US3003593A

US3003593A - Ratchet mechanism for preventing reverse rotation

Info

Publication number: US3003593A
Application number: US709981A
Authority: US
Inventors: Frederick O Luenberger
Original assignee: Us Electrical Motors Inc
Current assignee: US Electrical Motors Inc
Priority date: 1958-01-20
Filing date: 1958-01-20
Publication date: 1961-10-10
Anticipated expiration: 1978-10-10

Description

Oct. 10, 1961 F. o. LUENBERGER 3,003,593

RATCHET MECHANISM FOR PREVENTION REVERSE ROTATION Filed Jan. 20, 1958 2 Sheets-Sheet 1 1 R 11 f 10 i 14' 1e 9 v 5 13 8 J6: 15' 39 L 2@ 40 I 740 i E l xl l. I 12 I I i:' L T18 I 19 27 :E a j I 4A '3: .1 1. i E 29 7 II. la 1a ,IWIQEDEE/CM 0. lus/veseaee,

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Oct. 10, 1961 F. o. LUENBERGER RATCHET MECHANISM FOR PREVENTION REVERSE ROTATION Filed Jan. 20, 1958 2 Sheets-Sheet 2 INVENTOR.

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United States This invention relates to provisions for stopping or preventing backward motion of rotary apparatus.

Such devices in general are now well-known for use with vertical electrical motors adapted to drive pumps located within wells. One such ratchet device is described in Patent No. 2,793,714, issued May 28, 1957. However, other forms of backstops may be utilized in association with the present invention.

The backstops come into operation when the power to the motor is interrupted. The hydraulic forces then acting on the pump runners produce a resultant torque urg ing the rotor of the motor in a reverse direction. If this reverse rotation be permitted, serious injury to the motor might result.

Without further provisions, such ratchets abruptly stop reverse rotation, with attendant severe stresses on the ratchet mechanisms. Such stresses are especially pronounced when the motor is of relatively large capacity.

It is one of the objects of this invention to make it possible to interpose an opposing resilient (instead of an unyielding) force against reverse rotation. Thereby the harmful and destructive stresses and strains on the mechanism are greatly minimized.

It is another object of this invention to provide a simple and compact and inexpensive resilient device to accomplish these results.

In the preferred embodiment of the invention, the resilient-device is in the form of aresilient open ring 'which is caused to expand upon imposition of the atent O F any oscillation or rebounds if the reversing force is 7 suddenly removed.

This invention possesses many other advantages, and

has other objects which maybe made more clearly apparent from a consideration of one embodiment of the invention. For this purpose, there is shown a form in the drawings accompanying and forming a part of the present specification. This form will now be described indetail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be. taken in a limiting sense,:since the scopejof this invention is" bestdefined by the appended claims.

Referring to the drawings:

FIGURE 1 is a fragmentary vertical section of the upper portion of a structure incorporating the invention installed in connection with a vertical electric motor;

-FIG. 2 is a sectional view, taken generally along the plane indicated by line 2--2 of FIG. 1;

FIG. 3 is a sectional view, taken along a plane corresponding to line 33 of FIG. 1; and

FIGS. 4 and 5 are enlarged fragmentary sectional views, taken respectively along planes corresponding to lines 4-4 and 55 of FIG. 3.

In FIG. 1 there is shown an electric motor bracket 1, integrally formed with a central boss 2. This boss 2 is joined to the bracket 1 by ribs 1a. The boss serves to support bearing structures for the rotor of the motor.

Thus the rotor of the electric motor is mounted upon a vertical hollow shaft 3 to drive it. This hollow shaft 3 is shown as keyed to a lower coupling member 4. The lower coupling member 4 in turn supports the inner races 5 of a series of thrust ball bearing structures 6. The

Patented Oct. 10, 1961 outer races 7 of these ball bearing structures are appropriately accommodated in the central boss 2.

The hollow shaft 3 has a threaded upper end for the accommodation of a nut 8 adapted to rest upon the upper surface of the coupling member 4.

