EP0355904B1 - Grinding or polishing spindle with a hydrostatic bearing - Google Patents

Grinding or polishing spindle with a hydrostatic bearing Download PDF

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Publication number
EP0355904B1
EP0355904B1 EP89202054A EP89202054A EP0355904B1 EP 0355904 B1 EP0355904 B1 EP 0355904B1 EP 89202054 A EP89202054 A EP 89202054A EP 89202054 A EP89202054 A EP 89202054A EP 0355904 B1 EP0355904 B1 EP 0355904B1
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EP
European Patent Office
Prior art keywords
grinding
spindle
tool head
shaft
bearing
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
EP89202054A
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German (de)
French (fr)
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EP0355904A3 (en
EP0355904A2 (en
Inventor
Wilhelm König
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Individual
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Individual
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Publication date
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Priority to AT89202054T priority Critical patent/ATE88402T1/en
Publication of EP0355904A2 publication Critical patent/EP0355904A2/en
Publication of EP0355904A3 publication Critical patent/EP0355904A3/en
Application granted granted Critical
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    • 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
    • B24B41/00—Component parts such as frames, beds, carriages, headstocks
    • B24B41/04—Headstocks; Working-spindles; Features relating thereto
    • 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
    • B24B19/00—Single-purpose machines or devices for particular grinding operations not covered by any other main group
    • B24B19/14—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding turbine blades, propeller blades or the like

Definitions

  • the invention relates to a grinding and polishing spindle with hydrostatic bearing, with a spindle housing, a shaft and a tool head, and with supply of a pressure medium through bores in the spindle housing and in at least one bearing sleeve to at least one bearing point.
  • Such a grinding spindle is known, for example, from DE-Z: Oil Hydraulics and Pneumatics 16 (1972) No. 6, p. 275 and is used primarily because of the high concentricity.
  • the one-piece connection of the shank and tool head avoids imbalances, such as those which occur in the case of grinding and polishing tool heads which are detachably connected to the spindle, due to the tolerances at the connection point.
  • the entire tool can be produced in one setup, which ensures high concentricity.
  • a one-piece grinding rotor is already known from DE 35 15 443 A1. In this case, however, only the spindle and the grinding wheel flange are connected to one another in one piece, while the grinding tool itself is still releasable and is therefore fastened to the grinding rotor with corresponding tolerances.
  • the well-known grinding rotor is roller-bearing, which also causes runout errors.
  • the shaft 1 runs in a fixed bearing sleeve 2.
  • the tool head 11 has been manufactured in the clamping with the shaft, so that only the tolerance of these two diameters is decisive for the freedom from impact in the working area. This is particularly important for electroplated tools, since the galvanized abrasive grit must work evenly on the circumference.
  • tool heads that are inseparably connected to the shank by gluing or welding. However, these must then be dressed using the bearing points of the shaft.
  • the tool head is driven together with the shaft 1 by the drive motor 5, which is fixed in the spindle housing 6.
  • the drive motor 5 which is fixed in the spindle housing 6.
  • the fixed bearing sleeve 2 can also be replaced.
  • changes in tolerance can be compensated for by changes in the pressure of the cooling medium.
  • Appropriate quantity metering allows storage temperatures to be set to the desired values.
  • the particularly critical bearing point on the processing side is formed by a coolant film, which is created by a hydrostatic pressure as it emerges from the feed bores 7, 8 and in the pocket 3.
  • the pressure medium is subject to a specific flow which can be influenced by the groove arrangement 12.
  • the coolant is transported in the direction of the bore 9.
  • the coolant can either emerge from the bore 9 (return transport to the coolant container, cleaned) or else enter the working area of the tool head 11 via the bores 14 and 15 and the radial bore 16.
  • the main part of the coolant emerges via the feed part 4.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Constituent Portions Of Griding Lathes, Driving, Sensing And Control (AREA)
  • Polishing Bodies And Polishing Tools (AREA)
  • Turning (AREA)
  • Auxiliary Devices For Machine Tools (AREA)

Abstract

A one-part tool consisting of an effective tool range with a spindle and mounted hydrostatically in a plain bearing, by virtue of the regions, namely effective tool range/spindle bearing points, obtainable in chucking fixture, without the use of ball bearings, possesses an extremely high degree of true running and thereby guarantees the highest possible cutting performances and lifetimes, whilst ensuring the best surface qualities. <IMAGE>

Description

Die Erfindung betrifft eine Schleif- und Polierspindel mit hydrostatischer Lagerung, mit einem Spindelgehäuse, einem Schaft und einem Werkzeugkopf, und mit Zuführungen eines Druckmittels über Bohrungen im Spindelgehäuse und in wenigstens einer Lagerhülse zu wenigstens einer Lagerstelle.The invention relates to a grinding and polishing spindle with hydrostatic bearing, with a spindle housing, a shaft and a tool head, and with supply of a pressure medium through bores in the spindle housing and in at least one bearing sleeve to at least one bearing point.

