JPH0727149A - Centrifugal fluid clutch - Google Patents

Abstract

PURPOSE:To provide a simple centrifugal fluid clutch which is constituted to transmit a drive force to the driven shaft of an engine auxiliary machine with high efficiency and reduce a cost through simplification of constitution. CONSTITUTION:A pulley 2 is rotatably supported on a rotary shaft 1 and inner plates 4 are fixed on the rotary shaft 1 in a closed space the interior of which is sealed with viscous fluid 3. A centrifugal weight 6 having outer plates 5 inserted between the adjoining inner plates 4 is disposed in a manner to be divided into four sections. The centrifugal weight 6 is engaged with the side wall of the pulley 2 such that it is radially slidable through a gearing mechanism 9 and pressed in a central direction through the force of a spring means. When the centrifugal weight 6 is moved outward by means of a centrifugal force, rotation is transmitted in a state that it is limited to a given speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal fluid clutch capable of efficiently transmitting a driving force to a driven shaft such as an auxiliary machine.

[0002]

2. Description of the Related Art In a system for transmitting a driving force of an automobile engine or the like to a driven rotating body, various auxiliary machines such as an alternator, a power steering pump, or a cooler compressor are generally arranged around the system. Engine power is used to drive the machine. To transmit the driving force to the accessory, generally, pulleys are provided on both the output shaft of the engine and the input shaft of the accessory, and a belt is stretched between the pulleys to transmit the power.

The method of transmitting the driving force to such an auxiliary machine is as follows.
Especially when the engine rotates at high speed, the rotation ratio between the engine and the auxiliary machine is set to a constant value, so there are various problems such as excessive high speed rotation being transmitted to the auxiliary machine. As an example of the method, for example, Japanese Patent Laid-Open No. 4-10
Japanese Patent No. 9034 proposes an accessory drive device in which a planetary reduction mechanism is combined with a one-way clutch and a fluid clutch.

[0004]

In the method of directly transmitting the engine driving force to the auxiliary machine by the pulley and the belt as described above, the rotation becomes unnecessarily high and the power is transmitted as pointed out in the above patent publication. There are various problems such as the possibility of damage due to the impact force at the time of shutting off, the decrease in durability, the increase in noise, and the increase in power loss due to deterioration in efficiency.

In view of the above, in the accessory drive system according to the above publication, a fluid clutch is combined to facilitate the transmission of power, thereby preventing discomfort due to impact and improving durability.

However, the clutch of such a mechanism has a problem that the mechanism of the entire apparatus is complicated, and therefore the entire mechanism is large and the cost is high, and it cannot be easily used in view of space and cost. .

In the present invention, in consideration of the problems of the conventional clutch mechanism for an auxiliary machine, the driving force is efficiently transmitted to a driven shaft such as an engine auxiliary machine, and the structure is simple and inexpensive. The challenge is to provide a simple clutch.

[0008]

As a means for solving the above problems, the present invention provides an outer ring rotatably supported on a rotary shaft, and places a viscous fluid in a sealed space formed between the rotary shaft and the outer ring. A plurality of disc-shaped inner plates are fixed on the outer circumference of the rotating shaft at a predetermined interval, and an outer plate that is inserted into the gap between the inner plates is integrally formed. Equipped with a meshing part that slides and guides the centrifugal weight between the weight and the outer ring in the radial direction and engages so as to transmit torque from the centrifugal weight, and spring means for urging the centrifugal weight in the central axis direction. The centrifugal fluid clutch is composed of

[0009]

The clutch of the present invention configured as described above has both functions of a centrifugal clutch and a fluid clutch in spite of being an extremely simple structure, and of course, it is used not only for auxiliary machines around the engine,
It can be used even in the main rotating shaft system.

During low-speed rotation, the centrifugal weight rotates due to the viscous resistance of the surface where the outer plate of the centrifugal weight overlaps the inner plate, and torque transmission is transmitted from the rotating shaft to the outer ring via the inner plate, the centrifugal weight, and the meshing portion.

