JPH074449A - Centrifugal fluid clutch - Google Patents

Abstract

PURPOSE:To provide a centrifugal fluid clutch which has no converting shock, and can maintain the frequency of an outer ring constant regardless of the frequency of an input shaft. CONSTITUTION:A vane pump 32 rotated by the difference of the relative frequencies of an input shaft 1 and an output outer ring 2 between both members is provided, a communicating passage of the discharge opening 34 and the suction opening 33 of the vane pump 32 is provided on the output outer ring 2, and a centrifugal control valve 23 to open and close the communicating passage 35 according to the value of the centrifugal force is provided on the output outer ring 2, so as to compose this centrifugal fluid clutch.

Description

Detailed Description of the Invention

[0001]

This invention relates to centrifugal fluid clutches.

[0002]

2. Description of the Related Art Since an auxiliary machine such as an alternator for an automobile or a compressor for an air conditioner is usually driven by a belt from a crankshaft of an engine, the number of revolutions thereof greatly increases or decreases according to the change in the number of revolutions of the engine.

On the other hand, when the number of revolutions of the auxiliary machine changes, especially when the auxiliary machine rotates at high speed, the efficiency is lowered and the durability is also disadvantageous. In order to solve such a problem, Japanese Patent Laid-Open No. 109034/1992 proposes a transmission that limits the increase in the rotation speed of auxiliary machinery. In this transmission, a planetary gear speed reduction mechanism, a one-way clutch, and a fluid clutch are incorporated between an input shaft from the engine and an output pulley that drives an auxiliary machine by a belt.

When the engine is running at low speed, the fluid clutch is in the connected state, and the output pulley rotates in the direct connected state with the input shaft. When the engine rotates at high speed, the fluid clutch is disengaged by the action of centrifugal force, and the output pulley is connected to the input shaft via the planetary gear speed reduction mechanism and the one-way clutch, so that the output pulley is decelerated.

As a result, according to the transmission described above, FIG.
As shown in, when the engine speed rises above a certain level, the clutch is switched and the rotation of the auxiliary machine is decelerated.

[0006]

According to the above-described transmission, the increase in the rotational speed of the auxiliary machine can be limited to some extent. However, as can be seen in FIG. 5, the rotational speed of the auxiliary machine changes as the engine speed changes. The numbers also change considerably. Therefore, the accessory cannot always be driven in an efficient rotation range.

Further, there is an abrupt changeover between the direct drive and the deceleration drive in the process of accelerating and decelerating the engine, and the rotational speed of the auxiliary machine changes significantly at that time, so that it is difficult to carry out smooth operation.

Even if the switching shock can be alleviated to some extent by using the fluid clutch, it is difficult to completely eliminate it.

Therefore, the present invention has no switching shock,
An object of the present invention is to provide a centrifugal fluid clutch that can keep the rotation speed of an output outer ring constant regardless of the rotation speed of an input shaft.

[0010]

In order to solve the above-mentioned problems, the present invention rotatably fits an output outer ring around an input shaft, and stores a required fluid inside the output outer ring around the input shaft. A vane pump chamber is provided, the rotor is fixed to an input shaft penetrating the vane pump chamber, and a required number of vanes are mounted on the outer peripheral surface of the rotor slidably in a radial direction to form a vane pump. And a discharge port are connected by a communication passage provided in the output outer ring, and a centrifugal control valve that slides in the radial direction of the output outer ring to open and close the communication passage is provided in the communication passage. is there.

[0011]

In the centrifugal fluid clutch having the above structure, when the input shaft rotates at a low speed, the centrifugal control valve closes the communication passage to prevent the circulation of fluid, so that the input shaft and the output outer ring rotate together. To do.

When the rotation speed of the input shaft increases to a certain level or more, the centrifugal control valve operates to open the communication passage, and the fluid circulates. For this reason, relative rotation occurs between the input shaft and the output outer ring, and even if the number of rotations of the input shaft increases, the rotation of the output outer ring is kept constant.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 and 2, in a centrifugal fluid clutch according to an embodiment, an output outer ring 2 is rotatably fitted around an input shaft 1.

