JPH08166027A - Pulley unit with built-in clutch - Google Patents

Abstract

PURPOSE: To provide a pulley unit with a built-in clutch which can operate a one-way clutch with excellent accuracy, and which can be easily assembled with the small number of parts. CONSTITUTION: A plurality of balls 8 are respectively built into between a plurality of raceway grooves 3 formed on the outside diameter surface of an inner ring 1 and a plurality of raceway grooves 5 formed on the inside diameter surface of a pulley 2, and each ball 8 in each groove is retained by crown-shape retainers 9. A clutch retainer 11 and a one-way clutch 10 consisting of an engaging piece 12 and an elastic member, are built into between a pair of crown retainers 9, and a radial load and a moment load are supported by both side balls 8 so that these loads can be prevented from being applied to the one-way clutch 10. The clutch retainer 11 is radially divided into two, the balls 8 are collected before one of ball rows out of rows respectively built into a plurality of raceway grooves 3, 5, are retained by one of the crown-shape retainers 9, and the divided retainers 11a, 11b are successively inserted from a clearance formed on the collected balls to the inside, and after insertion, the other crown- shape retainer 9 is attached to retain the other ball 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch built-in type pulley unit suitable for use as a drive pulley of an auxiliary machine of an automobile, especially an alternator.

[0002]

2. Description of the Related Art Generally, in an internal combustion engine, driving energy is generated during an explosion process and driving force is not generated during other processes, so that the crankshaft undergoes angular velocity fluctuation during one revolution.

Therefore, a method is adopted in which a flywheel is attached to the crankshaft of a normal internal combustion engine to increase the inertial force so as to approximate smooth running.

However, due to the torsional strength of the crankshaft, there is a limit to increase the inertial force, and it is not possible to completely suppress angular velocity fluctuations. In particular, a diesel engine has a larger angular velocity fluctuation than a gasoline engine, and there are some that reach a speed fluctuation of ± 20% or more at a low speed rotation.

Therefore, when an engine accessory such as an alternator, which has a large inertial force and is about to rotate at a substantially constant speed, is driven by a crankshaft whose angular velocity fluctuates slightly as a drive source, the angular velocity of the crankshaft is increased. Due to the fluctuation, slip occurs between the pulley and the belt provided on the rotating shaft of the engine accessory, and the belt is easily worn.

In order to solve the above-mentioned problems, in the belt transmission device disclosed in Japanese Patent Laid-Open No. 61-228153, a rotary shaft of an engine accessory and a pulley supported by the rotary shaft are provided. A one-way clutch is incorporated between them to transmit the rotational force of the crankshaft to the rotary shaft when the angular velocity of the crankshaft increases, and to interrupt the rotational force transmission to the rotary shaft when the angular velocity of the crankshaft decreases.

That is, in the above belt transmission, when the angular velocity of the crankshaft increases, the one-way clutch is engaged to connect the rotary shaft of the engine accessory and the pulley, and the rotational force of the crankshaft is transmitted to the rotary shaft. When the rotation of the rotary shaft becomes faster than the rotation of the pulley, the one-way clutch is disengaged so that the rotary shaft is freely rotated. Therefore, there is a feature that slip does not occur between the belt and the pulley and the life of the belt can be prevented from being shortened.

[0008]

By the way, in the above belt transmission, when a one-way clutch is directly installed between the rotary shaft and the pulley, the radial load and moment load acting on the pulley act on the one-way clutch. For,
There are areas to be improved in order to operate the one-way clutch accurately and reliably.

An object of the present invention is to provide a pulley unit which can operate a one-way clutch with high accuracy and reliability and which can smoothly rotate a pulley during idling and which has a small number of parts and is easy to assemble. Is.

[0010]

In order to solve the above-mentioned problems, according to the present invention, a double row radial bearing type is provided for each of the outer diameter surface of the inner ring and the inner diameter surface of a pulley provided outside the inner ring. The raceway groove of each row is formed, and balls that can roll along the raceway groove of each row are held by a crown type cage that can be inserted between both members from the side between the inner ring and the pulley, and a pair of crown type holding A one-way clutch is installed between the two parts, and the one-way clutch is retained by the clutch retainer and the retainer, and when the inner ring and the pulley relatively rotate in one direction, the inner ring outer diameter surface and the pulley inner diameter surface The clutch retainer is divided into two in the radial direction. The clutch retainer is divided into two in the radial direction. The clutch retainer is divided into two in a radial direction. The adopted configuration is adopted.

[0011]

As described above, by incorporating the balls between the double-row raceway grooves formed in the inner ring and the double-row raceway grooves provided in the pulley, the radial load and moment load acting on the pulley can be increased by the double-row raceway groove. Since it can be supported by the ball, the one-way clutch incorporated between the ball rows does not exert an unreasonable force, and the one-way clutch can be operated reliably and accurately.

