US2292728A - Cam mechanism - Google Patents
Cam mechanism Download PDFInfo
- Publication number
- US2292728A US2292728A US311125A US31112539A US2292728A US 2292728 A US2292728 A US 2292728A US 311125 A US311125 A US 311125A US 31112539 A US31112539 A US 31112539A US 2292728 A US2292728 A US 2292728A
- Authority
- US
- United States
- Prior art keywords
- cam
- roller
- width
- track
- nose
- 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
Links
- 230000007246 mechanism Effects 0.000 title description 10
- 238000010276 construction Methods 0.000 description 3
- 239000000446 fuel Substances 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
- F02M59/02—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type
- F02M59/10—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by the piston-drive
- F02M59/102—Mechanical drive, e.g. tappets or cams
-
- 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
- Y10T74/00—Machine element or mechanism
- Y10T74/21—Elements
- Y10T74/2101—Cams
Definitions
- This invention relates to cam mechanisms and in particular to those intended for operating fuel pumps and other parts of internal combustion engines.
- the object of the invention is to provide a cam mechanism which will be more efcient in operation and in which the cam is less liable to Wear than those at present in use.
- the rolling or bearing surfaces of the two cooperating parts of the cam mechanism e. g., the cam itself and of the roller or its equivalent, have been of the same Width over their whole circumferential peripheries.
- the rollers have been narrower than the cams and the cams have been narrower than the rollers, the determining factor, assuming that the roller engages the cam without any slip, being the linear pressure or the specific load per unit area as calculated in accordance with the theory of elasticity.
- the Width of the track or rollerengaging surface of the base circle of the cam being less than that of the cam nose or projection.
- Change-over from the narrow track ofthe base circle to the full width of the cam nose or projection is designed in accordance with the load curve of the cam, and the inoperative or nonbearing surfaces on both sides of the narrow portion of the track may form the surfaces of a cone or of a cylinder.
- the cam roller is of especially light construction with respect to its moment of inertia about its axis of rotation.
- Figure 1 is a perspective View showing a cam and its roller
- Figure 2 shows in perspective a cam on an enlarged scale
- Figure 3 is an edge View showing a cam with conical non-bearing surfaces
- Figure 4 is a similar View of a cam having a cylindrical non-bearing surface on either side of the narrow roller-engaging track.
- the cam I which is adapted to be fixed to its driving shaft 2, -cooperates with a roller 3 which is in operative connection with the plunger of a pump, not shown, and is recip-v rocated in the direction of the arrow 4 when the cam I is rotated by the shaft 2.
- the track or rolling surface of the base circle 5 of the cam is narrow in comparison with the projecting portion or cam nose 6, the non-bearing surfaces on either side of the narrow track 5 being either conical, as shown at l in Figure 3, or cylindrical as shown at 8 in Figure 4.
- the cam is shown detached from its shaft which fits into the bore I0.
- the merging or change-over from the narrow track portion 5 to the full width projecting portion 6 is designed to suit the load curve of the cam and preferably the roller 3 is 0f light construction with relation to its moment of inertia about its axis of rotation.
- the increased specic surface pressure is obtained by making the heavily loaded bearing surface of the cam nose 6 of the full width of the cam whilst the base circle, which is only lightly loaded, and also the part between the cam nose and the base circle are reduced in width.
- the width of the track on the base circle of the cam Will be chosen less than 2A; of the width of the cam itself.
- the oil film between the roller and the track ' is so crushed that a damaging of the track in consequence of the acceleration when the cam begins to be raised is no longer to be feared.
- a cam mechanism which comprises a roller and a cam, a base surface and a nose surface on the cam for engaging the roller, the roller surface being at least as wide as the nose surface, the base surface being substantially narrower than the nose surface and proportioned in width on a basis of the load on the nose surface in relation to the load on the base surface, whereby the specific surface pressure is such that the slippage between the roller and the cam surfaces is practically eliminated.
- a cam according to claim 1 in which the base surface is less than two-thirds the width of the nose surface.
- a cam mechanism comprising a roller, a
Description
A ug. 11, 1942. H, WLTI' 2,292,728
CAM MECHANISM Filed Deo. 27, 1939 ATTORNEYS Patented Aug. 11, 1942 CAM MECHANISM Heinrich Wlti, Winterthur-Wumingen, Switzer- Sulzer Frres, Socit Anonyme, Winterthur, Switzerland Application December 27, 1939, Serial No. 311,125 In Switzerland February 8, 1939 land, assignor to 3 Claims.
