JP2006336700A - One-way clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a one-way clutch increasing the life of a sprag by minimizing the damage of the sprag. <P>SOLUTION: The profile of the sprag is so designed that a strut angle increases from α<SB>i</SB>to α<SB>j</SB>as a sprag height increases from an engagement start position where a sprag height is Hi to a sprag height equal to a first height H<SB>j</SB>, and the strut angle is decreased from α<SB>j</SB>to α<SB>l</SB>as the sprag height increases from the first height H<SB>j</SB>to a second height H<SB>l</SB>. The profile of the sprag is set so that the strut angle is increased more than α<SB>l</SB>as the sprag height increases more than the second height H<SB>l</SB>. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a one-way clutch.

  In order to transmit torque efficiently, the conventional sprag-type one-way clutch monotonically increases the strat angle (defined below) as the sprag height (defined below) increases from the position where sprag engagement begins. It is supposed to be.

However, with the conventional sprag type one-way clutch, the strat angle increases monotonously as the sprag height increases from the position where sprag engagement begins, so the transmission torque capacity is excessively larger than necessary. Thus, there is a problem that the sprags are easily damaged and the life of the sprags is short.
JP 2003-21171 A

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a one-way clutch in which a sprag is not easily damaged and has a long sprag life.

In order to solve the above problems, the one-way clutch of the present invention is
Inner ring,
Outer ring,
A sprag disposed between the inner ring and the outer ring,
The sprag is
Contour in which the strat angle increases as the sprag height increases from the first sprag engagement position to the first height, and decreases as the sprag height increases from the first height to the second height. It is characterized by having.

  The sprag height and strat angle are defined as follows.

として定義する。 As shown in FIG. 1, the contact circle radius of the sprag 1 at the contact point A with the inner ring 2 of the sprag 1 is r _i, and the contact circle radius of the sprag 1 at the contact point B with the outer ring 3 of the sprag 1 is r _0. The inner ring side sprag inner cam rotation angle is φ, and the outer ring side cam surface at the contact point B between the contact ring center O _i of the inner ring side cam surface at the contact point A with the inner ring 2 of the sprag 1 and the outer ring 3 of the sprag 1 is shown. When the distance from the contact circle center O ₀ is 1, the sprag height H is

Define as

Further, the strut angle is determined by the line segment connecting the contact point A with the inner ring 2 of the sprag 1 and the contact point B with the outer ring 3 of the sprag 1 and the inner ring side cam surface at the contact point A with the inner ring 2 of the sprag 1. It is defined as an angle α formed by a line segment connecting the contact circle center O _i and the contact point A between the inner ring 2 of the sprag 1.

  Further, the phrase “the strat angle increases as the sprag height increases to the first height” is not limited to the case where the strat angle increases monotonously as the sprag height increases to the first height. It is assumed that the stratified angle is partially constant as the height increases to the first height, the stratified angle does not decrease, and the stratified angle increases as a whole.

  Similarly, the phrase “the strat angle decreases as the sprag height increases from the first height to the second height” is the same as the stratification as the sprag height increases from the first height to the second height. Not only when the angle decreases monotonically, but also as the sprag height increases from the first height to the second height, the strat angle is partially constant and the strat angle does not increase, and The case where the strat angle is decreased as a whole is also included.

  According to the present invention, the sprag has a strat angle that increases as the sprag height increases from the first sprag engagement position to the first height, and the sprag height increases from the first height to the second height. Since it has a contour in which the strat angle decreases as it increases, the response to the input torque when the sprag height is not less than the first height and not more than the second height can be relaxed as compared with the conventional case. Therefore, even if an excessive impact torque is input, when the sprag height is not less than the first height and not more than the second height, the torque received by the sprag from the outer ring and the inner ring can be reduced. . Therefore, breakage of the sprags can be prevented and the life of the sprags can be extended.

  In one embodiment of the one-way clutch, the sprag has a contour in which the strat angle increases as the sprag height increases from the second height.

  The phrase “the strat angle increases as the sprag height increases from the second height” is used not only when the strat angle increases monotonously as the sprag height increases from the second height. As the height increases from the second height, the strat angle is partially constant, the strat angle does not decrease, and the strat angle increases in a region where the sprag height is greater than or equal to the second height. This includes cases where

  According to the embodiment, since the sprag has a contour in which the strat angle increases as the sprag height increases from the second height, the maximum torque that can be loaded by the one-way clutch is increased. be able to.

  According to the one-way clutch of the present invention, the sprag increases as the sprag height increases to the first height from the position where the sprag starts to mesh, and the sprag height increases from the first height to the first height. Since it has a contour in which the strat angle decreases as it increases to 2 heights, the sprag height is not less than the first height and not more than the second height compared to the prior art even if an excessive impact torque is input. In some cases, the torque received by the sprags from the outer ring and the inner ring can be reduced, damage to the sprags can be prevented, and the life of the sprags can be extended.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 2 is a diagram illustrating a relationship (strat angle curve) between the sprag height and the strat angle of the one-way clutch according to the embodiment of the present invention.

  In addition, the point shown by i in FIG. 2 is a figure which shows the position of the meshing start of the said sprags.

As shown in FIG. 2, in this embodiment, in accordance with sprag height sprag height from engagement point i of sprags H _i is increased to H _j, strut angle is increased monotonically from alpha _i to alpha _j Yes. Further, as the sprag height increases from H _j to H _k , the strat angle decreases monotonously from α _j to α _k . Furthermore, as the sprag height increases from H _k to H _l , the strat angle becomes a constant value α _k = α _l . Further, as the sprag height increases from H _l , the Strat angle increases monotonously from α _k = α _l . H _j is the first height, and H _l is the second height.

