JP4321982B2 - One-way clutch - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a one-way clutch, and in particular, to reduce the size and increase the torque.
[0002]
[Prior art]
As a one-way clutch used in a drive unit of an electric device or office device, the one shown in FIG. 11 is conventionally known (for example, see Japanese Patent Application Laid-Open No. 9-89011). This one-way clutch is provided with several roller storage portions 34 on the inner surface of the outer ring 32 fitted around the shaft 31, and a predetermined wedge angle between the shaft 31 and the bottom surface of each roller storage portion 34. A cam surface 35 is provided. Further, a spring accommodating portion 36 is provided at the enlarged side end portion of the roller accommodating portion 34.
[0003]
The roller 37 housed in the roller housing portion 34 is pressed against the spring member 38 housed in the spring housing portion 36, and the roller 37 is biased in the narrow direction of the housing portion 34, thereby stabilizing the action of the roller 37. I am letting.
[0004]
An outer ring 39 is fitted around the outer ring 32 in a state in which the rotation is stopped. The outer ring 39 closes one end surface of the roller storage portion 34 in the axial direction at one end surface thereof. The other end face is closed by a lid member (not shown).
[0005]
The one-way clutch is used by incorporating the outer ring 39 into a boss portion of a rotating member such as a gear, and when the shaft 31 and the outer ring 32 rotate in a relatively fixed direction (see arrow A in the figure) The roller 37 engages and locks on the narrow side of the storage portion 34, and the shaft 31 and the torque limiter are integrated to transmit torque. When the rotation direction is the reverse direction, the roller 37 moves to the enlargement side of the storage portion 34, so that the roller 37 becomes free and the one-way clutch runs idle, and torque transmission is interrupted.
[0006]
[Problems to be solved by the invention]
In various devices in which the above one-way clutch is used, it is required to reduce the size and increase the torque of the one-way clutch as the device body becomes smaller. However, since the outer diameter of the conventional structure is always larger than the diameter of the shaft 31, there is a certain limit to downsizing. In addition, the smaller the size, the more difficult it is to manufacture the parts, and the torque value is usually small, and it is difficult to simultaneously achieve ease of manufacturing and higher torque as well as downsizing.
[0007]
Therefore, the present invention focuses on the structure of the internal member, simplifies the structure, and reinforces the rolling element storage portion, thereby reducing the size of the one-way clutch and increasing the ease of manufacture. The task is to achieve torque.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides an inner member, an outer ring fitted to the inner member so as to be relatively rotatable, a rolling element interposed between the inner member and the outer ring, and the rolling element in one direction. A rolling member storage portion having a predetermined wedge angle between opposing surfaces of the inner member and the outer ring, and a spring storage portion communicating with the rolling body storage portion. In the one-way clutch in which the rolling member housed in the rolling element housing portion is urged in the narrow direction of the housing portion by the spring member housed in the inner member, the internal member has a notched portion and a shaft on one shaft. The cut-out circular part has a rectangular flat surface formed by cutting out from the one end part to the middle of the shaft in the length direction, and the cut-off circle having a subarc at one end part. A rounded end having an end surface and having a dominant arc on the end surface of the shaft portion on the flat surface side Has, the segmental portion is provided rolling elements accommodating portion and the spring housing portion of the formation and the cam surface of the rolling member accommodating portion, a spring seat of the spring housing portion on said flat surface of said segmental portion The configuration was adopted.
[0009]
The one-way clutch having the above structure is used by connecting one end portion of an inner member to a shaft, and the inner member integral with the shaft rotates relative to the outer ring in a fixed direction, so Locking by biting occurs, and torque is transmitted. Further, due to the rotation in the reverse direction, the rolling element becomes free, and the transmission of torque is interrupted. Since the rolling element storage portion and the spring member storage portion are provided in the non-circular portion of the internal member, the size can be significantly reduced compared to the conventional one. In addition, since the cam surface and the spring seat are formed on the same flat surface, the shape of the internal member is simplified and the manufacture is facilitated.
[0010]
In addition, although the number (it is equal to the number of rolling elements) of said rolling-element accommodating part and a spring member accommodating part is determined according to load capacity, only one set may be provided.
[0011]
A configuration in which a reinforcing plate is installed on the flat surface and the cam surface and the spring seat are formed on the reinforcing plate can be employed. According to this configuration, the cam surface can sufficiently withstand the surface pressure received from the rolling element during locking. For this reason, while the allowable torque value can be set high, the internal member itself can be manufactured by a method that is easy to mold, such as resin molding or sintering.