The output outer ring 2 is composed of three members, a main body ring 3, an intermediate ring 4 and a lid ring 5 (see FIG. 3). The main body ring 3 has a hole 6 for inserting the input shaft 1 formed in the central portion thereof and a belt receiving surface 7 formed on the outer peripheral surface thereof. The belt receiving surface 7 projects inward.

On the inner surface of the main body ring 3, discharge side communication grooves 8, 8 are provided at two centrally symmetrical positions. A bearing 9 is interposed between the hole 6 and the input shaft 1 and a seal member 11 is attached to the outer surface of the bearing 9.

The lid ring 5 is formed with a hole 12 for inserting the input shaft 1 in the central portion thereof, and the suction side communication groove 1 is formed on the inner surface thereof.
3 and 13 are provided at two points of central symmetry.

The lid ring 5 is inserted around the input shaft 1, a bearing 14 is interposed between the hole 12 and the input shaft 1, and a seal member 15 is attached to the outer surface of the bearing 14. The lid ring 5 abuts against the inner surface of the belt receiving surface 7 of the main body ring 1 and is integrated with the intermediate ring 5 and the main body ring 3 by bolts 16 (see FIG. 1).

The intermediate ring 4 has an elliptical hole 17 formed in the central portion thereof, and two recesses 18, 18 are provided in the extended portion of the outer peripheral surface on the major axis side of the elliptical hole 17. A valve hole 19 provided on the bottom surface of the recess 18, 18 has an axial communication hole 2
1 intersects and communicates.

The recess 18 forms a valve chamber 22 by being sandwiched between the main body ring 3 and the lid ring 5, and the valve chamber 2
The centrifugal control valve 23 is housed in the inside of the unit 2. Centrifugal control valve 2
3 comprises a weight portion 24 which is slidable in the radial direction inside the valve chamber 22, and a valve portion 25 which is provided on the inner surface of the weight portion 24 so as to project into the valve hole 19. It can be inserted and removed freely.

The centrifugal control valve 23 is urged in the inner diameter direction by an urging spring 26 interposed between the weight portion 24 and the valve chamber 22, and the spring force causes the valve portion 25 to be inserted into the valve hole 19. Then, the communication hole 21 is closed.

Inside the elliptical hole 17, the input shaft 1
A rotor 27 is fixed around the. This rotor 27
Is in sliding contact with the inner surfaces of the main body ring 3 and the lid ring 5 that close both sides of the elliptical hole 17. A chamber surrounded by the outer peripheral surface of the rotor 27, the inner peripheral surface of the elliptical hole 17, the main body ring 3 and the lid ring 5 becomes a vane pump chamber 31.

On the outer peripheral surface of the rotor 27, axial vane grooves 28 are radially provided at regular intervals in the circumferential direction, and the vanes 29 are radially slidably mounted in the respective vane grooves 28. . When the relative rotation between the input shaft 1 and the output outer ring 2 occurs, each vane 29 rotates while slidingly contacting the inner peripheral surface of the elliptical hole 17 of the vane pump chamber 31.

The rotor 27 in the vane pump chamber 31 described above.
The vane 29 mounted on the rotor 27 and the rotor 27 constitutes a vane pump 32, and the vane pump chamber 31 and the communication passages 35 and 35 'are filled with hydraulic oil.

The vane pump chamber 31 has an elliptical hole 17
The both ends of the major axis are widest, and the width becomes gradually narrower in the minor axis direction. One end of the suction-side communication grooves 13, 13 faces a center-symmetrical position of a portion that gradually widens in the rotation direction of the input shaft 1 (see the arrow in FIG. 1) from the narrowest portion.
It is the suction port 33, 33 '. Further, one ends of the discharge-side communication grooves 8 and 8 face the respective suction ports 33 and 33 'in positions substantially symmetrical with respect to the major axis, and the discharge ports 34 and 3
It is 4 '.

