JP2002005198A - Reverse input shut-off clutch unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a casing structure and the attaching/detaching work, and miniaturize a clutch unit. SOLUTION: A clutch part A comprises an axle 1 and a clutch inner ring 2 as input side members, a clutch outer ring 3 and a housing 4 as output side members, a roller 5 as a torque transmission member, a holder 6, a centering spring 7 as an elastic member, a resistance ring 8 and a fixed ring 9 as stationary side members, and a viscous fluid, for example, grease 10, interposed between the resistance ring 8 and the holder 6. The axle 1 is connected to a drive source, and rotatably supported on the casing B on one end side of the clutch part A in a cantilever manner. A means for increasing the viscous resistance is provided on one end of the holder 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reverse input block having a function of transmitting forward / reverse rotation torque from an input side to an output side, while blocking forward / reverse rotation torque from an output side and not transmitting it to the input side. The clutch unit can be used for an electric slide door, an electric curtain, an electric auxiliary wheelchair, an electric auxiliary cart, and the like.

[0002]

2. Description of the Related Art For example, courier trucks tend to be of an electric assist type due to an increase in loads, an aging of courier workers, and the advancement of women. In this case, it is preferable that electric assist can be performed for both forward and backward movements, and that manual operation can be performed when the drive source is stopped. Such a function can be realized, for example, by using a clutch unit described in Japanese Patent Application Laid-Open No. H8-177878 proposed by the present applicant for an axle portion. The clutch unit described in the same publication has a viscous fluid such as silicone oil interposed between a retainer holding a torque transmitting member and a stationary rotating member fixed in a stationary system in a rotational direction, and an input rotating member. And the retainer are connected by a centering spring, and the forward / reverse rotation torque from the input rotary member is transmitted to the output rotary member through the rotation delay of the retainer due to the viscous shear resistance of the viscous fluid, and the rotation from the output rotary member. The forward / reverse rotation torque cuts off the output system rotating member through the centering action of the retainer by the centering spring.

[0003]

SUMMARY OF THE INVENTION The above-mentioned JP-A-8-1
In 77878, a structure in which both ends of a clutch portion are supported at both ends by a casing is shown as an embodiment. However, there is a demand for simplification of the casing structure and simplification of mounting and dismounting operations. There is also a demand for compact clutch units and improved durability.

An object of the present invention is to simplify the casing structure of this type of clutch unit and to simplify the mounting and dismounting operations.

Another object of the present invention is to reduce the size of the clutch unit.

Another object of the present invention is to prevent foreign matter from entering the inside of the clutch and improve the durability of the clutch unit.

[0007]

In order to achieve the above object, the present invention provides an input member, an output member, and an intervening member between an input member and an output member. A torque transmission member that can be engaged and disengaged in the rotational direction, a retainer that holds the torque transmission member, and controls engagement and disengagement of the torque transmission member through relative rotation with respect to the input side member;
An elastic member that connects the input-side member and the retainer in the rotational direction, a stationary-side member, a clutch unit having a viscous fluid interposed between the retainer and the stationary-side member, and an input-side member of the clutch unit. And a casing to which the stationary member is fixed rotatably at one end side, and forward / reverse rotation torque from the input side member is transmitted to the output side member, and forward / reverse rotation torque from the output side member is provided. A configuration is provided in which the rotational torque is interrupted between the input side member and the rotational torque.

Here, the “input side member” is directly (directly connected to the drive source) or indirect (gear,
(Connected to a driving source via a power transmission means such as a chain or a belt). The input side member has a clutch surface on which the torque transmitting member engages and disengages, and includes a clutch surface directly provided on the shaft member, a ring member having the clutch surface fixed to the shaft member, and the like. It is.

The "output-side member" is a member that rotates integrally with the input-side member and idles with respect to the input-side member through the engagement and disengagement of the torque transmitting member. The output-side member has a clutch surface that engages and disengages with the torque transmission member, and includes a member in which the clutch surface is directly provided on the housing, a member in which a ring-shaped member having the clutch surface is fixed to the housing, and the like.

The "torque transmitting member" includes a roller-shaped member, a ball-shaped member, a sprag-shaped member, and the like.

The "viscous fluid" imparts viscous resistance (rotational resistance) to the retainer when the retainer relatively rotates with respect to the stationary member, and causes the retainer and the input member to rotate relative to each other. Rotation delay of the vessel). Here, the viscous resistance (rotational resistance) is obtained due to the viscous shear resistance and stirring resistance of the viscous fluid. The viscous fluid is not particularly limited as long as such a function can be obtained. For example, a highly viscous fluid such as silicone oil or grease can be used. If grease is used as the viscous fluid, even if it leaks from the sealed part for some reason, the adverse effect (denaturation and deterioration) due to mixing with the lubricating grease inside the clutch (lubricating grease sealed in the power transmission part) is eliminated, or , Can be suppressed. In particular, by making the grease as a viscous fluid and the lubricating grease sealed inside the clutch the same, or
Preferred results can be obtained by making them the same kind with little aggression to each other.