Eine derartige Schleifspindel ist beispielsweise aus der DE-Z: Ölhydraulik und Pneumatik 16 (1972) Nr. 6, S. 275 bekannt und wird vor allem wegen der hohen Rundlaufgenauigkeit verwendet.Such a grinding spindle is known, for example, from DE-Z: Oil Hydraulics and Pneumatics 16 (1972) No. 6, p. 275 and is used primarily because of the high concentricity.

Bei der automatischen Bearbeitung von schlecht zugänglichen Werkstückkonturen sind extrem lange und schlanke Schleifspindeln erforderlich. Dies gilt insbesondere für das Schleifen und Polieren von Turbinen- und Verdichterschaufeln für Francis-Spiral-Turbinenräder und Peltonturbinenräder.When machining workpiece contours that are difficult to access automatically, extremely long and slim grinding spindles are required. This applies in particular to the grinding and polishing of turbine and compressor blades for Francis spiral turbine wheels and Pelton turbine wheels.

Die heutigen automatischen Bearbeitungsmethoden stellen folgende Anforderungen:

  • hohe Spindelstabilität
  • Umfangsgeschwindigkeiten bis 200m/sec,
  • hohe Rundlaufgenauigkeit
  • extreme Kühlmittelpräsenz für Werkzeug und Werkstück
Der Erfindung liegt die Aufgabe zugrunde, eine Schleifspindel der eingangs genannten Art so auszubilden, daß ein hochgenaues Schleifen und Polieren mit großer Abtragsleistung auch von schlecht zugänglichen Werkstückkonturen ermöglicht wird.Today's automatic processing methods have the following requirements:
  • high spindle stability
  • Peripheral speeds up to 200m / sec,
  • high concentricity
  • extreme presence of coolant for tool and workpiece
The invention has for its object to design a grinding spindle of the type mentioned so that a highly accurate grinding and polishing with a high stock removal rate even from poorly accessible workpiece contours.

Diese Aufgabe wird bei einer Vorrichtung der eingangs genannten Art dadurch gelöst, daß der Schaft mit dem Werkzeugkopf einteilig verbunden ist, daß die Ableitung zumindest eines Teils des Druckmittels aus den Lagerstellen in den Arbeitsbereich des Werkzeugkopfes zur Unterstützung der Werkzeugkopf- und Werkstückkühlung über einen Ringspalt zwischen Schaft und Lagerhülse und über Axial- und Radialbohrungen im Schaft und im Werkzeugkopf erfolgt.This object is achieved in a device of the type mentioned above in that the shaft is connected in one piece to the tool head, that the discharge of at least part of the pressure medium from the bearing points into the working area of the tool head to support the tool head and workpiece cooling via an annular gap between Shank and bearing sleeve and via axial and radial bores in the shaft and in the tool head.

Durch die einteilige Verbindung von Schaft und Werkzeugkopf werden Unwuchten vermieden, wie sie bei lösbar mit der Spindel verbundenen Schleif- und Polierwerkzeugköpfen durch die Toleranzen an der Verbindungsstelle auftreten. Das gesamte Werkzeug ist in einer Aufspannung herstellbar, wodurch eine hohe Rundlaufgenauigkeit erreicht wird. Aus der DE 35 15 443 A1 ist zwar bereits ein einteiliger Schleifrotor bekannt. Bei diesem werden jedoch nur die Spindel und der Schleifscheibenflansch einteilig miteinander verbunden, während das Schleifwerkzeug selbst nach wie vor lösbar und deshalb mit entsprechenden Toleranzen auf dem Schleifrotor befestigt ist. Darüberhinaus ist der bekannte Schleifrotor wälzgelagert, wodurch ebenfalls Rundlauffehler entstehen.The one-piece connection of the shank and tool head avoids imbalances, such as those which occur in the case of grinding and polishing tool heads which are detachably connected to the spindle, due to the tolerances at the connection point. The entire tool can be produced in one setup, which ensures high concentricity. A one-piece grinding rotor is already known from DE 35 15 443 A1. In this case, however, only the spindle and the grinding wheel flange are connected to one another in one piece, while the grinding tool itself is still releasable and is therefore fastened to the grinding rotor with corresponding tolerances. In addition, the well-known grinding rotor is roller-bearing, which also causes runout errors.