In assembling the pulley unit, the pulley is fitted on the outer side of the inner ring, the inner ring and the pulley are offset in one direction, and a plurality of rows of raceway grooves are formed from the side of the crescent space formed between the members. Incorporate multiple balls in between.

After the balls are assembled, the inner ring and the pulley are concentrically held, the balls of one of the multiple rows of balls are arranged at an equal angle, and the crown cage is inserted to insert the balls. Hold.

The balls of the other ball row are gathered in the lower part between the raceway grooves, and one split cage for supporting the engaging element and the elastic member is inserted between the inner ring and the pulley from the space formed on the gathered balls. . Next, the collective balls are moved by 180 ° to incorporate the remaining split cages, and then the balls of the other ball row are arranged at an equal angle and the remaining crown cages are inserted.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, the pulley unit A has an inner ring 1 and a pulley 2 provided outside thereof. The outer ring surface of the inner ring 1 is provided with double-row raceway grooves 3 and a cylindrical surface 4 between the raceway grooves 3.

On the other hand, the inner diameter surface of the pulley 2 is provided with a plurality of rows of raceway grooves 5 and a plurality of cam surfaces 6 between the raceway grooves 5.
A wedge-shaped space 7 is formed between the cam surface 6 and the cylindrical surface 4 of the inner ring 1.

The double-row raceway grooves 3 and 5 are grooves for radial ball bearings having an arcuate cross section, and the raceway grooves 3 facing each other in the radial direction.
A plurality of balls 8 are incorporated between the five.

Each of the double-row balls 8 is held by a snap-on type crown-shaped cage 9 which is inserted laterally between the inner ring 1 and the pulley 2, and the pair of crown-shaped cages 9 is held.
A one-way clutch 10 is incorporated between them.

The one-way clutch 10 is a clutch holder 1
1 and a plurality of engaging elements 12 and elastic members 13 held by the holder 11.

The engagement element 12 is a roller. The engagement element 12 is incorporated in a wedge-shaped space 7 formed between the cylindrical surface 4 of the inner ring 1 and the cam surface 6 of the pulley 2. The engagement element 12 is pressed by the elastic member 13 toward the narrow portion of the wedge-shaped space 7 and is in contact with the cylindrical surface 4 and the cam surface 6.

It should be noted that the engaging element 12 made of a sprag may be used instead of the engaging element 12 made of a roller. When the engagement element 12 is a sprag, a cylindrical surface is formed instead of the cam surface 6 of the pulley 2.

The clutch holder 11 has two radial positions.
Has been split. Reference numerals 11a and 11b denote split cages.
Moreover, 14 shows a seal.

FIG. 3 shows an example of use of the pulley unit A shown in the above embodiment, in which the rotating shaft 22 of an engine accessory 21 such as an alternator using the crankshaft 20 as a drive source.
The above-mentioned pulley unit A is attached to, and the belt 24 is stretched between the pulley 2 of the pulley unit A and the pulley 23 attached to the crankshaft 20.

Here, in the pulley unit A, when the pulley 23 of the crankshaft 20 rotates in the direction of the arrow, the engaging element 12 of the one-way clutch 10 engages the cam surface 6 of the pulley 2 and the cylindrical surface 4 of the inner ring 1 with the clutch. It is supposed to be assembled.

When the crankshaft 20 is rotated in the direction of the arrow accompanied by a slight change in the angular velocity in the above-mentioned usage state, when the angular velocity of the crankshaft 20 increases,
The rotational force is transmitted to the pulley 2 of the pulley unit A via the belt 24.

At this time, the one-way clutch 10 has the pulley 2
Since the cam surface 6 and the cylindrical surface 4 of the inner ring 1 are in clutch engagement, the rotation of the pulley 2 is transmitted to the rotary shaft 22 of the engine accessory 21 via the inner ring 1.

The angular velocity of the crankshaft 20 decreases,
When the rotation speed of the rotation shaft 22 becomes faster than the rotation speed of the crankshaft 20, the one-way clutch 10 is disengaged and the rotation shaft 22 idles with respect to the pulley 2. Therefore, the pulley 2
Is rotated by the movement of the belt 24 regardless of the rotation shaft 22, so that the pulley 2 is not driven in the opposite direction from the rotation shaft 22 of the engine accessory 21.
It is possible to suppress the shortening of the life of the. Further, since the radial load and moment load acting on the pulley 2 can be supported by the double-row balls 8, the one-way clutch 1
The one-way clutch 10 can be operated with high accuracy without applying an unreasonable force to 0.