This invention relates to cam mechanisms and in particular to those intended for operating fuel pumps and other parts of internal combustion engines.
The object of the invention is to provide a cam mechanism which will be more efcient in operation and in which the cam is less liable to Wear than those at present in use.
Hitherto the rolling or bearing surfaces of the two cooperating parts of the cam mechanism, e. g., the cam itself and of the roller or its equivalent, have been of the same Width over their whole circumferential peripheries. In some cases the rollers have been narrower than the cams and the cams have been narrower than the rollers, the determining factor, assuming that the roller engages the cam without any slip, being the linear pressure or the specific load per unit area as calculated in accordance with the theory of elasticity.
In very highly loaded cam mechanisms, for instance those intended for operating fuel pumps, it has been found that the operating surface tends in certain circumstances to become worn in spite of the fact that the surfaces both of the cam and of the roller have been accurately machined and uniformly hardened. This wear readily occurs when starting, i. e., at low load and with cold and viscous oil when tests show that the rollers slip to a considerable extent relatively to the cam. For instance it has been found that a roller turned through an angle of only 150, when it should theoretically have a turn through 800 and that it is this slip which causes the wear since Wear invariably occurs at those places where, through high stressing of the roller, the latter is rotated through less than the theoretical angle.
According to this invention this drawback is avoided by the Width of the track or rollerengaging surface of the base circle of the cam being less than that of the cam nose or projection. Change-over from the narrow track ofthe base circle to the full width of the cam nose or projection is designed in accordance with the load curve of the cam, and the inoperative or nonbearing surfaces on both sides of the narrow portion of the track may form the surfaces of a cone or of a cylinder. Preferably the cam roller is of especially light construction with respect to its moment of inertia about its axis of rotation.
In the accompanying drawing which shows somewhat diagrammatically one construction of cam mechanism according to the present invention,
Figure 1 is a perspective View showing a cam and its roller,
Figure 2 shows in perspective a cam on an enlarged scale,
Figure 3 is an edge View showing a cam with conical non-bearing surfaces, and
Figure 4 is a similar View of a cam having a cylindrical non-bearing surface on either side of the narrow roller-engaging track.
In Figures 1 and 2 the cam I, which is adapted to be fixed to its driving shaft 2, -cooperates with a roller 3 which is in operative connection with the plunger of a pump, not shown, and is recip-v rocated in the direction of the arrow 4 when the cam I is rotated by the shaft 2.
As more clearly shown in Figure 2, the track or rolling surface of the base circle 5 of the cam is narrow in comparison with the projecting portion or cam nose 6, the non-bearing surfaces on either side of the narrow track 5 being either conical, as shown at l in Figure 3, or cylindrical as shown at 8 in Figure 4. In Figure 2 the cam is shown detached from its shaft which fits into the bore I0.
The merging or change-over from the narrow track portion 5 to the full width projecting portion 6 is designed to suit the load curve of the cam and preferably the roller 3 is 0f light construction with relation to its moment of inertia about its axis of rotation.
By means of the present invention the increased specic surface pressure is obtained by making the heavily loaded bearing surface of the cam nose 6 of the full width of the cam whilst the base circle, which is only lightly loaded, and also the part between the cam nose and the base circle are reduced in width.
Preferably the width of the track on the base circle of the cam Will be chosen less than 2A; of the width of the cam itself. Already with base circle roller-engaging surfaces, whose width is only somewhat less than 2/3 of the width of the cam, the oil film between the roller and the track 'is so crushed that a damaging of the track in consequence of the acceleration when the cam begins to be raised is no longer to be feared.
I claim:
1. A cam mechanism which comprises a roller and a cam, a base surface and a nose surface on the cam for engaging the roller, the roller surface being at least as wide as the nose surface, the base surface being substantially narrower than the nose surface and proportioned in width on a basis of the load on the nose surface in relation to the load on the base surface, whereby the specific surface pressure is such that the slippage between the roller and the cam surfaces is practically eliminated.