The other end of the suction side communication groove 13 and the other end of the discharge side communication groove 8 are respectively connected to both ends of the communication hole 21, and as a whole, the respective suction ports 33, 33 'and the discharge port 34. , 34 ′ communicating with each other, and a centrifugal control valve 23 is formed in the middle of the communication passages 35, 35 ′.
It will be opened and closed by.

The centrifugal fluid clutch of the embodiment is as described above. For example, the input shaft 1 is connected to the crankshaft of the engine, and the belt hung on the belt receiving surface 7 of the output outer ring 2 is used as an auxiliary machine such as an alternator. It is hung and used.

When the number of revolutions of the engine is less than a certain value, the centrifugal control valve 23 closes the communication passages 35 and 35 'and the working oil does not circulate, so that the pump cannot rotate relative to the input shaft 1. The output outer ring 2 rotates together (see "direct connection state" in FIG. 4). When the rotational speed of the engine increases above a certain level, the centrifugal force acting on the centrifugal control valve 23 increases above a certain level, and the centrifugal control valve 23 overcomes the spring force of the biasing spring 26 and operates in the outer diameter direction. , The communication passages 35 and 35 'are opened.

As a result, the working oil can be circulated from the discharge ports 34, 34 'to the suction ports 33, 33', which constitutes the vane pump 31, the input shaft 1 and the rotor 2 integral therewith.
7 and the output outer ring 2 are in a state of being capable of relative rotation without resistance.
As a result, the output outer ring 2 causes a rotation difference (deceleration) with respect to the rotation increase of the input shaft 1, and the rotation increase is suppressed. When the rotation speed of the output outer ring 2 is excessively reduced to a predetermined value or less, the centrifugal control valve 23 is closed again, the circulation of the hydraulic oil is limited, and the speed is increased by the resistance. In this way, the input shaft 1
Even if the number of rotations increases, the rotation of the output outer ring 2 is kept substantially constant (see "Relative rotation state" in FIG. 4).

[0029]

Since the present invention is as described above, it is possible to smoothly control the increase in the rotation speed of the output outer wheel with respect to the increase in the rotation speed on the input side. Further, the control speed can be freely adjusted only by changing the spring constant of the biasing spring of the centrifugal control valve. Furthermore, since the dimension in the axial direction is short, it is advantageous in terms of mounting space.

[Brief description of drawings]

FIG. 1 is a partially omitted front view of an embodiment.

FIG. 2 is an enlarged sectional view taken along line II-II of the above.

FIG. 3 is a partially exploded perspective view of the above.

[Fig. 4] Same speed characteristic diagram

FIG. 5 is a speed characteristic diagram of a conventional example.

[Explanation of symbols]

 1 Input Shaft 2 Output Outer Ring 3 Main Body Ring 4 Intermediate Ring 5 Lid Ring 6 Hole 7 Belt Bearing Surface 8 Discharge Side Communication Groove 9 Bearing 11 Seal Member 12 Hole 13 Suction Side Communication Groove 14 Bearing 15 Seal Member 16 Bolt 17 Elliptical Hole 18 Concave 19 Valve hole 21 Communication hole 22 Valve chamber 23 Centrifugal control valve 24 Weight part 25 Valve part 26 Energizing spring 27 Rotor 28 Vane groove 29 Vane 31 Vane pump chamber 32 Vane pump 33, 33 'Suction port 34, 34' Discharge port 35 , 35 'communication passage

Claims (1)

[Claims] 1. An output outer ring is rotatably fitted around an input shaft, a vane pump chamber accommodating a required fluid is provided around the input shaft inside the output outer ring, and a rotor is provided on the input shaft penetrating the vane pump chamber. And a required number of vanes are mounted on the outer peripheral surface of the rotor slidably in the radial direction to form a vane pump, and the inlet and outlet of the vane pump are connected by a communication passage provided in the output outer ring. A centrifugal fluid clutch provided with a centrifugal control valve that slides in the radial direction of the output outer ring in the middle of the communication passage to open and close the communication passage.