JPH10213157A - Viscous fluid coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a desired pump function and form an outer peripheral face of a rotor simultaneously with the molding of the rotor by providing a plurality of projection parts on the outer peripheral face of the rotor and forming a side face of the projection in the direction of rotor rotation into a trapezoidal shape which is inclined from one face side which opposes to a projection on outer periphery of an operation chamber toward the direction of rotation of the rotor over the other face side thereof. SOLUTION: A plurality of projection parts 14b are formed continuously in the peripheral direction on an outer peripheral face of a rotor. The projection part 14b has a trapezoidal shape in which a side face in the direction of rotation of the rotor is inclined from one face side which opposes to a projection piece 13a toward the direction of rotation of the rotor over the other face side there. Consequently, sufficient rise of pressure is obtained due to the collision of viscous fluid against the projection piece 13a, and viscous fluid is discharged into a storage chamber through a through hole 13b so that a desired pump function is obtained due to a pump mechanism. Since the trapezoidal projection part 14b does not obstruct the removal of dies when the rotor is molded by die casting by using a metallic material such as aluminum, it does not necessitate post-machining and can be molded simultaneously when the rotor is molded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a viscous fluid coupling such as a fluid coupling for an engine cooling fan.

[0002]

2. Description of the Related Art Conventional viscous fluid couplings include those disclosed in Japanese Patent Publication No. 55-4971 and Japanese Utility Model Laid-Open Publication No. 2-47429. These viscous fluid couplings include a rotor fixed on a shaft driven by an engine, a housing rotatably supported on the shaft, a storage chamber for the viscous fluid in the housing, and a storage chamber. A partition member communicating with the return passage and partitioning into a working chamber accommodating the rotor; a protrusion formed on the outer periphery of the working chamber so as to protrude from the storage chamber side; and a protrusion formed near the protrusion. A pump mechanism configured to communicate with the working chamber and the storage chamber, and a pump mechanism that is operated by relative rotation between the housing and the rotor to discharge fluid in the working chamber to the storage chamber. During the rotation, the torque of the rotor is transmitted to the housing by the shearing force of the viscous fluid interposed between the rotor and the housing in the working chamber, and the housing and the cooling provided integrally therewith. Rotating the actuator such as § emissions. Further, in the viscous fluid coupling, the flow of fluid from the storage chamber to the working chamber is stopped or regulated when the radiator passing air temperature is low, and the flow is allowed or increased when the air temperature is high, thereby transmitting torque from the rotor to the housing. Rotational driving of an actuator such as a cooling fan is controlled in response to a temperature change.

Here, in order to reduce torque transmission at a low temperature and reduce power loss, the pump mechanism collides a viscous fluid in the working chamber with a projection by rotation of a rotor, and a through hole provided in the vicinity of the projection. It is more discharged to the storage room. However, when the viscous fluid collides with the projections due to the rotation of the rotor and the viscous fluid escapes from the gap between the outer peripheral surface of the rotor and the housing, a desired pump function cannot be obtained. In the viscous fluid coupling disclosed in the above-mentioned publication, a cross-sectional shape including a rotating plane is substantially triangular on the outer peripheral surface of the rotor, and a projection whose top forms a twill line is provided, and the twill line is formed. As viewed from the protrusion of the pump mechanism, the rotor is formed so as to form a twist angle of about 30 to 60 degrees in the right direction when the rotor rotates rightward and in the left direction when the rotor rotates leftward. In such a viscous fluid coupling, gear cutting is formed on the outer periphery of the rotor.

[0004]

According to the above-mentioned conventional viscous fluid coupling, although a desired pump function can be ensured, a die cannot be cut due to the structure of the outer peripheral surface of the rotor. The outer peripheral surface cannot be formed at the same time as the rotor formed by die casting using the metal material. Therefore, it is necessary to bob the outer peripheral surface after the rotor is formed, which causes a problem that the manufacturing cost of the viscous fluid coupling increases.

[0005] The present invention has been made in view of the above circumstances, and has as its object to secure a desired pump function without increasing the manufacturing cost of the viscous fluid coupling.