An upper coupling member 9 is joined to the lower coupling member 4 in any convenient manner as by screws, such as 12 (FIG. 2). Upper coupling member 9 is keyed to a pump shaft 10 which extends downwardly and carries the subterranean pump runners. Shaft 10 is provided with a threaded upper end accommodating a nut 11 for the purpose of adjusting the vertical position of the shaft 10.

The upper coupling member 9 has slots or recesses 13 for the accommodation of inwardly directed bosses formed on the inner flange of a rotating ratchet member dicated most clearly in FIG. 2, is provided with a series of equiangularly spaced, downwardly directed apertures 15 for the accommodation of balls 16. These balls are retained against radial removalby the aid of a ring 17 extending around the upper edge of the member 14. These apertures are non-radial and extend inwardly toward the axis of rotation.

The balls 16 cooperate with another ratchet member 18 which has a series of equiangularly spaced recesses 19. This ratchet member is restrained against substantial movement in a manner to be hereinafter described.

When the rotary structure rotates in a counterclockwise direction, as indicated by arrow 20, there is no restraint against rotation. This is apparent from a consideration of the direction of the apertures 15 as viewed in FIG. "2. For this direction of rotation, the'wall of each aperture 15 tends to urge the associated balls 16 radially outwardly with respect to the ratchet member 18. Accordingly, the balls roll on the inner walls of the recessesv 19.

When there is a reversal of this desired direction of rotation as indicated by the arrow21 (FIG. 2), the balls 16 are urged by the walls of apertures 15-inwardly toward the abrupt portions 22 of the recesses 19. 7 As hereinafter explained, only a portion of the total number of balls are actually in restraining position. This position is shown, for example, by the diametrically opposite balls having their centers on a horizontal line 23 of FIG. 2.

Since there are twelve balls and only ten recesses, two diametrically opposite balls serve'simultaneously to restrain rotation, the other balls being out of register with any abrupt wall '22. Thus rotation is restrained after a very short, angular, travel of the rotary apparatus, since at least two of the balls 16 must be quite close to a corresponding abrupt wall 22 of recesses 19.

Since this mode of operation has been described in said prior patent, particularly FIGS. 6 and 7 thereof, further description of the action of the ratchet mechanism is considered unnecessary. Furthermore, any equivalent form of ratchet device could be substituted for the specific form herein disclosed, since the invention is not at all concerned with any particular form of ratchet device.

The inner ratchet member 18 is provided with an outwardly directed flange 24 (see also FIGS. 4 and 5). The outer periphery of the flange has a running fit within the internal diameter of a flange 25 extending from the upper edge of the boss 2. This flange is formed integrally with a casing or cover member 26.

Underlying the ratchet member 18 and resting upon the upper surface 27 of the boss 2 there is located a resilient split ring member 28. This spring member 28 is shown in the present instance as of rectangular cross-section, flat on both its upper and lower surfaces, and havingends 29 and 30. Each=of these ends is provided with an .arcuate .recess .31 or 32. Furthermore, .the ring .is made of material sufliciently springy so that it may be expanded when an expanding force is exerted by forces acting on the utecesses :31and52.

This expanding forceis created f-by the i force imposed iupon the rratchet :member .18, due to the urging of balls 16 against .walls22. 'illhus thefiange 24 of ratchet member 18 carries an abutmentror pin 33 that :is force-fitted into ithe fiange This .pin 33, as shown most clearly 'in FIG. 4, rextends downwardly and in contact with the recess On 'the :other hand, a pin 34 is anchored firmly-in the boss'2 and extends upwardly to serve as an :abutment for '-the recess 31. Accordingly, when the ratchet member 18 tends itO move in a clockwise direction as indicated -byi.the:arrow'35of 3, the pin 33 serves to expand the ring 28 resiliently. The abutment =pin 84'beingstationary, this expansion occurs until stopped by the resilient force -exerted by=the spring-ring 28. The ring 29 has ample clearance -within flange 25 to permit -'-thisexpansion.

