US2728430A - Retractable vane clutch - Google Patents

Description

w. A. ROTH RETRACTABLE VANE CLUTCH? Dec. 27, 1955 2 Sheets-Sheet 1 .K 1 PM n A W A Q \r N W w W 1 MANWM 1,1 m NM NM W w WWW a ww h ww w MN. ww N\ M \\v 7/// Filed Feb. 25, 1953 RETRACTABLE VANE CLUTCH William A. Roth, St. Paul, Minn assignor of twelve and one-half per cent to Joseph J. Palkowitch, St. Paul, twelve and one-half per cent to Paul Vance, and twelve and one-half per cent to Louis R. Unger, both of South St. Paul, and seventeen and one-half per cent to Arthur J. Alberts, St. Paul, Minn.

Application February 25, 1953, Serial No. 338,643

9 Claims. (Cl. 192-58) This invention relates to an improvement in retractable vane type clutch and deals particularly with a clutch capable of transmitting power between a drive shaft and a driven shaft. I

Various types of hydraulic clutches have been employed which comprise or incorporate rotors rotating eccentrically in casings and provided with vanes capable of forcing fluid upon relative rotation between the members. A clutch effect is accomplished by controlling the flow of fluid to by-pass the vanes. The present invention incorporates some of the same structures, but controls the flow of fluid by wholly or partially retracting the vanes so as to minimize the circulation of the hydraulic fluid.

A feature of the present invention resides in the provision of a clutch including a casing and a rotor enclosed therein. The rotor is mounted eccentrically with respect to the interior of the casing and is provided with radially slidable vanes which may engage the inner surface of the rotor. By partially retracting these vanes, fluid is permitted to pass the vanes, permitting rotation of the rotor relative to the casing. The amount of relative rotation depends upon the resistance to rotation of the driven member, and the degree of retraction of the vanes.

An added feature of the present invention resides in the provision of a means of partially or entirely retracting the vanes so that a portion or all of the liquid may by-pass about the vanes. The means controlling the vane retraction are preferably manually controlled to provide a manually controllable operation.

A further feature of the present invention resides in the provision of a means for retracting the vanes which maintains the vanes at all times in a predetermined proportion of retraction. In other words, if the vanes are retracted one-fourth of the maximum distance, they remain in this proportion throughout the entire revolution only, contacting the casing surface, or substantially contacting this surface at the point of substantial contact between the rotor and the casing.

Still another feature of the invention resides in the provision of a clutch having retractable vanes and in which the vanes are not partially retracted throughout a portion of the circumference and then contact the casing surface throughout the remainder of the revolution. As a result wear upon the vanes and upon the casing is avoided.

These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of my specification:

Figure 1 is a sectional view through the axis of the clutch, the position of the section being indicated by the lines 11 of Figure 2.

Figure 2 is a cross-sectional view through the center of the clutch taken on section line 2-2 of Figure 1.

Figure 3 is a perspective view of a portion of one of the vanes.

Figure 4 is a sectional view of the manual clutch control.

Patent The clutch is indicated in general by the letter A. The clutch includes a housing having a generally cylindrical shell, 10, having a closing plate, 11, at one end thereof. In the particular form of construction, the end plate, 11 is integral with a driven shaft 12. A closing plate 13 is secured by bolts 14 or other suitable means to the opposite end of the casing sleeve of the cylindrical shell 10 and includes a hollow boss 15 secured thereto.

A drive shaft 16 extends through the boss 15 and is supported in proper relation to the housing by means of a ball thrust bearing 17; An inwardly extending projection 19 is provided on the closure plate 11 coaxial with the driven shaft 12 and is encircled by a ball thrust hearing 20. A rotor 21 is connected integrally to a disc-like flange 22 integral with the drive shaft 16. The bearing 20 extends within the rotor 21 and assists in supporting the same.

As best illustrated in Figure 2 of the drawings, the rotor 21 is provided with a series of radially extending grooves or slots 22 in its periphery. These grooves 22 are arranged substantially on planes which intersect the axis of the drive shaft. These slots 22 extend inwardly to a point spaced from the inner cylinder surface 23 of the rotor 21 and elongated apertures 24 are provided at the base of each slot for accommodating a vane controlling means which will be later described. As indicated in Figure 2 of the drawings, the inner surface 25 of the easing shell 10 is cylindrical and is eccentric with respect to the axes of the drive shaft and driven shaft. Accordingly, a crescent shaped pocket 26 is provided externally of the periphery of the rotor, this pocket being capable of containing hydraulic fluid. A series of vanes 27 are slidably supported in the slots 22, these vanes being radially movable in order that the outer extremity of each vane may contact the inner surface of the housing shell 10.

The vanes 27 are constructed as best illustrated in Figure 3 of the drawings. Each vane includes a flat blade 29 which is connected along one edge by a narrow neck 30 to a substantially cylindrical pivot 31. A vane wing 32 is pivotally supported upon the substantially cylindrical projection 31, this wing extending on opposite sides of the blade 29 and being provided with two spaced casing engaging surfaces 33. These surfaces 33 are provided with a recessed intermediate portion 34. The provision of the spaced surfaces permits the vanes to follow the contour of the inner surface 25 of the casing and at the same time provide a relatively narrow area of contact so as to minimize friction.