[0006]

SUMMARY OF THE INVENTION The technical solution of the present invention taken to solve the above-mentioned problem is that a rotor fixed on a shaft driven by an engine is rotatably supported on the shaft. A housing, a partition member that divides the interior of the housing into a storage chamber for viscous fluid, a storage chamber that communicates with the storage chamber via a return passage, and partitions the working chamber that houses the rotor; A protrusion formed to protrude from the chamber side and a through hole formed in close proximity to the protrusion and communicating the working chamber and the storage chamber, and actuated by relative rotation of the housing and the rotor, A viscous fluid coupling comprising a pump mechanism for discharging a fluid in the working chamber to the storage chamber, wherein the outer peripheral surface of the rotor has a side face on the rotor rotation direction side facing the protrusion. The convex portion of the trapezoidal shape inclined toward the one side in the rotational direction of the rotor over the other side of the motor is that provided plural.

According to the above-described means, the viscous fluid interposed between the outer peripheral surface of the rotor and the housing during rotation of the rotor and the one surface side of the rotor facing the protrusion of the pump mechanism are interposed between the outer peripheral surface of the rotor and the housing. The viscous fluid that is going to move is forced to flow to one surface side of the rotor by the inclined surface of the trapezoidal convex portion. Accordingly, a sufficient pressure increase is obtained by the collision of the viscous fluid with the projection, and the viscous fluid is discharged to the storage chamber through the through hole. In addition, the trapezoidal convex portion does not hinder die cutting during rotor molding,
Molded simultaneously with rotor molding.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A viscous fluid coupling according to the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show an embodiment of a viscous fluid coupling of an engine cooling fan according to the present invention. A fluid coupling 10 is shown.

In the fluid coupling 10, a rotor 14 is fixed on a shaft 11 driven by an engine, and housings 12, 13 are rotatably mounted. The housing 12 is rotatably supported on the shaft 11 via a bearing 15, and a housing 13 having an inner space is fixed to the housing 12 with screws. In the housings 12 and 13, a plate 16 fixed near the opening of the inner space of the housing 13 and an operating chamber R <b> 1 between the housing 13 and the housing 12 are formed.
A storage room R2 is formed between the storage space R2 and the inner space of the storage chamber R3. The rotor 14 disposed in the working chamber R1 is provided with a plurality of annular grooves concentrically radially outward on the right side in the figure, and the inner wall of the housing 12 is provided with the annular grooves. A plurality of annular projections to be fitted are provided concentrically,
These annular grooves and annular projections constitute a labyrinth mechanism L. At the lower end of the housing 13 defining the working chamber R1, a through hole 13b for communicating the two chambers R1 and R2 and a protruding piece 13a protruding to the working chamber R1 in the direction of rotation of the rotor 14 are provided in close proximity thereto. Have been. This through hole 13b
When the relative rotation occurs between the rotor 14 and the housing 13, the viscous fluid flowing due to the rotation of the rotor 14 collides with the protruding piece 13 a, and the pressure rises and the pumping action pushes the viscous fluid into the through hole 13 b. Is performed, and the viscous fluid in the working chamber R1 is discharged to the storage chamber R2. Therefore, these two 13a and 13b constitute a pump mechanism.

In the plate 16, the storage room R2 is
1, a communication hole 16a is formed in the portion of the rotor 14 which is located at the same position in the radial direction as the communication passage 16a and at which the inner peripheral edge of the labyrinth mechanism L is located. The communication passage 16 from the storage room R2.
The fluid that has entered the working chamber R1 through the hole a is guided to the labyrinth mechanism L through the through hole 14a.

A hole is formed in the housing 13 on the same axis as the axis of the shaft 11, and a bush 20 is formed in the hole.
The rod 17 is fitted rotatably in a liquid-tight manner through the. One end of the rod 17 protruding into the storage chamber R2 is connected to the communication passage 1 of the plate 16 by rotation of the rod 17.
A plate-shaped valve V capable of opening and closing 6a is fixed. At the other end of the rod 17 projecting to the outside, a known bimetal 18 as a temperature-sensitive operating means is disposed. The bimetal 18 is locked by the other end of the rod 17 and a locking portion 19 protruding from the housing 13. The bimetal 18 is deformed according to the ambient temperature of the engine, rotates the rod 17 forward and backward, and slides the valve V. To open and close the communication passage 16a.

