US2208177A - Rotary motor - Google Patents

Description

y 16, 1940- E. G. BARRETT 2,208,177

ROTARY MOTOR Filed July 1, 1939 3 Sheets-Sheet l tn-iiiJ'EEf y 'u P Elm r Gparrefi E. G. BARRETT 2,208,177

ROTARY MOTOR July 16, 1940.

3 Sheets-Sheet 5 Filed July 1, 1939 Patented July 16, 1940 UNITED STATES PATENT OFFICE 3Claims.

My invention relates to improvements in rotary motors and more particularly to motors of this class having two aligned cylinders, in each of which a piston spacing drum, or smaller diameter than the cylinder, isjournaled for free rotary motion eccentrically of the axis of the cylinder in which it is mounted. The present application is a continuation-in-part of my application Ser. No. 140,260, filed on May 1, 1937, now aban doned. The eccentric mounting of the drums with respect to the mounting of the pistons within the cylinders, is such that a sealing line of contact is maintained at all times between the peripheral surface of the drums and one side wall of the cylinders, providing crescent shaped working and expansion chambers through which sliding vane-like pistons are caused to travel by expansion of a working fluid, which is supplied serially to the chambers.

An object of my invention is to provide a rotary motor casing casting in which the cylinders are of substantially uniform diameter and with their axes aligned, thereby simplifying the production of the casting and the assembly of parts therewith, thus insuring more perfect lit and seal between the relatively movable parts of the assembly during operation.

A further object of my invention is therefore to provide a motor of this character with greatly simplified construction and which is capable of large output for its weight.

With these and other objects in view, the instant invention further comprises certain novel features of refinement and advantages in the construction of a motor casing having aligned cylinders and a distributing valve cooperating therewith, and to the relatively movable parts which are assembled in cooperative relationship with said cylinders and valve, all as will be more fully described hereinafter and illustrated in the accompanying drawings, in which:

Figure 1 is a view partly in section taken longitudinally through the motor and valve casing;

Fig. 2 is a transverse sectional view taken on line 2-2 of Fig. 1;

Fig. 3 is a further longitudinal sectional view taken on line 3-3 of Fig. 2;

Fig. 4 is a detail sectional view taken on line 4-4 of'Fig. 1 through the motor casing at the position of the distributing valve parts being shown in elevation;

Fig. 5 is a further detail view partly in section, illustrating the mounting of a piston-spacing trunnion in an end plate of a rotary drum member apart from the casing:

Fig. 6 is a view similar to Fig. 2 showing a modiflded form of the invention;

Fig. 7 is a detail view partly in section of the 6 piston sealing blocks and their mounting, shown in Fig. 6; and

Fig. 8 is a fragmentary view of one of the end plates of a rotary piston drum showing a mounting for an end portion of the piston sealing block. 1.

In the drawings, briefly described above, I have illustrated the casing 5 of the motor as comprising a single casting which is cored out at opposite ends to provide aligned cylinders 6 and I of uniform diameter. Separating these cylinders is a web or division wall 8 which is formed integral with the casing. By reference to the sectional views in Figs. 1 and 3, it will be noted that this division wall is disposed nearer to one end of the casing 5 than to the other end, and that 20 by this arrangement the capacity of the cylinder 1, which receives its working fluid serially from the cylinder 6 through the distributing valve 9, is enlarged without increasing the bore of cylinder 1. The opposite ends of the cylinder casing may 25 thus be of uniform dimensions and shape, to which uniformly cast and interchangeable heads I0 and II may be fitted and secured by bolts 12. Packed shaft bearings l3 and II are formed in each of the head members In and II so as to 30 align with the packed shaft bearing l5, arranged at the center of the division wall 8, when the head members are secured over the ends of the cylinders 6 and l, by bolts l2. The shaft l6, supported by these hearings, thus passes centrally 35 through the two cylinders, division wall and head members to the outside of the casing where a pulley, or other power take-oil means not shown may be attached to either or both ends of the shaft as desired. The inner face of each of the 40 head members I 0 and II, as well as the opposite faces of the division wall 8, are each cored out around the shaft bearings l3, l4, and I5 to form annular recesses which are of slightly less diameter than the diameter of the cylinders 6 and I, 45 thus providing cylindrical bearing faces l1, l8, l9 and 20 at opposite ends of each cylinder in which the opposite ends of the piston spacing drums ii and 22 are iournaled.

These recessed annular bearings are disposed 50 with their centers eccentric to the axis of the shaft l6 and with their cylindrical bearing faces intersecting the ends of the cylinder walls at one side of the cylinders 6 and 1 so as to extend contiguous therewith, as shown in Figs. 1 and 3. 55

vane-like pistons is keyed The rotatable drums 2| and 22 are therefore eccentrically mounted with respect to the longitudinal axes of the cylinder walls with which they are held in line-sealing contact from end to end of the cylinders, and provide with the cylinder walls, crescent- shaped expansion chambers 23 and 24. Each slotted at diametrically opposite points to provide elongated openings 25 and 26 of a length equal to the length of the cylinders, through which vane-like pistons or members 21 and 28 extend from the shaft It to the cylinder walls with which they have sliding engagement.

