US2455480A

US2455480A - Diaphragm pump

Info

Publication number: US2455480A
Application number: US562163A
Authority: US
Inventors: Harold F Hadley
Original assignee: DAPCO PRODUCTS Inc
Current assignee: DAPCO PRODUCTS Inc
Priority date: 1944-11-06
Filing date: 1944-11-06
Publication date: 1948-12-07
Anticipated expiration: 1965-12-07

Description

H. F. HADLEY 2,455,480

DIAPHRAGM PUMP Filed Nov. 6. 1944 1 13 J4 M ATToRN Patented Dec. '7, 1948 DIAPHBAGM PUMP Harold F. Hadley, Defiance, Ohio,asslgnor to Dapco Products, Inc., a corporation of Ohio Application November s, 1944, serial No. 562,163

4 claims. (ci. 25a-17o) This invention relates to fluid pumps and more particularly to pumps or compressors of the diaphragm type especially adapted for compressing gases. v

Pumps and compressors of the diaphragm type have been constructed for comparatively low, pressure and small volume operation especially for compressing air and other gases, and have proven fairly satisfactory for this character of work. When attempts have been made to use a compressor of the usual diaphragm type for high pressures or large volume operations, diaphragm rupture and other attendant diiculties have been encountered which in the past have resulted infailures.

The present invention has for a principal ob- .lect the provision of a fluid pump or compressor of the diaphragm type `capable oi operation at high pressures and of compressing comparatively large volumes of gas for long periods of time without diaphragm failure.

Another object of the invention is the provision of a diaphragm compressor especially adapted for compressing gases to high pressures in conjunction with a valve arrangement which permits gas to be compressed uncontaminated with oil or other lubricant.

Another object is the provision of a unitary '1 diaphragm construction wherein a metallic ilexible element is bonded to a metal member in such a manner that th'e diaphragm is capable of operation over'long periods of time at high pressures without failure.

Another object is the provision of a unitary diaphragm construction which may be readily replaced in a comparatively short time without the use of special tools.

Still another object is the provision of a dia' drawing of a form of the invention, which may be preferred, in which:

Figure 1 is a vertical sectional view illustrating a compressor embodying a form of my invention;

Figure 2 is a horizontal view taken substantially on the line 2--2 of Figure 1; y

Figure 3 is a fragmentary vertical sectional view taken substantially on theline 23 of Figure 1 s Figure 4 is a horizontal sectional view taken substantially on the line 4--4 of Figure 3;4

Figure 5 is a plan view showing a portion of the diaphragm arrangement per se:

Figure 6 is a sectional view showing a portion of the diaphragm construction.

While I have illustrated the arrangement of my invention as particularly adapted for use in compressing gases, such as air to comparatively high pressure, it is to be understood that my invention may be utilized for pumping liquids. or as a vacuum producing means, or for any otherpur-` pose where it may be found to have yutility.

Referring to the drawingsin detail, the apparatus is inclusive of a housing I0 formed with an opening in the front thereof normally closed by a cover Il, the latter having a screened breather opening I2 to facilitate equalization of air pressure in the housing. The housing-I0 is adapted to be secured to the frame structure or end-plate I3 of a motor I4 adapted to actuate the compressor. The upper portion of the compressor housing I0 is enlarged or ared outwardly as at IG the enlarged portion having-a peripheral flange I1.

The diaphragm construction of my invention is inclusive of an annulus or ring preferably formed of metal, as for example', brass to which is bonded or vulcanized a iiexible element or diaphragm 22 as at 23. The iiexiblel element 22 is of annular conguration, the inner wall of which is bonded or vulcanized to a circular member or metal disc 25. As the diaphragm construction forms an important part of the present invention. it will be hereinafter described in further detail. The member 25 is formed with a circular recess 26 adapted to receive a disc-like member 21 lixedly secured to member 25 by means of screws 28.'

Integrally formed with' member 21 are shaped depending bosses 30 and 3l having aligned openings adapted to accommodate a journal pin 32 retained in place by screws 33. A connecting rod 35 has its upper end bored to accommodate a needle bearing 31 which surrounds the journal pin 32. Positioned between boss 3| and the connecting rod is a thrust bearing 38 preferably of the self-lubricating type. Boss 30 and the upper end of the connecting rod 35 are formed with laterally extending projections designated 40 and 4I respectively. Positioned between each set oi projections are resilient elements I2 as shown in Figure these elements being preferably blocks or rubber, synthetic rubber or the like. The resilient element 42 are subjected to initial compression for the purpose of exerting continuous lateral pressure upon the thrust bearing 35 and thus function as a vibrationdamping means for cap H6, the latter securing a ball bearing 41 inthe end of the connecting rod. The inner race of the bearing 41 fits the exterior surface of a cylindrical member B8 which is bored to nt the motol` shaft iig, the member i8 being fixed to the shaft by means of a key 55. The axis of the exterior cylindrical surface of member 48 is eccentric with respect to the axis o'f the motor shaft I9, which eccentricity causes reciprocation of the connecting rod 35,

members

25 and 27, and diaphragm 22 during rotation of the motor shaft. Member 48 is formed with a projection 52 for the purpose of counterbalancing the "pull" of the reciprocating parts of the-compressor structure.

Positioned above the diaphragm construction is a` valve carrying member or plate 55. A head 56 of the compressor having heat radiating fins is formed with an annular surface 51 arranged to secure the plate 55 in position on the housing i6, there being annular gaskets 55 interposed between the head 56 and plate 55 andbetween the plate 55 and member 20 to effect sealed joints. The head 55 and plate 55 are secured in position by means of screws 59 threaded into openings formed in the peripheral portion i1 of the housing I0. The plate 55 is provided with a concentrically arranged upwardly extending wall 50 which with a depending annular wall 5l on the head 55 forms an air inlet'passage 52 for the compressor chamber 53. Interposed between-the adjacent edges of walls 60 and 5I is a resilient gasket 54 of compressible materIaL-.as for example, rubber or the like arranged to seal the joint between the walls. The wall 5I is provided with an annular abutment 65 so that the high pressure of the compressed air or fluid will not dislodge the sealing member 63. The head 55 has a threaded opening 56 to accommodate an air lter (not shown).

