CN220168396U

CN220168396U - Viscous coupling

Info

Publication number: CN220168396U
Application number: CN202222200266.3U
Authority: CN
Inventors: T·莫泽; F·格贝尔; N·所罗门
Original assignee: Borg Warner Co ltd
Current assignee: Borg Warner Co ltd
Priority date: 2021-08-19
Filing date: 2022-08-19
Publication date: 2023-12-12
Anticipated expiration: 2032-08-19
Also published as: DE202021104446U1

Abstract

The viscous coupling includes a housing (24) carrying a plurality of first ribs (74, 86) arranged concentrically about a central axis (a); a rotor (22) rotatable about the central axis (a) relative to the housing (24) in a predetermined rotational direction and carrying a plurality of second ribs (42, 54), wherein the first ribs (74, 86) and the second ribs (42, 54) are arranged in a working chamber (60) enclosed by the housing (24); a fluid container (26); a fluid discharge line (92) for directing fluid from the working chamber (60) to the fluid reservoir (26); a scraper (28) movably arranged between the housing (24) and the rotor (22) and designed for scraping off fluid from the rotor (22) and delivering the fluid to the fluid discharge line (92); and a stop (33, 34) of the doctor blade (28) arranged beside the rotor (22).

Description

Viscous coupling

Technical Field

The utility model is derived from a known technique with a viscous coupling as in US10,563,708B 2.

Background

The viscous coupling has a scraper that, during operation, abuts a rotor arranged in the working chamber to scrape off fluid and supply the fluid to a fluid discharge line leading from the working chamber to a fluid reservoir. Such blades are subject to considerable material wear and abrasion, which can lead to blade failure and thus viscous coupling failure.

Disclosure of Invention

The purpose of the utility model is to prevent premature failure of the viscous coupling due to wear.

The viscous coupling according to the present utility model comprises: -a housing carrying a plurality of first ribs arranged concentrically about a central axis, -a rotor rotatable in a predetermined rotational direction about the central axis with respect to the housing, and-a plurality of second ribs, wherein the first ribs and the second ribs are arranged in a working chamber enclosed by the housing, -a fluid container, -a fluid discharge line guiding a fluid from the working chamber to the fluid container, -a scraper movably arranged between the housing and the rotor and designed for scraping fluid from the rotor and delivering the fluid to the fluid discharge line, characterized in that a stop of the scraper is arranged beside the rotor and is in contact with the stop at least after an allowable amount of wear and abrasion of material, while the stop scrapes fluid from the rotor and delivers the fluid to the fluid discharge line. The doctor blade protrudes axially beyond the rotor on at least one side, preferably on two opposite sides.

If material wears from the doctor blade during operation, there is typically no problem initially until the wear reaches the point where the doctor blade fails, such as when the doctor blade breaks. In the case of the new viscous coupling, the stop of the doctor blade according to the utility model does not therefore have to be arranged in such a way that the doctor blade can initially rest against the latter. Instead, the doctor blade may also only function when a part of the doctor blade or a part of the rotor wears away due to wear. In this way, the doctor blade can initially rest on the rotor and effectively scrape fluid from the rotor, as in a conventional viscous coupling. Only when the wear reaches a problematic level, so that the doctor blade may be about to fail, the stop will come into play and at least from then on prevent the doctor blade from continuing to bear against the (already partially worn) rotor. If the blade is no longer resting against the rotor, the blade is not able to effectively scrape fluid off the rotor, but in the case of the very rare use of a viscous coupling in large quantities, this is less important if failure can be avoided.

Thus, according to the utility model, the risk of failure due to wear can be significantly reduced in case of very frequent use of the viscous coupling, whereas the efficiency of the doctor blade is not reduced in case of less frequent use of the viscous coupling.

In an advantageous development of the utility model, provision is made for two stops to be provided on opposite sides of the rotor, against which the opposite edges of the doctor blade can rest. In this way, the tilting moment can be reduced or even completely avoided and thus failure of the doctor blade due to wear can be avoided more reliably.

The blades of the new viscous coupling may have two radially inwardly protruding edge areas on the inner surface of the blade facing the rotor, so that the blade may abut against the stop by these opposite edge areas, even if the inner surface of the blade is completely out of contact with the rotor before any removal of material due to wear occurs. However, it is also possible that the blades of the new viscous coupling may initially abut the rotor with the inner surface of the blade and that the inner surface of the blade will only, over time, take a shape that prevents contact with the rotor by means of the stop, as a result of wear leading to removal of material.