This resilient force created by ring 28 opposing rotation of the ratchet member 18, cushions the-shock of any sudden reverse rotation.

-If the 'force due to this reverse rotation is suddenly removed, the spring ring 28-may havea-tendency to oscillate and =vibrate. In order-to damp .these oscillations, use "is made "of a=friction p'late 36 (FIGS. 4 and disposed on the under surfacecfthe'flange 24 and in contract with 'the upper surface of the ring 28. This frictional plate 36'maylbe of any appropriatefabric or metal 'and'may be accommodated -in a recess adjacent the edge of the flange 24.

Another friction plate 37 is firmly disposed on the *upper surface of the flange 24in order to 'restrain'sudden movement of the ratchet member 18.

The'flange '24 is urged-resiliently downwardly against thespring ring 28-by the aid of compression springs 38 (FIG. 1*) that are arranged equiangularly around the axis of-thedevice and'thaburgea pressure ring 39 downward-ly. Fourof thesesprings 38 may be used. They are held in appropriate position by the aid of the screws "40-threaded -'into-the upper surface of the boss *2.

The inventor claims:

1. For use with a pumpstructure: a support; a shaft extending transverse to the support and adapted to drive .the-pumppmeans mountingthe shaft so that the shaft is capable of continuous rotation relative to the support; saidsshaft havingsa desired .direction of rotation; selecrtively operable means for rotating said shaftmember in said-desired direction; apair of ratchet members,-one of ;the-members'heing. carried :by.the-.shaft;:the second ratchet rrnerriher being mounted byxtheisupport; means confining :the.-second:ratchet member for movement relative to the support about the axis of said shaft; an open ring hav- .ing spaced ends; eachend having a concave recess; apin carried by said support andtengaging the concave recess at one end of the ring for anchoring the corresponding ring end; and a pin carried by the second ratchet member and engaging the concave recess at the other end of the ring, whereby said ring resiliently opposes movement of said second ratchet member about said axis .upon engagement of said ratchet members.

2. For use with a pump structure: asupport ;p1' oviding a recess; a shaft havingan axis aligned with the recess and adaptedto drive the ,pump; .means mounting the shaft so that the shaft is capable of continuous rotation relative .to thesupport; said shaft having a desired direction of rotation; a pair of ratchet members; one ofthe members having a flange received in the recess and-confined .for movement about the axis of the recess; a -flat resilient open ring between the flange and-the-bottorn of ,therecess; anchor means cooperable with the'suppoi't for confining one end of the ring; anchor means carried by the said one member and engagingthe-otherend of the ring; the second-of said ratchet members being carried by said shaft; and means frictionally urging said flange into contact with said ring to provide dampingto all movement of the-said one ratchet member.

3. For use with a pump structure: a-support providing a recess; a shaft having an axis aligned with the recess and adapted to drive the pump, and rotatable relative to the support; =said shaft having a desired direction of rotation; a pair of ratchet members; one of the members having a'flange received in the recess and confined for movement about the axis of the recess; a flat resilient open-ring between the flange and the'bottom of the recess;

anchor means cooperable with the support for confining one-end of the ring; anchor means carried by "the said one member and engaging the other end of'the ring; the second of said ratchet members being carried by said shaft; andmeans firictionally urging said flange into contact with said spring including an annular elementengaging the flange, and resilient means mounted on the support urging the annular element against said flange, andadjustable to provide a selected damping force.

References Citedin the'file of this patent UNITED STATES PATENTS 1,495,207 Rybeck May 27, 1924 1,841,255 Rybeck Jan. 12, 1932 1,867,987 'Ruegg July 19, 1932 2,734,359 Mulheim et a1 Feb. 14, 1956 2,750,007 Turner et al. June 12, 1956 2,766,863 'Berg Oct. .16, 1956 FOREIGN PATENTS 238,210 Great Britain Feb. 11,1926