Diaphragm type air pump

• US 4,137,020 A
• Filed: 12/22/1977
• Issued: 01/30/1979
• Est. Priority Date: 12/26/1976
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Naganuma, Naohiro, Ito, Mikiji, Nagano, Shojiro
• Primary Examiner(s): Freeh, William L.
• Application Number:
  US05/863,580
• Time in Patent Office: 404 Days
• Field of Search: 417/470, 417/471, 417/534, 417/439, 74/18.1
• US Class Current: 417/534
• CPC Class Codes: F02B 67/04 of mechanically-driven auxiliary apparatus
• CPC Class Codes: F04B 39/02 Lubrication of machines or engines in general F01M
• CPC Class Codes: F04B 45/041 double acting plate-like flexible pumping member
• CPC Class Codes: F16J 15/52 by means of sealing bellows or diaphragms connection of valves to inflatable elastic bodies B60C29/00

Abstract

A diaphragm is interposed between first and second housings to form first and second diaphragm chambers at both sides thereof for pumping out air in accordance with expansion and contraction of the chambers. A shaft for reciprocally moving the diaphragm is connected thereto at one end and extends through a hole formed in a bushing which is fixed to the second housing. A lever is pivotally secured to the housing to perform a pivotal movement and operatively connected at its inner end to the other end of the shaft in a lever compartment of the housing and at its outer end to an eccentric cam formed on an engine crankshaft, so that the motion of the cam is transmitted to the shaft as the reciprocal movement through the pivotal movement of the lever. A bellows is disposed in the second diaphragm chamber surrounding a portion of the shaft, wherein the upper and lower ends are respectively and air-tightly connected to the diaphragm and the bushing to form a bellows chamber. An axially extending groove is formed on either the inner surface of the hole or the outer surface of the shaft, so that the bellows chamber is communicated with the lever compartment by the groove. The compartment is communicated with an engine crankcase and thereby filled with a large amount of engine oil mist. The bellows chamber is also subjected to expansion and contraction in accordance with the reciprocal movement of the shaft to alternately draw into and force out air in the compartment, so that a portion of the mist is forcibly introduced into the groove to lubricate the shaft and the bushing.

Claims

1. A diaphragm type air pump comprising:

first and second housing means;

a diaphragm interposed between said first and second housing means to respectively form first and second diaphragm chambers at both sides thereof;

first and second inlet openings respectively formed on said first and second housing means for operatively communicating said diaphragm chambers with the outside thereof;

first and second outlet openings respectively formed on said first and second housing means for operatively communicating said diaphragm chambers with an outlet pipe of the air pump;

first and second inlet valve members respectively associated with said first and second openings for opening and closing the same in accordance with expansion and contraction of said diaphragm chambers;

first and second outlet valve members respectively associated with said first and second outlet openings for opening and closing the same in accordance with expansion and contraction of said diaphragm chambers;

a shaft connected at one end to said diaphragm and extending through said second diaphragm chamber;

a bushing fixed to said second housing means and having a hole through which said shaft extends, an axially extending groove being formed on one of the inner surface of said hole and the outer surface of said shaft;

a bellows disposed in said second diaphragm chamber and surrounding a portion of said shaft, one end of said bellows being air-tightly fixed to said diaphragm and the other end being air-tightly fixed to said bushing to form a bellows chamber inside of said bellows, whereby said diaphragm chamber outside of said bellows being air-tightly isolated from said bellows chamber;

said second housing means having a lever compartment into which the other end of said shaft protrudes from said bushing;

a lever pivotally fixed to said second housing means, the inner end being disposed in said compartment and operatively connected to said other end of said shaft, and the outer end of said lever being operatively connected to an eccentric cam formed on a crankshaft of said engine, whereby said lever is driven by said eccentric cam to perform a pivotal movement,

said pivotal movement of said lever being transmitted to said diaphragm through said shaft so that said diaphragm is reciprocally moved in said diaphragm chambers, and thereby said diaphragm chambers are respectively expanded and contracted in accordance with the reciprocal movement of said diaphragm for alternately drawing air thereinto through the respective inlet openings and forcing out the drawn air therefrom through the respective outlet openings.

2. A diaphragm type air pump as set forth in claim 1, wherein said lever compartment is communicated with a crankcase of said engine filled with engine-oil mist, whereby lubrication between said shaft and bushing is forcibly carried out through said groove in accordance with the expansion and contraction of said bellows chamber.

3. A diaphragm type air pump as set forth in claim 1, wherein said outer end of said lever is of a forked end having two parallel legs within which said eccentric cam is operatively received,

said inner end of said lever is formed with a slot, and

said other end of said shaft is of a forked end having parallel legs for operatively receiving said inner end of said shaft, said other end having a pin held by said legs at both sides and said pin extending through said slot formed on said inner end.