A COVER FOR FRICTION CLUTCHES TECHNICAL FIELD

The present invention relates to a cover used in friction clutches positioned between the engine output and transmission shaft in tractors and which provide transfer of power by means of friction connection.

PRIOR ART

In tractors, there are friction clutches positioned between the engine output and the transmission shaft and which provide power transfer by means of friction connection. The friction clutch has a cover. The drive arms are controlled by means of command arms provided on said cover, and the movement of the pressure plate is provided.

Friction clutches get heated during use due to the frictions. This heating leads to decrease of the strength of the parts, shortening of the usage lifetimes, decrease in the usage performances and changing of the friction characteristics on the friction surfaces.

The application with reference TR201609564 relates to a cover having a circular body part comprising an outer wall and an inner wall facing an inner gap provided at the center thereof; in order to be used in friction clutches positioned between the engine output and transmission shaft in tractors. As an improvement, there is at least one channel extending from the inner wall towards the outer wall inside the body part.

As a result, because of all of the abovementioned problems, an improvement is required in the related technical field.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to a cover for use in friction clutches positioned between the engine output and the transmission shaft in tractors, for eliminating the above mentioned disadvantages and for bringing new advantages to the related technical field. An object of the present invention is to provide a cover which reduces heating problems of friction clutch in tractors.

In order to realize all of the above mentioned objects and the objects which are to be deducted from the detailed description below, the present invention is a cover having a body part in order to be used in friction clutches positioned between the engine output and transmission shaft in tractors. Accordingly, the cover comprises at least one metal foam part provided inside the body part. Thus, the weight of the cover and thus, the weight of the friction clutch wherein the cover is provided are reduced and thanks to the metal foam part, the cooling performance of the cover and of the friction clutch is increased.

In a preferred embodiment of the invention, the metal foam part is provided in a manner at least partially filling at least one inner gap provided inside the body. In a preferred embodiment of the invention, the cover has a circular body part around an axis of revolution X. Preferably, the body part of the cover comprises an inner gap, the metal foam part being located into the inner gap.

In a preferred embodiment of the invention, the inner gap extends according a geometrical plane which is perpendicular to the axis of revolution X.

Alternatively, the inner gap has an annular form.

Alternatively, the inner gap comprises a plurality of radial extensions located outside of the annular form. In a preferred embodiment of the invention, the body part comprises at least one lateral extension extending outwardly from an outer wall of the body part, and the metal foam part extends inwards said lateral extension. Thus, the amount of metal foam filled into the cover is increased. In a preferred embodiment of the invention, the metal foam part is aluminum foam.

In a preferred embodiment of the invention, the metal foam part is provided in the form of open porous metal foam. Thus, air channels are obtained inside the metal foam part. Thus, air circulation and cooling are provided inside the cover during rotation and at the same time, the total surface area of the cover is increased, and the performance of heat transfer by means of convection is increased. Alternatively, a frictional surface can be provided on a face of the cover.

In a preferred embodiment of the invention, the cover comprises a frictional surface able to be in contact with a friction disc.

Alternatively, the frictional surface is perpendicular or substantially perpendicular to the axis of revolution X.

Alternatively, the frictional surface is located on an internal face of the cover.

A further object of the invention is to propose a friction clutch comprising at least a friction disc and a cover as defined above, said cover comprising a frictional surface which rubs onto the friction disc.

This friction clutch according to the further object of the invention has the advantage of increasing the heat convection surface inside of the cover without changing the external envelope of the frictional clutch.

BRIEF DESCRIPTION OF THE FIGURES

In Figure 1 , a representative isometric view of the subject matter cover in order to be used in friction clutches positioned between the engine output and the transmission shaft in tractors is given.

In Figure 2, a representative isometric cross sectional view of the subject matter cover is given.

In Figure 3a, a representative upper view of the subject matter cover is given.

In Figure 3b, A-A cross sectional view mentioned in Figure 3a for the subject matter cover is given.

In Figure 4a, a representative side view of the subject matter cover is given.

In Figure 4b, B-B cross sectional view mentioned in Figure 4a for the subject matter cover is given.

In Figure 5a, C-C cross sectional view mentioned in Figure 4a for the subject matter cover is given. In Figure 5b, D-D cross sectional view mentioned in Figure 4a for the subject matter cover is given. In Figure 6, a cross-sectional view of a friction clutch comprising the subject matter cover is given.