The casing supports the input-side member in a cantilever manner at one end of the clutch unit so as to be rotatable, and the stationary-side member is fixed to the casing. Therefore, the structure of the casing is simplified as compared with the conventional configuration, and the attachment / detachment operation is also simplified.

In the above configuration, when the input-side member rotates by receiving the input rotational torque, the retainer connected to the input-side member via the elastic member rotates. At this time, the retainer receives viscous resistance from the viscous fluid interposed between the retainer and the stationary side member. Therefore, the elastic member bends in the rotation direction, and a relative rotation (rotation delay of the retainer) occurs between the retainer and the input-side member. Then, by the relative rotation of the retainer, the torque transmitting member held by the retainer receives a force from the retainer and engages with the input / output side member. Thereby, the rotational torque from the input side member is transmitted to the output side member via the torque transmission member,
The output member rotates integrally with the input member.

When the drive source stops and the rotation of the input-side member and the holder stops, the viscous fluid loses viscous resistance, and the holder rotates relative to the input-side member by the elastic restoring force of the elastic member (see the above description). Relative rotation in the opposite direction),
Both circumferential positions are centered. Then, by the centering of the retainer, the torque transmitting member held by the retainer receives a force from the retainer and separates from the input / output side member. Thereby, the output-side member is released from the input system, and the output-side member can idle with respect to the input-side member.

[0015] In the above structure, the annular recess into which the one end of the retainer is inserted is provided in the stationary member, and the viscous fluid is sealed in the gap between the one end of the retainer and the annular concave of the stationary member. , Relative rotation of cage (switching function)
The necessary viscous resistance can be suitably obtained from one end of the retainer.

In this case, a cylindrical portion is formed at one end of the retainer, and a viscous fluid is filled in a gap between the inner diameter surface, the outer diameter surface, and the end surface and the annular concave portion of the stationary member. Since the viscous resistance acts on the retainer through the three surfaces, even if the axial dimension of the viscous fluid enclosing part is shortened, a sufficient viscous resistance can be obtained. The size in the axial direction can be reduced.

Further, if a plurality of cylindrical portions are radially arranged at one end of the retainer, and a plurality of annular concave portions of the stationary member are also radially arranged corresponding to the respective cylindrical portions, the holding is achieved. For containers, multiple inner diameter surfaces, multiple outer diameter surfaces,
In addition, viscous resistance acts through the plurality of end surfaces, and the axial dimension of the viscous fluid sealing portion can be further reduced.

In addition, the inner diameter surface of the cylindrical portion as described above,
If a plurality of uneven portions are formed on at least one of the outer diameter surface and the end surface, the viscous fluid is agitated by the uneven portions when the retainer rotates, and the stirring resistance increases. This is even more effective in reducing the dimension in the direction. Further, if a disk-shaped portion extending in the radial direction is formed at one end of the retainer, the axial dimension of the viscous fluid sealing portion can be reduced to, for example, about the thickness width of the disk-shaped portion,
The axial size of the clutch unit can be greatly reduced.

Furthermore, by arranging a plurality of disk-shaped portions in the axial direction and arranging a plurality of annular concave portions of the stationary member corresponding to the respective disk-shaped portions in the axial direction, the viscous resistance applied to the retainer can be improved. Therefore, the axial dimension of the viscous fluid sealing portion can be effectively reduced. And
Also in this case, if a plurality of irregularities are formed on at least one of the inner diameter surface, the outer diameter surface, and both end surfaces of the disc-shaped portion, the viscous fluid is stirred by the irregularities when the retainer rotates. The stirring resistance is increased, which is more effective in reducing the axial dimension of the viscous fluid sealed portion.

On the other hand, if a seal portion for sealing the viscous fluid sealed in the gap is provided between one end of the retainer and the annular concave portion of the stationary member, leakage of the viscous fluid can be prevented. , It is possible to always stably obtain a viscous resistance to This seal portion can be configured as a labyrinth seal obtained by making the gap between one end of the retainer and the annular recess minute at the axial end of the viscous fluid sealing portion, or an O-ring or a lip seal, for example. And the like.

Further, if the stationary side member is provided with a storage section for storing a preliminary viscous fluid, even if the viscous fluid leaks (slightly leaks), the leakage by the preliminary viscous fluid in the storage section occurs. Since the amount is appropriately replenished, the shortage of the viscous fluid and the accompanying shortage of the viscous resistance to the retainer can be prevented,
Viscous resistance to the retainer can be more stably obtained.

In the above arrangement, if the stationary side member is provided with a lip which forms a seal between the stationary side member and the output side member, foreign matter such as dust, mud, water and the like hardly enters the inside of the clutch. Detrimental effects such as biting of foreign matter into the clutch and deterioration of the properties of the contact surface due to the foreign matter are avoided, and the durability of the clutch unit is improved. In particular, if the lip is composed of an outer lip that forms a labyrinth seal with the output side member and an inner lip that forms a contact seal with the output side member, the sealing function of the inner lip becomes the outer lip. As a result, a high sealing property is obtained, and the sealing property is maintained for a long time.