[0012]
Moreover, the structure which provided the control part which blocks | prevents backward beyond a fixed level to said spring member is employable . By this restricting portion, it is possible to prevent the rolling element from being locked during idling.
[0013]
The inner member is formed by a shaft integrated portion and a lid portion in which the shaft is integrated with the notch circle portion, and the shaft integrated portion and the lid portion support radial inner surfaces of both ends of the outer ring. A configuration in which a bearing is formed can be employed.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments will be described below with reference to the accompanying drawings. The one-way torque limiter according to the first embodiment shown in FIGS. 1 and 2 includes an inner member 1, an outer ring 2, rollers 3, and a spring member 4.
[0015]
The internal member 1 is configured by a combination of a shaft integrated member 1a and a lid member 1b. The shaft integrated member 1a is formed by forming a missing circle portion 5 and a shaft portion 6 on one shaft. The notch circle part 5 has a rectangular flat surface 7 formed by cutting away from one end part to the middle of the shaft in the length direction, and has a notch circular end face 8 at one end part. In addition, a non-circular end surface 9 is formed on the end surface of the shaft portion 6 on the flat surface 7 side. The non-circular end surface 8 and the non-circular end surface 9 have a size relationship in which the former has a subarc 11 and the latter has a dominant arc 12. The flat surface 7 is a common surface that forms the cam surface 13 and the spring seat 14 (see FIG. 4A), as will be described later.
[0016]
The lid member 1b is provided with a flange portion 15 having a diameter larger than that of the shaft portion 6 and a notched circular convex portion 16 matching the end surface shape of the notched circular end surface 9 on the inner surface side thereof. In addition, a cutout circular hole 17 that matches the cutout circular end surface 8 is provided on the cutout circular side of the cutout convex portion 16.
[0017]
The outer ring 2 has a cylindrical shape that is rotatably fitted to the inner member 1, and is provided with a plurality of longitudinal ribs 18 for preventing rotation on the outer diameter surface thereof.
[0018]
When the shaft integrated portion 1a of the inner member 1 is fitted into the inner diameter surface of the outer ring 2, a radial bearing 19a that supports one end portion of the outer ring 2 is formed by the outer diameter surface of the shaft portion 6 (see FIG. 1). The roller 3 and the spring member 4 are housed in a space surrounded by the inner diameter surface of the outer ring 2 and the flat surface 7 of the shaft-integrating member 1a. Further, in order to prevent them from coming out, A non-circular convex portion 16 is inserted. A radial bearing 19 b that supports the other end portion of the outer ring 2 is formed by the inserted circular convex portion 16 and the outer diameter surface of the circular portion 5.
[0019]
As described above, the shaft integrated member 1 a and the lid member 1 b are inserted into the outer ring 2 with the shaft integrated part 1 a inserted therein, and are rolled into a space between the flat surface 7 and the inner surface of the outer ring 2. In order to insert the lid member 1b after the 3 and the spring member 4 are assembled, they are formed by separate members. Apart from this, an assembly method in which both the members 1a and 1b are combined first, the roller 3 and the spring member 4 are incorporated, and then the spring member 4 is inserted into the outer ring 2 with care so that the spring member 4 does not come off. Can take. When this method is adopted, both the members 1a and 1b can be formed by a single member.
[0020]
Moreover, in FIG. 1, the part which protruded outside from the outer ring | wheel 2 among the axial parts 6 is a part which fulfill | performs the function as an axis | shaft, The length is determined according to a function. Since the part that functions as the shaft is integrated, it is called “shaft integrated member 1a”. However, the part having the function as the shaft is formed separately, and the radial bearing 19a and the missing circle are formed. A member composed of the portion 5 may be provided and connected to the shaft by an appropriate means.
[0021]
The roller 3 is formed to have a diameter slightly smaller than the maximum height of the space formed by the inner diameter surface of the outer ring 2 and the flat surface 7 of the notch 5, and the roller 3 is accommodated by storing the roller 3 in the space. An irregularly shaped void remains on both sides of the plate (see FIG. 3). The occupied portion of the one empty space 3 becomes the roller storage portion 21, and the remaining space becomes the spring storage portion 21 ′. The portion of the flat surface 7 that forms the roller storage portion 21 becomes the cam surface 13, and a predetermined wedge angle α is formed by the cam surface 13 and the inner diameter surface of the outer ring 2.
