JP2003074672A - Pulley unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulley unit capable of reducing axial slippage between a pulley and a shaft body. SOLUTION: This pulley unit comprises: the pulley 1; a rotor shaft 2 relatively rotatable with the pulley 1 and concentrically arranged on the inside of the pulley 1; a one-way clutch 3 interposed in the annular space between the pulley 1 and the rotor shaft 2; and a ball bearing 4 provided adjacently to the axial direction of the one-way clutch 3 in the annular space. The raceway curvatures of both the inner and outer rings of the ball bearing 4 are set to 50.5%-52.0%, and the residual radial clearance of the ball bearing 4 is set to less than 20 μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulley unit having a built-in one-way clutch, and more particularly to a compressor for an air conditioner, a water pump, which is driven from a crankshaft of an engine of an automobile or the like via a belt, The present invention relates to a pulley unit mounted on an auxiliary machine such as an alternator and a cooling fan.

[0002]

2. Description of the Related Art Various accessories mounted on an engine of an automobile are driven by a crankshaft of the engine via a belt. Among the auxiliary machines, the alternator is rotationally driven by the crankshaft of the engine to generate electricity. If such an alternator is connected to the crankshaft of the engine so as to rotate synchronously, the power generation efficiency of the alternator decreases as the rotation speed of the crankshaft decreases. In order to prevent such a decrease in power generation efficiency, an alternator having a one-way clutch built in its pulley portion has been devised. In this alternator, if the rotation speed of the crankshaft decreases,
Rotation of the alternator rotor is continued by utilizing inertial forces, which increases the alternator's power generation efficiency.

FIG. 10 shows a pulley unit. This pulley unit includes a pulley 1, a rotor shaft 2, a one-way clutch 3, a deep groove ball bearing 44, and a needle roller bearing 45. The cam surface 10 is formed on the outer peripheral surface of the rotor shaft 2 in the axial direction.
Are formed. The pulley 1 has a belt 6 on its outer periphery.
Can be hung. The pulley 1 is rotationally driven by driving the belt 6 by a crankshaft of an automobile engine (not shown). The rotor shaft 2 is fixed to the rotor of the alternator. One-way clutch 3 is cage 1
2 and a plurality of rollers 13 housed in each of the plurality of pockets of the cage 12. Around 13
Is constantly pressed by the coil spring (not shown) toward the narrow side (lock side) of the wedge-shaped space. The wedge-shaped space is a circumferential annular space for rolling the rollers 13 formed between the inner peripheral surface of the outer ring 11 and the cam surface 10 of the rotor shaft 2, and is narrowed in the lock side direction. The one-way clutch 3, the deep groove ball bearing 44 and the needle roller bearing 45 are sealed by the seal rings 20 and 21 and the seal ring body 22 and are lubricated with a common lubricant.

In operation, when the rotation speed of the pulley 1 becomes relatively faster than that of the rotor shaft 2, the rollers 13 of the one-way clutch 3 are rolled to the narrow side of the wedge-shaped space and are locked. Become. The locked state is a state in which the outer ring 11 and the rotor shaft 2 are integrally rotatable via the rollers 13. The outer ring 11 and the pulley 1 are integrally provided. As a result, in the locked state, the pulley 1 and the rotor shaft 2 rotate integrally, and the rotational power can be transmitted from the pulley 1 to the rotor shaft 2.

When the rotation speed of the pulley 1 becomes relatively slower than that of the rotor shaft 2, the rollers 13 of the one-way clutch 3 roll to the wide side (free side) opposite to the narrow side of the wedge-shaped space. It is made to be in a free state. The free state is a state in which the outer ring 11 and the rotor shaft 2 can freely rotate with respect to each other. As a result, the transmission of rotational power from the pulley 1 to the rotor shaft 2 is cut off. If the rotor shaft 2 is rotating before the transmission is interrupted, the rotor shaft 2 continues to rotate only by its own rotational inertia after the interruption.

