CS226732B2 - Free wheel - Google Patents

Description

1,226,732

BACKGROUND OF THE INVENTION The present invention relates to mechanisms for transmitting motion in a single direction, more specifically a freewheel. Nowadays, there is a problem in the engineering industry to ensure reliable starting of the internal combustion engine at any time of year, which is related to the lack of reliability and durability of the current starting drives and special freighters, which are one of the main elements of the drives.

There is a known freewheel comprising a ring with an inner cylindrical surface, a double eccentric, whose discs are rotated 180 ° relative to each other and the clamping elements formed in the roller bearings and pressed by the spring to the rim surface. In this freewheel, the clamping elements are permanently in contact with the rim surface and are therefore abraded at idling and limiting the idling speed. Furthermore, the arrangement of the clamping elements in the rolling bearings reduces the load capacity of the mechanism. By contacting the clamping member with the inner cylindrical surface of the rim, the sliding friction coefficient between them is dependent on the material-contacting and lubrication ranges and is very high, which prevents sufficient reliability.

Also known is a freewheel whose construction is most similar to the freewheel of the invention and from which the invention is based. The freewheel includes a double eccentric, with an inner cylindrical surface and clamping elements arranged between the double eccentric and the rim with the inner cylinder, with which they cooperate, and the formed eccentric sleeves connected by the relic so that In this freewheel, a contactless movement of the clamping eccentric sleeves with respect to the inner cylindrical surface of the rim is provided opposite to the abovementioned freewheel, thus allowing the use of said clamping elements even at relatively high overtaking speeds with low frictional forces and preventing In this freewheel, the clamping eccentric sleeves are axially offset relative to each other, thereby generating an additional bending moment by radial forces, which limits the clutch loadability which can only be increased by increasing the bending moment. their main dimensions ·

In addition, when the clamping eccentric inner sleeves are in contact with the cylindrical surface of the rim, the slip coefficient depends on the gripping properties of the grease material, which is quite high, which is an obstacle to sufficient reliability. SUMMARY OF THE INVENTION It is an object of the present invention to provide a freewheel structure which, by virtue of the improved twin eccentric and clamping elements cooperating with a double eccentric, provides an increased load capacity without increasing the main freewheel dimensions.

This object is achieved with a freewheel consisting of an internal cylindrical surface, a double eccentric with saxially arranged discs and clamping eccentric sleeves mounted on the outer surfaces of the double eccentric and interconnected by a pin with the possibility of a relative radial displacement. in that the double eccentric is provided with cams arranged between its disks relative to the longitudinal diaphragm plane of the freewheel and extending its outer surfaces with the outer surface of the disks, each clamping eccentric sleeve surrounding the outer surface of the corresponding cam with its entire surface the koteučeya is provided with two outside jaws / archs which are in contact with the inner cylindrical surface of the rim.

The embodiment of the double eccentric with cams arranged between the discs of the double eccentric, cooperating with the inner surface of the clamping eccentric sleeves and the outer arch projections cooperating with the inner cylindrical surface of the rim allows to increase the axial length of the working surfaces of the clamping eccentric sleeves, thereby increasing the freewheel load capacity. , without increasing its axial dimensions.

It is advantageous to make said clamping eccentric receptacles with radial projections in the freewheel with cutouts along the width of the idle part, since in this case the width of the working surfaces of these sleeves increases without increasing the axial dimensions of the freewheel. 228,732 Μ 4 **

It is desirable that the arc length of the outer arches of the clamping eccentric sleeves is equal to 0.1-0.5 radius of the inner cylindrical surface of the freewheel rim and that the angle between the dots and their contact surfaces whose points are closest to each other is in the range of 20 to 70 %

Such an embodiment of the radial projections allows the wedge connection to be achieved at the point of contact of the radial projections of the clamping eccentric sleeves with the inner cylindrical surface of the freewheel ring, which provides the necessary coefficient of friction and contactlessness between the clamping elements and the inner cylindrical surface of the freewheel rim at idle, thereby ensuring operating reliability of the freewheel.

It is also expedient for the freewheel according to the invention to cover the working surfaces of said radial projections of the clamping eccentric sleeves with a hard metal friction material.