[0023]

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

FIG. 1 shows an axle portion of an electric assist cart (electric assist cart) using a reverse input cutoff clutch unit according to a first embodiment of the present invention.

The clutch section A includes an axle 1 and an inner clutch wheel 2 as input members, an outer clutch wheel 3 and a housing 4 as output members, a roller 5 as a torque transmitting member, a retainer 6, and a centering spring as an elastic member. 7,
A resistance ring 8 and a fixed ring 9 as stationary members, and a viscous fluid, for example, grease 10, interposed between the resistance ring 8 and the retainer 6 are provided.

The axle 1 is directly connected to a drive source (not shown) (for example, a drive unit composed of an electric motor and a speed reduction mechanism) or connected via a power transmission means such as a chain. At one end (the left side in the figure: the center side of the axle 1), the casing B is rotatably supported in a cantilever manner via a rolling bearing 11. The rolling bearing 11 is of a sealed type in which seals are attached to both ends or one of the clutch end faces. The clutch inner ring 2 is fitted and fixed to the outer periphery of the axle 1.

The housing 4 is a hub for connecting the wheels 12 in the example shown in FIG. That is, a flange portion 4 a extending in the outer diameter direction is integrally formed on the outer periphery of the housing 4, and the wheel 12 is connected to the flange portion 4 a by the hub bolt 13. A tire 20 is mounted on the wheel 12. The clutch outer ring 3 is fitted and fixed to the inner circumference on one end side of the housing 4. Incidentally, the housing 4 and the wheel 12 may be formed as an integral structure. Also, housing 4
Are two rolling bearings 1 spaced apart in the axial direction.
It is rotatably supported by the axle 1 at 4 and 15. Of the two rolling bearings 14, 15, the rolling bearing 15 located on the outside (the other end side) is of a sealed type in which a seal is attached to both ends or one of the clutch end faces. With such a support structure, it is possible to withstand high-speed rotation and high load. Further, by forming the rolling bearing 11 located at one end of the clutch portion A and the rolling bearing 15 located at the other end of the clutch portion A into a sealed type, dust and
Foreign matter such as mud and water hardly enters.

As shown in FIG. 2A, the retainer 6 has a substantially cylindrical shape, and has a plurality of (same in number as the number of rollers 5) window-shaped pockets 6a for accommodating the rollers 5, and one end thereof. The cylindrical portion 6b formed in the portion has a plurality of uneven portions 6b1.
Is provided at the other end, and a notch-shaped stopper portion 6c for engaging the centering spring 7 is provided. The plurality of pockets 6a and the concavo-convex portions 6b1 are circumferentially arranged at a predetermined pitch.

The resistance ring 8 is made of, for example, rubber or resin, and is fixed to the inner periphery of the fixing ring 9 by a suitable means such as press-fitting or bonding. The resistance ring 8 is provided with an annular concave portion 8a opened to the other end side and an inner lip 8b extending from the other end in an outer diameter inclined direction.

As shown in an enlarged view in FIG. 2B, a cylindrical portion 6b at one end of the retainer 6 is inserted into an annular concave portion 8a of the resistance ring 8, and an inner diameter surface and an outer diameter of the cylindrical portion 6b are formed. Grease 10 as a viscous fluid is sealed in the gap between the face and the end face and the annular recess 8a. In this embodiment, the same grease 10 as the lubricating grease sealed in the power transmission portion (between the clutch inner ring 2 and the clutch outer ring 3 and the roller 5) of the clutch portion A is used.

The fixing ring 9 is made of, for example, metal or resin, and is fixed to the other end of the casing B by an appropriate means such as a bolt 16 (see FIG. 1). The fixing ring 9 is provided with an outer lip 9a extending from the other end.

The inner lip 8b of the resistance ring 8 contacts one end of the housing 4 to form a contact seal, and the outer lip 9a of the fixed ring 9 faces the one end of the housing 4 via a predetermined gap. To form a labyrinth seal. As a result, foreign matters such as dust, mud,
It is prevented from invading the inside. Also, the inner lip 8
Since the sealing function b is protected by the outer lip 9a, a high sealing property is obtained, and the sealing property is maintained for a long time. Incidentally, the resistance ring 8 and the fixing ring 9 may be made of resin, and both may be integrally formed.

FIG. 3 shows a section taken along line XX of FIG.
A centering spring 7 is interposed between the clutch inner ring 2 and the retainer 6. The centering spring 7 includes an annular portion 7a and a pair of engagement portions 7b extending from both ends of the annular portion 7a toward the inner diameter side. Further, corresponding to the engaging portion 7b of the centering spring 7, the notch-shaped stopper portions 6c, 2c are provided at the other end of the retainer 6 and the other end of the clutch inner ring 2, respectively.
a is provided. The centering spring 7 has its annular portion 7a fitted on the outer periphery of the other end of the retainer 6, and a pair of engaging portions 7b formed by the retainer 6 and the stopper 6 of the clutch inner ring 2.
c, 2a.

