US2803196A

US2803196A - Pump

Info

Publication number: US2803196A
Application number: US398509A
Authority: US
Inventors: Ludwig T Stoyke
Original assignee: Sundstrand Machine Tool Co
Current assignee: Sundstrand Machine Tool Co
Priority date: 1953-12-16
Filing date: 1953-12-16
Publication date: 1957-08-20
Anticipated expiration: 1974-08-20

Description

L. T. STOYKE PUMP Filed Dec. 16, 1953 Aug. 20, 1957 7 fi 6 i a. r I W! V United States Patent PUMP Ludwig T. Stoyke, Rockford, Ill., assignor to Sundstrand Machine Tool Co., a corporation of Illinois This invention relates to pumps and more particularly to a means for preventing hum or vibration during pump operation.

It is the general object of this invention to provide a new and improved fuel pump having improved means for eliminating hum or vibration.

I A further object is to provide a fuel pump with an antihum device which is easy to manufacture, of simple construetion and easily insertable and replaceable in a pump.

Another object is to provide a fuel pump embodying a casing with a reservoir portion to which the intake of a pumping mechanism opens, a removable closure, a pumpmg mechanism end plate for the reservoir and an antihum device associated therewith.

Another object is to provide a fuel pump such as described above with an air-tight diaphragm embodying two thin nylon plastic halves of flexible thin-walled construction sealed together to form an air space therebetween and means associated with the fuel pump intake reservoir for releasably supporting the diaphragm on the pumping mechanism end plate so that said diaphragm may be easily snapped into or out of position.

Another object is to provide an anti-hum device for such a fuel pump including a diaphragm as described above and a retainer therefor embodying a ring mounted on the reservoir side of the pumping mechanism end plate and having a plurality of spring teeth for releasably recelving the diaphragm, the end plate having a recess adacent the diaphragm so that said diaphragm is positioned in the pump intake reservoir in a spaced relation from the end plate and has its entire external surface area immersed in fuel in the reservoir.

Other and further objects of the invention will be readily apparent from the following description and drawings in which:

Fig. 1 is a longitudinal, vertical section through a pump showing the preferred form of the invention;

Fig. 2 is a fragmentary view approximately along the line 22 of Fig. 1; and

3 is a sectional view taken along the line 33 of While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail an illustrative embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

In the form selected for purposes of disclosure, the invention is embodied in a fuel pump of the type disclosed and claimed in Patent No. 2,232,983, dated Feb ruary 25, 1941. As illustrated in Fig. 1, a fuel pump consists generally of a two-

part casing

10, 11, a pumping device or mechanism 12, a drive shaft 13, a mechanical seal 14 for the drive shaft, and a strainer 15. A control valve mechanism 16 forms no part of the present invention but may be of any appropriate type suitable for use with an oil burner type fuel pump. It is contemplated that the shaft 13 will be connected by suitable means to a driving motor (not shown), and that an inlet port 17 will be connected to a source of fuel supply'such as a tank (not shown).

The

casing parts

10 and 11 are formed to provide a somewhat cylindrical recess or reservoir 18 in which the pumping mechanism 12 and strainer 15 are positioned. The pumping mechanism generally consists of an externally-toothed roller 19 secured to the shaft 13 by a pin 20, an internally-toothed ring gear 21 having the lower portion thereof meshing with the roller 19 and an intermediate crescent guard 22. The complete details of this mechanism are disclosed in said prior application and function in a well-known manner to draw fuel into the inlet port 17, through the chamber 18 and in through the intake port 22a- (Fig. 2) in the pumping mechanism end plate 24. Upon rotation of the shaft 13 in a clock- Wise direction, the fuel is carried in the cavities of the roller and ring past the crescent guide 22 then forced out through a discharge port (not shown) and is conducted to the outlet valve mechanism 16 and from said valve mechanism it passes either through suitable means adapted for connection to an oil burner or through a by-pass port 26 (Fig. 1) operable to allow return passage of fuel to a fuel tank when the plug 27 is removed and a return conduit connected therein. The strainer 15 is generally cupshaped and has

adjacent ends

28 and 29 positioned on casing part 10. The strainer surrounds the pumping mechanism so that all of the fuel entering the inlet port 17 must pass through the strainer to reach the pumping mechanism 12.