[0022]
Further, the spring member 4 is formed by bending a rectangular elastic metal plate into a U shape to form a fixing portion 22, and holding the portion between the spring seat 14 and the inner diameter surface of the outer ring 2, The free end portion is pressed against the roller 3, and the roller 3 is urged toward the narrow side of the roller accommodating portion 21, thereby stabilizing the operation.
[0023]
The one-way clutch of the first embodiment is as described above. When the outer ring 2 rotates relative to the inner member 1 in the direction of arrow A (see FIG. 3), the roller 3 is narrowed in the storage portion 21. As a result of moving in the direction (moving from the alternate long and short dash line in FIG. 3 to the solid line state), it bites and locks and transmits torque. When the rotation direction is opposite to the above, the roller 3 moves in the enlargement direction, so that the lock is released, the roller 3 is idled, and the torque transmission is interrupted.
[0024]
When the roller 3 moves in the enlargement direction, the roller 3 compresses the spring member 4 and retreats to the range indicated by the angle β beyond the most enlarged portion. In this case, if the reverse amount becomes larger than a certain amount, a reverse wedge angle α is generated on the spring accommodating portion 21 ′ side, so that the roller 3 that has started idling may be locked.
[0025]
If the spring force of the spring member is set large in order to prevent the roller 3 from being locked during idling, the original function of the spring member is exerted such that an appropriate urging force is applied to stabilize the operation of the roller 3. Is difficult. In addition, a means for providing a rib for restricting the backward movement of the roller 3 between the cam surface 13 and the spring seat 14 can be considered, but the flatness of the flat surface 7 is impaired, so that the ease of manufacture is hindered.
[0026]
For this reason, in the present invention, in order to prevent the roller 3 from being locked at the time of idling, the spring member 4 is prevented from being bent more than a certain amount in order to prevent the roller 3 from being locked during idling. The portion 23 is provided (see FIGS. 4A to 5B).
[0027]
FIG. 4A shows that the restricting portion 23 is formed by bending the free end portion of the fixing portion 22 bent in the U shape of the spring member 4 inward and butting it against the other side. The flexibility to the back is limited. In FIG. 4B, a restricting portion 23 is formed by inserting a shaft into the U-shaped curved portion of the spring member 4, thereby limiting the flexibility of the spring member 4 to the rear in the same manner as described above. Is.
[0028]
5 (a), a restriction portion 23 by folding is provided at the free end of the spring member 4, and the distance between the roller 3 and the inner surface of the outer ring 2 is narrowed so that the backward movement of the roller 3 is restricted. It is a thing. FIG. 5 (b) shows a structure in which a restricting portion 23 for preventing the spring member from being bent more than a certain amount is formed by bending the distal end portion of the fixing portion 22 of the spring member 4 toward the inside of the free end portion. It is.
[0029]
By providing the restriction member 23 as described above on the spring member 4, the common surface forming the cam surface 13 and the spring seat 14 is held as the flat surface 7, and the biasing force on the roller 3 is substantially changed. In addition, it is possible to prevent the roller 3 from retreating beyond a certain level during idling and to prevent the lock.
[0030]
Next, in the one-way clutch of the second embodiment shown in FIGS. 6 to 8, a metal reinforcing plate 24 having a predetermined hardness is placed on the flat surface 7 in the one-way clutch of the first embodiment. The cam surface 13 and the spring seat 14 are formed on the surface of the reinforcing plate 24. The reinforcing plate 24 is formed of a metal plate such as an iron plate and bonded to the flat surface 7. By installing such a reinforcing plate 24, the shaft-integrated member 1a of the internal member 1 is an easily formed material such as resin or sintered alloy, but the rollers 3 Can withstand the high surface pressure received from Since other configurations and operations are the same as those in the first embodiment, the same reference numerals are given to the same portions, and descriptions thereof are omitted.
[0031]
In addition, the examples (refer FIG. 9 (a) to FIG.10 (b)) which provide the control part 23 in the spring member 4 are the same as that of the said case.
[0032]
【The invention's effect】
Since the present invention is as described above, the following effects can be obtained.