  A one-way clutch in which the sprag height and the strat angle are as shown in FIG. 2 is designed as follows.

  First, derivation of an expression that expresses the relationship between the strat angle α and the sprag height H using the design value of the sprag is performed with reference to FIG.

As described above, the contact circle radius of the sprag 1 at the contact point A with the inner ring 2 of the sprag 1 is r _i , the contact circle radius of the sprag 1 at the contact point B with the outer ring 3 of the sprag 1 is r ₀ , and the inner ring The side sprag inner cam rotation angle is φ, and the contact circle of the outer ring side cam surface at the contact point B between the contact ring center O _i of the inner ring side cam surface at the contact point A with the inner ring 2 of the sprag 1 and the outer ring 3 of the sprag 1. When the distance from the center O ₀ is 1, the sprag height H is defined by the following equation (1).

Further, as is clear from the relationship shown in FIG. 1, the strat angle α defined above, the distance l between the contact circle center O _i and the contact circle center O ₀ , and the sprag height H are as follows. In the meantime, the relationship shown in the following formula (2) is established.

Therefore, since the following formula (3) is derived from the formula (1),

The following formula (4) is derived from the formula (2) and the formula (3).

Therefore, by using the following formula:

The following formula (5) is derived.

The formula (5), the strut angle curve representing the strut angle in sprag height, an equation expressed by the l and r _s is the design value of the sprag. The formula (5), by adjusting the l and r _s, which means that can achieve the goals of the strut angle curve.

  A specific calculation example is shown below.

In the above formula (5), the combination of one l, r _s, so can only be achieved monotonous increase or monotonous decrease curve, if the trend of the curve is changed to change its l the change point as a boundary, r _s . Therefore, the design in one of sprag plurality of l, r _s i.e. a plurality of cam surfaces.

When designing the Strat angle curve of FIG. 2, the coordinates of the points i, j,. For example, when the A section shown in FIG. 2 is realized, by substituting the coordinates (H _i , α _i ) and (H _j , α _j ) of the i point and the j point into the equation (5), the following equation ( 6) and (7) are obtained.

The above formula is two undetermined constants l, since two independent equations for r _s, calculated by, l, r _s is determined. Specifically, to determine l, a r _s by numerical calculation using a computer.

The same calculation is performed for B section, C section, and D section shown in FIG. Specifically, to set the coordinate as shown in Table 1 below, l calculated in each section, by a design value r _s, to achieve a strut angle curve shown in FIG.
[Table 1]

In Table 1 above, H _i <H _j <H _k <H _l <H _m and α _k = α _l <α _i <α _j <α _m . H _m is the sprag height in the vicinity of the region where the sprag rollover occurs, and the coordinates (H _m , α _m ) of the end point m having the largest sprag height are the strat angle of the conventional one-way clutch. It is set to be equivalent to the coordinates through which the curve (variation of strat angle with respect to sprag height) passes.

According to the one-way clutch of the above embodiment, as shown in FIG. 2, sprags, increases from meshing starting position for the sprag the sprag height is H _i to H _j sprag height is first height As the strat angle increases from α _i to α _j and the sprag height increases from H _j to the second height H _l , the strat angle decreases from α _j to α _l Compared with the prior art, the response to the input torque when the sprag height is H _j or more and H ₁ or less can be relaxed. Therefore, even if an excessive impact torque is input, the torque received by the sprags from the outer ring and the inner ring when the sprag height is not less than H _{j and not} more than H ₁ can be reduced. Therefore, breakage of the sprag can be prevented and the life of the sprag can be extended.

Further, according to the above-described embodiment, the sprag has a contour in which the strat angle increases from α _l as the sprag height increases from the second height H _l, so that the one-way clutch can be loaded. Maximum torque can be increased.

Further, according to the above embodiment, the conventional unidirectional clutch strat angle curve (variation of the strat angle with respect to the sprag height) passes through the coordinates (H _m , α _m ) of the end point m having the largest sprag height. Since the coordinates are set to be equal to the coordinates, the maximum torque that can be loaded by the one-way clutch does not decrease compared to the conventional case. In other words, since the strat angle near the area where the sprag rollover occurs is set equal to the strat angle of the conventional one-way clutch, the maximum torque that the one-way clutch can load compared to the conventional one. Will not drop.

In the above embodiment, the strat angle is set to a constant value α _k (= α _l ) for a certain period while the sprag height is increased from H _k , that is, for a period in which the sprag height is not less than H _{k and not} more than H _l. Was set to be. However, in the present invention, the sprag is monotonically decreased as the sprag height increases from the first height to the second height, and the sprag height increases from the second height. The strat angle may increase monotonously.

It is a figure explaining sprag height and a strat angle. It is a figure which shows the relationship between the sprag height and strat angle of the one-way clutch of one Embodiment of this invention.

Explanation of symbols

At the contact point between 1 sprag 2 inner ring 3 outer r _i the inner race and the contact radius r ₀ sprag contact circle radius φ inner side sprags within the inner ring of the cam rotation angle O _i sprag at the contact point between the outer ring of at the point of contact of the sprag Center of contact circle of inner ring side cam surface Contact circle center of outer ring side cam surface at the point of contact of O ₀ sprag with outer ring l Distance between O _i and O ₀ H Sprag height H _i First height H _l Second height Α Strat angle

Claims (2)

Inner ring,
Outer ring,
A sprag disposed between the inner ring and the outer ring,
In the sprag, the strat angle increases as the sprag height increases from the position where the sprag starts to mesh to the first height, and the strat angle increases as the sprag height increases from the first height to the second height. One-way clutch characterized in that it has a decreasing contour. The one-way clutch according to claim 1,
The one-way clutch according to claim 1, wherein the sprag has a contour in which the strat angle increases as the sprag height increases from the second height.

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