When assembling the pulley unit A shown in FIG. 1, as shown in FIG. 4, the inner ring 1 and the pulley 2 provided on the outer side of the inner ring 1 are biased to each other to form a crescent space formed between the members 1 and 2. Double-row raceway grooves 3 facing each other from the side in the radial direction,
A plurality of balls 8 are simultaneously assembled in each of the spaces 5.

Next, as shown in FIG. 5, the inner ring 1 and the pulley 2 are concentrically held, and the balls 8 of one of the multiple rows of balls are arranged at an equal angle, and the inner ring 1 and the pulley 2 are arranged. The coronal cage 9 is inserted from the side between the two.

The balls 8 in one of the ball rows are connected to the coronal cage 9.
Then, the balls 8 of the other ball row are collected in the lower portion between the raceway grooves 3 and 5, and the engaging element 12 and the elastic member 13 are provided between the inner ring 1 and the pulley 2 from the space formed on the collecting ball 8. One of the split holders 11a to be held is inserted.

FIG. 6 shows the inserted state of one of the split cages 11a. After the split cage 11a is inserted, the collective ball 8 is moved 180 ° in the circumferential direction and is formed below the collective ball 8. The other split cage 11b is inserted from the space between the inner ring 1 and the pulley 2 (see FIG. 7).

Next, the balls 8 of the other ball row are arranged at equal angles, and the balls 8 are held by inserting the remaining crown-shaped cages 9 (see FIG. 8).

After inserting the crown-shaped cage 9, grease is filled and seals 14 are fitted between both ends of the inner ring 1 and the pulley 2 to prevent the grease from leaking.

Here, as shown in FIG. 9, the balls 8 of one of the double-row ball rows are connected to the small-diameter cylindrical portion 1a of the inner ring 1.
If a double row angular contact ball bearing is used in which the balls 8 of each row of balls are angularly contacted by being guided by the bearing inner ring 15 that is press-fitted into the pulley, an assembly method of inserting the respective parts from the axial direction of the pulley 2 into the inside is adopted. However, in this case, since the bearing inner ring 15 is required, the number of parts is increased and the dimensional accuracy of parts needs to be managed at a high level, which is disadvantageous in terms of cost.

In the embodiment, since the raceway grooves 3 and 5 are the grooves of the radial ball bearing, highly precise dimensional control is not required, and the clutch retainer 11 is divided into two in the radial direction. Since the assembly method as shown in FIGS. 4 to 8 can be adopted, the bearing inner ring 15 shown in FIG. 9 can be omitted, and the cost can be reduced.

[0037]

As described above, in the pulley unit according to the present invention, since the radial load and the moment load acting on the pulley can be supported by the double-row balls, the pulley unit is installed between the double-row ball rows. The load does not act on the one-way clutch, so that the one-way clutch can be operated reliably and accurately, and the pulley can be smoothly rotated when idling.

Further, since the raceway groove for ball guide is a radial bearing type groove, there is no need for highly precise dimensional control,
Moreover, by dividing the clutch retainer into two in the radial direction, the pulley unit can be easily assembled without using the bearing inner ring, and it is possible to provide a inexpensive pulley unit with a small number of parts.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a pulley unit with a built-in clutch according to the present invention.

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

FIG. 3 is a schematic view showing a usage example of the above pulley unit.

FIG. 4 is a front view showing the first stage of assembly of the pulley unit.

FIG. 5 is a sectional view showing a second stage of assembling the pulley unit.

FIG. 6 is a sectional view showing a third stage of assembling the pulley unit.

FIG. 7 is a sectional view showing a fourth step of assembling the pulley unit.

FIG. 8 is a sectional view showing a fifth step of assembling the pulley unit.

FIG. 9 is a sectional view of a pulley unit using a bearing inner ring.

[Explanation of symbols]

 1 Inner ring 2 Pulleys 3, 5 Raceway grooves 8 Ball 9 Crown type retainer 10 One-way clutch 11 Clutch retainer 12 Engager 13 Elastic member

Claims (1)

[Claims] 1. A double-row radial bearing type raceway groove is formed on each of the outer diameter surface of the inner ring and the inner diameter surface of a pulley provided on the outer side of the inner ring, and can be rolled along the raceway grooves of each row. Is held by a crown type cage that can be inserted between both members from the side between the inner ring and the pulley, and a one-way clutch is incorporated between a pair of crown type cages, and the one-way clutch is the clutch cage. And a retainer held by the retainer, which engages the outer diameter surface of the inner ring with the inner diameter surface of the pulley when the inner ring and the pulley relatively rotate in one direction, and releases the engagement when the inner ring and the pulley relatively rotate in the other direction. A clutch built-in type pulley unit, comprising a clutch and an elastic member that presses the engaging member in a clutch engaging direction, wherein the clutch holder is divided into two in the radial direction.