2. A cam according to claim 1 in which the base surface is less than two-thirds the width of the nose surface.
3. A cam mechanism comprising a roller, a
cam in operative engagement with the roller, the l0
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CH2292728X | 1939-02-08 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2292728A true US2292728A (en) | 1942-08-11 |
Family
ID=4568428
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US311125A Expired - Lifetime US2292728A (en) | 1939-02-08 | 1939-12-27 | Cam mechanism |
Country Status (1)
Country | Link |
---|---|
US (1) | US2292728A (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2490644A (en) * | 1944-02-28 | 1949-12-06 | John A Mcgrew | Locomotive valve gear |
US2567689A (en) * | 1947-02-24 | 1951-09-11 | Austin Motor Co Ltd | Cam for operating valves of internal-combustion engines |
US2581233A (en) * | 1948-06-07 | 1952-01-01 | Austin Motor Co Ltd | Cam for operating valves of internal-combustion engines |
US2628605A (en) * | 1950-11-02 | 1953-02-17 | Chrysler Corp | Cam mechanism and method for manufacturing the same |
US2899830A (en) * | 1959-08-18 | laiming | ||
US3190428A (en) * | 1962-08-24 | 1965-06-22 | Teletype Corp | Auxiliary case shift mechanism for teletypewriter receivers to prevent garble |
EP1058001A1 (en) * | 1999-05-31 | 2000-12-06 | SIG Schweizerische Industrie-Gesellschaft | High pressure feed pump |
US20100196531A1 (en) * | 2009-02-05 | 2010-08-05 | Krones Ag | Reduction of wear on control cams |
-
1939
- 1939-12-27 US US311125A patent/US2292728A/en not_active Expired - Lifetime
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2899830A (en) * | 1959-08-18 | laiming | ||
US2490644A (en) * | 1944-02-28 | 1949-12-06 | John A Mcgrew | Locomotive valve gear |
US2567689A (en) * | 1947-02-24 | 1951-09-11 | Austin Motor Co Ltd | Cam for operating valves of internal-combustion engines |
US2581233A (en) * | 1948-06-07 | 1952-01-01 | Austin Motor Co Ltd | Cam for operating valves of internal-combustion engines |
US2628605A (en) * | 1950-11-02 | 1953-02-17 | Chrysler Corp | Cam mechanism and method for manufacturing the same |
US3190428A (en) * | 1962-08-24 | 1965-06-22 | Teletype Corp | Auxiliary case shift mechanism for teletypewriter receivers to prevent garble |
EP1058001A1 (en) * | 1999-05-31 | 2000-12-06 | SIG Schweizerische Industrie-Gesellschaft | High pressure feed pump |
JP2000356184A (en) * | 1999-05-31 | 2000-12-26 | Sig (Schweiz Ind Ges) | High pressure delivery pump |
US20100196531A1 (en) * | 2009-02-05 | 2010-08-05 | Krones Ag | Reduction of wear on control cams |
US8162639B2 (en) * | 2009-02-05 | 2012-04-24 | Krones Ag | Reduction of wear on control cams |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2292728A (en) | Cam mechanism | |
US2345125A (en) | High pressure pump | |
US5618046A (en) | Piston ring assembly | |
US2552004A (en) | Washer-capscrew combination | |
US3034363A (en) | Cam drive | |
US2151853A (en) | Internal combustion engine | |
US2245743A (en) | Rotary valve | |
US2343067A (en) | Motion transmitting device | |
US2183436A (en) | Reciprocating ram pump | |
US4852708A (en) | Spring shield for starter drives for internal combustion engines | |
US5286177A (en) | Fluid pump having floating reciprocating shaft | |
DE2729807A1 (en) | FUEL INJECTION PUMP | |
US3374685A (en) | Face cam disc and cam follower arrangement | |
US3118595A (en) | Sealing rotary piston engine | |
US3610057A (en) | Sliding contact cam and tappet | |
DE953223C (en) | Device for reducing the volumetric and friction losses in liquid high-pressure pumps, in particular in pumps with pistons arranged in a star shape | |
US1757778A (en) | Internal-combustion engine | |
DE1904779B2 (en) | CAMSHAFT FOR AN IN-LINE FUEL INJECTION PUMP FOR COMBUSTION MACHINES | |
US2222138A (en) | Mechanical clearance regulator | |
US2156202A (en) | Airplane engine | |
US2316114A (en) | Machine element | |
US1718963A (en) | Wrist-pin construction | |
JPS6347635Y2 (en) | ||
US1373929A (en) | Roller thrust-bearing for friction-drums | |
CN207686891U (en) | Diesel engine array jet pump |