[0006]

A deep groove ball bearing 44 is described with reference to FIGS. 10 and 11. This bearing 44
Receives an axial load. The bearing 44 includes an inner ring 50,
An outer ring 51, a cage 56, and a plurality of balls 52 are provided. Inner ring 5
0 and the outer ring 51 have raceway grooves 53 and 54, respectively. The raceway grooves 53, 54 correspond to the arc of a circle 55 indicated by an imaginary line having a diameter larger than that of the ball 52. If the radius of curvature of the raceway grooves 53 and 54 is R and the diameter of the balls 52 is D, the raceway groove 5
The orbital curvatures (%) of 3, 54 are expressed as in equation (1).

Orbital curvature = (R / D) × 100 (1) From the above equation (1), when the orbital curvature is 50%, the radius of the ball 52 (D / 2) and the radius of curvature of the orbital grooves 53 and 54. (R) are the same. Therefore, when the orbital curvature is 50%, the ball 52
Will be fitted into the track grooves 53 and 54 without any gap. Thus, when the orbital curvature is 50%, the bearing 1
The axial deviation of 1 is completely eliminated. In this state, the balls 52 are fitted into the raceway grooves 53, 54 without any clearance, so that the sliding friction between the balls 52 and the raceway grooves 53, 54 may cause seizure of the raceway grooves 53, 54. ,
It may affect the life of the lubricant. In order to deal with this, the raceway curvature is 52 in the raceway groove 53 of the inner ring 50.
~ 52.5%, 53.0-5 in the raceway groove 54 of the outer ring 51
It is set to 3.5%.

As shown in FIG. 12, the bearing 44 needs to be press-fitted between the pulley 1 and the rotor shaft 2.
Therefore, the radial clearance of the bearing 44 (radial internal c
The clearance is set to be several times larger than the standard radial clearance in consideration of the tolerance. For example, in the case of the bearing 44 having a JIS (Japanese Industrial Standard) bearing number 6807, a true radial clearance (radial internal) before mounting is provided.
clearance before mounting) is set to 50 to 100 μm. When such a bearing 44 is press-fitted between the pulley 1 and the rotor shaft 2, the fitting reduces the radial gap. Therefore, the radial clearance (remaining radial clearance) after mounting the ball bearing 44 is about 21 to 52.
will be set to μm.

Orbital curvature of the orbital groove 53 52-52.5%,
Deep groove ball bearing 44 with orbital curvature of the orbital groove 54 of 53.0 to 53.5% and true radial gap before installation of 75 to 99 μm
When the pulley 1 and the rotor shaft 2 are press-fitted to each other, as shown in Table 7, the residual radial clearance (radial intern
al clearance after mounting) is 21 to 52 μm, and axial internal clearance is 140 to 52 μm.
It becomes 239 μm.

[0010]

[Table 7] As shown in FIG. 13, the axial gap is formed by the raceway groove 5
The axial deviations of the inner and outer rings 50, 51 due to the orbital curvatures of 3, 54 and the residual radial clearance are shown.

The main object of the present invention is to provide a pulley unit capable of reducing the axial deviation between the pulley and the shaft.

[0012]

A pulley unit according to the present invention comprises a pulley, a shaft which is rotatable relative to the pulley and which is arranged concentrically inside the pulley, the pulley and the shaft. And a ball bearing provided adjacent to each other in the axial direction of the one-way clutch in the annular space.

In the pulley unit of the present invention, the first
In addition, the orbital curvatures of the inner and outer rings of the ball bearing are both set to 50.5% or more and 52.0% or less. Secondly, the residual radial clearance of the ball bearing is set to less than 20 μm. Thirdly, in the ball bearing, both the first and second settings are made. Fourthly, the orbital curvatures of the inner and outer rings of the ball bearing are both 50.5%.
It is set to 51.0% or less. Fifth, the orbital curvature of at least one of the inner ring and the outer ring of the ball bearing is set to 50.5% or more and 51.0% or less. Where the orbital curvature is
For the outer ring, if the radius of curvature of the raceway groove of the outer ring is Ro and the diameter of the ball is D, it is expressed by (Ro / D) × 100%.
For the inner ring, if the radius of curvature of the raceway groove of the inner ring is Ri and the diameter of the ball is D, it is expressed by (Ri / D) × 100%.

