Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C3/00—Shafts; Axles; Cranks; Eccentrics
  • F16C3/04—Crankshafts, eccentric-shafts; Cranks, eccentrics
  • F16C3/22—Cranks; Eccentrics
  • F16C3/28—Adjustable cranks or eccentrics
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
  • B23H7/00—Processes or apparatus applicable to both electrical discharge machining and electrochemical machining
  • B23H7/26—Apparatus for moving or positioning electrode relatively to workpiece; Mounting of electrode
  • B23H7/28—Moving electrode in a plane normal to the feed direction, e.g. orbiting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B35/00—Machines or devices designed for superfinishing surfaces on work, i.e. by means of abrading blocks reciprocating with high frequency
  • B24B35/005—Machines or devices designed for superfinishing surfaces on work, i.e. by means of abrading blocks reciprocating with high frequency for making three-dimensional objects

Definitions

• the invention relates to a drive device for replacing a planetary movement in the production of molded parts by grinding, primarily for a table mounted in a machine frame of a mold grinding machine, which table can be driven by at least one eccentric shaft which eccentrically penetrates a hollow shaft and by means of positive traction mechanism drives eccentric gear formed is connected.
• a classic area of application for such drive devices is the machining of molded parts, etc. made of graphite for the production of electrodes for the dies produced by spark erosion for forging components, injection molding tools and molds.
• This known method is mainly used in the construction of complicated and precise construction parts made of high quality materials.
• published European patent application No. 0118606 conveys a machine for producing an electrode of a certain spatial shape by means of a shape grinding tool of the same spatial shape but of different (larger) dimensions.
• a drive device for generating a planetary movement of the table on which the workpiece can be clamped is also disclosed.
• Two eccentric drives of the same type are used, each in one on the machine frame attached housing and motor driven by toothed belts.
• a specific eccentricity is set by means of an electric motor specially provided for this purpose, a clutch acting on the inner shaft being simultaneously actuated by means of a lifting cylinder, and the inner shaft being detached from the sleeve surrounding it. the inner shaft for driving by the electric motor is exposed. After the desired eccentricity has been reached, the parts of the coupling are separated again and the inner shaft is firmly connected to the sleeve by the force of a spring.
• a drive device for achieving a planetary movement of a work table is also known, the eccentric gear connected to the work table being driven by an electric motor by means of an additional drive unit using drive belts.
• the drive unit consists of a housing arranged on a machine frame, in which a sleeve connected to the electric motor by means of a drive wheel attached to it is mounted, through which a shaft connected to an output gear and intended for driving the eccentric shafts of the eccentric gears is guided.
• the upper end of the sleeve and the shaft is coupled by a planetary gear, the sleeve carrying the ring gear and this being coupled to the sun gear attached to the shaft by three pairs of intermeshing planet gears.
• the latter are mounted in a planet carrier driven by a stepper motor. By means of these planet carriers, the speed connection is The relationship between the sleeve and shaft changed and transferred to the eccentric gear.
• the drive unit is encapsulated and equipped with an oil bath for lubrication and cooling purposes.
• ⁇ r driving belt running over the sleeve of the drive unit meshes with the drive wheels provided on the sleeves of the eccentric gears and the drive wheel on the shaft of the drive unit drives the drive wheels of the eccentric shafts of the eccentric gears. Only during the duration of the eccentricity change does the sleeve and shaft have a different speed.
• the sleeve of the eccentric gear is mounted in a housing and has one to the axis of rotation by the dimension of the max.
• Eccentricity offset through bore in which the eccentric shaft is supported. This eccentric shaft is formed at the end facing the work table with a crank pin which is mounted in the work table.
• the object of the invention is therefore to fix Exercise of the listed shortcomings, whereby a cheaper drive concept, higher reliability and more precise functioning should be achieved.