In the state shown in the figure, the pair of engaging portions 7b respectively contact the circumferential side walls of the stopper portions 6c and 2a with elastic force, whereby the clutch inner ring 2 and the retainer 6 rotate in the rotational direction. The cage 6 is connected, and the cage 6 is positioned (centered) in the circumferential direction with respect to the clutch inner ring 2.

FIG. 4 shows a section taken along line YY in FIG. A plurality of (the same number as the number of rollers 5) flat cam surfaces (clutch surfaces) 2b are provided at predetermined circumferential intervals on the outer periphery of the clutch inner ring 2, and a cylindrical inner peripheral surface (clutch surface) of the clutch outer ring 3 is provided. 3a, a wedge gap is formed symmetrically in both the forward and reverse rotation directions. Each roller 5 is disposed between each cam surface 2b of the clutch inner ring 2 and the cylindrical inner peripheral surface 3a of the clutch outer ring 3, and is accommodated and held in a pocket 6a of a retainer 6. The figure shows a state in which the retainer 6 is centered by the centering spring 7, and in this state, the circumferential center of the pocket 6a of the retainer 6 and the circumferential center of the cam surface 2b coincide. Therefore, the roller 5 is located substantially at the center of the cam surface 2b, and separates from the wedge gaps in both the forward and reverse rotation directions. The diameter of the roller 5 is set slightly smaller than the radial distance between the cam surface 2b and the cylindrical inner peripheral surface 3a, and the distance between the roller 5 and the cam surface 2b and the cylindrical inner peripheral surface 3a is reduced. Has a radial gap. Hereinafter, this state is referred to as a neutral position.

In FIG. 1, when a drive source (not shown) is operated, its rotational torque is input to the axle 1, and the axle 1 and the clutch inner ring 2 rotate. Then, the retainer 6 rotates by receiving a rotational torque from the clutch inner ring 2 via the centering spring 7, and at this time, the retainer 6 becomes viscous resistance (viscous shear resistance) of the grease 10 interposed between the retainer 6 and the resistance ring 8. And stirring resistance). Therefore, the engaging portion 7b of the centering spring 7 bends, and a relative rotation (a rotation delay of the retainer 4) occurs between the retainer 6 and the clutch inner ring 2 accordingly. Note that the viscous resistance of the grease 10 is proportional to the rotation speed of the cage 6, and if the spring torque of the centering spring 7 is K1 and the viscous resistance of the grease 10 is K2, FIG.
As shown in the above, the relationship of K1 <K2 is established above the set rotation speed (meshing start rotation speed).

When relative rotation occurs between the retainer 6 and the clutch inner ring 2, as shown in FIG. 5B, the roller 5 housed in the pocket 6a of the retainer 6 is moved by the retainer 6 (the retainer 6). 6) and engages in the wedge gap in that direction. At this time, since the clutch inner ring 2 is rotating in the direction of the arrow, the roller 5 is engaged between the cam surface 2b and the cylindrical inner peripheral surface 3a from the principle of wedge. As a result, rotational torque is transmitted from the clutch inner ring 2 to the clutch outer ring 3 via the roller 5, and the clutch outer ring 3 rotates integrally with the retainer 6 and the clutch inner ring 2. Then, the housing 4 and the wheel 12 are rotated by the rotation of the clutch outer ring 3, and the electric assist traveling is performed. This electric assist traveling automatically switches from forward to reverse and from reverse to forward according to a change in the rotation direction of the drive source.

When the drive source is stopped and the rotation of the axle 1, the clutch inner ring 2 and the retainer 6 is stopped, the viscous resistance of the grease 10 disappears. And is centered at the neutral position shown in FIG.
The retainer 6 receives a viscous resistance from the grease 10 when relatively rotated to the neutral position. Since the viscous resistance is proportional to the relative rotational speed, the retainer 6 is driven at a lower speed than the driving source (meshing start rotational speed). Therefore, it can rotate.

When the retainer 6 is centered with respect to the clutch inner ring 2 in this manner, the roller 5 separates from the wedge gap and returns to the neutral position, so that the clutch outer ring 3 becomes normal with respect to the clutch inner ring 2. It becomes idle in both reverse rotation directions and is released from the input system. Therefore, in this state, the housing 4 and the wheel 12 can be rotated manually, whereby even when the drive source is stopped,
The carriage can be manually moved forward or backward.