The edge v35 of the blades 29 opposite the cylindrical projection 31 is provided with an elongated key hole slot 36. This slot 36 is of substantial width inwardly of the inner vane edge 35 as indicated at 37 and this relatively wide portion is connected to the marginal edge of the blade by a relatively narrow entrance portion 39. This arrangement is provided in order to produce a simple detachable connection between the vanes and the vane controlling elements.

The vane controlling elements are best seen from comparing Figures 1 and 2 of the drawings. As shown in Figure 1, each vane controlling member 40 includes an enlarged end portion 41 which extends longitudinally of the enlarged portion of a corresponding vane slot 36. A radially extending flat arm 42 of a of extending through the relatively narrow entrance portion 39 extends toward the center of the rotor. The inner extremity of the web 42 is provided with longitudinally extending opposed arms 43 which extend in a direction parallel to the axis of the rotor and spaced outwardly therefrom. The arms 43 are shown as having rounded bearing ends 44 which are directed outwardly toward the periphery of the rotor.

From the foregoing description, it should be clear that Patented Dec. 27, 1955 thickness capable each individual vane 27 may be projected or retracted in a radial direction and the vane controlling means 40 moves radially in conjunction therewith the same as would be the case if the two parts were integral.

A controlling shaft 45 extends through an axial bore 46 in the driven shaft 12 and is rotatably supported with respect thereto. One end of the control shaft 45 is en closed within a sleeve 47 secured to the projection 19 and which may be integral therewith. As indicated in Figure 2 of the drawings the sleeve 47 is provided with one or more longitudinally extending slots 49 therein. The control shaft 45 is freely rotatable within the sleeve 47.

A pair of generally cylindrical cams 50 are supported upon the sleeve 47 to slide longitudinally with respect thereto. Each cylindrical cam 50 is provided with one or more inwardly extending splines 51 which extend into the groove or grooves 49 to hold the earns 56 from rotation relative to the sleeve 47, while still permitting axial movement thereof. The inner surfaces of the splines 51 are threaded and the control shaft 45 is also threaded. The end of the control shaft within the rotor includes a right hand threaded portion 52 and a left hand threaded portion 53 and the inner edges of the splines are correspondingly threaded. Accordingly, rotation of the control shaft 45 relative to the sleeve 47 will act to move the cams 50 either toward or away from one another depending upon the relative direction of movement therebetween.

The cams 50 are provided with an inner cam surface 58 against which the outwardly directed rounded bearing portions 44 of the vane controlling members 40 may engage. These cam surfaces are properly designed so that the vanes will always be maintained at a desired proportion of retraction throughout each revolution of the rotor, the only point of continuous substantial contact between the vanes and the casing being at the point of substantial contact between the rotor and the casing. For example, in Figure 2 of the drawings, it will be noted that the top of the rotor is in closely spaced substantially sealing relation with the inner surface 25 of the housing, while at the opposite or lower portion of the rotor, a considerable space is provided between the rotor and the casing. Regardless of the position of the retracting members, the cams 56 permit the vanes to be in the position indicated by the uppermost vane 27 in Figure 2.

In order to accomplish this result, the inner surface of the cams 50 is shaped so that the surface engaged by the bearing portions 44 is always circular. At the innermost extremities 55 of the earns, the cam surface is circular and has a center which is concentric with the inner housing surface 25. Accordingly, upon rotation of the rotor relative to the casing, the vanes are free to follow the surface of the housing. The outermost extremity 56 of each cam surface is circular in section and has at its center the center of the rotor. Accordingly, when the earns 55) are drawn together until the bearing portions 44 are in contact with the outer portions 56 of the cam surfaces 53, the cams will be withdrawn into the rotor so that the shoes or wings 32 are substantially flush with the rotor surface.

Because of the fact that the vanes always pass through the position indicated by the uppermost vane in Figure 2 of the drawings, the upper surface of the cam is flat in section when the section is taken as in Figure I through the point of substantial contact between the housing and the rotor. The opposite or lower portion of the cam as viewed in Figure 1 is inclined as the movement of the cams toward one another must gradually retract the cams from the lowermost position shown in Figure 1. As previously stated, any section normal to the axis of the cam between the outermost end 55 and the outermost end 56 of the cam surface is circular, all of the circles being tangent at the upper extremity of the cam.