• this object is achieved by two side-by-side r parallel to the planetary movement of the table, rotating at the same speed, each with one of the two drive shafts of an eccentric gear drive, of which the one drive element or traction mechanism has an adjustment variable of the eccentric gear changeable adjusting device is assigned solved.
• This drive concept proves to be a simple and undemanding design in a dusty operation which places high demands on the operating personnel and the machine. This makes it possible to improve the quality by increasing the accuracy and the reliability of a form grinding machine.
• the table of a machine requires additional guidance, for example parallelogram guidance in one axis.
• Toothed belts, chains etc. can be used as positive drive elements, which convey the required precision in the eccentric gears.
• Either one or the other of the two drive elements can be used to change the eccentricity.
• the direction of rotation of the drive elements or the direction of rotation the eccentric gear with regard to the machine frame can be freely selected.
• the drive concept according to the invention is particularly suitable for at least two eccentric gears which are connected to the table by virtue of the fact that at least one deflecting roller which is partially wrapped around by the drive elements and forms sections of the drive elements with the eccentric gears is assigned to the traction mechanism gears and that one is used to adjust the eccentric gears
• the length of the sections of the drive element of a traction mechanism transmission or an additional rotary movement of the hollow shaft or the eccentric shaft is provided in the eccentric adjustment mechanism.
• the drive concept with at least two eccentric gears can also be operated with a deflecting roller, the latter being designed to be drivable only in one direction of rotation and the section trailing with respect to the deflecting roller, the resiliently biased sections of a drive element formed between a deflecting roller and the eccentric gears with an actuating element that changes its length connected is.
• the deflection roller of the drive element or traction mechanism used to adjust the eccentric gear cannot be driven against the direction of rotation in order to ensure the additional rotation of one of the drive shafts of the eccentric gear intended for adjustment.
• This embodiment also enjoys the advantages of the solution according to the invention.
• One embodiment is particularly advantageous the teaching according to the invention, if the deflection rollers guiding the drive elements are provided in a parallel plane laterally offset from the eccentric gears and if an at least approximately parallel movable pair of rollers is arranged between the eccentric gears and the deflection rollers, between which the sections of a drive element looping around the rollers are guided, such that the length of the sections of these drive elements which form between each eccentric gear and a deflection roller can be changed.
• This embodiment should prove to be an optimal solution from an economic point of view because it should achieve the required stability and power transmission.
• rollers are advantageously equipped with the same diameters and the sections of the rotating drive member behave complementarily in their change in length, as a result of which a favorable arrangement of the rotating members can be achieved.
• An ideal arrangement and mode of operation can be achieved by forming parallel runs of the sections running around the rollers, so that favorable geometrical relationships between the drivable organs continue to occur.
• rollers are preferably mounted in a carrier element, which can be formed from two plates brought together on one side; pulley-like training.
• the carrier element is expediently provided with an actuating element, such as a piston-cylinder unit, threaded spindle, Actuator or the like. Provided device.
• an actuating element such as a piston-cylinder unit, threaded spindle, Actuator or the like.
• this drive device is further favored in that the drive motor is arranged on a common axis of the deflection rollers of the two traction mechanism transmissions.
• wrap angle of all drivable drive elements belonging to the drive concept is at least 180 °, as a result of which a reliable transmission of forces can be achieved.
• the eccentric drives themselves are designed by simple means and almost maintenance-free. Modest bearing housings are required in order to be able to accommodate a drivable hollow shaft with an eccentric rotary bearing and to pass an eccentric shaft, which is connected to the table, through the latter.