FIG. 7 illustrates a second embodiment of the present invention, in which the outer diameter surface 6 of the cylindrical portion 6b at one end of the retainer 6 is shown.
A plurality of uneven portions are formed on b1. More specifically, the cylindrical portion 6b shown in FIG.
A plurality of hemispherical recesses 21 are formed in one, and FIG.
The cylindrical portion 6b shown in (1) has a plurality of linear grooves 22 extending in the axial direction on its outer diameter surface 6b1. In this case, if necessary, the uneven portions 21 and 22 described above may be formed on the inner diameter surface 6b2 instead of or together with the outer diameter surface 6b1 of the cylindrical portion 6b. In FIG. 7, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof is omitted (the same applies to FIGS. 8 to 15 below).

According to such a configuration, when the retainer 6 rotates, the viscous fluid is agitated by the irregularities of the outer diameter surface 6b1 and / or the inner diameter surface 6b2 of the cylindrical portion 6b,
The stirring resistance and, consequently, the viscous resistance applied to the cage 6 increase. As a result, the axial length of the cylindrical portion 6b required for obtaining the required viscous resistance can be reduced, and the clutch unit can be made more compact in the axial direction.

FIG. 8 illustrates a third embodiment of the present invention, in which an annular concave portion 8a of a resistance ring 8 is formed to extend to one end side, and one end wall of the annular concave portion 8a and a retainer 6 are formed. A storage section 23 for storing a preliminary viscous fluid is provided between the cylindrical section 6b and one end face of the cylindrical section 6b. And the inner diameter surface and the outer diameter surface of the opening side end of the annular concave portion 8a,
Seal portions 24 and 25 configured as labyrinth seals with a small gap therebetween are provided between the outer diameter surface and the inner diameter surface of the thick portion formed on the torque transmitting portion side of the cylindrical portion 6b. .

According to such a configuration, the seal portion 24,
Even if the viscous fluid gradually and slightly leaks out of the annular recess 8a from 25, the leaked fluid is replenished by the viscous fluid stored in the storage part 23. Therefore, the viscous resistance can be given to the retainer 6 in a stable state.

FIG. 9 illustrates a fourth embodiment of the present invention, in which a sealing member for sealing a gap filled with a viscous fluid between one end of a retainer 6 and an annular recess 8a of a resistance ring 8 is shown. Is interposed. More specifically, FIG.
Is between the inner diameter surface and the outer diameter surface at the opening end of the annular concave portion 8a and the outer diameter surface and the inner diameter surface of the thick portion formed on the torque transmitting portion side of the cylindrical portion 6b of the retainer 6. , And a pair of O-rings 26 and 27 interposed therebetween. FIG.
(B) shows a pair of lip seals 28,
29.

According to such a configuration, since the viscous fluid can be prevented from leaking to the outside from the annular concave portion 8a, adverse effects such as insufficient viscous resistance to the retainer 6 and a malfunction of torque transmission resulting therefrom. Can be avoided, and a normal and stable clutch operation can always be performed.

FIG. 10 exemplifies a fifth embodiment of the present invention, in which a plurality of (three in the illustrated example) cylindrical portions 6d, 6e, 6f are formed coaxially, in other words, a plurality of cylindrical portions 6 in the radial direction.
d, 6e, and 6f are arranged, and a plurality of annular concave portions 8d, 8e, and 8f into which the respective cylindrical portions are inserted are inserted into the resistance ring 8.
Are arranged in the radial direction. A viscous fluid is sealed in gaps between the outer, inner, and end faces of the cylindrical portions 6d, 6e, and 6f and the annular recesses 8d, 8e, and 8f. The plurality of annular concave portions 8d, 8e, 8f are in a state where they are communicated with each other.

According to such a configuration, the cylindrical portions 6d,
Since the contact area with the viscous fluid increases with an increase in the number of 6e, 6f and the viscous resistance increases, even if the axial dimension of the cylindrical portions 6d, 6e, 6f is shortened by the corresponding amount. , Required viscosity resistance is obtained. In this embodiment, as in the above-described second embodiment, each of the cylindrical portions 6 is formed.
An uneven portion may be formed on the outer diameter surface and / or the inner diameter surface of d, 6e, and 6f.

FIG. 11 exemplifies a sixth embodiment of the present invention, in which a disk-shaped portion 6g is formed at one end of the retainer 6 so as to extend in the radial direction so that the thickness width direction thereof coincides with the axial direction. A viscous fluid is sealed in gaps between the outer diameter surface, the inner diameter surface, and both end surfaces of the disk-shaped portion 6g and the annular concave portion 8g. Note that the annular recess 8g is provided in the disc-shaped
And a resistance ring 8 corresponding to one end of the
And is formed across the auxiliary ring 8c corresponding to the other end of the disk-shaped portion 6g.

According to such a configuration, the disk-shaped portion 6
In addition to ensuring a sufficient contact area between g and the viscous fluid, the viscous fluid enclosing portion may be formed in accordance with the thickness width of the disk-shaped portion 6g. Can be greatly shortened.