When rotating at high speed, when the centrifugal force acting on the centrifugal weight becomes high enough to overcome the elastic force of the spring means, the centrifugal weight is guided through the meshing portion and gradually slides outward to face the inner plate. The surface becomes smaller, and torque is not transmitted to the outer ring as it is.

Therefore, above a predetermined rotation speed determined by setting the elastic force of the spring means to a predetermined value in advance, the rotation of the rotating shaft is not transmitted to the outer ring as it is, and is determined by the relationship between the elastic force and the viscous fluid. It is kept at a predetermined speed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a main sectional view of the centrifugal fluid clutch of the embodiment, and FIG. 2 is a sectional view taken along the line II-II of FIG.

As shown in the figure, a centrifugal fluid clutch (hereinafter simply referred to as a clutch) has a pulley 2 rotatably supported on a rotary shaft 1 as an input shaft to which a rotational force is transmitted from an engine or the like, and a pulley 2 A closed space is formed between the rotary shaft 1 and the viscous fluid 3 is enclosed in the closed space.
A belt guide groove for hanging a belt is provided on the outer circumference of the pulley 2.

In the closed space, a plurality of inner plates 4 are fixed to the outer periphery of the rotary shaft 1 at predetermined intervals, and are inserted into the gaps between the inner plates 4 so that the inner plates 4 and the inner plates 4 slide on each other at their overlapping surfaces. A plurality of centrifugal weights 6 each having an outer plate 5 that is in dynamic engagement are arranged in the circumferential direction (in the example shown in FIG.
It is provided separately.

Centrifugal weight 6 divided into a plurality as described above
The back surface of each block is pressed in the axial direction of the rotary shaft by a spring 7 provided on the inner peripheral wall of the pulley 2. The elastic force of the spring 7 is set to a value suitable for allowing the centrifugal weight 6 to move outward by the centrifugal force so as to prevent the rotation of the rotating shaft 1 from being transmitted to the pulley 2 at a predetermined rotational speed or more. It

A bearing seal 8 seals the inside of the pulley as a closed space. A meshing mechanism 9 guides the centrifugal weight 6 to slide in the radial direction between the side wall of the centrifugal weight 6 and the side wall of the pulley 2 and transmits the rotational torque to the pulley 2. Although not shown in the drawings, a stopper is provided at the end of the meshing mechanism 9 so that the centrifugal weight 6 does not approach the outer circumference of the inner plate 4 below the minimum clearance provided between the centrifugal weight 6 and the inner plate 4 shown in FIG. Are provided respectively.

The clutch of the embodiment having the above construction operates as follows. When the driving force is input to the rotating shaft 1 at a low speed (the rotating direction may be either left or right), the inner plate 4 is fixed to the rotating shaft 1 and thus rotates together with the rotating shaft 1. Since the centrifugal force is smaller than the elastic force of the spring 7 at low speed rotation, the outer plate 5 of the centrifugal weight 6 is sufficiently inserted between the inner plates 4 by being pushed by the spring 7. Therefore, the rotation torque is the outer plate 5
And the inner plate 4 are sufficiently transmitted to the centrifugal weight 6 by the shearing force of the viscous fluid acting on the surfaces facing each other. When the centrifugal weight 6 rotates, the centrifugal weight 6 is engaged with the pulley 2 by the meshing mechanism 9, so that the pulley 2 rotates and torque is transmitted.

When the engine rotates at a high speed, the centrifugal force acting on the centrifugal weight 6 increases accordingly, and when the engine elastic force finally becomes larger than a predetermined elastic force set by the spring 7, the centrifugal weight 6 is radiused by the meshing mechanism 9. Slide and move outward while being guided in the direction. For this reason, the sliding surfaces where the outer plate 5 and the inner plate 4 face each other are reduced, and therefore the torque transmitted is also reduced. Therefore, the pulley 2 rises in proportion to the rotation of the input shaft from the low speed rotation to the predetermined rotation speed, but when the centrifugal force is higher than the elastic force of the spring, the rotation is transmitted to the pulley 2 by viscous resistance. Is reduced, and the rotation speed is not transmitted above a predetermined level. The state of transmission of such rotation is shown in FIG.

