Patent ID: 12253121

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention are described with reference toFIG.1toFIG.9. Note, however, the present invention is not limited to these embodiments.

Embodiment 1

The cam clutch100according to the first embodiment of the present invention includes, as shown inFIG.1andFIG.2, an inner race110and an outer race120provided on the same axis rotatably relative to each other, a cam mechanism disposed between an outer circumferential surface of the inner race110and an inner circumferential surface of the outer race120that face each other, and an operating mode switch mechanism140that switches the operating modes of the cam clutch100.

The cam mechanism is made up of a plurality of cams131circumferentially aligned on the same circumference, and a biasing means (not shown) passed over the plurality of cams131, set in respective retention grooves132of the cams, to bias the cams radially inwards. The cams131should preferably be disposed along the circumferential direction with little looseness. This configuration can realize a high torque transmission capacity.

The cam mechanism according to this embodiment includes first cams and second cams that rotate in different engaging directions. Below, the first and second cams may be referred to as cams131except when specifically mentioned separately.

As shown inFIG.5, on one side face of the cam131is protruded an engaging portion136that can engage with the cam orientation changing part141of the operating mode switch mechanism140.

The arrangement of the first cams and second cams in the cam mechanism is not limited to a particular layout. Preferably, the first cams131aand second cams131bare arranged alternately, as illustrated inFIG.3. This configuration allows control of the orientation of the first cams131aand second cams131bby the same operating mode switch mechanism140shared by the first cams131aand second cams131b, so that an increase in structural complexity or size of the cam clutch100can be avoided. It is also possible to control the orientation of the first cams131aand second cams131bsimultaneously.

It is not necessary for the first cams131aand second cams131bto be arranged alternately on the same circumference. Therefore, the numbers of the first cams131aand second cams131bmay be the same, or different.

The first cams131aand second cams131bhave outer shapes that are identical to each other, for example, except that the engaging portion136is provided on different side faces, the first cams131areversed front to back being used as the second cams131b. The first cams131aand second cams131bmay have outer shapes that are different from each other. By having identical outer shapes, the number of parts can be reduced.

The first cam131ais configured to make frictional engagement with the inner race110and outer race120when the outer race120rotates in one direction, and to tilt in the direction in which it separates from the inner race110and outer race120when the outer race120rotates in the other direction.

Therefore, the second cam131b, which is the first cam131areversed front to back, is configured to make frictional engagement with the inner race110and outer race120when the outer race120rotates in the other direction, and to tilt in the direction in which it separates from the inner race110and outer race120when the outer race120rotates in one direction.

A ring-like garter spring, for example, is used as the biasing means (not shown). The garter spring is provided such as to pass through the respective retention grooves132in the first cams131aand second cams131b.

The biasing means may be any resilient member that can bias each of the plurality of cams131either radially inwards or outwards. A plurality of plate springs or torsion springs or the like may also be used.

The cam clutch100according to this embodiment includes an operating mode switch mechanism for switching between a free state that allows relative rotation between the inner race110and outer race120and a locked state that prohibits relative rotation between the inner race110and outer race120.

The operating mode switch mechanism140of this embodiment includes a cam orientation changing part141that is provided such as to be axially movable independently of the rotation of the inner race110and outer race120to restrict the orientation of the cams131.

The operating mode switch mechanism140of this embodiment includes, as shown inFIGS.2,4,6, etc., an annular plate-like main body142provided such as to be rotatable relative to the inner race110and outer race120, and the cam orientation changing part141in a circular form provided on one side of the main body142facing the cams131such as to restrict the radial position of the engaging portions136while making sliding contact with the engaging portions136, when coming into contact with the engaging portions136of the cams131.

The cam orientation changing part141is configured to switchably lock and unlock the orientation of the cams131by an axial movement of the main body142.

The engaging portion136is provided to such a position that the cams131can be brought to a condition not simultaneously touching the inner race110and outer race120when the radial position of the engaging portion136is changed by the cam orientation changing part141, e.g., at a more peripheral side of the cam131than the perpendicular line on the contact point between the cam131and the inner race110.

While the cam orientation changing part141in this embodiment is formed in a circular groove-like shape, the cam orientation changing part141may have any shape corresponding to the shape of the engaging portion136, such as a single circular protruded portion on the radially inner side, as long as the cam orientation changing part141is able to lock and unlock the orientation of the cams131.

In this embodiment, the main body142has an annular plate-like shape, with the cam orientation changing part141integrally formed therewith. As long as it is possible to move the cam orientation changing part141in the axial direction, the main body may have other shapes such as a lever, or may be formed as a separate part independently of the cam orientation changing part141.

Moreover, bearing rollers and such may be arranged as required between the inner race110and the outer race120in addition to the first cams131aand second cams131b.

Hereinafter, the operation of the cam clutch100according to the above first embodiment will be described.

Here, it is assumed that the cam clutch is in the locked state where the outer race120is not allowed to rotate relative to the inner race110in both forward direction and the reverse direction when the cam orientation changing part141is in the position where it does not touch the engaging portions136and does not restrict the orientation of the cams131. Namely, the cam clutch100functions as a two-way clutch.