(1) Since the cam surface that receives the rolling element and the spring seat that receives the spring member are formed on a common flat surface, the internal member can be easily manufactured. Moreover, since it is a flat surface and does not have directionality, the internal member can be used as a common part for one-way clutches having different locking directions.
(2) By installing the reinforcing plate on the flat surface, the torque can be increased, and the internal member can be manufactured by a method that facilitates molding of a resin or a sintered alloy.
(3) By providing the restricting portion on the spring member, it is possible to prevent locking during idling without substantially affecting the urging function for the rolling element.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a first embodiment. FIG. 2 is an exploded perspective view of the same. FIG. 3 is a cross-sectional view taken along line XX of FIG. FIG. 5A is a sectional view of a modified example. FIG. 6B is a sectional view of the second embodiment. FIG. 7 is an exploded perspective view of the same. 8 is a cross-sectional view taken along line YY in FIG. 6. FIG. 9A is a cross-sectional view of a modified example. FIG. 10B is a cross-sectional view of another modified example. FIG. 10A is a cross-sectional view of the modified example. FIG. 11 is a cross-sectional view of a modified example of FIG.
DESCRIPTION OF SYMBOLS 1 Inner member 1a Shaft integrated member 1b Cover member 2 Outer ring 3 Roller 4 Spring member 5 Round part 6 Shaft part 7 Flat surface 8 Round circular end surface 9 Round circular end surface 11 Inferior arc 12 Superior arc 13 Cam surface 14 Spring seat 15 Flange Part 16 Missing circular convex 17 Missing circular hole 18 Rib 19a Radial bearing 19b Radial bearing 21 Roller accommodating part 21 'Spring accommodating part 22 Fixing part 23 Restricting part 24 Reinforcing plate

Claims (4)

An inner member (1), an outer ring (2) fitted to the inner member (1) in a relatively rotatable manner, a rolling element (3) interposed between the inner member (1) and the outer ring (2), and It consists of a spring member (4) that urges the rolling element (3) in one direction, and the internal member (1) is constituted by a combination of a shaft integrated member (1a) and a lid member (1b). 1) Rolling element accommodating portion having a predetermined wedge angle (alpha) between the facing surfaces of the _second shaft integral member (1a) and outer ring (2) and (21), the spring through the rolling member accommodating portion (21) A storage part (21 ′) is provided, and the rolling element (3) stored in the rolling element storage part (21) is accommodated in the storage part (21) by a spring member (4) stored in the spring storage part (21 ′). One direction formed by urging the lid member (1b) into the end of the shaft integrated member (1a) to prevent the rolling element (3) and the spring member (4) from coming off. In the clutch,
The shaft integrated member (1a) of the internal member (1) is formed by forming a notch (5) and a shaft (6) on one shaft, and the notch (5) It has a rectangular flat surface (7) formed by cutting the length from one end to the middle in the length direction, and has a rounded end surface (8) having an inferior arc (11) at one end, An end face (9) having a dominant arc (12) on the end face on the flat face (7) side of the shaft portion (6) ;
One rolling element (3) having a diameter slightly smaller than the maximum height of the space surrounded by the inner diameter surface of the outer ring (2) and the flat surface (7 ) of the notch (5 ) is accommodated, and the rolling element ( 3) A pair of the above-mentioned rolling element storage part (21) and one spring storage part (21 ') by the remaining space and one space generated on both sides and the occupied part of the rolling element (3). Only provided
The cam surface (13) of the rolling element storage portion (21) and the spring seat (14) of the spring storage portion (21 ′) are formed on the common flat surface (7) of the cutout portion (5). ,
The spring member (4) is formed of an elastic metal plate curved in a U-shape, and a fixing portion (22) at one end thereof is held between the spring seat (14) and the inner diameter surface of the outer ring (2). The one-way clutch characterized by pressing the free end of the other end against the rolling element (3) .   The reinforcing plate (24) is installed on the flat surface (7), and the cam surface (13) and the spring seat (14) are provided on the reinforcing plate (24). One-way clutch as described. The one-way clutch according to claim 1 or 2, characterized in that the spring member (4) is provided with a restricting portion (23) for preventing backward bending beyond a certain level . Radial bearing for supporting the both end portions inside diameter surface of the shaft integral portion (1a) and the cover member the outer ring in (1b) (2) of the inner member (1) of the (19a), that the formation of the (19b) The one-way clutch according to any one of claims 1 to 3, wherein

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