In this embodiment, a pulley 30 is fixed and a rotating shaft 31 of a water pump (not shown).
Is fitted with a spring material, which attenuates whirling vibrations caused by unbalance of a cooling fan (not shown) fixed to the housings 12 and 13 and the rotor 14, and the vibrations are reduced by a water pump. It is prevented from being transmitted to the rotating shaft 31 and causing stress damage. An annular cavity 12a is formed on the outer periphery of the bearing of the bearing 15 of the housing 12, and the working chamber R
1 prevents heat due to shearing of the viscous fluid from being conducted to the bearing 15. As a result, a rise in the temperature of the bearing 15 can be suppressed, and a low-grade grease to be filled in the bearing 15 can be used. The hollow portion 12a is provided with a plurality of radially extending ribs (not shown) to secure the rigidity of a portion of the housing 12 where the bearing 15 is fitted and fixed. The cavity 12a
As shown in FIG. 7, the inside may be filled with rubber, plastic, ceramic, or the like as a heat insulating material, whereby heat transfer to the bearing 15 can be further suppressed.

In this embodiment, as shown in FIGS. 2 to 4, the outer peripheral surface of the rotor 14 has a rotor 1 whose side in the rotation direction of the rotor 14 faces the protruding piece 13a.
4, a plurality of trapezoidal projections 14 b that are inclined in the rotation direction of the rotor 14 from one surface side to the other surface side are formed continuously in the circumferential direction. The inclination angle θ of the inclined surface of the convex portion 14b with respect to the plane of the rotor 14 is set to 30 to 70 °.

In the fluid coupling having such a configuration, when the temperature of the air passing through the radiator (not shown) is lower than a predetermined value, the valve V fully closes the communication passage 16a. Therefore, the flow of the viscous fluid from the storage chamber R2 to the working chamber R1 is prevented, and the viscous fluid in the working chamber R2 is
With the rotation of 4, the water is discharged into the storage room R1 by the pump mechanism. At this time, the outer peripheral surface of the rotor 14 and the housing 1
The viscous fluid interposed between 2 and 13 and the viscous fluid that is going to move from one side of the rotor 14 facing the projecting piece 13a of the pump mechanism to the other side via the outer peripheral surface of the rotor 14 and between the housings 12 and 13 are As shown in FIG. 3, the inclined surface of the trapezoidal convex portion forcibly causes the one side of the rotor 14 to flow. As a result, a sufficient pressure increase is obtained by the collision of the viscous fluid with the protruding piece 13a, the viscous fluid is discharged to the storage chamber R2 through the through hole 13b, and a desired pump function by the pump mechanism is obtained, and the labyrinth L Torque transmission is reduced.

When the temperature of the air passing through the radiator gradually increases, the valve V gradually opens the communication passage 16a, the fluid interposed in the labyrinth mechanism L increases, and the shear force generated increases. Transmission of torque to the cooling fan increases, and the rotation speed of the cooling fan increases according to the temperature of the engine, and reaches a predetermined high-temperature rotation speed. Thus, a characteristic of the fan rotation speed with respect to the radiator passing air temperature as shown in FIG. 6 is obtained.

As described above, according to the present embodiment, the desired pump function of the pump mechanism can be ensured by the trapezoidal convex portion 14b formed on the outer periphery of the rotor 14, and the characteristic shown in FIG. Can be maintained. Also, by appropriately changing the area of the outer peripheral surface of the convex portion 14b, the amount of torque transmission on the outer peripheral surface is changed, so that the fan rotation speed in the low temperature range in FIG. 6 can be changed. , While keeping the fan speed at a low temperature at a predetermined value, and ensuring the cooling capacity of the condenser and the like.

Further, according to the present embodiment, the trapezoidal projections 14b do not hinder die-cutting at the time of forming the rotor 14 by die-casting using a metal material such as aluminum, so that post-processing is required. In addition, since the rotor is formed at the same time as the rotor is formed, the above-described excellent effects can be obtained without increasing the manufacturing cost.

