DE102008049618A1 - Electromagnetically operatable friction disk clutch for use in drive unit for blower of motor vehicle, has rotor and magnet part rotatably coupled with one another by friction surface sections connected with electromagnet arrangement - Google Patents

Abstract

The clutch (1) has a shiftable electromagnet arrangement (16) for connecting friction surface sections (14a, 14b) to bring a rotor (14) to be driven into different number of revolutions stages with a rotating driving element e.g. clutch shaft (3). The rotor and a permanent magnet part (9) are rotatably coupled with one another by the friction surface sections connected with the electromagnet arrangement. A rotating eddy current part (6) is rotatably connected with the driving element, and the rotor is rotatably supported with respect to the driving element.

Description

The The invention relates to a friction disc clutch according to claim 1 and a drive unit according to claim 13.

friction disc clutches using the eddy current principle or drive units in which such Frictional disk clutches are integrated, for example, in Vehicle area for used the drive of ancillaries. In particular, can be thus reliably set up different performance levels or operating states. In this case, electromagnetic arrangements have proven to make appropriate switching operations to be able to. So it is possible a driven element of the accessory such as a fan hub a fan assembly in a vehicle over to drive the vehicle engine, with different speed levels can be set up.

task It is the object of the present invention to provide variable speed arrangements Drive a driven element with regard to an advantageous Gradation of switching states or to improve a compact design.

These Task is by the claims 1 and 13 solved. The dependent ones claims relate to advantageous variants of the invention.

The Invention goes first from an electromagnetically actuated friction disc clutch with a drive element and a relative to the drive element rotatable mounted element to be driven, wherein an eddy current coupling with an eddy current part and a movable relative to the eddy current part Permanent magnet part is present, so that when rotating eddy current part the permanent magnet part is rotated, and wherein a switchable electromagnet assembly for connecting Reibscheibenabschnitten is provided to drive when rotating drive element To bring element into different speed levels. there becomes the permanent magnet part according to the eddy current coupling principle set in rotation, whereby the speed of the eddy current part different from the rotational speed of the permanent magnet part. The drive element, which acts on the drive element on the drive side, can z. As a drive wheel, a shaft or a rotatable section be a driven component, wherein the drive element itself also a drive effect by a drive motor in particular one Internal combustion engine experiences.

Of the Essence of the invention is that the element to be driven and the permanent magnet part via the Reibscheibenabschnitte connected to the solenoid assembly are rotatably coupled with each other. The invention particularly relates a fan clutch for a Motor vehicle, with which advantageously several different speed levels can be set up. So anytime a currently required fan power, each for different possible operating conditions z. B. the parent Unit may differ, for example, the vehicle, adapted or set. In particular, a one-to-one translation be excluded, what at high or maximum speeds of the Drive element or a drive motor to unwanted, because according to highest Speeds z. B. the fan to lead would.

The In addition, the element to be driven can in particular detached in its design be from the arrangement of the eddy current coupling, in particular free of eddy current or Permanent magnet sections and / or moving parts of the Reibscheibenabschnitte. Thus, the driven part can be particularly space-saving in particular and be simple.

Of the the output side lying part of the eddy current coupling or here the Permanent magnet part is according to the eddy current principle in a for drive-side eddy current part lower speed or towing speed moved.

in the In view of improved ease of assembly, the friction disc clutch as recorded on a drive shaft assembly via a existing connection flange with a counterpart, for example an output side or shaft of a drive motor are connected. The friction disc clutch is thus optionally as an additional element Advantageously separately assembled or disassembled.

It is further proposed that the eddy current coupling a first and a second permanent magnet part movable relative to each other are. In particular, the two permanent magnet parts comprise separate Components which are adjacent but each rotatably mounted. In particular, the two permanent magnet parts are radially offset or on different diameters but at least almost the same axial height in terms of z. B. on a longitudinal axis the friction disc clutch or a rotation axis of the drive element. This carries to the compact design of the friction disc clutch. The two Permanent magnet parts are in particular roller bearings.