With either setting, the axial clearance of the ball bearing is reduced. As a result, the axial displacement between the pulley and the shaft body is reduced. As a result, the inclination of the pulley unit due to the belt load is suppressed, which suppresses damage to the one-way clutch and the bearing, heat generation, a reduction in the life of the lubricant, and vibration and noise of the belt.

Preferably, the ball bearing is arranged on one side of the one-way clutch, and the roller bearing is arranged on the other side of the one-way clutch. The residual radial clearance of the ball bearing is set smaller than that of the roller bearing. With this setting, rattling of the ball bearing in the radial direction and the axial direction can be reduced. This makes it possible to achieve a more integrated structure of the pulley and the shaft body so as to improve the rigidity against moment load.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The details of the present invention will be described below based on the embodiments shown in the drawings.

1 to 5, a pulley unit according to an embodiment of the present invention will be described. The pulley unit A includes a pulley 1, a rotor shaft 2, and a one-way clutch 3.
A deep groove ball bearing 4 and a needle roller bearing 5.

The rotor shaft 2 is supported in a cantilever state as an example of a shaft body. The rotor shaft 2 is rotatable relative to the pulley 1 and is concentrically arranged inside thereof. When the pulley 1 is an outer ring body, the rotor shaft 2 is an inner ring body. The outer peripheral surface of the rotor shaft 2 has three regions, that is, an axial intermediate region (a region where a one-way clutch is mounted) X1,
It is divided into an axial direction one side area (area where ball bearings are mounted) X2 and an axial other side area (area where roller bearings are mounted) X3.

The one-way clutch 3 is interposed in the axial middle of the annular space between the pulley 1 and the rotor shaft 2 (the space corresponding to the one-way clutch mounting area X1). The one-way clutch 3 includes a cage 12, rollers 13, and a coil spring 14. The inner surface of the pulley 1 and the outer surface of the rotor shaft 2 form a raceway surface on which the rollers 13 of the one-way clutch 3 roll.
With this raceway surface configuration, the inner and outer rings of the one-way clutch 3 are shared by the pulley 1 and the rotor shaft 2. Cage 12
Pockets 12a are provided at several positions in the circumferential direction. The pocket 12a is formed so as to penetrate the inside and outside in the radial direction. The roller 13 is stored in the pocket 12a. A pillar portion 12b exists between the pockets 12a of the cage 12. A protrusion 12c is integrally formed on the inner wall surface of the column portion 12b. The coil spring 14 is attached to the protrusion 12c of the retainer 12. The coil spring 14 connects the roller 13 to the rotor shaft 2
The cam surface 10 and the inner peripheral surface of the pulley 1 are urged toward the narrow side (lock side) of the wedge-shaped space.

The deep groove ball bearing 4 is arranged as one rolling bearing on one axial side of the one-way clutch 3 (space corresponding to the ball bearing mounting area X2) in the annular space. The deep groove ball bearing 4 has a plurality of balls 23 and a cage 24. On the inner surface of the pulley 1 and the outer surface of the rotor shaft 2, deep groove raceways 25 and 26, on which the balls 23 of the deep groove ball bearing 4 roll, are formed. Due to the raceway grooves 25 and 26, the inner and outer rings of the deep groove ball bearing 4 are shared by the pulley 1 and the rotor shaft 2. As shown in FIG. 4, the retainer 24 is formed in a crown shape and has a plurality of pockets 24 a for accommodating the balls 23.

The needle roller bearing 5 is arranged as the other rolling bearing on the other side in the axial direction of the one-way clutch 3 (the space corresponding to the roller bearing mounting region X3) which is the free end side of the pulley unit A. The deep groove ball bearing 4 is arranged on the accessory side, for example, the alternator side. The needle roller bearing 5 has a plurality of rollers 33 and a cage 34. The inner surface of the pulley 1 and the outer surface of the rotor shaft 2 form a raceway surface on which the rollers 33 of the needle roller bearing 5 roll. With this raceway structure, the inner and outer rings of the needle roller bearing 5 are shared by the pulley 1 and the rotor shaft 2.

In the above, the ball bearing 4 is arranged on the base end side of the rotor shaft 2, and the roller bearing 5 is arranged on the free end side of the rotor shaft 2.