FIG. 5 shows a partial side view of another embodiment of the rotor according to the invention. In this embodiment, on the outer peripheral surface of the rotor, the side surface on the rotational direction side of the rotor is inclined in the rotational direction of the rotor from one surface side of the rotor facing the projecting piece of the pump mechanism to the other surface side, A plurality of trapezoidal convex portions 114b inclined in the anti-rotation direction of the rotor from one surface side of the rotor facing the projecting piece of the pump mechanism to the other surface side are opposite to the protruding piece of the pump mechanism. Individually formed. Incidentally, the inclination angle θ of the inclined surface of the convex portion 114b with respect to the rotor plane is 30 in the same manner as in the above-described embodiment.
It is set to ~ 70 °. According to this embodiment, the same effects as those of the above-described embodiment can be obtained regardless of the rotation direction (forward rotation, reverse rotation) of the rotor.

[0019]

As described above, according to the present invention, the outer peripheral surface of the rotor moves from one surface of the rotor facing the viscous fluid interposed between the outer peripheral surface of the rotor and the housing and the protrusion of the pump mechanism during rotation of the rotor to the other surface. The viscous fluid that is about to move through the housing and the housing is forced to flow to one side of the rotor by the inclined surface of the trapezoidal projection, so that sufficient pressure is generated by the collision of the viscous fluid with the projection of the pump mechanism. As a result, the desired pump function of the pump mechanism can be secured. Also, since the trapezoidal projection does not prevent the die from being cut out during the formation of the rotor by die-casting using a metal material such as aluminum, the post-processing is not required, and the protrusion is formed at the same time as the rotor is formed. The effect of securing the desired pump function described above can be achieved without increasing the cost.

Further, by appropriately changing the area of the outer peripheral surface of the convex portion, it is possible to change the fan rotation speed in the low temperature range, thereby suppressing the torque transmission at the low temperature and increasing the fan speed at the low temperature. The rotation speed can be maintained at a predetermined value, and the cooling capacity of the condenser and the like can be secured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment of a viscous fluid coupling according to the present invention.

FIG. 2 is a side view of the rotor of the embodiment of FIG. 1;

FIG. 3 is an explanatory diagram of a relationship between an outer peripheral surface of a rotor and a pump mechanism according to the embodiment of FIG. 1;

FIG. 4 is a partially enlarged view of the outer peripheral surface of the rotor in the embodiment of FIG.

FIG. 5 is a partially enlarged view of the outer peripheral surface of a rotor according to another embodiment of the viscous fluid coupling according to the present invention.

FIG. 6 is a characteristic diagram of a fan rotation speed with respect to a radiator passing air temperature of a viscous fluid coupling according to the present invention.

FIG. 7 is a partial cross-sectional view showing a modification of the bearing of the viscous fluid coupling shown in FIG.

[Explanation of symbols]

 Reference Signs List 10 fluid coupling (viscous fluid coupling) 11 shaft 12, 13 housing 13a projecting piece (pump mechanism) 13b through-hole (pump mechanism) 14 rotor 14b convex part 16 plate (partition member) L labyrinth mechanism V valve R1 working chamber R2 storage Room

Claims (1)

[Claims] 1. A rotor fixed on a shaft driven by an engine, a housing rotatably mounted on the shaft, a storage chamber for viscous fluid in the housing and a return passage with the storage chamber. And a partition member that communicates with a working chamber that houses the rotor,
A protrusion formed on the outer periphery of the working chamber so as to protrude from the storage chamber side, and a through hole formed in proximity to the protrusion and communicating the working chamber and the storage chamber; and the housing, the rotor, A viscous fluid coupling comprising a pump mechanism that operates by the relative rotation of and discharges the fluid in the working chamber to the storage chamber, wherein the outer circumferential surface of the rotor faces the protrusion in the rotor rotation direction side. A viscous fluid coupling, comprising a plurality of trapezoidal projections inclined from one surface side of the rotor to the other surface side in the rotation direction of the rotor.