In a further advantageous development of the utility model, it is provided that the stop is designed as a ring, which extends in the circumferential direction of the rotor and is arranged concentrically to the rotor. If two stops are present, two such rings may be provided, respectively, between which the rotor is arranged. Annular stops can be cost-effectively implemented. Alternatively, the stop may be formed by the housing itself, that is, the stop may be integrally formed with the housing.

Drawings

Further details and advantages of the utility model are explained by examples of embodiments with reference to the accompanying drawings. Here:

FIG. 1 shows an isometric front view of a viscous coupling with an axial flow fan attached;

FIG. 2 illustrates a perspective view of the rear side of the viscous coupling of FIG. 1;

FIG. 3 illustrates a cross-sectional view of the viscous coupling of FIG. 1;

fig. 4 shows an isometric view of a scraper of the viscous coupling;

FIG. 5 schematically illustrates a partial cross-sectional view of the viscous coupling; and

fig. 6 schematically shows a detail of fig. 5.

Detailed Description

Fig. 1, 2 and 3 show an adhesive coupling 10 connected to an axial flow fan 14. The viscous coupling 10 has a drive shaft 20 that drives a rotor 22 disposed in a housing 24. The rotor 22 is arranged in the working chamber 60 of the housing 24 and has second ribs 42, 54 which are arranged concentrically with respect to the geometric central axis a of the drive shaft 20. When the working chamber is filled with a fluid, such as oil, during operation, and the rotor 22 rotates, torque is generated in the fluid due to friction with the second ribs 42, 54. It can be said that the fluid receives torque in the working chamber by shearing action. This torque of the fluid causes the housing 24 to rotate about the geometric center axis a due to friction. To increase friction with the fluid, the housing 24 may have concentric grooves, first ribs 74, 86 or annular walls on both sides of the rotor 22 along which the fluid flows.

The viscosity of the fluid in working chamber 60 imparts rotational movement of drive shaft 20 to housing 24, thereby forming the power take off portion of the coupling. The housing 24 is made up of a plurality of housing components 70, 72 that can be rotated relative to the drive shaft 20 by one or more bearings 58.

If working chamber 60 is filled with fluid, the viscous coupling thus functions, i.e. drive shaft 20 acts as the drive member for the coupling, being connected to housing 24, i.e. to the power take-off. To separate drive shaft 20 and housing 24, the working chamber is emptied by transferring fluid from working chamber 60 through fluid drain line 92 into fluid reservoir 26. The fluid discharge line 92 may be formed, for example, by two bores 102, 104 in the housing 24 extending at right angles to each other.

A fluid supply line containing a valve 112, such as a solenoid valve, leads from the fluid reservoir 26 back to the working chamber 60. If valve 112 is open, fluid may flow from fluid reservoir 26 into working chamber 60, thereby engaging the viscous coupling. If valve 112 is closed, working chamber 60 is emptied and the viscous coupling becomes disabled. The valve 112 is actuated by an actuator 114, such as an electromagnet.

In the example of the embodiment shown, the fluid container 26 is part of the rotor 22, that is to say, it is arranged between the disc-shaped rotor body 30 and the cover 88. However, the fluid container 26 may also be arranged in the housing 24 such that it can be moved relative to the rotor 22, or it may be arranged outside the housing 24.

To transfer fluid from working chamber 60 into fluid discharge line 92, doctor 28 is floatingly disposed in the chamber at inlet 100 of fluid discharge line 92 between rotor 22 and housing 24. During operation, the scraper 28 scrapes fluid off the rotor 22 such that the scraped fluid flows under centrifugal force into the fluid discharge line 92 and thence into the fluid reservoir 26. The doctor blade 28 shown in fig. 4 has two arms 29 extending in the circumferential direction of the rotor 22, which arms are connected by at least one transverse web 27. Between the two arms 29, a flow path extends below the transverse web 27, through which fluid can be led to the inlet 100 of the fluid discharge line 92.

During operation, the doctor blade 28 drags the rotor 22, and therefore wear occurs on both the doctor blade 28 and the rotor 22, that is, erosion of the material. In the case of a relatively large rotor 22 this is not a problem and can be largely ignored, but over time it can result in the doctor blade 28 no longer fulfilling its function and in the case of a conventional viscous coupling it can even break.

In the illustrated viscous coupling, the stops 33, 34 are thus connected to the housing 24 on both sides of the rotor 22. Each of the stops 33, 34, which may be designed, for example, as a ring, is arranged between the housing 24 and the rotor 22.