• the eccentric shaft on the End facing the table has a journal-like bearing dipping into a bearing provided on the table, but alternatively the eccentric shaft at the end near the table can be provided with a bore which is eccentrically offset with respect to its axis of rotation and serves as a bearing for a projecting journal connected to the table. This allows a cavity for a lubricant to be created in a cost-effective manner.
• the neck-like part of the hollow shaft protruding from the bearing housing on one side is suitable for formation as a toothed belt pulley or sprocket of a traction mechanism gear, and in addition to this transmission means, the bearing of the toothed belt wheel of the further traction mechanism gear can be formed on the hollow shaft.
• This design leaves it open to the designer which traction mechanism gear unit he wants to use for adjusting the eccentric gear unit. This makes it possible to assign the adjusting drive to the hollow shaft or the eccentric shaft to change the planetary movement.
• the toothed belt pulley rotatably arranged on the hollow shaft is provided and connected to the eccentric shaft via a driver, which in turn is provided at the end with a radially projecting shoulder. At the same time, this shoulder serves to axially limit the hollow shaft.
• the eccentricity or the degree of the planetary movement can be controlled by a device provided on or connected to an eccentric gear. be changed or changed. This device can be controlled manually or according to a program, so different
• Forms of movement can be transferred to the tool or workpiece. Varying the eccentricity over time can be important in making various shapes.
• Coordination of an encoder with a control program for a non-circular movement can also be used.
• FIG. 1 shows a section along the line I - I in Fig. 3, an embodiment according to the invention
• FIG. 5 shows a longitudinal section through an eccentric gear of an embodiment according to the invention.
• FIG. 1 to 3 schematically shows a drive device 1 for generating a planetary movement of a table
• FIG. 2 illustrates a machine tool or grinding machine (not shown) or another machine that can be used in the process engineering area.
• a mold grinding machine a cutting process of known type, is described here.
• the figures mentioned convey the arrangement and function of a drive device 1 of a mold grinding machine for the production of moldings, the table 2 or tool carrier of which is driven by means of positive-locking traction mechanisms 11, 12.
• These traction mechanism transmissions 3, 4 each consist of an endless drive element 5, 6 and deflection rollers 7, 8 which are positively connected to the drive. Toothed belts or chains are suitable as drive elements 5, 6 and their direction of rotation is synchronous in the same direction.
• traction mechanism gears 3 and 4 drive eccentric gears 3, 4 coupled to the table 2, which have an eccentrically deviating hollow shaft (not visible in FIGS. 1 to 4) and an eccentric shaft guided through this (both in FIG. 1 to 4 not visible).
• the design of the eccentric gear 3, 4 is explained in more detail in the text of FIG. 5.
• the traction mechanism gears 3, 4 run next to one another, parallel to the planetary movement, which can be circular or different, around deflection rollers 7, 8, 9 and the eccentric gears 3, 4 and are each through one of the two drive shafts - hollow shaft 26 or eccentric shaft 28 the drive organs 5,6 connected to the drive.
• an adjustment device 10 is provided which changes the size of the eccentric gears 3, 4.
• FIG. 4 I An alternative drive device shown in FIG. 4 I has two eccentric gears 3, 4 and two deflection rollers 7, 8 arranged on a common axis or shaft.
• the deflection rollers 7, 8 with the eccentric gears 3.4 form sections 13, 14 on the drive members 5, 6 of the traction mechanism gears 3, 4, the traction mechanism gears 11, 12 in each case being affected by these significant sections 13, 14 is, which is used to adjust the eccentric gear 3.4.
• the eccentric gears 3, 4 are adjusted by changing the length of these sections 13, 14, which change complementarily to one another, ie one section 13, 14 extends to the same extent as the other section 14, 13 shortened.
• the drive alternative in FIG. 4 has a deflection roller 7 which can only be driven in one direction (direction of rotation).
• the drive member 6 of the adjustable eccentric drive is resiliently biased, i.e. the trailing section 13 is provided for changing the eccentricity, while section 14 is provided with a counter roller 15 for removing a loose sag of this section 14.