Preferably, the two permanent magnet parts act together with a common or a single eddy current part of the eddy current coupling men, eg Example, designed as a ribbed aluminum casting with cast ring of ferromagnetic material. The permanent magnet parts are equipped with respect to the eddy current part with individual permanent magnets, which are directed on the side lying to the eddy current part with magnetic poles in alternating polarity to the eddy current part. In the axial direction, the permanent magnets are slightly spaced over a gap to the eddy current part or rib wheel, at its side adjacent to the gap of the ferromagnetic ring is slightly covered by cast. It is in principle not excluded that a separate eddy current part is provided for each permanent magnet part or z. B. in each case a ferromagnetic ring is present.

Advantageous the eddy current part is rotatably connected to the drive element. This is the by eddy currents Heat generated in the eddy current component always dissipated, since with the drive element forcibly also the eddy current part rotates. It is therefore excluded that upon rotation of the permanent magnet part the eddy current part is stationary and thus a heat accumulation takes place. Because of the Rotation of the eddy current portion is achieved or is an air cooling effect always for a sufficiently high heat dissipation taken care of away from the eddy current part.

advantageously, are the first and the second permanent magnet part via a Three-ring bearing rotatably mounted. With a three-ring camp is one Optimized use of available space possible or a simpler installation of the arrangement possible. In particular, with it the two permanent magnet parts in a common axial section but are radially offset from each other to be positioned, wherein in axial Direction of the needed Space the axial dimension of the three-ring bearing only slightly exceeds.

In an advantageous embodiment of the subject invention, the solenoid assembly comprises a first electromagnet for rotationally fixed coupling of first friction disc sections and a second electromagnet for non-rotatably coupling second Reibscheibenabschnitten. The friction disc sections are in particular Sections, which can be brought into contact with each other and then connected non-positively are and again except Plant can be brought, for. B. a resiliently deflectable in the axial direction Anchor plate, which is fixed against an axially fixed Section can be used electromagnetically. With the switchable coupling options Different operating conditions can be realized reliably. The order of two electromagnets can be done advantageously, for example if these offset radially to each other at axially equal height in terms are positioned on an axis of the drive element. The electromagnets can partly arranged surrounded by sections for guiding magnetic lines of force which, for example, through disc sections and to transverse extending or axially extending web portions of the drive element be formed.

advantageously, Both solenoids can be controlled individually energize as well as together or simultaneously.

It is moreover advantageous that the first electromagnet is designed such in the energized state, a first armature disc, the permanent magnet recording the first permanent magnet part is assigned to move axially and with a friction portion on the element to be driven in a rotationally fixed manner couple. The non-rotatable coupling is when the current is removed again automatically by restoring forces z. B. solved with a force acting on the first anchor disc spring washer. In order to can specifically the first permanent magnet part of the eddy current arrangement driven and over this driven the driven element.

It is also advantageous that the second electromagnet is formed in the energized Condition a second armature disc, the permanent magnet recording the second permanent magnet part is assigned to offset axially and with a friction section on the element to be driven in a rotationally fixed manner couple. Thus, according to the first electromagnet one achieves advantageous mode of action, bringing the two permanent magnet parts the eddy current coupling individually or in each case for the drive of the driven Elements are switchable. It is advantageous if the two permanent magnet parts at a considered speed of the drive element or so that the eddy current part rotate at different speeds have different speeds. This is adjustable and z. B. dependent from the respective gap width between eddy current and permanent magnet part or number of permanent magnets or their radial position on the permanent magnet part. The friction sections on the driven element are in particular in a plane on the drive element. The element to be driven can According to the invention comparatively be designed simply, for example, as a flat possibly one-piece disc made of a metallic material with transversely projecting web sections on the opposite side to the friction side Side, for storage of the element to be driven or for encircling serve the electromagnets.

It is also advantageous that the two permanent magnet parts always rotate upon movement of the drive element under the eddy current effect, which after their connection a nearly verzö smooth driving allows.