FIG. 12 exemplifies a seventh embodiment of the present invention, in which one end of the retainer 6 has a plurality (two in the illustrated example) extending in the radial direction so that the thickness width direction and the axial direction coincide with each other. One)
The disk-shaped portions 6h and 6i are arranged in the axial direction, and a plurality of annular recesses 8 into which the disk-shaped portions 6h and 6i are inserted, straddling the resistance ring 8 and the auxiliary ring 8c fixed thereto.
h, 8i are arranged in the axial direction.

More specifically, a disc-shaped portion 6h is formed integrally with an annular shaft portion 6j at one end of the retainer 6, and
The other disk-shaped portions 6i are separately serrated or splined. On the inner peripheral surface of the resistance ring 8, a plurality of (two in the illustrated example) disk-shaped partitions 8j and 8k are serrated or spline-coupled at predetermined intervals, whereby the respective disk-shaped portions 6h and 6i are connected.
Is divided into a plurality of individual annular recesses 8h and 8i. In this case, the individual annular concave portions 8h and 8i are in a state where they are communicated with each other. Then, the outer diameter surfaces and both end surfaces of each of the disk-shaped portions 6h and 6i,
Clearances between the individual annular concave portions 8h and 8i, and inner diameter surfaces of the disk-shaped portions 6h and 6i (inner diameter surfaces of the annular shaft portions 6j).
, A viscous fluid is sealed in a gap between the common annular concave portion 8l.

According to such a configuration, the total contact area between the plurality of disk-shaped portions 6h and 6i and the viscous fluid becomes sufficiently large, and the axial size of the viscous fluid enclosing portion is shortened by a corresponding amount. Also, the required viscous resistance can be obtained.

FIGS. 13 (a) and 13 (b) illustrate an eighth embodiment of the present invention, in which notched stopper portions 6c and 2a formed in the retainer 6 and the clutch inner ring 2 are provided in the circumferential direction. The plate-shaped piece 30 having a spring force is incorporated as a centering spring. This plate-shaped piece 30 is made of SUS
And the like, and are formed in a U-shape, and both side surfaces 30a thereof are in elastic contact with the circumferential side walls of the stoppers 6c and 2a, respectively.

According to such a configuration, in addition to the plate-like piece 30 functioning properly as a centering spring, the structure of the centering spring is simplified, and the assembling work thereof is facilitated, and the manufacturing process is simplified. Workability can be improved.

FIG. 14 illustrates a ninth embodiment of the present invention, in which the retainer 6 is formed of an elastic material such as resin or rubber, and the inner periphery of the retainer 6 at the end on the side of the torque transmitting portion. Part, integrally formed with a protruding portion 6k protruding toward the inner diameter side,
The protrusion 6k is engaged with an engagement recess 2k formed on the outer peripheral portion of the clutch inner ring 2. The protruding portion 6k has a spring force in the circumferential direction.

More specifically, the protruding portion 6k shown in FIG.
Has an inner diameter side distal end 6k1 engaged with the engagement concave portion 2k of the clutch inner ring 2, and a proximal end 6k2 having a smaller circumferential thickness than the inner diameter side distal end 6k1. End 6
k2 has a spring force in the circumferential direction. Also,
The protruding portion 6k in FIG. 14B includes two protruding pieces 6k3 which are arranged in parallel in the circumferential direction and are engaged with the engaging recesses 2k of the clutch inner ring 2, and each protruding piece 6k3 is arranged in the circumferential direction. Has a spring force.

According to such a configuration, since the projecting portion 6k integrally formed with the retainer 6 functions properly as a centering spring, a separate centering spring is not required, and the number of parts can be reduced, and the number of parts can be reduced. In addition, it is possible to simplify the assembling work. FIG. 15 shows the first embodiment of the present invention.
In the illustrated embodiment, the retainer 6 is formed of an elastic material such as resin or rubber, and a notch 61 formed at the end of the retainer 6 on the side of the torque transmitting portion has a gap between them. A pair of tongue pieces 6m that become narrower as they move toward the tip
Are integrally provided, and an engaging projection 2m integrally formed on the outer peripheral portion of the clutch inner ring 2 is interposed between the pair of tongue pieces 6m. The tip portions of the pair of tongues 6m are in contact with both side surfaces of the engaging projection 2m, and the pair of tongues 6m has a spring force in the circumferential direction.

Even in the case of such a configuration, the retainer 6
Since the tongue piece 6m integrally formed with the tongue appropriately functions as a centering spring, a separate centering spring is not required, the number of parts can be reduced, and the assembling work can be simplified.

In the present invention, the clutch portion is formed by using a viscous fluid. However, instead of using a viscous fluid, an electromagnetic or eddy current is used, or the clutch is formed by using a powder or the like. It is also possible to configure.

In each of the above embodiments, the present invention is applied to a clutch unit in which the input side member is disposed on the inner peripheral side of the retainer and the output side member is disposed on the outer peripheral side of the retainer. For example, the present invention is similarly applied to a clutch unit disclosed in Japanese Patent Application Laid-Open No. H8-177878 where the input side member is disposed on the outer peripheral side of the retainer and the output side member is disposed on the inner peripheral side of the retainer. can do.