The flat cam surface 10 used for the one-way clutch 3 is formed at several circumferential positions in the axially intermediate region X1 of the rotor shaft 2. Areas X on both sides of the rotor shaft 2 in the axial direction
The inner ring raceways of the ball bearing 4 and the bearing 5 are secured at 2 and X3. The intermediate region X1 of the rotor shaft 2 has eight cam surfaces 1
With 0, it has an octagonal outer shape. Both side regions X2 and X3 of the rotor shaft 2 have a cylindrical outer shape.

The outer diameter of the region X2 of the rotor shaft 2 is set so that the one-way clutch 3, the ball bearing 4, and the roller bearing 5 can be easily assembled between the pulley 1 and the rotor shaft 2 from one direction. The dimension is set larger than the outer diameter dimension of the region X3.

In the region X3 of the rotor shaft 2, the positioning groove 4 is formed.
0 is provided. A ring-shaped projection 34a, which is provided on the inner circumference of the cage 34 of the roller bearing 5 and faces inward in the radial direction, is engaged with the positioning groove 40. Thereby, the cage 34
Are axially positioned.

The inner peripheral surface of the retainer 12 of the one-way clutch 3 is formed in a shape that matches the outer shape of the region X1 of the rotor shaft 2, that is, an octagon. The cage 12 is a roller 13
By being externally fitted to the region X1 of the rotor shaft 2 in the state of holding, the rotation is prevented in the circumferential direction. The cage 12 is also prevented from moving toward the ball bearing 4 by the tapered step portion 41 connecting the cam surface 10 in the region X1 of the rotor shaft 2 and the region X2. As a result, the cage 34 of the roller bearing 5 axially positioned with respect to the rotor shaft 2 blocks the movement of the roller bearing 5 toward the roller bearing 5.

The outer peripheral surface of the pulley 1 is provided with a belt guide surface 39. The belt 6 indicated by the chain double-dashed line is wound around the belt guide surface 39. The pulley 1 is rotationally driven by the crankshaft of an automobile engine. Rotor shaft 2
Is fixed to a rotor of an alternator as an example of an input shaft of an auxiliary machine. The one-way clutch 3 has a plurality of rollers 13 housed in a cage 12. The cam surfaces 10 are formed on the outer peripheral surface of the rotor shaft 2 in the same number as the rollers 13. Due to the cam surface 10, the radial space between the cam surface 10 and the inner peripheral surface of the pulley 1 becomes narrower toward one side in the circumferential direction (clockwise direction in FIG. 2). One side in the circumferential direction is the lock side. The radial space that gradually narrows toward the lock side is referred to as a wedge-shaped space in this specification. The roller 13 is arranged in a wedge-shaped space between the cam surface 10 and the inner peripheral surface of the pulley 1, and is urged toward its lock side by a coil spring 14. One-way clutch 3,
The deep groove ball bearing 4 and the needle roller bearing 5 are sealed by the seal rings 20 and 21 and the seal ring 22. The one-way clutch 3 and both bearings 4 and 5 are lubricated with a common lubricant.

In operation, the rotation speed of the pulley 1 becomes relatively faster than that of the rotor shaft 2. Then, the roller 13 of the one-way clutch 3 is rolled to the lock side of the wedge-shaped space as shown by the solid line in FIG. Due to the rolling in the lock side direction, the roller 13 cannot be rolled because it is sandwiched between the inner surface of the pulley 1 and the outer surface of the rotor shaft 2.
This state is called a locked state. In this locked state, the pulley 1 and the rotor shaft 2 are integrated via the roller 13. Therefore, in this locked state, the rotor shaft 2 cannot rotate freely with respect to the pulley 1, but rotates synchronously.

The rotation speed of the pulley 1 becomes relatively slower than that of the rotor shaft 2. Then, the roller 13 of the one-way clutch 3 is rolled to the wide side of the wedge-shaped space, that is, the unlock side, as shown by the phantom line in FIG. Due to the rolling of the roller 13 to the unlock side, the rotor shaft 2
Is in a free state in which it can freely rotate with respect to the pulley 1. In this free state, the transmission of rotational power from the pulley 1 to the rotor shaft 2 is cut off. As a result, the rotor shaft 2
Continues to rotate only by its own rotational inertial force.