In the above embodiment, the driving force is transmitted mainly by the non-contact viscous resistance of the inner plate 4 and the outer plate 5, but the inner plate and the centrifugal weight may have a contact (pressing) structure at low speed. The transmission power can be further improved.

FIG. 4 shows another embodiment, which is shown in FIG.
It is an example of arranging in a power transmission path of a wheel drive vehicle. In this case, the main drive shaft 11 for transmitting the drive force from the engine 10 shown in FIG. 5 is fastened to the rotary shaft 1 of FIG. 4, and the outer ring 2 ′ is fastened to the driven shaft on the wheel side.

The internal structure of the clutch 12 is basically the same as that shown in FIG. 1, but in consideration of the restriction of the mounting space, the outer diameter is smaller than that for driving the auxiliary machine, and the shape is long in the axial direction. The number of minute inner plates 4 and outer plates 5 is increased. The same functional members are designated by the same reference numerals and description thereof will be omitted.

When the clutch of this embodiment constructed as described above is used in a four-wheel drive vehicle, the following effects are obtained.

When traveling on a bad road requiring four-wheel drive or when starting, the vehicle travels at a low speed, the outer plate 6 is sufficiently fitted to the inner plate 4 by the spring force, and the driving torque is transmitted like a so-called viscous coupling. Demonstrate four-wheel drive. In particular, in high-speed traveling that does not require four-wheel drive, the outer plate 6 spreads to the outer diameter side due to centrifugal force and the torque transmission force is lost, so that substantially two-wheel drive is performed. That is, four-wheel drive and two-wheel drive are automatically switched according to the traveling speed.

[0025]

As described above in detail, according to the present invention, a centrifugal weight having an outer plate that engages with an inner plate fixed to a rotating shaft is provided in a space in which a viscous fluid between the outer ring and the outer ring is sealed, and Rotation is transmitted to the outer ring via the meshing part,
Since the spring means is pushed back by centrifugal force to maintain the rotation of the centrifugal weight at a predetermined speed during high-speed rotation, sufficient transmission torque is obtained during low-speed operation, the auxiliary machinery is efficiently driven, and during high-speed operation, the auxiliary torque is supplemented. It is possible to prevent the machine from over-rotating, and thus it is possible to obtain the effects of downsizing the auxiliary machine, improving reliability, and reducing noise. In addition, the auxiliary machine can be driven at an efficient rotation speed, and fuel consumption can be improved.

Further, since it is a continuously variable shift, there are various advantages such as no shift shock, smooth shift is possible, and a very simple structure enables low cost manufacturing.

[Brief description of drawings]

FIG. 1 is a main sectional view of a centrifugal fluid clutch according to an embodiment.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is an explanatory diagram of operation

FIG. 4 is a main sectional view of a centrifugal fluid clutch according to another embodiment.

FIG. 5 is an explanatory diagram of an application example.

[Explanation of symbols]

 1 Rotating shaft 2 Pulley 3 Viscous fluid 4 Inner plate 5 Outer plate 6 Centrifugal weight 7 Spring 8 Bearing seal 9 Engaging mechanism

Claims (1)

[Claims] 1. An outer ring rotatably supported on a rotating shaft is provided, a viscous fluid is enclosed in a sealed space formed between the rotating shaft and the outer ring, and a plurality of disc-shaped inner members are provided on the outer periphery of the rotating shaft. The plates are fixed at a predetermined interval, and the centrifugal weight is slid in the radial direction between the centrifugal weight and the outer ring that are divided into circumferential centrifugal weights that integrally have outer plates that are inserted into the gaps between the inner plates. A centrifugal fluid clutch comprising a meshing portion that guides and engages so as to transmit torque from the centrifugal weight, and spring means that biases the centrifugal weight in the central axis direction.