Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
  • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
  • F01L1/32—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for rotating lift valves, e.g. to diminish wear

Definitions

• the invention relates to a valve rotating device according to the preamble of claim 1.
• valve seat and the valve stem are subject to heavy wear.
• a valve rotating device is usually provided. The rotation also cleans the valve seat of oil carbon.
• a generic valve rotating device is shown in US Pat. No. 2,624,323.
• a plate spring is arranged at a distance from balls, which generate the twisting movement.
• a three-point support with inserted balls is provided on one side of the plate spring.
• the cover which is also the lower valve spring plate, is over a disc-shaped plate spring rotatably mounted, which rests directly on the balls of the base body.
• the balls are held by the tangential springs at the upper point of the inclined ball track.
• the disc spring presses onto the balls and these roll to the lowest point of the inclined ball track in the body. They turn the disc spring and press the tangential springs together.
• the rotary movement of the plate spring is transmitted to the valve via the cover, the valve spring, the upper spring plate and the clamping pieces. If the valve closes, the diaphragm spring is relieved. The balls are pushed back into the starting position by the tangential springs without rolling.
• the invention is based on the object of providing a valve turning device which has a simple structure and a good turning function and at the same time is particularly low-wear.
• a basic idea of the invention is to consistently separate the rotation principle and the necessary force introduction and force transmission principle from one another. If the valve rotating device is compressed under the initiation of a valve spring force, the axial spring device absorbs the essential forces. Due to the power transmission package pivot bearing / axial spring device / cover, the upper part of the valve rotating device is non-positively connected to each other under the valve spring force. With a vertical movement - reducing the distance between the cover and the base body - the outer surface of the cover now rotates the base body via the roller bearing. This rotation takes place relative to the cover via a frictional connection between the components cover - balls - base body.
• the axial spring device is arranged separately and at a distance from the balls, the balls and the ball raceways are hardly loaded axially. The so-called pitting on the balls and in the ball pockets and thus the wear on the valve rotating device is largely eliminated. Furthermore, the axial spring device is also no longer exposed to the bending, deformation and flexing forces which in the generic valve turning device on the occur in the generic valve rotating device on the known plate spring. The associated signs of wear on the plate spring are thus basically avoided in the valve rotating device according to the invention.
• the valve turning device according to the invention drastically improves the service life, which represents an enormous economic advantage, particularly in the case of long-life internal combustion engines.
• the rolling bearing has two races as a standard component, between which rolling elements are arranged in a cage.
• the cover is mounted and guided relative to the base body by the roller bearing about the axis of rotation.
• the rotational movement generated is guided radially exclusively by the needle bearing.
• the axial needle bearing has conically arranged races or lateral edge shoulders on the two races, between which the cylindrical needle-shaped rolling elements are arranged with their cages.
• the base body it is preferred that three to six, preferably four, ball pockets are provided, which are evenly distributed along the circumference of the base body.
• a significantly reduced number of balls can be provided according to the invention, since the individual balls are hardly loaded. If the number of balls remains the same, for example from eight to ten, the ball diameter can also be halved so that the ball diameter is between 3 mm and 10 mm. This means less effort in the production of the base body and the ball raceways arranged therein.
• the inclination of the ball raceways is relatively small in the generic valve rotating device, it is preferred according to the invention that the inclination of the ball raceway of the ball pockets is uniform and is between 6 and 15 degrees. Due to the low load on the individual balls in the valve rotating device according to the invention, the prerequisite for a greater inclination of the ball raceway is created, which improves the twisting movement.
• a preferred embodiment of the invention further consists in the axial spring device comprising at least one plate spring, preferably a plate spring package.
• Disc springs are a particularly cost-effective way of axially pressing apart the cover and the base body. When using a disc spring assembly, the desired axial forces can be set inexpensively and at the same time with high accuracy.
• the pivot bearing which is arranged on an axial side of the axial spring device, can either lie on the cover or on the base body, the latter being the preferred embodiment.