The relationship between the orbital curvature of the deep groove ball bearing 4 and the residual radial clearance and axial clearance will be described in several patterns. The radius of curvature of the raceway grooves 25 and 26 is R, and the ball 23
Assuming that the diameter of D is D, the orbital curvature is expressed by the following equation, as shown in equation (1).

Orbital curvature = (R / D) × 100 When the orbital curvatures of the orbital grooves 25 and 26 are set small: the orbital curvatures of the orbital grooves 25 and 26 are 50.5, respectively.
% To 52.0%. Residual radial clearance is 0
˜30 μm. The relationship between the residual radial clearance (μm) and the axial clearance (μm) is shown in Table 1 below.

[0032]

[Table 1] From Table 1, the range of the axial gap in the range of the residual radial gap of 10 to 30 μm is 42 to 149 μm.
This fact is due to the residual radial clearances 21-5 shown in Table 7.
140 to 239 of the axial gap in the range of 2 μm
It is shown that the range of the axial gap is generally smaller than the range of μm. Residual radial gap is 10μ
When it is less than m, the axial gap becomes 0 to 62 μm, and the axial gap becomes smaller.

When the residual radial gap is reduced:
The residual radial clearance of the deep groove ball bearing 4 is less than 20 μm. As with the conventional example, the orbital curvature of the orbital groove 26 is 52.0 to 52.5%, and the orbital curvature of the orbital groove 25 is 53.0 to 53.5%. Table 2 shows the values of the axial gaps in this case.

[0034]

[Table 2] As is clear from Table 2, the residual radial gap is 20 μm.
If it is less than 1.0 μm, the axial gap becomes 0 to 130 μm, and if the residual radial gap is less than 10 μm, the axial gap becomes 0 to 62 μm, which is smaller than the conventional example.

Table 3 is shown as a comparative example. In Table 3, the residual radial gaps 21 to 52 μm represent the axial gap 109.
Is about 200 μm.

[0036]

[Table 3] In the case of the deep groove ball bearing 4 having the relationship between the residual radial clearance and the axial clearance shown in Table 3, the axial clearance is
For example, an axial deviation between the pulley 1 and the rotor shaft 2 is caused by the action of axial vibration on the pulley unit accompanying the vibration of the engine. As a result, the rollers 13 of the one-way clutch 3 and the rollers of the needle roller bearing 5 are
Sliding in the axial direction with respect to the inner and outer rings, the meshing with the inner and outer rings may deteriorate due to meandering rolling, and vibration may occur.
The axial slip causes the rollers 13 of the one-way clutch 3, the rollers of the needle roller bearing 5 and the inner and outer races to peel, wear, and generate heat, which may shorten the life of the lubricant.

As a more preferable example, the deep groove ball bearing 4
The orbital curvatures of the orbital grooves 25 and 26 inside and outside of are respectively 5
It is set to 0.5% or more and 51.0% or less. Table 4 shows the values of the axial gaps in this case.

[0038]

[Table 4] As is clear from Table 4, the residual radial gap is 10 to 3
The axial gap in the range of 0 μm is 42 to 103 μm.
m, which is smaller than that of the conventional example shown in Table 7. As a more preferable example, it can be seen that when the residual radial gap is in the range of 0 to 20 μm, the axial gap becomes 0 to 85 μm, which is smaller.

According to the thus constructed pulley unit A, the track curvature is set to 50.5% or more and 52.0% or less, the residual radial clearance is set to less than 20 μm, or a combination thereof. , The axial gap can be reduced.

When the axial gap becomes small, the pulley 1
Therefore, the axial displacement of the rotor shaft 2 can be minimized. As a result, the rollers 13 of the one-way clutch 3 and the rollers 33 of the needle roller bearing 5 slide axially with respect to the inner and outer raceway grooves, the meandering rolling deteriorates the meshing with the raceway ring, and vibrations occur. It can be suppressed from occurring. By suppressing the axial slippage, it is possible to suppress the separation and wear of the rollers 13 and 33 and the bearing rings, and to suppress the decrease in the life of the lubricant due to heat generation.