The cladding of the working surfaces of the radial eccentric protrusions by the friction material provides a further increase in the freewheel operating reliability. In the following, one particular embodiment of the invention will be described with reference to the drawings, in which: Figure 1 shows an overall view of the freewheel in cross-section; Figure 2 is a sectional view along the line II-II in Figure 1; Fig. 3 is a sectional view taken along line III-III in Fig. 2;

The freewheel consists of a double eccentric 1 (Fig. 1, 2) comprising cams 2 and 3 and axially mounted discs of fa - 5 - 226 732

The cams 2, 2 are arranged between the discs of the double eccentric 1 on opposite sides with respect to the longitudinal diametric plane of the freewheel, their outer surfaces forming an extension of the outer surfaces 4,% of the double eccentric 1. clamping eccentric sleeve 6, 2 · Clamping eccentric shell 6 surrounds the outer surface of disc 4 and cam 2 of double eccentric 1 along the length »

The clamping eccentric sleeve 2 also surrounds the inner surface of the outer surface of the cam 2a of the cam 2 of the double eccentric 1 with its inner surface. The outer surfaces of the clamping eccentric sleeves 6, 2 are provided with corresponding double radial projections 8, 11 and 10 ' 2 2 are connected to each other by a pin 12, one end of which is pressed into the opening of the clamping eccentric sleeve 6, and the other end is engaged with the radial groove 13 of the clamping eccentric sleeve 2 and the ring 14 with the flat surface 15 »in which they are mounted on a double eccentric / clamping eccentric sleeve 6» 2 »

The clamping eccentric sleeve 6 (FIG. 2) is provided with a notch 16 along the axis of its idle portion, that is to say in which the main freewheel load transmission is not applied, with the notch 12 provided with a clamping eccentric sleeve 2, thereby providing in axial mounting, the work surface 18 of the clamping eccentric sleeve 6 is mounted on the surface 20 of the cam 2 in the idle portion 17 of the clamping eccentric sleeve 2 »8 the work surface 228 732 19 (FIG. 1, 2) the clamping eccentric sleeves 2 on the surface 21 of the cam 2 in the idle portion of the notch 16 (Fig. 2) of the clamping eccentric sleeve 6 ·

Such an increase in length along the axis of the work surfaces 18, 19 of the eccentric sleeves 6, 2 makes it possible to increase its load capacity more than the length of the cams 2, 2 along the axis in the idle portions of the eccentric sleeves 6, 2 ' twice and reduce the bending moment due to the radial clamping and load transfer forces, the eccentric sleeve 6 cooperates with its working surface 18 with the double-eccentric disc disk surface 20 and the working surface of the cam 2 and the eccentric sleeve 2 co-operate with its working surface 19 with the working surface 21 of the double eccentric disc 2 of the working platform 2 '' of the freewheel, the eccentric sleeve 6 is secured against radial shifting with its inner surface 22 (FIG. 1) in contact with the outer surface of the disc of the double eccentric 1. The same applies to the eccentric sleeve 24 which, with its inner surface 23 in contact with the outer surface of the double eccentric reel 2, and the eccentric sleeve 6, 2, are aligned concentrically with the inner cylindrical surface 15 of the crown 14 as they are secured to the disks 2 of the double eccentric 1 by a pin 12 which fits into the 226 732 engages radial groove 15 of the eccentric sleeve 14 and radial projections 8, 2 (FIG. 2) of the eccentric sleeve 6 and between the radial projections 10, 11 of the eccentric sleeve 2, radial clearance. the smallest size of which is determined within the tolerance range of the functional fit is determined by the ends of the radial projections 8, 9 ', 10 and 11.

Execution of eccentric sleeves 6, 2 with outer radial projections 8, 2? 12? 11? Whose arc length is equal to 0.4 radius of inner cylindrical surface 15 of ring 14a with radius of radial projections 8, 9, 10 of eccentric sleeves 6, 2? about 0.05 mm greater than the radius of the inner cylindrical surface 15 of the rim 14, wherein the radial projections 8, 20 ' on the eccentric sleeves 6, 2 ' allows to reach the contact point of the radial projections 8, 12 " H of the eccentric sleeves 42 with the inner cylindrical surface 15 of the ring 14 when clamped as a result of perfect wedge contact and radial movement of projections 8.2 »12» HP ° inner cylindrical surface 15 rim 14 «lim allows to reach on working pl of the radial projections 8, 12 ', 11 ' of the inner cylindrical surface 15 of the sliding friction coefficient, the value of which can be determined by f according to equation 2 f_ = .-------- sin β, (FIG. 4) • np - 8 - 226 732 where fg is the sliding friction coefficient on the contact cylindrical surfaces, f the sliding friction coefficient on the cylindrical surface, - the angle of the radial projection relative to the mecha symmetry axis -nismu ·

