US3830601A - Apex sealing member for rotary piston engine - Google Patents

Apex sealing member for rotary piston engine Download PDF

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Publication number
US3830601A
US3830601A US00332084A US33208473A US3830601A US 3830601 A US3830601 A US 3830601A US 00332084 A US00332084 A US 00332084A US 33208473 A US33208473 A US 33208473A US 3830601 A US3830601 A US 3830601A
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US
United States
Prior art keywords
sealing member
apex
chilled
unchilled
engine
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00332084A
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English (en)
Inventor
R Yamazaki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mazda Motor Corp
Yoshiwa Kogyo KK
Original Assignee
Yoshiwa Kogyo KK
Toyo Kogyo Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Yoshiwa Kogyo KK, Toyo Kogyo Co Ltd filed Critical Yoshiwa Kogyo KK
Application granted granted Critical
Publication of US3830601A publication Critical patent/US3830601A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
    • F01C19/00—Sealing arrangements in rotary-piston machines or engines
    • F01C19/005—Structure and composition of sealing elements such as sealing strips, sealing rings and the like; Coating of these elements
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49229—Prime mover or fluid pump making
    • Y10T29/49249—Piston making

Definitions

  • the apex sealing member is made of cast iron but composed of an upper portion having a chilled structure and formed with a sliding top surface for sliding engagement with the inner peripheral surface of the engine housing, of a lower portion having a chilled structure to be operatively received within the apex seal groove, and of an intermediate portion left unchilled and sandwitched between the upper and lower chilled portions.
  • the present invention generally relates to an internal combustion engine of rotary type, and more particularly to an improvement in an apex sealing member for use with a rotor of the rotary piston engine.
  • this sealing member When, however, this sealing member is put into actual use in the combustion chamber working at a high temperature, it will easily suffer from heavy thermal deformation due to the considerable difference in the coefficients of thermal expansion between the chilled upper portion and the lower unchilled portion.
  • This thermal deformation will lead to the longitudinal warping or bending of the sealing member with its longitudinal ends raised from the bottom of the apex seal groove, which is formed in each apex portion of the engine rotor. Accordingly, the so-called blow-by of the combustion gases through the depressed central portion of the apex sealing member occurs to invite deterioration of the sealing efficiency.
  • this warping moreover, only the raised end portions of the sealing member will be excessively pressed to result in the so-called fatigue rapture.
  • an object of the present invention to provide an apex sealing member for use with a rotary piston engine.
  • Another object of the invention is to provide an apex sealing member made of cast iron, in which the undesirable thermal deformation is substantially eliminated without affecting the intrinsic tough property of the material.
  • Still another object is to provide an apex sealing member of cast iron, which is integrally composed of an upper portion having a chilled structure and formed with a sliding top surface for sliding engagement with the inner peripheral surface of the engine housing of the rotary piston engine, of a lower portion having a chilled structure to be received within an apex seal groove, and of an intermediate portion left unchilled and sandwitched between the upper and lower portions.
  • the apex sealing member has a three-layered structure in which an unchilled tough cast iron layer is integrally interposed between upper and lower chilled hard layers.
  • an unchilled tough cast iron layer is integrally interposed between upper and lower chilled hard layers.
  • FIG. 1 is a perspective view showing an apex sealing member according to the present invention.
  • FIG. 2 is an explanatory view illustrating the method for comparatively gauging the thermal deformations of the present and conventional apex sealing members.
  • an apex sealing member according to the present invention is generally indicated at reference numeral 10.
  • the sealing member 10 is made of cast iron comprising, as shown, an intermediate portion ll, an upper portion 12 and a lower portion 13.
  • a detailed discussion on the method of manufacturing and chilling one surface of an apex sealing member appears in US. Patent 3,658,451, and accordingly merely a short description will be given of the present method of manufacture.
  • the present sealing member 10 is manufactured, for instance, from an elongated body made of acicular cast iron, which is composed by weight of 3.6 percent of carbon, 2.1 percent of silicon, 0.4 percent of manganese, 0.5 percent of chromium, 1.5 percent of molybdenum, 1.0 percent of copper, and the balance is iron.
  • the lower portion 13 and the upper portion 12 formed with a sliding contact surface are locally molten within a short time period by the use of either of the electron beam, plasma or laser beam method in a manner to leave the intermediate portion 11 unchilled. Then, the elongated body with the locally molten portions is quickly cooled down as a whole to obtain the chilled structures at the upper and lower portions 12 and 13.
  • the melting and chilling step may be, if desired, performed separately on the upper and lower portions. Then, the locally chilled body is subjected to machining to be fittedly received in the apex seal groove.
  • the apex sealing member thus obtained has, for example, such dimensions as the length a of mm, the height b of 8.5 mm, and the width 0 of 5 mm, as shown.
  • the thickness or height t, of the upper chilled layer 12 is about 2.5 mm, but the thickness t of the lower chilled layer 13 is, preferably, slightly less than 2.5 mm, thus leaving the unchilled layer 11 of about 3.5 mm. In this way, it is preferable for the practicaly purposes that the upper chilled layer 12 has a larger thickness than that of the lower chilled layer 13.
  • the upper portion of the apex sealing member is exposed directly to the hot combustion gases to thereby have a steep negative temperature gradient toward the remaining portion which is received in the apex seal groove.
  • the upper portion is formed with the sliding top surface which is in moving contact with the inner peripheral surface of the engine housing of the rotary piston engine, so that its thickness will be progressively worn out in the cource of operation. If, therefore,- there exists the steeper temperature gradient across an interface between two materials having different coefficients of thermal expansion, it is well known in the art that the interface will warp the more.
  • the upper interface between the chilled and unchilled layers 12 and 13 should preferably be positioned not above the outer edges of the apex seal groove but in the particular groove where the temperature gradient is more gentle. This positioning will practically be exemplified by the above thickness relationship that the upper chilled layer 12 has a larger thickness than that of the lower chilled layer 13.
  • the thickness of the intermediate unchilled layer 11 should be at least one-fifth of that of the whole sealing member 10.
  • the thickness control of these three layers can be carried out by selecting appropriate values of the energy level, energy density and scanning speed of the electron beam as used.
  • the measuring system is, as shown, of common type, in which either of the apex sealing members is horizontally supported at two supports 14 and 15 spaced from each other at a distance of about 50 mm.
  • a dial gauge 16 is disposed at the opposite halfway of the two supports 14 and 15 so as to gauge the thermal deformation of the apex sealing member in terms of the displacement of the halfway portion with respect to its ends.
  • the measurements were made at an atmospheric temperature of about 15C and at an elevated temperature of 300C.
  • the resultant thermal deformations will be tabulated in the following:
  • the present seal- 1 ing member far less suffers from the thermal deformation, and it can be said that the deformation value 5,LL of the present invention will never involve practical difficulties.
  • the apex sealing member according to the present invention will experience highly reduced thermal deformation even when it is exposed to the hot combustion gases.
  • the present sealing member is free over a prolonged period of operation time from the undesirable blow-by, pitching phenomena, thus improving the durability of its sealing effects.
  • the power performance of the rotary piston engine employing the present sealing member is highly augmented, because the improved sealing effects leads to increase in the obtainable compression ratio of the engine.
  • An apex sealing member for use with a rotary piston engine, comprising an elongated body of cast iron to be operatively received within an apex seal groove which is formed in each apex portion of a multi-lobed rotor of the engine, said elongated body including an upper portion having a chilled structure and formed with a sliding top surface for sliding engagement with the inner peripheral surface of the engine housing, a lower portion having a chilled structure to be received within the apex seal groove, and an intermediate portion left unchilled and sandwiched between said upper and lower portions.
  • An apex sealing member according to claim 1 wherein the thickness of said intermediate portion is at least one-fifth of the whole thickness of said elongated body.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
US00332084A 1972-02-17 1973-02-13 Apex sealing member for rotary piston engine Expired - Lifetime US3830601A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP47017461A JPS5134923B2 (enrdf_load_stackoverflow) 1972-02-17 1972-02-17