Furthermore, the orbital curvature is 50.5% or more.
By setting 0% or less to be small, it is possible to suppress the inclination due to the bending of the pulley unit A when the load of the belt B acts on the free end portion of the pulley unit A. As a result, it is possible to prevent the edge portion of the roller 13 of the one-way clutch 3 or the roller 33 of the needle roller bearing 5 from hitting the raceway groove and damaging the edge portion or generating heat. Furthermore, by suppressing the inclination of the pulley unit A,
The belt B becomes difficult to swing, and vibration and noise can be suppressed.

In the case of this embodiment, the radial gap may be a negative gap. Instead of the deep groove ball bearing 4, a ball bearing having inner and outer rings separate from the pulley 1 and the rotor shaft 2 may be used. A ball bearing may be provided on the other side of the one-way clutch 3, or a pulley unit without a bearing may be used.

The orbital curvature is preferably set to 50.5% or more and 51.5% or less for at least one of the inner ring and the outer ring. The orbital curvature is more preferably set to 50.5% or more and 51.5% or less for both the inner ring and the outer ring. The track curvature is even more preferably 5 for both the inner and outer rings.
It is set to 0.5% or more and 51.0% or less.

In this case, Tables 5 and 6 show the relationship between the residual radial clearance and the axial clearance when only one of the inner and outer races is used.

[0045]

[Table 5]

[0046]

[Table 6] In Table 5, the orbital curvature is 50.5% or more at the inner ring 5
It is set to 1.0% or less and 53% to 53.5% for the outer ring. In Table 6, the inner ring is set to 52% or more and 52.5% or less, and the outer ring is set to 50.5% or more and 51% or less.

Referring to FIGS. 6 and 7, a pulley unit according to another embodiment of the present invention will be described. Detailed description of portions corresponding to those in FIGS. 1 and 3 is omitted. In the case of this pulley unit B, the region X3 in the rotor shaft 2
An annular groove 42 into which the lower end of the seal ring 21 in the radial direction is fitted is formed on the outer diameter surface of the. The other structure is similar to that described above, and therefore detailed description of the structure and operation thereof is omitted.

In the case of this pulley unit B, the residual radial clearance of the ball bearing 4 is set to be smaller than the residual radial clearance of the roller bearing 5.

Assuming that the above-mentioned magnitude relation of the residual radial clearance in the ball bearing 4 and the bearing 5 is satisfied,
The residual radial clearance of the ball bearing 4 is set in the range of −20 to 25 μm, preferably in the range of −5 to 10 μm. The residual radial clearance of the roller bearing 5 is in the range of 5 to 35 μm,
It is preferably set in the range of 5 to 20 μm.

Here, FIG. 8 shows the relationship between the residual radial clearance of the ball bearing 4 and the life. In FIG. 8, the horizontal axis represents the life (%) and the vertical axis represents the residual radial clearance (μm). In this relationship, the residual radial gap is 0 μm, and the life of the ball bearing 4 is 100%.

In the case of the ball bearing 4, the residual radial clearance is -1.
If it is set to 0 μm or less, heat generation and grease deterioration occur, so that the life is drastically reduced, and it is desirable to set it to −5 μm or more.

Thus, when the residual radial clearance of the ball bearing 4 is set to be small, the radial and axial play of the ball bearing 4 is reduced as much as possible. Therefore, the pulley 1 and the rotor shaft 2 can be integrated at a high level, and the rigidity against moment load is improved. In addition, since the degree of freedom of the roller 13 of the one-way clutch 3 can be reduced by the ball bearing 4, the behavior of the roller 13 can be stabilized, and minute slip and skew of the roller 13 can be reduced. Therefore, the operation of the one-way clutch 3 can be stabilized, and the durability of the one-way clutch 3 and thus the pulley unit can be improved.

