Viscous coupling for a coolant pump

Abstract

A viscous coupling may include: a housing part and an input body rotatable relative to the housing part that at least partially delimit an interior space; a shaft rotatable relative to the housing part and on which an output body arranged in the interior space may be formed for conjoint rotation with the shaft; a coupling region formed between the output and input bodies and configured to hold a viscous fluid to assure a coupling between the input body and the output body; a holding chamber for collecting coolant leaking from the coolant pump; a housing wall conformed integrally with the housing part and partially delimiting the holding chamber; and an actuator housing and an electric actuator therein by which a degree of the coupling between the input body and the output body may be adjustable. The actuator housing may at least partially cover the holding chamber.

Claims

1. A viscous coupling for a coolant pump, comprising: a housing part and an input body rotatable relative to the housing part, the housing part and the input body at least partially delimiting an interior space; a shaft that is rotatable relative to the housing part and on which an output body arranged in the interior space is formed for conjoint rotation with the shaft; a coupling region formed between the output body and the input body, the coupling region configured to hold a viscous fluid to assure a coupling between the input body and the output body; a holding chamber for collecting coolant leaking from the coolant pump; a housing wall conformed integrally with the housing part, the housing wall partially delimiting the holding chamber; and an actuator housing and an electric actuator therein by which a degree of coupling between the input body and the output body is adjustable; wherein the actuator housing at least partially covers the holding chamber; and wherein the housing part has an opening through which the shaft passes, wherein a bearing collar surrounding the opening protrudes in an axial direction of the shaft away from the housing part, and the bearing collar is rotatably mounted on the shaft and delimits the holding chamber radially inwardly.

2. The viscous coupling according to claim 1, wherein the housing part is a housing plate delimiting the interior space in an axial direction of the shaft, wherein the housing wall protrudes away from the housing plate in the axial direction such that the housing wall radially outwardly delimits the holding chamber.

3. The viscous coupling according to Claim 1, wherein at least one of: a first through hole is provided in the housing wall to form an outer vent; and a second through hole is provided in the bearing collar to form an inner vent.

4. The viscous coupling according to claim 3, further comprising an extension protruding in the axial direction on the actuator housing and closing the first through hole.

5. The viscous coupling according to claim 1, wherein, in a view along the axial direction, the actuator housing has a geometry of an annular body and is formed with a through hole through which the shaft passes, wherein the electric actuator includes an electric coil having a coil winding extending circumferentially around the through hole.

6. The viscous coupling according to claim 1, further comprising a sealing structure formed on a side of the actuator housing facing the housing part to seal the holding chamber off from an external environment.

7. The viscous coupling according to claim 6, wherein the sealing structure is sprayed onto the actuator housing.

8. The viscous coupling according to claim 6, wherein the sealing structure is embodied as a sealing ring, and is made from an elastic material, or is embodied as a sealing plug.

9. The viscous coupling according to claim 1, wherein the housing wall has a first wall section, which has a geometry of a circle segment in a cross section perpendicular to the axial direction, and a second wall section, which mates with the first wall section to form the housing wall and is curved.

10. The viscous coupling according to claim 1, wherein the input body is constructed in at least two parts including a pot-shaped base body and a cover which closes the base body, the base body arranged in the axial direction between the housing part and the cover, wherein an external thread is formed on the cover, and by which the cover is screwed into a mating internal thread provided on the base body.

11. The viscous coupling according to claim 10, wherein the cover is made from aluminium, and the base body is made from a steel.

12. The viscous coupling according to claim 10, further comprising a sheave that is one of: (i) attached to the cover by a threaded connection for conjoint rotation therewith to transfer an external turning moment radially outwards, or (ii) conformed integrally on the base body to transfer the external turning moment radially outwards to the base body.

13. The viscous coupling according to claim 10, further comprising an annular magnetic insulator made from a stainless steel arranged on a pot bottom of the pot-shaped base body, extending in a circumferential direction of the pot bottom, dividing the pot bottom into a radially inner and a radially outer bottom part, and connected to the two bottom parts via a laser weld joint.

14. The viscous coupling according to claim 13, wherein the annular magnetic insulator is a deep-drawn sheet metal formed part or a component turned from a blank.

15. The viscous coupling according to claim 13, further comprising a load relieving groove conformed inside the magnetic insulator and that runs around an entire circumference thereof.

16. The viscous coupling according to claim 1, wherein the housing wall is embodied as a peripheral wall and has a round geometry in a cross section perpendicular to the axial direction.

17. The viscous coupling according to claim 16, wherein the housing wall delimits the holding chamber along a circumferential direction.