Publications (1)

Publication Number Publication Date
US3830601A true US3830601A (en) 1974-08-20

Family

ID=11944648

Family Applications (1)

Application Number Title Priority Date Filing Date
US00332084A Expired - Lifetime US3830601A (en) 1972-02-17 1973-02-13 Apex sealing member for rotary piston engine

Country Status (3)

Country Link
US (1) US3830601A (enrdf_load_stackoverflow)
JP (1) JPS5134923B2 (enrdf_load_stackoverflow)
DE (1) DE2307786B2 (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3909310A (en) * 1973-08-24 1975-09-30 Ford Motor Co Apex seal design
US3947046A (en) * 1973-05-30 1976-03-30 Riken Piston Ring Kogyo Kabushiki Kaisha Oil seal ring for internal combustion engine
US4094618A (en) * 1976-03-31 1978-06-13 Toyo Kogyo Co., Ltd. Rotary piston engines
US4100664A (en) * 1975-01-17 1978-07-18 Caterpillar Tractor Co. Apex seal for rotary engines
US4125399A (en) * 1976-08-31 1978-11-14 Toyo Kogyo Co., Ltd. Apex seals for rotary piston engines
US4545825A (en) * 1983-03-26 1985-10-08 Mazda Motor Corporation Apex seals for high power rotary piston engines
US4936912A (en) * 1988-06-27 1990-06-26 Deere & Company Sintered apex seal material

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3658451A (en) * 1969-09-13 1972-04-25 Toyo Kogyo Co Apex seal for rotary piston engine
US3672798A (en) * 1969-03-06 1972-06-27 Daimler Benz Ag Radial sealing bar for pistons of rotary piston internal combustion engines

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3672798A (en) * 1969-03-06 1972-06-27 Daimler Benz Ag Radial sealing bar for pistons of rotary piston internal combustion engines
US3658451A (en) * 1969-09-13 1972-04-25 Toyo Kogyo Co Apex seal for rotary piston engine

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3947046A (en) * 1973-05-30 1976-03-30 Riken Piston Ring Kogyo Kabushiki Kaisha Oil seal ring for internal combustion engine
US3909310A (en) * 1973-08-24 1975-09-30 Ford Motor Co Apex seal design
US4100664A (en) * 1975-01-17 1978-07-18 Caterpillar Tractor Co. Apex seal for rotary engines
US4094618A (en) * 1976-03-31 1978-06-13 Toyo Kogyo Co., Ltd. Rotary piston engines
US4125399A (en) * 1976-08-31 1978-11-14 Toyo Kogyo Co., Ltd. Apex seals for rotary piston engines
US4545825A (en) * 1983-03-26 1985-10-08 Mazda Motor Corporation Apex seals for high power rotary piston engines
US4936912A (en) * 1988-06-27 1990-06-26 Deere & Company Sintered apex seal material

Also Published As

Publication number Publication date
DE2307786B2 (de) 1974-10-17
DE2307786A1 (de) 1973-08-30
JPS5134923B2 (enrdf_load_stackoverflow) 1976-09-29
JPS4884209A (enrdf_load_stackoverflow) 1973-11-09

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