When the main body142is moved toward the cams131manually or by a suitable drive source, the cam orientation changing part141engages with the engaging portions136and restricts the orientation of both cams131aand131bsuch that the cams131aand131bdo not simultaneously contact the inner race110and outer race120, which enables the cam clutch100to function in the free state that allows relative rotation in both directions.

In the above embodiment, the cams131aand131bare both provided for applications in opposite directions. Instead, the cam clutch may be configured to be switched between the one-way clutch mode and the free state by using only one set of the cams131aor131b.

Alternatively, the engaging portion136may be provided to only one set of the cams131aor131b. This way, the cam clutch can be configured to be switched between the locked state and the one-way clutch mode by a movement of the main body142to cause the cam orientation changing part141to engage with the engaging portions136of only one set of cams.

Further, as shown inFIG.7, the groove of the cam orientation changing part141may be made deeper, and the engaging portions136of one set of cams131aor131bmay be made longer and axially slidable inside the groove of the cam orientation changing part141. By designing the cam orientation changing part141to be able to engage only with the longer ones of the engaging portions136of the cams131aor131bat a midway point of the axial movement of the cam orientation changing part141, it is possible to configure the cam clutch to switch between three modes, the locked state, one-way clutch mode, and free state.

Embodiment 2

FIG.8is a cross-sectional view of a plane containing the center axis of the configuration of a cam clutch according to a second embodiment of the present invention.

This cam clutch200has cam mechanisms configured the same as the cam clutch100of the first embodiment arranged along the axial direction, with the main body242of the operating mode switch mechanism240being shared in the center.

The operating mode switch mechanism240includes the main body242that is an annular plate provided such as to be rotatable relative to the inner race210and two outer races220, and cam orientation changing parts241in a circular shape on both sides of the main body242corresponding to the cams231on both sides.

In this cam clutch200, the operating mode switch mechanism240is designed to switch between three positions, a position where neither of the cam orientation changing parts241on both sides engages with the engaging portions236of the cams231on both sides, a position where one cam orientation changing part241engages with the engaging portions236, and a position where the other cam orientation changing part241engages with the engaging portions236.

Therefore, by moving the main body242in the axial direction manually or by a suitable drive source, the cam clutch can be switched from one to another of three operating modes, a neutral position where the clutch mechanisms on both sides are locked, a position where only one of them is in the free state where relative rotation is allowed in both directions while the other is in the locked state, and a position where this is reversed.

The neutral position may be omitted so that the cam clutch is switched between two operating modes.

The cam mechanisms on both sides of the operating mode switch mechanism240may each be configured to have any of the switching functions illustrated in the first embodiment, or different types of cam mechanisms may be combined as required.

For example, with cam mechanisms of the design shown inFIG.7on both sides, the cam clutch can be switched to five operating modes.

The shape and structure of the main body242may be changed to make the cam orientation changing parts241on both sides axially movable independently, so that the cam orientation changing parts241can engage with the engaging portions236simultaneously in the clutch mechanisms on both sides.

Embodiment 3

FIG.9is a cross-sectional view of a plane containing the center axis of the configuration of a cam clutch according to a third embodiment of the present invention.

This cam clutch300has two cam mechanisms configured the same as the cam clutch100of the first embodiment in a double structure, with an inner clutch mechanism arranged between the inner race310and an intermediate race350, and an outer clutch mechanism arranged between the intermediate race350and the outer race320.

The intermediate race350serves as the outer race in the inner clutch mechanism, and as the inner race in the outer clutch mechanism.

The operating mode switch mechanism340includes a main body342that is an annular plate provided such as to be rotatable relative to the inner race310, intermediate race350, and outer race320, and two cam orientation changing parts341in a circular shape on one side of the main body342facing the cams331, corresponding to the inner and outer rows of cams331.

In this cam clutch300, the inner and outer cam orientation changing parts341of the operating mode switch mechanism340and the engaging portions336of the inner and outer rows of cams331respectively have the same relationship as that in the cam clutch100of the first embodiment.

The two cam mechanisms may each be configured to have any of the switching functions illustrated in the first embodiment, or different types of cam mechanisms may be combined as required.

The groove depths of the inner and outer cam orientation changing parts341and the lengths of the respective engaging portions336of the inner and outer rows of cams331may be combined as required to make the cam clutch switchable between a plurality of modes corresponding to the axial movement positions.

Further, the shape and structure of the main body342may be changed to make the inner and outer cam orientation changing parts341axially moveable independently, so that the modes of the inner and outer cam mechanisms can be controlled independently.

While embodiments of the present invention have been described in detail, the present invention is not limited to the above-described embodiments and may be carried out with various design changes without departing from the scope of the present invention set forth in the claims.

REFERENCE SIGNS LIST

100,200,300Cam clutch110,210,310Inner race120,220,320Outer race131,231,331Cam131aFirst cam131bSecond cam132Retention groove136Engaging portion140,240,340Operating mode switch mechanism141,241,341Cam orientation changing part142,242,342Main body350Intermediate race