The outer wall 51 of the head 55 together with the walls 6|) and 6I denne an annular plenum chamber 68 surrounding the air inlet passage 52 the wall 51 having an air outlet passage 10 arranged to accommodate a tube 10' or other means for conveying the compressed air or other fluid to the place where it is used.

The valve mechanism of thev compressor is carried by the plate 55. In the form of the invention illustrated, the plate 55 is provided with a pair of 'inlet passages or ports 1i communicating between the walled passage 62 and the compression chamber 63, The inlet ports 1i are of elongated configuration, and are normallyclosed by flexiblel reed-like valves or plates 12. One end of each valve is xedly secured to the plate 55 by rivets 15, the valves being arranged in opposed relation as shown in Figure 2, i. e. the free or 'movable extremities of the valves extending in parallel but opposite directions so as to facilitate rapid passage of air or other fluid through the passage 62 into the compression chamber 52.

Similarly constructed valves 15 are arranged to normally close the outlet ports 18 and are also arranged with the free or movable extremities extending in parallel and opposite directions. This valve arrangement enhances the passage of gas lfrom the compression chamber 63 into the plenum chamber 85.

The diaphragm or flexible element 22 is pref' erably made of rubber, synthetic rubber of the neoprene type or the like and is so bonded to the

members

20 and 25 that continued ilexure during compression operations does not dislodge the bonds. The arrangement of my invention is particularly adaptable for compressing gases to comparatively high pressures as well as having utility in pumping liquids. I have found a comparatively thick diaphragm with respect to its width must be employed in order to secure satisfactory results under high pressures without encountering diaphragm failure. One example of a practical construction which I have employed in developing compression pressures exceeding 150 lbs. per square inch is as follows: a compressor in which the outside diameter of the flexible element 22 is seven inches, and the diam- 'eter of metal member 25 `is four and one half inches, a thickness of approximately three quarters of an inch for the flexible element has been found to be satisfactory. I have found that the following approximate proportions of flexible diaphragm dimensions will give satisfactory results. 'I'he thickness T (see Figure 6) of diaphragm or flexible element 22 should be at least equal to or greater than one half the width W of the element when the ratios of the diameter of member 25 to the diameter of the elementare substantially in the proportion of four and one half to seven. If the width of the flexible element 22 is increased, the' thickness should be proportionately increased.

While other proportions of width and thickness of flexible element 22 may be employed without departing from the spiritof the invention, I have found that by utilizing the above mentioned general proportions, very little bulging or flexure of the flexible element is encountered under pressure. It is not suillcient to materiallyl affect the compression stroke so that a high compression and volumetric efficiency is maintained even; at comparatively high pressures.

In the operation of the compressor. the motor i4 is started (that shown being electrically operdownward stroke of the connecting rod and dia- .4

phragm structure, as viewed in Figures 1 and 3, sets up a. differential in pressure between the compression chamber and passages 52 which causes the

inlet valves

12 and 13 to open, permitting air or other fluid to flow through the ports 1I into the compression chamber 55. Onthe upward stroke of the diaphragm construction, the valves 12 are closed, causing the air or fluid to be compressed in chamber 63. When the pressure within the chamber 53 exceeds that in the plenum chamber 58, the valves 15 are opened by reason of the higher pressure in chamber 52. causing the air or other fluid under pressure to flow through the outlet ports 15l`into the annular v plenum chamber or reservoir 56. The fluid uninvention, modiiications and different arrangements may be made other than is herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

Iclaim:

1. In combination, a compressor including a housing, a. plate in said housing, valved ports in said plate; a compressor head; a diaphragm constructionin said housing and forming with said plate a' compression chamber; said diaphragm construction including a metal ring removably secured to said housing; a disc-like member in said housing; an imperforate stretchable diaphragm of uniform thickness bonded to said ring and said disc; and mechanical means associated with said disc-like member for positively effecting successive suction and pumping strokes of said member and stretchable diaphragm, said metal ring, diaphragm and disc being of substantially the same thickness.

2. A removable pumping element for a compressor including a metal annulus; a metal disc arranged within said annulus and spaced therefrom; an imperforate stretchable element of rubber or the like vulcanized to said annulus and said disc; said element being of uniform thickness and substantially the thickness of said metal :annulus at the point of juncture therewith and of a width in cross section substantially twice the thickness thereof.

3. In combination, a pump including a housing; a. plate in said housing; valved ports in said plate; a diaphragm construction in said housing; said diaphragm construction and said plate forming a pumping chamber; said diaphragm construction including an annulus of nonresilient material removably secured to said housing; a disc-like member in said housing; an imperforate stretchable element of uniform thickness permanently bonded to said annulus and said member; and mechanical meansv associated with said disc-like member for eiecting successive pumping strokes of said member and stretchable element; said annulus, stretchable element and disc-like member being of substantially the same thickness.

4. A removable pumping element for a compressor including an annulus of non-resilient material; a disc-like member ofy non-resilient material arranged within said annulus and spaced therefrom; an imperforate stretchable element of rubber or the .like bonded to said annulus and said member; said element being of uniform thickness and substantially the thickness of said annulus at the point of juncture therewith and of a width incross-section substantially greater than the thickness thereof.

HAROLD F. HADLEY.

REFERENCES CITED The following references are of record in the le of this patent: