CN1069122C

CN1069122C - Sprag type one-way clutch

Info

Publication number: CN1069122C
Application number: CN96123140A
Authority: CN
Inventors: 猪狩康三郎
Original assignee: NSK Warner KK
Current assignee: NSK Warner KK
Priority date: 1996-12-20
Filing date: 1996-12-20
Publication date: 2001-08-01
Anticipated expiration: 2016-12-20
Also published as: HK1012201A1; CN1185551A

Abstract

The present invention relates to a wedge type one-way clutch which comprises an outer seat ring, an inner seat ring arranged in the outer seat ring, a plurality of wedges arranged between the outer seat ring and the inner seat, an annular holding rack for holding the wedges, and a spring piece, wherein the outer seat ring and the inner seat ring are mutually separated in a radial direction and are coaxially arranged to correspondingly rotate; the wedges are used for transmitting torque. The wedges are supported between the spring piece and the holding rack and are partially pressed along an engaging direction. The present invention is characterized in that the holding rack is erected with a cylindrical part with a window part which extends in a radial direction, the wedges are arranged in the window part and move around a pivoting shaft, and the spring piece is guided by the surface of the outer circumference of the cylindrical part along a basic circle.

Description

Free wheeling sprag clutch

The present invention relates to a kind of for example at automobile, two-wheel vehicle, in the industrial machine etc. with the overrunning clutch of the parts that act on transmission of torque or anti-reversing, particularly a kind of free wheeling sprag clutch with parts of minimizing.

Usually, free wheeling sprag clutch is provided with a voussoir as cam, as shown in Fig. 5 and 6, this clutch comprises a ring like steel wire dust cage 60, a plurality of voussoir 20, one annular springs 30 by wire cage supporting engage and voussoir are bearing between it and the wire cage 60 with groove in being formed on voussoir 20, and two

side plates

40 and 50, voussoir 20 is bearing between its axially relative end.

In wire cage 60 installed inside one inner race, the interior side contacts of the external peripheral surface of inner race and voussoir 20.And, an outer race is installed in the wire cage outside, with the outer side contacts of voussoir 20.Its result carries out the transmission of torque between interior outer race by voussoir 20.In Fig. 5 and 6, inner race and outer race are not shown.Yet in this free wheeling sprag clutch according to prior art, parts are too many, can not adapt to the strict demand to manufacturing and cost.

If reduce the quantity of voussoir in order to satisfy this requirement, then the guiding character of spring will become no good, this is because the groove in the voussoir provides guiding for spring, being difficult to keep whole spring when voussoir reduces is circular state, its result might be able to not obtain along the enough biasing force of engagement directive effect on voussoir.In this case, produce between the external peripheral surface of inner race and the voussoir and the inner circumferential surface of outer race and the problem that the engagement between the voussoir degenerates, and the life-span of spring suffer damage.

Therefore, the purpose of this invention is to provide a kind of free wheeling sprag clutch, wherein compared with prior art number of components has reduced, and can improve the guidance quality that voussoir is bearing in the spring between itself and the retainer, simultaneously between the external peripheral surface of inner race and the voussoir and the inner circumferential surface and the engagement between the voussoir of outer race become reliable, in addition, can not damage the life-span of spring.

For achieving the above object, the invention provides a kind of free wheeling sprag clutch, it comprises: one has the outer race of inner circumference raceway surface; One is arranged in the described outer race and has the inner race of annular excircle raceway surface, described outer race and described inner race mutually radially at a distance of and coaxial setting to relatively rotate; A plurality of voussoirs that are arranged between described outer race and the described inner race are used to transmit the torque between described excircle raceway surface and the described inner circumference raceway surface, form the groove of circumferential extension in the radially external peripheral surface of each described voussoir; One keeps the annular retainer of described voussoir swingably, and described retainer is provided with a barrel portion, has a window portion of radially extending; An and telescopic annular spring spare, described spring part is installed in the described groove, described voussoir is bearing between the barrel portion of itself and described retainer and along the described voussoir of an engagement direction bias voltage, it is characterized in that, have only a described voussoir to be installed in swingably in each described window portion, and described spring part is by the external peripheral surface edge circle guiding basically of the described barrel portion of described retainer.

According to the present invention, retainer is simultaneously as side plate and wire cage, therefore, reduced the quantity of part, therefore spring can, have been improved the circumference of spring and can not produce reducing of biasing force by the barrel portion guiding of retainer, the engagement of voussoir becomes reliably, and the life-span of spring has also improved.

Fig. 1 is the axial front view of free wheeling sprag clutch according to an embodiment of the invention.