Further It is suggested that while energizing the first and second electromagnet is a rotational speed of the element to be driven which depends on the respective speed of the driven Elements distinguishes if only one of the two electromagnets energized. It is made use of that an overlay the drive effect or addition of the individual with the switched Friction clutch couplings transferable Torques with simultaneous power supply of the two electromagnets is possible. It is thus next to the two different levels of transferable Torques at each individually connected electromagnet another or increased Drive stage or switching situation with the electromagnet arrangement available.

advantageously, are the first armature disc and the permanent magnet holder of the first permanent magnet part via a center ring of the three-ring bearing connected to each other, in particular axially opposite Arranged sides of the middle ring. This can be a space-saving Arrangement can be realized. Furthermore can over the middle ring a passage of driving forces or states of motion on the Three-ring bearing in a radially close to the axis or to the axis of the drive element inside area. From the one axially considered Side of the three-ring bearing, so eddy current side, thus can driving forces and movements of the respective permanent magnet holder on the transferred element to be driven become.

Further It is suggested that the second armature disc be radial to the first Anchored disc offset and / or on the permanent magnet of the second permanent magnet part is attached. Also with that becomes one compact design possible, in particular An axial width of the friction disc clutch is comparatively kept low.

It is also advantageous that the element to be driven via a roller bearing relative to the Drive element is stored and not energized first and second electromagnet in the rotating drive element by bearing friction in the rolling element bearing of the driven element can be brought into a low speed. So lets especially easy first or lowest speed for the driven Element for example, a fan hub will be realized. This speed is much lower than that Speed of the drive element and in particular on the choice of the type of rolling bearing influenced. Advantageously, for this rotation stage of element to be driven, no current supply to the electromagnets necessary so that an always prevailing basic speed, for example one impeller possible is.

Basically advantageous is it that even if the eddy current clutch is not to drive used of the driven element in a towing speed is, the eddy current always rotates and thus constantly one Heat dissipation of by eddy currents resulting heat given is. Overheating the coupling or adjacent components is avoided.

In a modified embodiment of the subject invention is in the axial direction of the first and the second permanent magnet part between the eddy current part and positioned to the element to be driven. It is here under the Eddy current part to understand the section in which the eddy currents can train z. B. a rib wheel with steel ring, and also a connecting portion between the drive element and this portion of the eddy current training. Advantageously, the driven element is not part of the eddy current coupling. The invention also relates a drive unit for a fan a vehicle, in particular with an internal combustion engine, wherein a of the above Friction disc clutches is present. This can be for a drive unit of a fan Achieve the above benefits.

Further Features and advantages of the invention will become apparent from the single figure explained in more detail.

there the figure shows schematically in section an inventive arrangement with an electromagnetically actuated Friction disc clutch.

In the figure is a drive unit with a Reibschaltkupplung or friction disc clutch 1 shown here as a fan clutch for a fan 2 designed. The friction disc clutch 1 includes a coupling shaft 3 , which end a connection flange 4 to the friction disc clutch 1 For example, on an output shaft of an internal combustion engine for driving the clutch shaft 3 to flank. Optionally, the friction disc clutch 1 flanged to a bearing block.

At the connection flange 4 opposite end of the coupling shaft 3 is firmly connected to this via connecting sections an eddy current part 6 an eddy current coupling 5 appropriate. The eddy current part 6 has a cooling fin ring 7 with a rib structure of a cast aluminum material, wherein in the cooling fin ring 7 a steel ring 8th is poured. The eddy current coupling 5 includes axially spaced over a gap to the eddy current portion 6 a radially outer permanent magnet part, which annularly arranged outer permanent magnets 9 alternating in side by side Having polarity. The outer permanent magnets 9 are on an outer permanent magnet carrier 10 taken, which has a three-ring bearing 11 on the outer bearing ring rotatable relative to the coupling shaft 3 is stored.

Radially further inside and approximately in alignment with the outer permanent magnets 9 and dimensioned to these slightly smaller are internal permanent magnets 12 on a permanent magnet carrier 13 positioned. The inner permanent magnet carrier 13 is also about the three-ring bearing 11 but over the middle ring 11a non-rotatable with respect to the coupling shaft 3 stored. The middle ring 11a is opposite to the outer rotatable bearing shell or an inner bearing shell of the three-ring bearing 11 rotatable.

In addition, one of the friction disc clutch 1 driven element, here a rotor 14 , which fulfills the function of a fan hub, via another roller bearing 15 rotatably mounted.

An electromagnet arrangement 16 is fixed in position via another rolling element bearing 17 opposite the coupling shaft 3 added. The electromagnet arrangement 16 includes an inner electromagnet 18 and an outer electromagnet 19 in a known design with a corresponding coil arrangement and power supply.