• the pivot bearing can be a simple sliding surface. According to the invention, however, it is preferred that the pivot bearing is a needle bearing.
• this rolling bearing variant a particularly low-friction rotation is achieved between the plate spring, which is non-positively supported on the base body, and the cover, on the other hand, in a small installation space. Overpressure of the valve rotating device is prevented according to the invention in that the balls are completely accommodated in the ball pocket at the lower point of the ball track and in that the base body rests against the cover in this position against the stop.
• the base body is firmly connected to the cylinder head, while the cover serves as the lower valve spring plate and is non-rotatably connected to it.
• the cover serves as the lower valve spring plate and is non-rotatably connected to it.
• Figure 1 is a schematic cross-sectional view through a valve rotating device according to the invention.
• FIG. 2 shows a schematic plan view of the main body of the valve rotating device from FIG. 1;
• Fig. 3 shows the detailed sectional view of section AA of Figure 1 in the rest position with the valve closed.
• Fig. 4 shows the detailed sectional view according to section AA of Fig. 1 when a valve spring force is applied with the valve open and
• Fig. 5 is a schematic cross-sectional view of a further embodiment of the valve rotating device according to the invention.
• a valve rotating device 10 comprises an annular base body 12 which has a central opening with a conical seat 34 for receiving a valve stem.
• a needle bearing is arranged as a roller bearing 24 in its radial ring area.
• a ball pocket base is designed as an inclined ball raceway 18, on which the ball 16 is held in a rest position by means of a tangential spring 20 at an upper dead center.
• a single disc spring 32 is arranged on the roller bearing 24 as an axial spring device 30.
• the axial spring device 30 is non-positively supported on a disk-shaped cover 22 which rests on the balls 16.
• the axial position of the cover 22 relative to the base body 12 is defined by a snap ring 26, the cover 22 being rotatable relative to the base body 12 and also axially displaceable to a certain extent in the direction of the base body 12. Only in this idle state there is static friction between the cover 22 and the base body 12 via the snap ring 26.
• guidance and thus a defined change in position occurs exclusively via the roller bearing 24. This additionally prevents frictional wear.
• the function of the valve rotating device 10 according to the invention can be seen clearly from FIGS. 3 and 4.
• a valve spring is compressed, which exerts an axial force on the cover 22.
• the cover 22 is axially displaced to the base body 12, the balls 16 being pressed into the ball pockets 14 against the spring action of the tangential springs 20. While the balls 16 have a defined projection over the base body 12 in a rest position, as can be seen from FIG. 3, the ball 16 is pressed completely into the ball pocket 14 when the spring force is applied according to FIG. 4.
• the ball 16 rolls on a ball raceway 18 provided with an inclination between 8 to 15 degrees, which leads to a defined rotation of the cover 22 relative to the base body 12.
• the cover 22 moves onto the base body 12 in a block, as can be seen from FIG. 4. This limits the maximum travel path of the cover 22. A so-called overpressing and thus damage to the balls 16 or the ball raceways 18 is thus ruled out.
• FIG. 5 A further preferred embodiment of a valve rotating device 10 ′ according to the invention can be seen in FIG. 5.
• the essential components of this embodiment correspond to those of the valve turning device 10 described above, so that the correspondingly designated components are not further explained.
• an axial spring device 30 ' is a plate spring assembly comprising a plurality of plate springs 32', by means of which a defined, high axial force can be set.
• the valve rotating device according to the invention with a separate arrangement of the balls 16 and the axial spring device 30 drastically relieves the balls 16 and the ball raceways 18 compared to the conventional devices, so that undesired deformations on these rotating components, the so-called pitting formation, are largely prevented.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Rolling Contact Bearings (AREA)
• Valve-Gear Or Valve Arrangements (AREA)
• Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)
• Taps Or Cocks (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7636717

Family Applications (1)

Country Status (6)

Families Citing this family (10)

Family Cites Families (10)

• 2000
  • 2000-03-28 DE DE10015417A patent/DE10015417A1/de not_active Withdrawn
• 2001
  • 2001-03-28 AT AT01927826T patent/ATE246310T1/de not_active IP Right Cessation
  • 2001-03-28 DE DE50100444T patent/DE50100444D1/de not_active Expired - Fee Related
  • 2001-03-28 AU AU2001254752A patent/AU2001254752A1/en not_active Abandoned
  • 2001-03-28 WO PCT/EP2001/003545 patent/WO2001073270A1/fr not_active Ceased
  • 2001-03-28 US US10/239,052 patent/US6662770B2/en not_active Expired - Fee Related
  • 2001-03-28 EP EP01927826A patent/EP1268986B1/fr not_active Expired - Lifetime

Non-Patent Citations (1)

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