18. The viscous coupling according to claim 1, further comprising a rib structure having ribs and that protrudes away from the housing part in the axial direction, wherein the housing wall, is arranged between two adjacent ribs, or wherein the rib structure forms a part of the housing wall.

19. A coolant pump for circulating a coolant, comprising: a viscous coupling having: a housing part and an input body rotatable relative to the housing part, the housing part and the input body at least partially delimiting an interior space; a shaft that is rotatable relative to the housing part and on which an output body arranged in the interior space is formed for conjoint rotation with the shaft; a coupling region formed between the output body and the input body, the coupling region configured to hold a viscous fluid to assure a coupling between the input body and the output body; a holding chamber for collecting coolant leaking from the coolant pump; a housing wall conformed integrally with the housing part, the housing wall partially delimiting the holding chamber; and an actuator housing and an electric actuator therein by which a degree of the coupling between the input body and the output body is adjustable; and moving blades arranged on the shaft for conjoint rotation therewith to circulate the coolant; wherein the actuator housing at least partially covers the holding chamber; and wherein the input body is constructed in at least two parts including a pot-shaped base body and a cover which closes the base body, the base body arranged in the axial direction between the housing part and the cover, wherein an external thread is formed on the cover, and by which the cover is screwed into a mating internal thread provided on the base body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawing, the schematic figures show:

(2) FIG. 1 a longitudinal cross section through an example of a viscous coupling according to the invention,

(3) FIG. 2 a perspective view of the viscous coupling of FIG. 1,

(4) FIG. 3 a separate, perspective view of a cover of the viscous coupling,

(5) FIG. 4 a separate, perspective view of a base body of the viscous coupling,

(6) FIG. 5 the cover shown in FIG. 3 and the base body 7 shown in FIG. 4 in a mounted state on the housing part of the viscous coupling,

(7) FIG. 6 a further development of FIG. 5 with a sheave mounted on the cover,

(8) FIG. 7 a separate representation of the housing part of the viscous coupling,

(9) FIG. 8 a separate, perspective representation of an actuator of the viscous coupling,

(10) FIG. 9 the actuator housing of the viscous coupling with an electric actuator arranged therein, mounted on the housing part,

(11) FIG. 10 a perspective representation of a first further development of the pot-shaped base body with an annular magnetic insulator provided on the base body,

(12) FIG. 11 a cross sectional view of the base body of FIG. 10,

(13) FIGS. 12,13 a second further development of the viscous coupling, in which the holding chamber is furnished with venting holes,

(14) FIGS. 14-19 further variants of the viscous coupling according to the invention.

DETAILED DESCRIPTION

(15) FIG. 1 illustrates a longitudinal cross section through an example of a viscous coupling 1 according to the invention for a coolant pump. FIG. 2 shows a perspective representation of the viscous coupling 1 of FIG. 1.

(16) Viscous coupling 1 comprises a housing part 2 and an input body 3 which is rotatable relative to housing part 2. Together with housing part 2, input body 3 delimits an interior space 4 of the viscous coupling 1. The viscous coupling 1 further comprises a shaft 5 which is rotatable relative to the housing part 2, and on which an output body 6 is provided for conjoint rotation. A pump impeller 35 by means of which the coolant pump is able to circulate a coolant, for example water, is also attached to the shaft 5 and rotates conjointly therewith. The output body 6 may also be displaced rotationally relative to the input body 3 to create the coupling 1.

(17) An axial direction A of the shaft 5 is defined by a central longitudinal axis M. A region between the shaft 5 and the housing part 2 is sealed with a sealing means, for example in the form of a slide ring seal 34. The purpose of the slide ring seal 34 is to minimise penetration of the region between the shaft 5 and the housing part 2 by coolant. However, since it is not possible to complete prevent all leakage of coolant through the slide ring seal 34 when the coupling 1 is in operation for a long period, a holding chamber 14 is provided in addition to the slide ring seal 34 on the housing part 2 and is able to at least temporarily hold leaked coolant which does succeed in getting into the region between the shaft 5 and the housing part 2 despite the presence of the slide ring seal 34.

(18) FIG. 1 indicates that a coupling region 13 is formed between the output body 6 and the input body 3, in which a viscous fluid (not shown) is present for coupling between the input body 3 and the output body 6.