The two stops 33, 34 may protrude radially outwards beyond the rotor 22, so that the doctor blade 28 may abut the stops 33, 34 by opposite edges. However, this configuration results in a gap between the rotor 22 and the doctor blade 28 through which fluid may flow, resulting in reduced efficiency of the doctor blade 28.

In the example of embodiment shown, the stops 33, 34 do not protrude radially outwards beyond the rotor 22 in the case of the new viscous coupling, and the stops 33, 34 do not act on the axially protruding edge region above the rotor in the case of the new doctor blade 28. Only when the inner surface of the doctor blade 28 abrades away a corresponding amount of material due to wear, the stops 33, 34 come into play and prevent contact between the doctor blade 28 and the rotor 22. On the one hand, the efficiency loss of the doctor blade 28 therefore only occurs in case the viscous coupling has been in use for a long time; on the other hand, due to the delayed effectiveness of the stops 33, 34, a loss of efficiency of the doctor blade 28 can be avoided; even in the case of an abnormally dense use, failure due to abrasion of the scraper 28 and thus abrasion of the viscous coupling can be reliably prevented.

The extent of radial displacement of the one or more stops 33, 34 on the novel viscous coupling relative to the rotor 22 can be freely selected over a wide range. In general, it is beneficial if the stops 33, 34 of the novel viscous coupling protrude in the radial direction by no more than 0.5mm, for example 0.4mm or less.

In one embodiment of the utility model, the stops 33, 34 are arranged radially inwards, so that an annular groove extends alongside the rotor 22.

Reference numerals

10 viscous coupling

14 axial fan

20 drive shaft

22 rotor

24 shell

26 fluid container

27 transverse web

28 scraper

29 arm

30 rotor body

33 stop piece

34 stop piece

42 second rib

54 second rib

58 bearing

60 working chamber

70 housing part

72 housing part

74 first rib

86 first rib

88 cover

92 fluid discharge line

100 inlet of fluid discharge line

102 holes

104 holes

112 valve

114 actuator

A central shaft

Claims

1. A viscous coupling comprising:

a housing (24) carrying a plurality of first ribs (74, 86) arranged concentrically about a central axis (A),

a rotor (22) rotatable about the central axis (A) relative to the housing (24) in a predetermined rotational direction and carrying a plurality of second ribs (42, 54), wherein the first ribs (74, 86) and the second ribs (42, 54) are arranged in a working chamber (60) enclosed by the housing (24),

a fluid container (26),

a fluid discharge line (92) for directing fluid from the working chamber (60) to the fluid reservoir (26),

a scraper (28) movably arranged between the housing (24) and the rotor (22) and designed for scraping off fluid from the rotor (22) and delivering the fluid to the fluid discharge line (92),

it is characterized in that the method comprises the steps of,

the stops (33, 34) of the doctor blade (28) are arranged beside the rotor (22).

2. Viscous coupling according to claim 1, characterized in that the stop (33, 34) is arranged radially inwards such that an annular groove extends alongside the rotor (22).

3. Viscous coupling according to claim 1, characterized in that the stop (33, 34) is designed as a ring, which extends circumferentially along the rotor (22).

4. Viscous coupling according to claim 1, characterized in that the rotor (22) is arranged between two stops (33, 34) against which the doctor blade (28) can abut with opposite edge portions at least after material wear and abrasion has occurred between the edge portions of the doctor blade (28).

5. Viscous coupling according to claim 1, characterized in that both stops (33, 34) are designed as rings, which stop extend in the circumferential direction along the rotor (22).

6. Viscous coupling according to claim 1, characterized in that the scraper (28) is arranged in a floating manner in a cavity at the inlet (100) of the fluid discharge line (92).

7. Viscous coupling according to claim 1, characterized in that the scraper (28) has two arms (29) extending in the circumferential direction of the rotor (22), which arms are connected by at least one transverse web (27).

8. Viscous coupling according to claim 1, wherein a fluid supply conduit directs fluid from the fluid reservoir (26) to the working chamber (60).

9. Viscous coupling according to claim 8, characterized in that a valve (112) is arranged on the fluid supply conduit.

10. Viscous coupling according to claim 1, characterized in that the scraper (28) abuts against the rotor (22) at least after an allowed wear has occurred, while the scraper scrapes off fluid from the rotor (22).

11. Viscous coupling according to claim 1, characterized in that one or more stops (33, 34) are connected to the housing (24) such that the housing cannot rotate.

12. Viscous coupling according to claim 1, characterized in that the scraper (28) protrudes beyond the rotor (22) in the axial direction, the scraper protruding beyond the rotor (22) on both sides.