The inner surface portion of each of the drums is arcuately recessed adjacent each of the slots 25 and 26 to provide long bearing surfaces for slotted trunnion blocks 29, through which blocks the pistons have radial sliding engagement. Ring- like plates 30 and 3| are secured to the ends of each drum adjacent the peripheries of the drums, and the inner faces of these plates are cored out at diametrically opposite points to provide socket bearings 32 in which the ends of the trunnion blocks 25 are journaled. These socket hearings, in the plates 30 and 3|, are preferably stepped as shown in Fig. 5, to provide increased annular bearing surfaces for the peripheral end portions of the blocks with the minimum of frictional resistance, due to end thrust in holding said piston spacing blocks firmly between the plates 30 and 3| and against the arcuately recessed and slotted surface portions of the drums.

It will be noted that o y one of each pair of to the shaft It, and that these two keyed pistons are preferably disposed at an angle of approximately 180 to each other in their respective cylinders. Such an arrangement has been found to produce smoother running with greater power output in a motor of this character. The other piston, of each pair of pistons, is freely journaled on the shaft IE but is held spaced from its companion piston by the trunnion blocks 29 and the segments of the drums and the end plates 30 and 3| in which the blocks are rockably mounted. The vanelike pistons are thus arranged radially at equidistant points with respect to the periphery of the drmns 2| and 22 through which they project during rotation of the shaft l6 and drums into the crescent- shaped expansion chamber 23 and 24 of the cylinders 6 and 1.

To insure against leakage of the working fluid at the ends of the eccentrically mounted rotatable drums, the ring- like plates 30 and 3| are formed slightly less in diameter than the diameter of the drums to which they are secured and the peripheral face of each of these plates is circumferentially grooved or recessed as at R adjacent the ends of the drums to provide annular seats for L-shaped sealing rings 33, the

outer surfaces of which rings bear upon the cylindrical bearings surfaces l1, |8, |9 and 20 in the heads and division wallmembers, as shown in Figs. 1 and'3, and illustrated in detail in Fig. 5. The rockable trunnion 29 is provided with an arcuate cutaway portion 291: so formed as to provide a stop edge 29b for engagement with the sealing ring 33 to prevent the complete rotation of said trunnion. A pin or small stub shaft S is associated with trunnion 29 and arranged for engagement with socket bearing 32. whereby the trunnion 29 will be carefully aligned and operate smoothly in the performance of its functions, inincluding the guiding of sliding piston 21.

drum is longitudinally The lower or base portion of the casing casting is formed with a longitudinal tapering bore 34 I which extends from end to end thereof parallel to the axes of the cylinders B and 1, and into this bore is frictionally fitted the tapering distributing and reversing valve 9, as shown in Figs. 1 and 4. This valve 9 is preferably held in sealing engagement with the walls of the bore by a nut 35 which is threaded upon the reduced extension 36 of the valve body which projects from one end of the bore. At the opposite end of the valve 9 an operating handle 31 is secured to a reduced extension 38 of the valve body which projects beyond the opposite ends of the casing. Connected to and extending into the casing adjacent the handle end of the valve 9 is a supply pipe and conduit 39 which communicates with a passage through the valve body by means of an arcuate recess 40 formed around the end of the valve body.

. The casing is further formed with pairs of inlet and exhaust ports P and P which communicate with each cylinder, these ports taking the form of elongated angularly arranged passageways extending through the base of the casing casting to opposite side of the valve bore immediately below each cylinder. It will be noted that these ports communicate with the crescent shaped chambers in each of the cylinders on opposite sides of the line where the drums make line-sealing contact with the cylinder walls. It will be further noted, by reference particularly to Fig. 3.that where these passageways or ports P and P join the cylinder walls that they are angularly arranged with respect to the longitudinal axes of the cylinders and that the pair of ports P and P in the smaller, or high pressure cylinder 6, are disposed at a greater angle to the longitudinal axis of the cylinder than the pair of ports in the lower pressure cylinder 1. By this arrangement an increased working pressure is caused to build up between the pistons working in cylinder 6 after each piston passes full piston stroke, which pressure or charge is to be carried over from the high pressure cylinder to exert a greater expansive force behind the pistons ,of the low pressure cylinder 1, than if the working fluid being fed behind one piston of the high pressure cylinder were immediately cut ofi at the point of maximum expansion of the working fluid and stroke of the piston by the companion piston entering the expansion chamber 23 of that cylinder. As the working fluid fed to cylinder 1 from the cylinder 6 is exhausted after performing its work in that cylinder, the ports P and P in cylinder 1 need only be angled slightly with respect to the longitudinal axis of that cylinder so as to prevent wear at the sliding edges of the vane-like piston.