Fig. 2 is the radial cross section view of free wheeling sprag clutch shown in Figure 1, has wherein omitted an outer race and an inner race.

Fig. 3 is the viewgraph of cross-section of first example that the shape of the window portion that is used for retainer embodiment illustrated in fig. 1 is shown.

Fig. 4 is the viewgraph of cross-section of second example that the shape of the window portion that is used for retainer embodiment illustrated in fig. 1 is shown.

Fig. 5 is the axial front view according to an example of the free wheeling sprag clutch of prior art.

Fig. 6 is the radial cross section view of free wheeling sprag clutch shown in Figure 5.

Fig. 7 is the viewgraph of cross-section of the 3rd example that the shape of the window portion that is used for retainer embodiment illustrated in fig. 1 is shown.

Describe the present invention with reference to the accompanying drawings in detail.Certainly, an embodiment that will describe below schematically illustrates the present invention, rather than restriction the present invention.Identical part has been used identical label in the whole accompanying drawing.

Fig. 1 is the front view from axially seeing of free wheeling sprag clutch 10 according to an embodiment of the invention.

Free wheeling sprag clutch 10 has an outer race 4 of being represented by dot and dash line, with one with the inner race 5 of outer race 4 coaxial settings, and comprise voussoir 2 between the inner circumference raceway surface of a plurality of excircle raceway surfaces that are arranged on inner race 5 and outer race 4, one along the circumferential annular retainer 1 of supporting wedges 2 equidistantly, and one is bearing in spring 3 between itself and the retainer 1 with voussoir 2.

As obviously finding out among Fig. 2, retainer 1 is provided with a cylindrical part 1c and an annular flange portion 1a, and the circumferential end of it and cylindrical part 1c is in aggregates and stretch out from its radially outward.Cylindrical part 1c is provided with the window portion 1d that radially extends in equidistant precalculated position along the circumferential direction, and voussoir 2 is installed among this window portion 1d.

The flange portion 1a of retainer 1 is formed with two otch 1b that partly are cut into barrel portion 1c from its radial edges.Otch 1b outwards setovers from the excircle of flange portion 1a, thereby the part 1b ' that is clipped between the otch 1b of flange portion 1a contacts with outer race 4, thereby prevents that retainer 1 from rotating with respect to outer race 4.

As shown in Figure 2, each voussoir 2 along the circumferential direction is formed with groove 2a on its cam face 2b (seeing Fig. 3 and 4) side, and spring 3 is directed to and is installed among these grooves 2a.Spring 3 is continuous circular shape sealing contact ring type, with the different position, position of the groove 2a of voussoir 2, it its with retainer 1 between supporting wedges 2, be held simultaneously frame 1 barrel portion 1c the external peripheral surface guiding and support.As mentioned above, the spring 3 of supporting wedges 2 also by the external peripheral surface guiding of the barrel portion 1c of retainer 1, therefore, can improve the circularity and the guidance quality of spring 3.

Promptly, the barrel portion 1c of retainer 1 and the groove 2a of voussoir 2 be to spring 3 guiding, therefore, even when selecting to increase or reduce the quantity of voussoir 2 when as required torque capacity, spring 3 always is in circular state, and overrunning clutch 10 can carry out reliable engagement operations.Also can use other any spring and be not only ring spring for spring 3.

Voussoir 2 as the transmission of torque part is described below in the free wheeling sprag clutch 10.As shown in Fig. 1 to 4 and 7, each voussoir 2 is cylindrical, and its part is excised preset thickness vertically.As shown in Fig. 3 and 4, voussoir 2 has a cam portion 2b who is made of irregular curve, and when when the place ahead is seen, the part of the circumference of this irregular curve disconnects, and the inner circumferential surface of cam portion 2b design and outer race 4 is relative also to be contacted.Be essentially circular portion 2c with the part relative with cam portion 2b of voussoir, it is designed to the relative and contact of external peripheral surface with inner race 5.

As shown in Fig. 3 and 4, the circumferential section 2c of voussoir 2 is installed among the window portion 1d of retainer 1 to do pivoted motion at its circumferencial direction.When voussoir 2 is done pivoted motion in the window portion 1d of retainer 1, relative two circumference edge portion 1e sliding contact of the circumferential section 2c of voussoir 2 and window portion 1d.Can find out that from first example as shown in Figure 3 the length of the circumferential section 2c of voussoir 2 and the sliding contact of circumference edge portion 1e is basically corresponding to the thickness of the circumference edge portion 1e of window portion 1d.Circumferential section 2c and circumference edge portion 1e are designed to curvature and equate basically.