For non-rotatable coupling with the rotor 14 are the with rotating clutch shaft 3 entrained permanent magnet carrier 10 and 13 via corresponding friction clutches, which by the solenoid assembly 16 are switchable, individually or together force-locking with the rotor 14 connectable. This is the outer permanent magnet carrier 10 an outer annular armature disc 20 on the to the rotor 14 facing side of the permanent magnet carrier 10 intended. The anchor disc 20 is about spring means, for example, a ring spring 21 , which is an axial mobility of the armature disk 20 allows, by screwing on the permanent magnet carrier 10 added. When the electromagnet is energized 19 becomes the anchor plate 20 electromagnetically to a friction surface section 14a of the rotor 14 positively tightened so that the rotor 14 with the speed of the permanent magnet carrier 10 rotates. With non-current-carrying electromagnet 19 is due to the restoring force of the annular spring 21 the anchor plate 20 out of contact with the friction surface portion 14a brought so that between friction surface section 14a and anchor disc 20 a defined gap prevails.

Accordingly, with the energized electromagnet 18 another anchor plate 22 , which have a ring spring 23 firmly with the middle ring 11a of the three-ring rolling bearing 11 screwed, frictionally with another friction surface section 14b of the rotor 14 get connected. This is, provided the anchor plate 20 is not in contact with the friction surface portion 14a , the rotor 14 at the same speed as the permanent magnet carrier 13 driven. When not energized electromagnet 18 is also the anchor plate here 22 by means of the ring spring 23 reset and spaced over an air gap to the friction surface portion 14b brought, so that rotor 14 and the anchor plate 22 are freely rotatable against each other.

With the friction disc clutch according to the invention 1 can the rotor 14 or the fan wheel 2 with rotating coupling shaft 3 be operated in four different speed levels. A same speed between the clutch shaft 3 and rotor 14 or a one-to-one translation is advantageous but not provided. In a first stage with non-energized electromagnets 18 and 19 becomes with rotating clutch shaft 3 the rotor 14 about the bearing friction of the rolling element bearing 15 set in a first low speed, provided that the frictional forces are sufficient or the fan is not too heavy.

In principle, in this state, an additional speed increase by a further eddy current coupling, not shown, also conceivable, with permanent magnets on the permanent magnet carrier 10 on the side with the permanent magnets 9 equipped rear side, with an axially opposite, not shown eddy current section on the rotor 14 interacts.

In a second stage, the internal clutch assembly or friction disc clutch 1 by energizing the inner electromagnet 18 be switched. In this case, the rotating permanent magnet carrier 13 via the frictional connection of the armature disk 22 with the friction surface portion 14b connected so that the rotor 14 rotated at a slightly higher speed than in the first stage.

In a third stage, in which the inner electromagnet 18 not energized but the outer electromagnet 19 energized and the anchor plate 20 at the friction surface portion 14a frictionally connected, the rotor is 14 over the permanent magnet carrier 10 driven, causing the rotor 14 rotates at a higher speed than the speed according to the second stage.

In a fourth shift stage or in a highest speed stage of the rotor 14 , which with the friction disc clutch 1 is feasible, both are electromagnets 18 and 19 energized, causing the rotor 14 driven accordingly with higher drive torque faster than in the third Stage rotates. Thus, for example, in the second stage, drive torques of approximately 20 to 30 Newton meters (Nm) or in the third stage of approximately 60 to 90 Nm or in the fourth stage of approximately 80 to 120 Nm are transmitted to the rotor ,

A power loss due to the inventive friction disc clutch shown 1 can be kept relatively low, for example, compared to previously used arrangements such as with viscosity clutches for the realization of two or three different speed levels.