In controlling the supply and exhaust of the working fluid to the cylinders, as well as the serial transfer of the working fluid from one cylinder to the other, the valve body 0 is longitudinally and transversely cored out as shown in Fig. 4 to provide angularly disposed passageways 4|-42 and 43, which in normal set positions of the valve communicate with the ports P and P of the high and low pressure cylinders 6 and 1. By the arrangement of passageways through the valve body as illustrated reversal of the motor may be effected by rotation of the valve body 9 by the handle 31 from the position shown in Fig. 4 to a position where the working changes or modifications in the structure illustrated particularly in Figs. 2 and 5. These changes will therefore be described as follows:

Secured to the shaft lGa, in each of the longitudinally arranged cylinders (one of which is designated at 6a) is a single vane-like piston 21a, counterbalanced by an arcuate weighted portion 28a. disposed on the opposite side of the shaft l6a from the vane. By this construction and arrangement of parts, the pistons in the adjacent cylinder, which are separated by the vertical partition wall 8a, are preferably disposed 180 apart so that when one vane is at its xero position within one cylinder the other piston is at its maximum driving position for either direction or rotation with the motor.

In Fig. 6 the piston vane 21a is shown extended to its maximum through the rockable sealing block 29a. This block which is illustrated in detail in Fig. 7 is independently, rockably mounted between the opposite edge portions 24a of the slot 25a which extends for the full length of the piston drum Ma. The drum which would usually be formed from a steel cylinder will function to resiliently hold the blocks in frictional en gagement with the sides of the piston vanes during angular movement of the pistons and thus effectively close and seal the slot through the drum.

As illustrated particularly in Figs. 7 and my improved sealing block,29a permits its end bearing portions which extend into the recesses 32a below the retaining ring 33 in the end plates or walls 30, to be moved out toward the periphery of the drum am much further than would be possible with the construction illustrated in Fig. 5. This is an important improvement in that the oscillating motion of this block is thereby reduced as well as the eccentric weight of such parts.

By this construction a very simple and eflicient sealing and guiding means for the vanes is provided all of which will operate with the minimum of vibration and wear upon the relatively movable parts so that increased power output for weight is possible in a motor which can be readily reversed with equal power output in either direction of rotation.

While I have shown but two embodiments of my invention, I am aware that minorchanges may be made therein, by those skilled in the art,

which'do not depart from the spirit and scope of the invention as described and covered by the appended claims.

I claim:

1. A rotary motor comprising a casing including a cylinder, a shaft journaled in said casing and extending through said cylinder, a drum rotatably mounted in said cylinder with its axis eccentric to the axis of said cylinder and its periphery in engagement with a side wall of the cylinder providing with the cylinder a crescentshaped expansion chamber, a vane carried by said shaft and extending radially through a slot in said drum for sliding engagementlwith the walls of said cylinder, a ring-like plate secured to and end of said drum, a trunnion bearing formed in a face of said plate, and a trunnion associated with said drum said vane and said plate in rockable relation with said plate and slidable relation with said vane, said trunnion having a cutaway portion forming a recess, and a ring of L-shaped section in sealing relation with the ring-like plate and the trunnion.

2. A rotary'motor comprising a casing having two aligned cylinders of substantially uniform diameter, said cylinders being separated by aplates and transversely extending wall to extend centrally through said cylinder, a drum surrounding said shaft in each of'said cylinders and journaled at its ends in said wall and head plates with its axis eccentric to the axis of said shaft,

longitudinally extending slots formed in said drums at diametrically opposite points, a pair of vane-like pistons for each cylinder carried by said shaft and extending radially through the slots in said drum for sliding engagement with the walls of said cylinder, an inlet and an exhaust port formed in the wall ofeach cylinder adjacent the periphery of each drum, said ports extending entirely through the walls of the cylinder and generally longitudinally of each cylinder at an angle to the axis thereof, and a reversing valve communicating with said ports.

3. A rotary motorcomprising a casing including a cylinder, a shaft journaled in said casing and extending through said cylinder, a drum rotatably mounted in said cylinder with its axis eccentric to the axis of said cylinder and its periphery in engagement with a side wall of the cylinder providing with the cylinder a crescentshaped expansion chamber, a vane carried by said shaft and extending radially through a slot in said drum for sliding engagement with the walls of said cylinder, a ring-like plate secured to an end of said drum, 9. trunnion bearing and concentric arcuate recess formed in the inner face of said plate adjoining the periphery thereof, a sealing block associated with said drum in rockable supported relation with the recess in said plate and slidable relation with said vane, said sealing block having a substantially semicircular body portion adapted for frictional engagement with the longitudinal edge portions of said drum and being cut away to provide, a depending skirt slotted to receive said vane, said block having a trunnion projecting from the end thereof and extending into the trunnion bearing in said plate, and a ring of L-shaped section in sealing relation with said plate and trunnion.

ELMER G. BARRETT.

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