The rotor shaft 2, the one-way clutch 3, and the ball bearing 4
And each inner ring of the roller bearing 5 and the pulley 1
Are also used as the outer rings of the one-way clutch 3, the ball bearing 4, and the roller bearing 5, respectively, so that the number of parts can be reduced and the cost can be effectively reduced. Since the ball bearing 4, the one-way clutch 3, and the roller bearing 5 are assembled in this order, good assembling performance can be secured if the radial clearance of the roller bearing 5 is set to be large.

The inner peripheral surface of the pulley 1 is circular and the rotor shaft 2
If the wedge-shaped space is formed by providing the cam surface 21 on the outer peripheral surface of the roller, it becomes advantageous in the free state that the rollers 13 are less likely to move toward the side of the wedge-shaped space with a large spacing due to the centrifugal force of rotation. . However, the cam surface 10 may be provided on the pulley 1 or the outer ring element side.

Further, like the pulley unit C shown in FIG. 9, a structure in which the pulley 1 and the rotor shaft 2 are not used as the inner and outer rings of the one-way clutch 3, the ball bearing 4 and the roller bearing 5 is also included in the present invention. included. In this example, the one-way clutch 3 and the ball bearing 4 and the bearing 5 are equipped with inner rings 60, 61 and 62 and outer rings 63, 64 and 65, respectively. The outer ring 63 of the one-way clutch 3 extends long on both sides in the axial direction, and the outer rings 64 and 65 of the ball bearing 4 and the bearing 5 are fitted and fixed to the inner circumference of this extended portion by press fitting. I have to. Even in such a structure, the relationship between the radial clearances of the ball bearing 4 and the bearing 5 is the same as in the above-described embodiment. In this structure, the cage 12 of the one-way clutch 3 is provided with radially inwardly projecting pieces 12d at two locations on the circumference, and notches 60a at the two locations on the end surface of the inner ring 60, respectively. The cage 12 and the roller 13 are axially positioned by engaging with each other.

In this embodiment, by setting the residual radial clearance of the ball bearing small, rattling in the radial and axial directions of the ball bearing is reduced. Therefore, the pulley and the rotor shaft can be integrated at a high level to improve the rigidity against moment load. In addition, because the ball bearings can reduce the degree of freedom of the wedge member of the one-way clutch, the behavior of rolling elements such as balls and rollers, which are wedge members, can be stabilized, and the micro-slip of the wedge member can be reduced. It will be possible. As a result, the operation of the one-way clutch is stabilized, and the durability of the one-way clutch and eventually the pulley unit is improved.

[0057]

As described above, according to the present invention,
The axial clearance of the ball bearing becomes smaller. by this,
The axial deviation between the pulley and the shaft body is reduced. As a result, the inclination of the pulley unit due to the belt load is suppressed, which suppresses damage to the one-way clutch and the bearing, heat generation, a reduction in the life of the lubricant, and vibration and noise of the belt.

[Brief description of drawings]

FIG. 1 is a sectional view of a pulley unit according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line (2)-(2) of FIG.

FIG. 3 is a perspective view showing a rotor shaft and a one-way clutch holder shown in FIG. 1;

4 is a perspective view of a cage of the deep groove ball bearing shown in FIG. 1. FIG.

FIG. 5 is an explanatory view showing a locked and free state of the one-way clutch roller.

FIG. 6 is a sectional view of a pulley unit according to another embodiment of the present invention.

7 is a perspective view showing a rotor shaft and a one-way clutch retainer shown in FIG. 6;

FIG. 8 is a graph showing the relationship between the residual radial clearance of a ball bearing and its life.

FIG. 9 is a sectional view of a pulley unit according to still another embodiment of the present invention.

FIG. 10 is a sectional view of a conventional pulley unit.

FIG. 11 is a sectional view of a deep groove ball bearing.

FIG. 12 is an explanatory diagram of a residual radial gap.

FIG. 13 is an explanatory diagram of an axial gap.