In an oil burner installation an objectionable hum or vibration is sometimes encountered during operation of the pumping mechanism and, unless absorbed, will be transmitted to the fuel line and supply tank. In order to eliminate this hum or vibration, a closed air pocket 31 is formed in a portion of the recess or pump inlet reservoir 18 to absorb any pulsations set up in the pump before they are transferred to the fuel line or tank.

As illustrated in Figs. 1, 2 and 3 the air pocket 31 is provided by a diaphragm 32 removably supported by a retainer assembly comprising spring teeth 33 fixed to ring 34 which is mounted on the reservoir side of end plate 24 by screws 35. A recess or cavity 36 is provided in the end plate 24 adjacent the diaphragm 32 so that the diaphragm is in a spaced relation from the end plate and has it entire external surface area immersed in fuel in the reservoir 18.

The diaphragm 32 comprises two flexible sides 37 each side having a slightly concave outer face portion 38 and circumferential convex edge portion 39 circumscribing a hollow body portion, the diaphragm terminating in a substantially flat circumferential flange portion 40. The sides are of flexible thin wall construction formed of any suitable material and in a preferred construction consist of die molded nylon plastic material. The molded sides may be fixed together by use of a heat sealing machine which, when the proper amount of heat is applied, causes the edge portions 40 to become permanently fused and sealed, leaving an air space in the body portion and giving the body portion the general shape of a unitary hollow plastic button.

Prior attempts to prevent hum or vibration have embodied the use of closed air chambers but they have proven difiicult to seal and check for air tightness, not easily removable or replaceable and the anti-hum qualities have not been utilized to the maximum extent possible. The simple and compact construction of my anti-hum device enables it to be readily and inexpensively produced. The retainer assembly allows the diaphragm to be quickly replaced by snapping it into or out of position in the pump fuel reservoir and its unitary construction facilitates easy testing for air tightness prior to installation. The end plate and retainer assembly are constructed and arranged to position the diaphragm in a spaced relation from the end plate so that the entire external surface of the air pocket is immersed in fuel to insure maximum utilization of its anti-hum qualities.

I claim:

1. A fuel pumping device comprising, a casing having inlet and outlet ports, a recess in said casing communicating with the inlet port, pumping mechanism positioned in said recess and operable to draw fuel from the recess and force it out the outlet, a removable cover plate for said recess, an end plate for said pumping mechanism positioned in said recess and having a cavity opening into the recess, a metal ring mounted on said end plate and carrying a plurality of spring teeth adjacent the periphery of said cavity, a hollow button-shaped diaphragm of nylon plastic material with spaced flexible walls defining a body portion providing a closed air chamber between said walls, said body portion having a diameter less than the diameter of the cavity and said diaphragm having its edge portions releasably secured between the spring teeth and adjacent surface of the end plate and its body portion partially disposed within the cavity and in spaced relation from the end plate, the construction and arrange- A ment being such that the entire external surface area of the flexible walls defining said closed air chamber is positioned to be immersed in the fuel in said recess.

2. A fuel pumping device comprising, a casing provided with inlet and outlet ports, a recess in said casing communicating with the inlet port, pumping mechanism positioned in said recess and operable to draw fuel from the recess and force it out the outlet, a diaphragm of nylon plastic material comprising two flexible sides and a circumferential edge portion terminating in a substantially flat circumferential flange, the sides being sealed together along said flange to define a body portion providing a closed air chamber therebetween, and resilient means in said recess position to engage the flange for securing said diaphragm therein, said resilient means detachably securing said diaphragm in the recess, the construction and arrangement being such that the entire external surface area of the flexible walls defining said body portion is positioned to be immersed in the fuel in said recess.

References Cited in the file of this patent UNITED STATES PATENTS 2,232,983 Wahlmark Feb. 25, 1941 2,311,916 Wahlmark Feb. 23, 1943 2,418,667 Rockwell Apr. 8, 1947 2,512,765 Byram June 27, 1950