A seal is provided within the hub so as to prevent leakage from the housing. The seal includes a bearing ring 57 engageable against the inner race of the bearing 17 and a bearing ring 59 supported by the end of the hub. Two relatively rotatable sealing rings 60 and 61 are held in contact by a spring 62 interposed between the rings 57 and 60. Some means is provided for rotating the control shaft 45 externally of the clutch. Such a means is indicated in Figure 4. However, it should be understood that other means of controlling the element could be provided. In the particular arrangement illustrated, the driven shaft 12 is provided with a socket 63 extending axially into the same from its extremity. The end of the control shaft is provided with an externally threaded portion 64 rotatable within the socket 63. The inner diameter of the socket 63 is increasedat its extremity as indicated at 65 to accommodate a sleeve 66 hearing internal threads 67 cooperable with the external threads of the control shaft end 64. The sleeve 66 is connected by an end closure plate 69 to an external sleeve 70 spline connected at 71 to the external surface of the driven shaft 12.

A pair of parallel peripheral flanges 71 and 72 are provided encircling the sleeve 70. A rocker arm 73 is pivotally supported at 74 on a rotatable shaft75 and this arm 73 is provided with a pin or rocker 76 which is positioned between the flanges 71 and 72. In preferred form, one such rocker arm 73 is supported on each side of the sleeve 70 to balance the engagement. Pivotal movement of the rocker arm produces an axial movement of the sleeve '70 and correspondingly the connected sleeve 66. The pitch of the threads upon the control shaft 45 is suflicient to cause rotation of this control shaft upon longitudinal movement of the sleeve 66. Rotative movement of the control shaft 45 causes the cams 50 to move toward or away from one another.

The operation of my device is readily understood from the foregoing description of the parts thereof. The shaft 16 is driven by any suitable means, to drive the shaft 12. Suitable connections 'are provided to supply the power and the load. When the vanes are fully retracted, the rotor 21 may rotate freely within the casing 10. As the shaft 75 is rotated to oscillate the rocker arm 73, the control shaft 45 is rotated moving the earns 50 away from each other. This movement permits the bearing portions 44 of the vane controlling member 40 to travel about a larger diameter surface of the cams 50, permitting the vanes to move by centrifugal force closer to the inner surface. of the casing 10.

Outward movement of the vanes 27 decreases the amount of liquid which may by-pass over the vane ends. This causes the casing to rotate with the rotor, although at a slower speed due to slippage past the vanes. As the outward movement of the vanes increases, the slippage decreases. When the vanes are fully projected, the slippage stops and the casing and rotor rotate in unison.

The control described is effective in providing a neutral position of the clutch and also in disengaging the clutch to any desired degree. As the cams may be moved at any speed of rotation of the rotor or housing, the manual con trol may be effected whenever desired.

It should be noted that my clutch is symmetrical, and therefore may be rotated in either direction with similar results. In other words, the clutch is completely reversible, and functions just as effectively in one direction as in the other. Such an arrangement is believed unique in a device of this nature.

In accordance with the patent statutes, I have described the principles of construction and operation of my retractable vane type clutch and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1. A clutch including a housing, a generally cylindrical chamber within said housing, a rotor supported within said chamber and eccentrically with respect thereto, means rotatably supporting said rotor, vanes carried by said rotor in angularly spaced relation, said vanes being movable in a generally radial direction and engageable with the periphery of said chamber, and means for retracting said vanes, said means guiding said vanes in a circular path regardless of the degree of retraction thereof.

2. The structure described in claim 1 and in which said vane retracting means includes cam means and vane control means connected to said vanes and engageable with said cam means.

3. The structure described in claim 1 and including means for manually actuating said vane retracting means.

4. The structure described in claim 1 and in which the vane retracting means includes generally cylindrical cam means having a hollow interior cam surface.

5. The structure of claim 1 and in which the vane retracting means includes two spaced cams.

6. A clutch including a housing, a generally cylindrical chamber within said housing, a rotor supported within said chamber and eccentrically with respect thereto, means rotatably supporting said rotor, vanes carried by said rotor in angularly spaced relation, said vanes being movable in a generally radial direction and engageable with the periphery of said chamber, and means for retracting said vanes, said means guiding said vanes in a path in which the vanes are in contact with the inner surface of the housing, are substantially fully retracted, or travel in any intermediate path at which time the ends of the vanes are maintained at substantially the same proportional distance between the outer surface of the rotor and the inner surface of the housing.

7. A clutch including a housing, a generally cylindrical chamber within said housing, a rotor supported within said chamber and eccentrically with respect thereto, means rotatably supporting said rotor, vanes carried by said rotor in angularly spaced relation, said vanes being movable in a generally radial direction and engageable with the periphery of said chamber, the outer surface of the rotor susbtantially contacting the inner surface of the housing at substantially a common plane of tangency, and means for retracting said vanes, said means always guiding said vanes in a generally circular path through said plane of common tangency regardless of the degree of retraction.

8. The structure described in claim 7 and in which said retracting means comprises a cam.

9. The structure described in claim 7 and in which said retracting means comprises a cam having a cam surface comprising substantially a frustum of a cone having one side perpendicular to the base of the cone.

References Cited in the file of this patent UNITED STATES PATENTS 1,633,550 McKinney June 21, 1927 1,905,041 Monroe Apr. 25, 1933 2,175,413 Sharar Oct. 10, 1939 2,430,614 Jordan Nov. 11, 1947

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