[Explanation of symbols]

1 pulley 2 rotor shaft 3 one-way clutch 4 Deep groove ball bearing 5 needle roller bearings

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F16D 41/06 F16D 41/06 F

Claims (14)

[Claims] 1. A pulley, a shaft body which is rotatable relative to the pulley and which is concentrically arranged inside the pulley, and an annular space interposed between the pulley and the shaft body. A directional clutch and a ball bearing provided axially adjacent to the one-way clutch in the annular space, and the orbital curvatures of the inner and outer rings of the ball bearing are both set to 50.5% or more and 52.0% or less. The pulley unit that is used. 2. The residual radial clearance of the ball bearing is 20 μm.
The pulley unit according to claim 1, wherein the pulley unit is set to be less than m. 3. The ball bearing is disposed on one side of the one-way clutch in the annular space, while the roller bearing is disposed on the other side of the one-way clutch, and the residual radial of the ball bearing is disposed. The pulley unit according to claim 1 or 2, wherein the clearance is set to be smaller than the residual radial clearance of the roller bearing. 4. A pulley, a shaft body that is rotatable relative to the pulley and is concentrically arranged inside the pulley, and is interposed in an annular space between the pulley and the shaft body. A pulley unit comprising a one-way clutch and a ball bearing provided adjacent to each other in the axial direction of the one-way clutch in the annular space, wherein the residual radial clearance of the ball bearing is set to less than 20 μm. 5. A residual radial of the ball bearing, wherein the ball bearing is arranged on one side of the one-way clutch and the roller bearing is arranged on the other side of the one-way clutch in the annular space. The pulley unit according to claim 4, wherein the clearance is set to be smaller than the residual radial clearance of the roller bearing. 6. A pulley, a shaft body that is rotatable relative to the pulley and that is concentrically arranged inside the pulley, and an interposition in an annular space between the pulley and the shaft body. A directional clutch and a ball bearing provided axially adjacent to the one-way clutch in the annular space, and the raceway curvatures of the inner and outer rings of the ball bearing are both set to 50.5% or more and 51.0% or less. The pulley unit that is used. 7. A pulley, a shaft body which is rotatable relative to the pulley and which is concentrically arranged inside the pulley, and an annular space interposed between the pulley and the shaft body. A directional clutch and a ball bearing provided axially adjacent to the one-way clutch in the annular space, and the orbital curvatures of at least one of the inner ring and the outer ring of the ball bearing are both 50.5% or more and 51.0% or more. % And the residual radial clearance is set to less than 20 μm, the pulley unit. 8. A residual radial of the ball bearing, wherein the ball bearing is arranged on one side of the one-way clutch and the roller bearing is arranged on the other side of the one-way clutch in the annular space. The pulley unit according to claim 6 or 7, wherein the clearance is set to be smaller than the residual radial clearance of the roller bearing. 9. A pulley, a shaft body which is rotatable relative to the pulley and which is arranged concentrically inside the pulley, and an axially intermediate region of an annular space between the pulley and the shaft body ( A one-way clutch mounted in a one-way clutch mounting area), and one side area of the one-way clutch in the annular space.
A ball bearing arranged in (ball bearing mounting region), and the other side region of the one-way clutch in the annular space.
And a roller bearing arranged in the (roller bearing mounting region), wherein the residual radial clearance of the ball bearing is set smaller than the residual radial clearance of the roller bearing. 10. The residual radial clearance of the ball bearing is −2.
The pulley unit according to claim 9, wherein the pulley unit is set in a range of 0 to 25 µm. 11. The residual radial clearance of the roller bearing is 5
To 9 to 10 μm.
The pulley unit described in. 12. The shaft body is supported in a cantilevered state, the ball bearing is arranged on the base end side of the shaft body, and the roller bearing is arranged on the free end side of the shaft body. The pulley unit according to any one of claims 9 to 11. 13. The shaft body serves as each inner ring of the one-way clutch, the ball bearing and the roller bearing, and the pulley serves as each outer ring of the one-way clutch, the ball bearing and the roller bearing. The pulley unit according to any one of claims 9 to 12, which is also used. 14. A raceway groove of a ball group included in the ball bearing is provided in the ball bearing mounting area on the inner peripheral surface of the pulley, and the other area is formed in a cylindrical shape, The raceway groove of the ball group in the ball bearing mounting area,
14. The pulley unit according to claim 13, wherein flat cam surfaces are respectively provided at several places on the circumference of the one-way clutch mounting area of the shaft body, and the roller bearing mounting area is formed in a cylindrical shape. .