Said friction coefficient fnp is double and more than twice the friction coefficient f 1 acting on the work surfaces 18, 20, 19 «21 (FIGS. 1, 2) when contacting the discs 4,% of the double eccentric 1 , cams 2, and eccentric |

The design of the eccentric sleeves 6, 2 with radial protrusions 2 " 10 " 12 ' 12 allows the locking of the contact surfaces of the radial projections 2 ', 10 ', 12 with the inner cylindrical surface 15 of the freewheel 14, The sliding coefficient on the work surfaces 18, 20, 12, 21 becomes effective even without the wedge grooves on the inner cylindrical surface 15 of the rim 14 and the wedges on the outer surface of the clamping sleeves, i.e. the wedge locking is achieved in a more technologically advantageous manner and obtains it is possible to dimension these mechanisms with larger wedge angles (Fig. 4), where external torque is not needed for wedging

The magnitude of the boundary wedge angle results from the relation fgK - fx sin / i0 t dC-έ. ——--—---- *

With sin o + flf2K where R is the radius of the cylindrical inner rim and rim of the rim 14 to the radius vector of the double center line 1 and f is 226 732 the friction coefficient of the contact surfaces 18, 20, 19 »21,

The wedging angle oG (Fig. 4) is variable in terms of individual eccentric sleeve sections 6, 2, but has a maximum value when the radius of the double eccentric 1 (Fig. 1) is perpendicular to the axis of the double eccentric mechanism 1 leads through the centers of the double eccentric 1 and the rim 14 «

In order to increase the operational reliability of the eccentric mechanism, the working surfaces of the radial outlets θ, 2 1 1Q H H eccentric pockets 6, 2 are overlaid by rail 24 of the hard metal friction material ·

The freewheel according to the invention operates as follows: Rotates the double eccentric 1 anti-clockwise with respect to the rim 14 with a small angular acceleration, the eccentric sleeves 6, 2 are converted into a radial direction by applying a moment of inertia to these sleeves until the radial clearance between the cylindrical inner surface 15 of the rim 14 and the radial projections 8, 10 > H of the eccentric sleeves 6, 2 and n8 of the contact surface thereof will cause frictional forces, resulting in the gripping of the eccentric sleeves 6, 2 between the discs 2 1, the cams 2, 2 and the collar 14a thus transfer the torque. Upon increasing the rotation speed of the rim 14, the clamping of the mechanism is released and the eccentric sleeves 6, 2 rotate - 10 - 228 732

Suction on the discs 4, 5 of the double eccentric 1 until the pin 12 engages the radial groove 13 in the eccentric sleeve 21, forming radial clearance between the inner cylindrical surfaces 15 of the rim 14 and the radial projections 8, 10, 10 ' } providing contactless movement of mechanics at idle time. In idle mode, the eccentric sleeves 6, s ' 2 are held by the inner cylindrical surface 15 of the rim II. so that they are pressed against the discs 4, 5 of the double eccentric 1 by the inertia acting on them, the pin 12 being pressed into the radial groove 13 «

The freewheels according to the invention can most effectively be used as drive motors for internal combustion engines and gas turbines for motor vehicles and tractors, as well as for machine tools and pulse drive systems.

Claims (3)

Freewheel consisting of a ring with an inner cylindrical surface, a double eccentric with axially arranged disks and a clamping eccentric sleeve mounted on the outer surfaces of a double eccentric and interconnected by a pin with the possibility of a relative radial displacement, characterized in that the double eccentric (1) is provided with cams (2, 3) arranged between its discs (4, 5) with respect to the longitudinal diametrical plane of the clutch and extending the outer surfaces of the discs (4, 5), wherein each clamping eccentric sleeve (6, 7) surrounds the inner surface of the entire outer surface of the corresponding cam (2, 3) and the disc (4, 5) of the double eccentric (1) with its inner surface. 2. Freewheel according to claim 1, characterized in that each clamping eccentric sleeve (6, 7) is provided with a suctioned outer surface along corresponding cams (2, 3) by a pair of radial projections (8, 9, and 10, 11) which are in contact with each other. with an inner cylindrical surface (15) of the rim (14), wherein the length of the contact surface of each projection (8, 9 ' 10,11) perimeter of the circle is equal to 0.1 to 0.5 of the inner cylindrical surface (15) of the rim ( 14) and the angle of tangent to the contact surfaces whose points are closest to each other is 20 to 70 degrees. 3. Freewheel according to claim 1, characterized in that the active surfaces of the radial projections (8, 9 ', 10 ') of the eccentric sleeves (6 ' 7) are lined with a friction material (24). of hard metal *