In addition, radially curve inwardly forming curved section 1f according to the end of two relative circumference edge portion 1e of the window portion 1d of the retainer of second example shown in Figure 4, thereby formed circumference edge portion 1g is longer than circumference edge portion 1e shown in Figure 3.Circumferential section 2c and circumference edge portion 1g are designed to curvature and equate basically.

Can find out obviously that from top description voussoir 2 is received among the window portion 1d of retainer 1 and is designed to along the circumferential direction to do pivoted motion, but can not do pivoted motion vertically.

Compare with the voussoir 20 of the overrunning clutch according to prior art shown in Figure 5 and the relation between the wire cage 60, above-mentioned circumference edge portion 1e and 1g have following effect.In Fig. 5, the circumferential section of voussoir 20 only on a line against wire cage.In contrast, in Fig. 3 that embodiments of the invention are shown and 4, the circumference edge portion 1e of voussoir 2 and the window portion 1d of retainer 1 and 1g are not only at a line but contact on a face, and therefore, voussoir can smoothly and reliably be done pivoted motion with respect to the window portion 1d of retainer 1.Special when being designed to as shown in Figure 4, sliding contact between the circumferential section 2c of voussoir 2 and the circumference edge portion 1e of retainer 1 and the 1g can keep longer, therefore, voussoir 2 is can be with respect to the window portion 1d of retainer 1 more level and smooth and do pivoted motion more reliably.

In the embodiment shown in Fig. 3 and 4, the circular portion 2c of voussoir 2 and the circumference edge portion 1e of the window portion of retainer and the shape complementarity of 1g.Certainly, the circumferential section 2c of voussoir 2 needn't one be decided to be circle, and can be any shape with smoothed curve.

Certainly, in the present embodiment, even the window portion 1d of retainer 1 the 3rd example maintenance as shown in Figure 7 also can realize purpose of the present invention by the shape that the press radial punch goes out.

According to the free wheeling sprag clutch of the invention described above, has following effect.

The window portion of retainer plays side plate of the prior art and wire cage simultaneously, therefore, has compared with prior art reduced the quantity of part.

Retainer has barrel portion, this part has a window portion of radially extending, and voussoir, be installed in the window portion, therefore spring, can improve the circularity of spring by the external peripheral surface guiding of barrel portion, and spring can be led well by the barrel portion of voussoir and retainer, to produce the biasing force contact.In addition, spring is indeformable, therefore, improved the life-span of spring, and the operation of overrunning clutch becomes stable.

And, according to this embodiment, the circumferential section of the window portion of retainer is made predetermined structure, therefore, the pivoted motion of voussoir can smoothly and accurately be carried out.

Claims

1. free wheeling sprag clutch, it comprises:

One has the outer race of inner circumference raceway surface;

One is arranged in the described outer race and has the inner race of annular excircle raceway surface, described outer race and described inner race mutually radially at a distance of and coaxial setting to relatively rotate;

A plurality of voussoirs that are arranged between described outer race and the described inner race are used to transmit the torque between described excircle raceway surface and the described inner circumference raceway surface, form the groove of circumferential extension in the radially external peripheral surface of each described voussoir;

One keeps the annular retainer of described voussoir swingably, and described retainer is provided with a barrel portion, has a window portion of radially extending; And

One telescopic annular spring spare, described spring part is installed in the described groove, described voussoir is bearing between the barrel portion of itself and described retainer and along the described voussoir of an engagement direction bias voltage, it is characterized in that, have only a described voussoir to be installed in swingably in each described window portion, and described spring part is by the external peripheral surface edge circle guiding basically of the described barrel portion of described retainer.

2. free wheeling sprag clutch as claimed in claim 1, it is characterized in that, described retainer is provided with an annular flange portion that extends radially outwardly from an end of described barrel portion, and described flange portion has at least one undercut groove, and this undercut groove extends radially outwardly from an adjacent window apertures.

3. free wheeling sprag clutch as claimed in claim 1 is characterized in that, the edge of each described window is arranged on the circumferential direction of described retainer, contacts with corresponding voussoir, thereby guide voussoir in the scope of oscillating motion.

4. free wheeling sprag clutch as claimed in claim 3, it is characterized in that, each described window portion and the external frame of corresponding voussoir have complementary shape, like this, described edge by with the oscillating motion of the aspectant contact guidance voussoir of described voussoir complementation.

5. free wheeling sprag clutch as claimed in claim 1 is characterized in that described spring part is a helical spring.