Further, the present invention is not limited to the electric assist cart, but can be applied to an electric slide door, an electric curtain, an electric assist wheelchair, and the like.

[0062]

The present invention has the following effects.

(1) The torque transmission direction (forward rotation / reverse rotation) is automatically switched in accordance with the change in the rotation direction of the drive source.
When the drive source is stopped, the output side member is automatically released from the input system to enable manual operation from the output side, so it has been applied to electric slide doors, electric curtains, electric assist wheelchairs, electric assist carts, etc. In this case, the convenience of these devices can be further improved.

(2) Since the input-side member is rotatably supported on the casing at one end of the clutch portion in a cantilever manner and the stationary-side member is fixed to the casing, the input-side member is smaller than the conventional structure. The structure of the casing is simplified, and the attachment / detachment operation is also simplified.

(3) An annular recess into which one end of the retainer is inserted is provided on the stationary member, and a viscous fluid is filled in a gap between the one end of the retainer and the annular recess of the stationary member. With this configuration, the viscous resistance required for the relative rotation (switching function) of the cage can be appropriately obtained from one end of the cage, and the accuracy in layout can be ensured.

(4) A cylindrical portion is formed at one end of the retainer, and a viscous fluid is inserted into a gap between the inner diameter surface, the outer diameter surface, and the end surface of the cylindrical portion and the annular concave portion of the stationary member. , The viscous resistance acts on the retainer through the three surfaces, whereby the axial dimension of the viscous fluid enclosing portion can be shortened, and further, the axial dimension of the clutch unit is reduced. Can be made more compact.

(5) At one end of the retainer, a plurality of cylindrical portions are arranged in the radial direction, and a plurality of annular concave portions of the stationary member are arranged in the radial direction corresponding to the respective cylindrical portions. Therefore, the viscous resistance applied to the retainer increases according to the number of the cylindrical portion and the annular concave portion. As a result, the axial dimension of the viscous fluid sealing portion is reduced, and the clutch unit is more compact. Can further contribute.

(6) Since the disk-shaped portion extending in the radial direction is formed at one end of the retainer, the axial dimension of the viscous fluid sealing portion can be reduced to, for example, about the thickness and width of the disk-shaped portion. It is possible to greatly reduce the size of the clutch unit in the axial direction.

(7) A plurality of disk-shaped portions extending in the radial direction are arranged at one end of the retainer in the axial direction, and a plurality of annular concave portions of the stationary member are arranged in the axial direction corresponding to the respective disk-shaped portions. With the configuration, the viscous resistance applied to the retainer increases, which can contribute to downsizing of the clutch unit in the axial direction.

(8) Since a plurality of concave and convex portions are provided on the required surfaces of the cylindrical portion and the disk-shaped portion, the viscous fluid is stirred by the concave and convex portions when the retainer rotates, so that the stirring resistance increases. The clutch unit can be made more compact.

(9) Since a seal portion for sealing the viscous fluid sealed in the gap is provided between one end of the retainer and the annular concave portion of the stationary member, leakage of the viscous fluid can be prevented. In addition, it is possible to stably secure the viscous resistance applied to the cage.

(10) Since the storage portion for storing the preliminary viscous fluid is provided on the stationary member, even if a small amount of the viscous fluid leaks, the shortage is replenished by the preliminary viscous fluid. Therefore, it is possible to further stably secure the viscous resistance applied to the retainer.

(11) Since the stationary-side member is provided with a lip that forms a seal between the stationary-side member and the output-side member, foreign matter such as dust, mud, and water does not easily enter the inside of the clutch. Detrimental effects such as biting of foreign matter into the clutch and deterioration of the properties of the contact surface due to the foreign matter are avoided, and the durability of the clutch unit is improved.

(12) If the lip is constituted by an outer lip forming a labyrinth seal with the output side member and an inner lip forming a contact seal with the output side member, the inner lip seal Since the function is protected by the outer lip, a high sealing property is obtained and the sealing property is maintained for a long time.

(13) By using grease as the viscous fluid, even if it leaks from the sealing portion for some reason, the adverse effect (denaturation) due to mixing with the lubricating grease inside the clutch (lubricating grease sealed in the power transmission portion). ,
Deterioration) can be eliminated or suppressed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an axle portion of an electric assist cart using a clutch unit of the present invention.

FIG. 2 is a cross-sectional view of the retainer, the resistance ring, and the fixing ring {FIG. 2 (a)} and a partially enlarged cross-sectional view of FIG. 2 (a) {FIG. 2 (b)}.

FIG. 3 is a sectional view taken along line XX in FIG. 1;

FIG. 4 is a sectional view taken along line YY in FIG.

FIG. 5 is an enlarged sectional view showing a peripheral portion of a roller.

FIG. 6 is a diagram showing a relationship between a spring torque K1 and a viscous resistance K2.

FIGS. 7A and 7B are perspective views of a main part showing one end of a retainer according to a second embodiment of the present invention.