(19) FIG. 7 shows the housing part 2 in a separate illustration. According to FIG. 7, the housing part 2 is constructed substantially as a housing plate 15, which delimits the interior space 4 (see also FIG. 1 in this regard) in the axial direction A of shaft 5. A housing wall 16 is conformed integrally with housing part 2 and partially delimits the holding chamber 14. The housing wall 16 protrudes away from the housing plate 15 in the axial direction A of shaft 5 towards input body 3, thereby forming a radially outward limit to the holding chamber 14.

(20) The housing part 2 and the housing plate 15 includes an opening 17 which the shaft 5 passes through as shown in FIG. 1. A bearing collar 18 which surrounds the opening 17 and on which the shaft 5 is mounted rotatably by means of a bearing device 19, which may be embodied as a two-ring bearing 20, protrudes away from the housing part 2 and the housing plate 15 in axial direction A. The bearing collar 18 forms the radially inward limit of the holding chamber 14. The previously described slide ring seal 34 is also arranged between the shaft 5 and the bearing collar 18 (see FIG. 1 in this respect).

(21) In the following section, the structural design of the holding chamber 14 on the housing part 2 will be explained in detail with reference to FIGS. 7 to 9.

(22) According to FIG. 7, the housing wall 16 has a first wall section 21a, which when viewed from above along axial direction A has the geometry of a circle segment. A second wall section 21b, which mates with the first wall section 21a to form the housing wall 16 is curved. In variants of the example, other geometries for the first wall section 21a are also conceivable.

(23) FIG. 8 is a perspective representation of an actuator housing 22 of viscous coupling 1, in which an electric actuator (not shown) is arranged. The electric actuator may be used to adjust a degree of coupling between the input body 3 and the output body 6. For this purpose, the electric actuator comprises an electric coil 23, which is only indicated schematically in FIG. 1. The electric coil 23 may serve to shift a valve lever 25, which is also only indicated schematically in FIG. 1, by reciprocal magnetic action. The effective flow cross section of a fluid line, which is not shown in greater detail in the figures, but via which the viscous fluid may be introduced into the coupling region 13, is varied in known manner by means of the valve lever 25. This in turn entails a variation of the degree of coupling between the input body 3 and the output body 6 by the viscous fluid which is introduced into the coupling region 13. The more viscous fluid there is between the to bodies in the coupling region, the higher is the degree of coupling attained.

(24) When viewed from above along axial direction A, the actuator housing 22 is substantially annular in shape with a through opening 24. The coil winding (not shown) of the electric coil 23 extends in circumferential direction U around the through opening 24.

(25) FIG. 9 shows the actuator housing 22 with the electric actuator in a mounted state on housing part 2. As is shown in FIG. 9, the actuator housing 22 partially covers the holding chamber 14 in the axial direction, wherein the chamber is delimited by the housing wall 16. The housing part 2 and the actuator housing 22 delimit the holding chamber 14 in axial direction A and are positioned opposite each other in axial direction A.

(26) As is illustrated in FIG. 8, a sealing structure 27 may be formed on a side 26 of the actuator housing 22 facing housing part 2. The sealing structure 27 serves to seal the holding chamber 14 off from the external environment of the viscous coupling 1. The sealing structure 27 has the same contour in a cross section perpendicular to the axial direction A as the contour of the housing wall 16 that protrudes axially from the housing part 2.

(27) Now if one considers the lengthwise cross section of FIG. 1 again, it is noticeable that the input body 3 comprises a pot-shaped base body 7 and a cover 8, which closes off the base body 7 which is arranged between the housing part 2 and the cover 8 relative to the axial direction A.

(28) The input body 3 with the base body 7 and the cover 8 as well as the arrangement thereof on the housing part 2 will now be explained in greater detail with reference to the perspective illustrations in FIGS. 3 to 6. FIG. 3 shows the cover 8 separately, and FIG. 4 shows the pot-shaped base body 7 separately. FIG. 5 shows the cover 8 represented in FIG. 3 and the base body 7 represented in FIG. 4 mounted on the housing part 2.

(29) Cover 8 is shown to have an external thread 9 conformed thereon, by means of which the cover may be screwed into a mating internal thread 10 provided on the base body 7. In the example of the figures, the cover 8 is made of aluminium and the base body 7 is made from a steel.

(30) FIG. 6 shows a further development of the coupling 1 according to FIG. 5, in which a sheave 11 is screwed detachably onto the cover 8 in order to transmit an external turning moment radially outwardly. In a variant, such a sheave 11 may also be conformed radially outwardly and integrally with base body 7 (not shown in the figures).

