - that the friction wheel side on the impeller ( 27 ) and / or impeller on the friction disc ( 13 ) radially inward an inflow ring ( 28 ), in the middle an outflow ring ( 29 ) and radially outside with or without friction lining ( 25 ) provided friction ring ( 30 ) are arranged. Controllable coolant pump according to claim 1, characterized in that in the form of a friction ring ( 30 ) Opposite each other both Flügelradseitig on the friction disc ( 13 ) as well as the friction wheel side on the impeller ( 27 ) Surface elements, with a after 30 °, 60 °, 90 °, 120 ° or even after 180 ° circumferentially repeating, any distribution of different sized friction surfaces with intervening tooth pockets, are arranged such that the distribution of the friction surfaces ( 31 ) and the tooth pockets ( 32 ) on the friction disc ( 13 ) and on the impeller ( 27 ) are complementary to each other. Controllable coolant pump according to claim 1, characterized in that the overflow openings ( 20 ) immersed anchor side with each other via an annular groove ( 21 ) are connected. Controllable coolant pump according to Claim 1, characterized in that the impeller wheel region ( 26 ) of the shaft with one or more recesses ( 34 ) is provided.