FIG. 8 is an enlarged sectional view of a main part showing a peripheral structure of a cage according to a third embodiment of the present invention.

FIGS. 9A and 9B are enlarged cross-sectional views of a main part showing a peripheral structure of a cage according to a fourth embodiment of the present invention.

FIG. 10 is an enlarged sectional view of a main part showing a peripheral structure of a cage according to a fifth embodiment of the present invention.

FIG. 11 is an enlarged sectional view of a main part showing a peripheral structure of a cage according to a sixth embodiment of the present invention.

FIG. 12 is an enlarged sectional view of a main part showing a peripheral structure of a cage according to a seventh embodiment of the present invention.

FIG. 13 is an enlarged sectional view of a main part {FIG. 13 (a)} and an enlarged perspective view of a main part {FIG. 13 (b)} showing a peripheral structure of a cage according to an eighth embodiment of the present invention.

FIGS. 14A and 14B are enlarged cross-sectional views of a main part showing a peripheral structure of a cage according to a ninth embodiment of the present invention.

FIG. 15 is an essential part enlarged cross-sectional view showing a peripheral structure of a cage according to a tenth embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 axle (input side member) 2 clutch inner ring (input side member) 3 clutch outer ring (output side member) 4 housing (output side member) 5 roller (torque transmitting member) 6 cage 6b, 6d, 6e, 6f cylindrical portion 6g, 6h, 6i Disc-shaped portion 7 Centering spring (elastic member) 8 Resistance ring (stationary member) 8d, 8e, 8f, 8g, 8h, 8i, 8l Annular recess 9 Fixing ring (stationary member) 10 Grease (viscosity) fluid)

Claims (13)

[Claims] An input-side member, an output-side member, a torque transmission member interposed between the input-side member and the output-side member and capable of engaging and disengaging with these members in both forward and reverse rotation directions; A retainer that holds the torque transmitting member and controls engagement and disengagement of the torque transmitting member through relative rotation with respect to the input side member, and an elastic member that connects the input side member and the retainer in a rotational direction, A clutch portion having a stationary member and a viscous fluid interposed between the retainer and the stationary member; A casing to which the input-side member is rotatably supported in a cantilever manner at one end side of the clutch portion, and a casing to which the stationary-side member is fixed. A reverse input cutoff clutch unit that transmits to a side member and blocks forward and reverse rotation torque from the output side member to the input side member. 2. The stationary-side member has an annular recess into which one end of the retainer is inserted, and the viscous fluid is sealed in a gap between the one end of the retainer and the annular recess. The reverse input cut-off clutch unit according to claim 1. 3. A cylindrical portion is formed at one end of the retainer, and the viscous fluid is provided in an inner diameter surface, an outer diameter surface, and a gap between the end surface and the annular concave portion of the stationary member. 3. The reverse input cut-off clutch unit according to claim 2, wherein the clutch is enclosed. 4. A plurality of cylindrical portions are radially arranged at one end of the retainer, and a plurality of annular concave portions of the stationary member are radially arranged corresponding to the cylindrical portions. The reverse input cutoff clutch unit according to claim 2 or 3. 5. An inner diameter surface of a cylindrical portion of the cage,
The reverse input cutoff clutch unit according to claim 3 or 4, wherein at least one of the outer diameter surface and the end surface has a plurality of uneven portions. 6. A disk-shaped portion extending in a radial direction is formed at one end of the retainer, and an inner diameter surface, an outer diameter surface, and both end surfaces of the disk-shaped portion and an annular concave portion of the stationary member are formed. The reverse input cutoff clutch unit according to claim 2, wherein the viscous fluid is sealed in a gap. 7. A plurality of disk-shaped portions extending in the radial direction are arranged at one end of the retainer in the axial direction, and a plurality of annular concave portions of the stationary member are formed in the axial direction corresponding to the respective disk-shaped portions. The reverse input cutoff clutch unit according to claim 2 or 6, wherein the reverse input cutoff clutch unit is arranged. 8. The reverse of claim 6, wherein at least one of the inner diameter surface, the outer diameter surface, and both end surfaces of the disc-shaped portion of the cage has a plurality of uneven portions. Input cut-off clutch unit. 9. A seal portion for sealing a viscous fluid sealed in the gap is provided between one end of the retainer and an annular concave portion of the stationary-side member. 2. The reverse input cutoff clutch unit according to item 1. 10. The reverse input cutoff clutch unit according to claim 1, wherein a storage portion for storing a preliminary viscous fluid is provided in the stationary side member. 11. The reverse input cutoff clutch unit according to claim 1, wherein the stationary side member is provided with a lip forming a seal between the stationary side member and the output side member. 12. The lip according to claim 11, wherein the lip comprises an outer lip forming a labyrinth seal with the output side member, and an inner lip forming a contact seal with the output side member. The reverse input cutoff clutch unit as described. 13. The reverse input cutoff clutch unit according to claim 1, wherein the viscous fluid is grease.