• a pneumatic or hydraulic or mechanical actuating element 16 is installed, which changes the length of section 13, but also its position and direction, via a tensioning roller 17.
• the rollers 19, 20 are designed with diameters of the same size, so that different changes in length of the 'sections 13, 14 can be avoided.
• the rollers 19, 20 are at a fixed distance from one another and are mounted in a carrier element 21.
• the arrangement of the driven organs and their design is selected such that the sections 13, 14 of a drive element 6 which run around the rollers 19, 20 have parallel runs 24.
• the carrier element 21 is constructed in a sandwich-like manner and the plates are connected to one another by a web.
• the carrier element 21 is connected to an actuating member 16 formed from a piston-cylinder unit, which has a measuring scale 22, by means of which the eccentricity can be adjusted, adjusted or read. This measuring scale can also be provided with a vernier.
• the dash-dotted circles in FIG. 3 indicate the displaceability of the pair of rollers 18.
• the deflection rollers 7, 8 are arranged in pairs on an axis, which can also be connected to an electric or hydraulic drive motor 23.
• This arrangement of the eccentric gears 3, 4 and the deflection rollers 7, 8, 19, 20 enables an optimal connection to be made with the drive elements 5, 6. by the wrap angle on the traction mechanism 11 of the adjusting device 10 being approximately 180 °.
• the traction mechanism gear 12 for the pure eccentric drive is provided with a further deflection roller 9, which is provided between the motor deflection roller 8 and an eccentric gear 3, 4 within the arrangement of the drive elements of the drive device 1, so that the wrap angle at the motor-driven deflection roller 8 and on the eccentric gear 3, 4 also has approximately 180 °.
• This drive concept also enables a simple construction of the eccentric gears 3, 4, which can be attached to the machine frame and has a hollow shaft 26 with an eccentrically arranged rotary bearing 27, through which an eccentric shaft 28 driving a drivable table 2 is passed.
• the eccentric shaft 28 has, at the end directed towards the table 2, a table drive axis 30 offset eccentrically with respect to its axis of rotation 29, which is designed as a cylindrical bore 31 and in which a drive pin 32, which is rigidly connected to the table 2, is mounted.
• the table Z is supported by roller bearings 33, so that the bearing bore 31 permits the absorption of a lubricant.
• Hie hollow shaft 26 in turn is equipped with a toothed belt pulley 3-4 or other positive transmission means of the drive forces and serves to support the toothed belt pulley 35, which is connected to the eccentric shaft 28.
• a shaft bearing is formed on the toothed belt pulley 34 and the toothed belt pulley 35 which is supported at this point is provided with a driver 36 which is anchored in a shoulder 37 of the eccentric shaft 28.
• the recessed area of the shoulder 37 serves to axially limit the hollow shaft 26 and the eccentric shaft 28.
• the drive devices 1 can be controlled manually, for example with an adjusting spindle, pneumatically or hydraulically with a piston-cylinder unit or electrically or electromechanically with an actuator or spindle drive via the adjusting device 10.
• the motor drive can be controlled via a program.
• a measuring and comparison device 38 in conjunction with 'the Uebertragungsstoffn of the drive forces, Glasstoff ⁇ driven 11, 12, drive elements 5, 6 or Zahnriemenschei- ben 34, 35, by signals via a control circuit, the adjusting device 10 is controlled and the eccentricity / Planetary movement can be changed.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Ocean & Marine Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Retarders (AREA)
• Grinding And Polishing Of Tertiary Curved Surfaces And Surfaces With Complex Shapes (AREA)
• Transmission Devices (AREA)
• Constituent Portions Of Griding Lathes, Driving, Sensing And Control (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=4253221

Family Applications (1)

Country Status (4)

Cited By (1)

Citations (2)

• 1987
  • 1987-08-29 CH CH331087A patent/CH673323A5/de not_active IP Right Cessation
• 1988
  • 1988-08-24 WO PCT/CH1988/000146 patent/WO1989001846A1/de not_active Application Discontinuation
  • 1988-08-24 JP JP63506766A patent/JPH02500578A/ja active Pending
  • 1988-08-24 EP EP19880907141 patent/EP0329740A1/de not_active Withdrawn

Patent Citations (2)

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