DETAILED DESCRIPTION OF THE INVENTION In this detailed description, the subject matter cover 10 in order to be used in friction clutches positioned between the engine output and the transmission shaft in tractors is explained with references to examples without forming any restrictive effect only in order to make the subject more understandable. As can be seen in Figure 1 , the subject matter cover 10 has a circular body part 20 around the axis of revolution X. There are lateral extensions 30 extending outwardly from an outer wall 22 of the body part 20.

With reference to Figure 2, the cover 10 has a inner gap 21 . There is a metal foam part 50 which at least partially fills in said inner gap 21. The metal foam part 50 is provided in the form of an open porous metal foam form (open cell). Thus, pluralities of air channels (not illustrated in the figure) are obtained inside the metal foam part 50.

The cover 10 comprises a frictional surface 29 able to be in contact with a friction disc. The frictional surface 29 is perpendicular to the axis of revolution X.

As illustrated in Figure2, the frictional surface 29 is located on an internal face of the cover.

The inner gap 21 extends according a geometrical plane B-B which is perpendicular to the axis of revolution X. The inner gap 21 has an annular form.

The inner gap 21 comprises a plurality of radial extensions located outside of the annular form.

The cover 10 comprises also filler pipes 23 which extend axially from the inner gap 21 towards an external face 21 of the body part 20.

Thanks to the metal foam part 50 provided inside the cover 10, the weight of the cover 10 is reduced. At the same time, thanks to the metal foam part 50, the cooling performance of the cover 10 is increased. In details, thanks to the open porous metal foam form of the metal foam part 50, air circulation is provided therein and cooling thereof is facilitated. Moreover, thanks to the open porous metal foam form, the surface area of the cover 10 is increased, and heat transfer by means of convection is provided in a more effective manner.

Thanks to the metal foam part 50, the cover 10 gains vibration dampening characteristic. Thus, dampening of an amount of the vibrations, formed during movement transfer, is provided. Moreover, the sound occurring as a result of vibration is also reduced.

Thanks to the metal foam part 50 provided inside the cover 10, the total weight of the cover 10 and thus of the vehicle whereon said cover 10 will be positioned is reduced. By means of this, the carbon emission of the vehicle is reduced.

With reference to Figure 4a, 4b, 5a and 5b, in a possible embodiment of the present invention, the inner gap 21 extends from the body part 20 inwards the lateral extensions 30. Thus, the metal foam 50 also fills in the inner sections of the lateral extensions 30. By means of this, the amount of metal foam provided inside the cover 10 is increased.

The metal foam part 50 is made of aluminum foam.

A friction clutch 60 comprising the cover 10 is illustrated in Figure 6. The friction clutch 60 is used for the control of movement transfer from the motor to the transmission and to the tail axle in tractors. Accordingly, the movement received from the motor is transferred to the tail axle by means of friction between a pressure plate 65 and an external friction disc 64 connected to the tail axle.

In an exemplary embodiment of said friction clutch 60, said pressure plate 65 is positioned between the external disc 64 and the cover 10. A control lever 61 is connected onto the cover 10 by means of a pin 62 so as to have rotation freedom. An actuation lever 63 connected to said control lever 61 from one side, and connected to the pressure plate 65 from the other side is able to be actuated for clutching or declutching. For clutching or declutching, the actuation lever 63 moves in the movement axis X by means of the force applied onto the control lever 61 , and pushes the pressure plate 65 towards the external friction disc 64.

Friction clutch 60 comprises also an internal friction disc 66 located inside of the cover 10 and able to be engaged onto the frictional surface 29 of the cover 10. During clutching operation, the friction between internal friction disc 66 and the frictional surface 29 creates warm-up of the cover 10. The protection scope of the present invention is set forth in the annexed Claims and cannot be restricted to the illustrative disclosures given above, under the detailed description. It is because a person skilled in the relevant art can obviously produce similar embodiments under the light of the foregoing disclosures, without departing from the main principles of the present invention.

REFERENCE NUMBERS

10 Cover

20 Body part

21 Inner gap

22 Outer wall

23 Filler pipe

29 Frictional surface

30 Lateral extension

50 Metal foam part

60 Friction clutch

61 Control lever

62 Pin

63 Actuation lever

64 External friction disc

65 Pressure plate

66 Internal friction disc