(31) FIGS. 10 and 11 show a further development of the pot-shaped base body 7. According to this further development, an annular magnetic insulator 29 made from a stainless steel and running in circumferential direction U around pot bottom 28 is arranged on a pot bottom 28 of the pot-shaped base body 7. The magnetic insulator 29 serves to limit the effect of the magnetic field generated by the electric coil 23 spatically in the direction of the valve lever 25. The magnetic insulator 29 divides the pot bottom 28 into a radially inner and a radially outer bottom part 30a, 30b. The magnetic insulator 29 is preferably connected to the two base parts 30a, 30b via a laser weld joint. The magnetic insulator 29 may be a deep-drawn sheet metal formed part or a component turned from a blank. As FIGS. 10 and 11 illustrate clearly, a load relieving groove 31 running around the entire circumference inside the magnetic insulator 29, by means of which mechanical stresses in the annular magnetic insulator 29 may be reduced.

(32) FIGS. 12 and 13 show another further development of coupling 1, in which a first through hole 32a is provided in the housing wall 16 to function as an external venting means for the holding chamber 14. In addition, a second through hole 32b is provided in the bearing collar 18 to function as an internal venting means for the holding chamber 14. In order to seal the external venting means, that is to say the first through hole 32a, when the viscous coupling 1 is in operation, a finger-like extension 33 protruding axially away from the actuator housing 22 may be provided on the actuator housing 22 to close the first through hole 32a.

(33) FIGS. 14 and 15 show perspective views of a further variant of the viscous coupling 1. In this variant, the housing wall 16 is embodied as a peripheral wall 40. As shown in FIG. 14, the peripheral wall 40 may have a round, preferably circular geometry in a cross section perpendicular to the axial direction A. In the variant of FIGS. 14 and 15, the housing wall 16 embodied as a peripheral wall 40 completely delimits the holding chamber 14 along in the peripheral direction U′ of the housing wall 16.

(34) As FIG. 14 further shows, a rib structure 41 comprising a plurality of radially extending ribs 42 protrudes from housing part 2 embodied as housing plate 15, in the axial direction A. The ribs 42 are arranged at a distance from each other in the circumferential direction U. As shown in FIG. 14, the ribs 42 are preferably arranged equidistantly from each other with respect to the the circumferential direction U. In the variant according to FIGS. 14 and 15, the peripheral wall 40 or the housing wall 16 is arranged between two ribs 42 that are adjacent to each other in circumferential direction U.

(35) As may be seen in the illustration of FIG. 15, the sealing structure 27 on the side 26 of the actuator housing 22 facing the housing part 2 may be sprayed on. Alternatively, the sealing structure 27 may be a sealing ring, for example an O-ring made from an elastic material or alternatively a sealing plug.

(36) FIGS. 16 and 17 show perspective views of an alternative variant of the example of FIGS. 14 and 15. In this variant, the rib structure 41 as shown in FIG. 16 forms a part of the housing wall 16. Two ribs 42—additionally identified in FIG. 16 with reference numeral 42′—adjacent to each other in circumferential direction U and extending radially away from the bearing collar 18 each form a housing wall section 16a, 16b of the housing wall 16. The bearing collar 18 forms a housing wall section 16c that delimits the holding chamber 14 radially inwardly. The three housing wall sections 16a, 16b, 16c are complemented by a radially outer housing wall section 16d, which is located opposite the radial inner housing wall section 16c, to form housing wall 16. In this variant as well, the sealing structure 27 on the side 26 of the actuator housing 22 facing the housing part 2 may be sprayed on. In this case, the sealing structure 27 is arranged axially between the three housing wall sections 16a, 16b and 16d.

(37) FIGS. 18 and 19 show perspective of two further alternative variants of the viscous coupling. In the example of FIG. 18, the holding chamber 14 is delimited by a reservoir 43 which is conformed integrally with the actuator housing 22 and on the side 26 thereof facing the housing part 2. As is evident from FIG. 18, the receptacle 43 is designed so that it is open radially inwardly, that is to say towards the bearing collar 18. In an assembled state of the viscous coupling, this radially inwardly open side 44 of the receptacle 43 is closed by the bearing collar 18.

(38) FIG. 19 shows a variant of the example of FIG. 18. The example of FIG. 19 differs from that of FIG. 18 in that here the receptacle 43 is embodied as a separate component, which in the assembled state of viscous coupling 1 is clamped between housing part 2 or housing plate 15 and the actuator housing 22. In order to secure the receptacle 43 more effectively, outwardly protruding projections 45 may be provided thereon, and engage in matching recesses which in the assembled state of viscous coupling 1 are present (not shown) on housing part 2 or housing plate 15 and/or on the actuator housing 22.