L

friction disc clutch

2

fan

3

clutch shaft

4

flange

5

Eddy current clutch

6

Eddy current portion

7

Fins ring

8th

steel ring

9

permanent magnet

10

Permanent magnet support

11

Three ring bearings

11a

center ring

12

permanent magnet

13

Permanent magnet support

14

rotor

14a

Reibflächenabschnitt

14b

Reibflächenabschnitt

15

roller bearing

16

Solenoid assembly

17

roller bearing

18

electromagnet

19

electromagnet

20

armature disc

21

Ringfeder

22

armature disc

23

Ringfeder

Claims (13)

Electromagnetically actuated friction disc clutch ( 1 ) with a drive element ( 3 ) and one opposite the drive element ( 3 ) rotatably mounted driven element ( 14 ), wherein an eddy current coupling ( 5 ) with an eddy current part ( 6 ) and one opposite the eddy current part ( 6 ) movable permanent magnet part ( 9 . 10 . 12 . 13 ) is present, so that when rotating eddy current part ( 6 ) the permanent magnet part ( 9 . 10 . 12 . 13 ) is rotated, and wherein a switchable electromagnet arrangement ( 16 ) for connecting friction disk sections ( 20 . 14a . 22 . 14b ) is provided to rotate when the drive element ( 3 ) the element to be driven ( 14 ) in different speed levels, characterized in that the driven element ( 14 ) and the permanent magnet part ( 9 . 10 . 12 . 13 ) via the with the electromagnet arrangement ( 16 ) connected Reibscheibenabschnitte ( 20 . 14a . 22 . 14b ) are rotatably coupled together. A friction disc clutch according to claim 1, characterized in that the eddy current coupling ( 5 ) a first ( 12 . 13 ) and a second permanent magnet part ( 9 . 10 ), which are movable relative to each other. A friction disc clutch according to claim 1 or 2, characterized in that the eddy current part ( 6 ) rotatably with the drive element ( 3 ) connected is. Friction disc clutch according to one of the preceding claims, characterized in that the first ( 12 . 13 ) and the second permanent magnet part ( 9 . 10 ) via a three-ring bearing ( 11 ) are rotatably mounted. Friction disc clutch according to one of the preceding claims, characterized in that the electromagnet arrangement ( 16 ) a first electromagnet ( 18 ) for the rotationally fixed coupling of first friction disk sections ( 22 . 14b ) and a second electromagnet ( 19 ) for the rotationally fixed coupling of second friction disk sections ( 20 . 14a ). Friction disc clutch according to one of the preceding claims, characterized in that the first electromagnet ( 18 ) is designed in such a way, in the energized state, a first armature disc ( 22 ), a permanent magnet recording ( 13 ) is assigned to the first permanent magnet part, axially offset and with a friction section ( 14b ) on the element to be driven ( 14 ) rotatably to couple. Friction disc clutch according to one of the preceding claims, characterized in that the second electromagnet ( 19 ) is formed, in the energized state, a second armature disc ( 20 ), a permanent magnet recording ( 10 ) is assigned to the second permanent magnet part, axially offset and with a friction section ( 14a ) on the element to be driven ( 14 ) rotatably to couple. Friction disc clutch according to one of the preceding claims, characterized in that with simultaneous energization of the first ( 18 ) and second electromagnets ( 19 ) a speed of the element to be driven ( 14 ), which differs from the respective speed, if only one of the two electromagnets ( 18 . 19 ) is energized. Reibscheibenkupplung after one of hergehen claims, characterized in that the first anchor plate ( 22 ) and the permanent magnet holder ( 13 ) via a middle ring ( 11a ) of the three-ring camp ( 11 ) are interconnected. Friction disc clutch according to one of the preceding claims, characterized in that the second ( 20 ) Anchor disc radially to the first armature disc ( 22 ) and / or on the permanent magnet holder ( 10 ) of the second permanent magnet part is fixed. Friction disc clutch according to one of the preceding claims, characterized in that the element to be driven ( 14 ) via a roller bearing ( 15 ) relative to the drive element ( 3 ) is stored and when not energized first ( 18 ) and second electromagnets ( 19 ) with rotating drive element ( 3 ) by bearing friction in the rolling element bearing ( 15 ) of the element to be driven ( 14 ) Can be brought into a low speed. Friction disc clutch according to one of the preceding claims, characterized in that in the axial direction of the first ( 12 . 13 ) and the second permanent magnet part ( 9 . 10 ) between the eddy current part ( 6 ) and the element to be driven ( 14 ) is positioned. Drive unit for a fan ( 2 ) of a vehicle with a friction disc clutch ( 1 ) according to any one of the preceding claims.