US1491797A - Fluid motor - Google Patents

Description

F. Y. HARRISON FLUIlj MOTOR f F' ed Aprilv 19 Patented Apr. 29, 1924.

FRANK Y. HARRISON, OF DETROIT, MICHIGAN, ASSIGNOR TO MURPHY IRON WORKS, 'OF DETROIT, MICHIGAN, A CORPORATION O'F MICHIGAN.

y FLUID Moron.

Application filed April 20, 1922. Serial No. 555,733.

To all whom if-may concern.'

Be it known that I, FRANK Y. HAnmsoN, a citizen of the United States, residing at Detroit, in the county of Wayne and State f of Michigan, have invented certain new and 'useful Improvements in Fluid Motors, of

which the following is a specification.

The present inventionpertains to motors, engines, pumps and similar structures employing a cylinder and a reciprocating piston or plunger therein, its leading aim being to provide a construction of this general type wherein excessive wear between the piston and cylinder-wall and between-the piston-rod and its associated stuiiing-box will be eliminated and wherein undue strains will be removed from these and other parts of the mechanism thus in llarge measure tak- Iing away the underlaying causes for such objectionable wear.

By employing the features of construction incorporating the principles of this invention a fluid or liquid motor or pump may be provided capable of operating at very slow speed and without substantial leakage past the piston or through the stuing-box connection.

More specifically, but not restrictedly, one leading aim of the invention `1s to provide a hydraulic-motor for operating the movable elements or a portion or o-ne or more of them of a fuel-stoker for furnaces at a comparatively low speed, but with eliiciency and satisfaction.

In a motor of this reciprocatory style, it is obvious that atreduced speeds the matter of leakage around the piston and piston-rod becomes of great importance and such loss must be `practically eliminated if the motor is to be a success.

Such leakage depends upon the fit and wear of the parts involved, and the wear in turn, in large measure, is occasioned by strains or stresses imposed 'on these elements by reason of the lack of perfect alignment of these and complementary parts of the appliance.

The prime purpose of this invention is, therefore, to overcome such strains, wear, and leakage, thus rendering possible the' production'of a suitable Islow-speed motor of this type.

In the accompanying drawing, I have presented av desirable and preferred embodi-l q'ment of the invention and in such drawing:

The simple figure illustrates the greater portion of the mechanism in central, longitudinal section'.

By reference to this drawing, it will be perceived that the appliance includes a cylinder 'of usual construction having the customary demountable heads or end-walls 11 and 12 fastened thereto by the ordinary stud bolts and nuts, the cylinder having means 13 and 14, shown more or less diagrammatically, for the admission and eX- haust of the fluid or liquid, in the present instance, water, at the two end portions of the cylinder, the valve structure for controlling such admission and discharge not being shown because it is wellknown -and may be of any satisfactory style.

rlhe piston, slidingly mounted in such cylinder is composed of two parts 15 and 16 held together by means of cap screws 17, the piston having a peripheral groove 19 `accommodating two, hollow ring packings 20, 20, which may be readily replaced when required by temporarily taking olf'the piston section 16 for that purpose.l

Screwed into or otherwise suitably and rigidly fastened tothe part 15 of the piston or plunger is a cylindrical tube or sleeve 21 extending out through the cylinder end-wall or head 11 through a proper stutling-box 22 which maintains a pressure tight connection with the tube throughout its stroke or sliding travel.

yllhis sleeve or tube acts as a means to maintain the piston in proper and correct alignment with the cylinder wall with which it coacts and to assist in guiding'it in itsy reciprocations.

The piston rod 23, loosely housed inthe sleeve or tube, at its inner end has a head or enlargement 24 rounded or provided with v sections of spherical surfaces, 25 and 26.

The piston member 15 has a central aperture 27 through which the piston-rod loosely extends, a portion of the inner face of such part 15 being curved or concaved at 28 corresponding tol the adjacent face 25 of the piston-rod, and" the` other or companion piston-element 16 is internally equipped with a curved or concave face at 29 conforming. to and adapted to coact with the other rounded end face 26 of the piston-rod.

. It is to be noted, however, that there is a slight longitudinal or axial play or looseness between the ball head of, the piston-rod los and the ball-socket receiving such head and formed between the two sections of the piston. p

The other or outer end of the piston-rod, by any suitable .means, is operatively dilrectly connected to the part which it is A adapted to actuate.

It will be apparent, therefore, that the piston-rod has a slightly-loose, ball-andsocket, universal-joint connection with the piston, whereby the -piston-rod is free to move laterally in any direction without placing any strain on the piston and hence reducing wear to the minimum, the piston being held in proper alignment by the guiding, sliding tube or sleeve with which the stung-box maintains a tight connection.

When the piston is moving to the right by reason of fluid pressure, such as water pressure, in the left hand part of the cylinder, such pressure exerted on the piston member slides the piston to the right, the latter by reason of the contacting faces '25 and 28 forcing the piston-rod in the same direction.

Under these conditions there is no strain on the studs 17 and their nuts 18 which merely hold the companion parts of the piston together with the packing between them, because the piston-rod head does not bear on the curved face 29 of the piston-element 16 due to the loose connection specified.

On the other hand, when the piston is being forced to the left under liquid pressure in the cylinder to the right of the piston, the curved face 29 of the part 16 bears directly on the end of the piston-rod head carrying such rod also to the left.

During such left-hand movement of the piston and its rod, there is no substantial strain on the piston studs because the lefthand elementV 15 of the piston is pushed along by the complementary right-hand part, the studs under these conditions be- 1ng practically functionless.

Thus the piston is guided by the attached tube or sleeve in perfect alignment with no distortion strains on either by reason of wear or mal-alignment of the power-transmitting mechanical parts with which the piston isassociated.

Viewed in one way this particular embodiment of the invention comprises the employment of a ball and socket joint between the piston-rod and piston to give to the former the capability of movement trarfsverse to its axis thereby relieving the rod from undue and unnecessary strains and also protecting the piston from similar or resulting strains.

Such capacity for lateral movement prevents the direct employment of a stuffingbox therewith and accordingly the tube or sleeve is used to secure the liquid or fluid tight connection and to act as a guide for the piston. f

It will be clear that such a structure, representing only one embodiment of the invention, is adapted for several advantageous uses, and that many minor mechanical changes may be incorporated in the appliance without departure from the heart of the invention and without the sacrifice of any of its substantial benets.

' l claim:

In a structure of the character described,

lthe combination of a cylinder having an apertured cylinder-head, a transversely-divided piston having a ball-socket between its component parts, onev of said parts being apertured, means to fasten said piston parts together a sleeve rigid and sldable with said piston and extended through said head aperture, means to maintain a pressure tight connection between said cylinder-head and said sleeve, and `a piston-rod inside said sleeve and extended through said piston aperture and having a ball-head accommodated in said piston ball-socket Aloose longitudinally of the piston.

lln witness whereof I have hereunto set my hand and seal.

FRANK Y. HARRlSON. [n 5.]

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