Durch die Ableitung zumindest eines Teils des Druckmittels aus den Lagerstellen in den Arbeitsbereich des Werkzeugkopfes kann die Kühlung des Werkzeugkopfes und des Werkstückes wirkungsvoll unterstützt werden, so daß hohe Umfangsgeschwindigkeiten und große Abtragsleistungen ermöglicht werden. Gleichzeitig kann das Zuführteil für die direkte Zuführung von Kühlmittel entsprechend verkleinert werden, so daß die Zugänglichkeit zum Werkstück verbessert wird. Aus der DE-Z.: Maschine + Werkzeug, Coburg, 32/1979, S. 42 ist die Zuführung von Kühlmittel über die Spindel und durch die Schleifscheibe hindurch an sich bekannt. Dies hat sich aber nicht als praktikabel erwiesen wegen der Notwendigkeit der extrem feinen Säuberung des Kühlmittels,da sonst Ablagerungen die Zuführungsbohrungen aufgrund der hohen Zentrifugalkräfte schnell zusetzen. Bei der Erfindung besteht dieser Nachteil nicht, da das Druckmittel zur Verwendung als Lagermedium bereits fein gesäubert werden muß. Außerdem macht hier das Druckmittel nur einen Teil des gesamten Kühlmittels aus. Im Anspruch 2 ist eine vorteilhafte Ausgestaltung der Schleif- und Polierspindel angegeben, bei der ein Teil des Druckmittels direkt in einen Druckmittelbehälter rückführbar ist, wenn auf diesen Teil zur Kühlung von Werkzeugkopf und Werkstück verzichtet werden kann. Dadurch entfällt für diesen Teil die Reinigung.By cooling off at least part of the pressure medium from the bearing points into the working area of the tool head, the cooling of the tool head and the workpiece can be effectively supported, so that high peripheral speeds and large stock removal rates are made possible. At the same time, the supply part for the direct supply of coolant can be reduced accordingly, so that the accessibility to the workpiece is improved. From DE-Z .: Maschine + Werkzeug, Coburg, 32/1979, p. 42, the supply of coolant via the spindle and through the grinding wheel is known per se. However, this has not proven to be practical because of the need for extremely fine cleaning of the coolant, since otherwise deposits will quickly clog the feed holes due to the high centrifugal forces. This disadvantage does not exist with the invention, since the pressure medium for use as a storage medium must already be cleaned. In addition, the pressure medium only makes up part of the total coolant. In claim 2, an advantageous embodiment of the grinding and polishing spindle is specified, in which a part of the pressure medium can be returned directly to a pressure medium container if this part for cooling the tool head and workpiece can be dispensed with. This eliminates cleaning for this part.

Ein Ausführungsbeispiel ist nachfolgend unter Bezugnahme auf die Zeichnung näher beschrieben:
Bei der vorliegenden Erfindung läuft der Schaft 1 in einer feststehenden Lagerhülse 2. Der Werkzeugkopf 11 ist in der Aufspannung mit dem Schaft gefertigt worden, so daß nur die Toleranz dieser beiden Durchmesser für die Schlagfreiheit im Arbeitsbereich maßgeblich ist. Diese ist vor allem für galvanisch belegte Werkzeuge von Bedeutung, da der aufgalvanisierte Schleifkornbelag gleichmäßig am Umfang arbeiten muß.An exemplary embodiment is described in more detail below with reference to the drawing:
In the present invention, the shaft 1 runs in a fixed bearing sleeve 2. The tool head 11 has been manufactured in the clamping with the shaft, so that only the tolerance of these two diameters is decisive for the freedom from impact in the working area. This is particularly important for electroplated tools, since the galvanized abrasive grit must work evenly on the circumference.

Das gleiche gilt nach für Werkzeugköpfe, die durch Kleben oder Schweißen mit dem Schaft untrennbar verbunden werden. Diese müssen jedoch anschließend unter Verwendung der Lagerstellen des Schaftes abgerichtet werden.
Der Werkzeugkopf wird zusammen mit dem Schaft 1 vom Antriebsmotor 5 angetrieben, der im Spindelgehäuse 6 fixiert ist. Beim Werkzeugwechsel wird das Werkzeug mit Schaft gewechselt, notfalls kann die feststehende Lagerhülse 2 ebenfalls ausgetauscht werden. Bei der hydrostatischen Lagerung können Toleranzveränderungen durch Druckänderungen des Kühlmediums auskompensiert werden. Durch entsprechende Mengendosierungen lassen sich Lagertemperaturen auf gewünschte Werte einstellen. Die besonders kritische Lagerstelle an der Bearbeitungsseite wird durch einen Kühlmittelfilm gebildet, der durch einen hydrostatischen Druck beim Austritt aus den Zuführungsbohrungen 7, 8 und in der Tasche 3 entsteht. Das Druckmittel unterliegt einer bestimmten Strömung, die durch Rillenanordnung 12 beeinflußbar ist. Infolge der Schaftdrehung wird das Kühlmittel in Richtung der Bohrung 9 transportiert. Das Kühlmittel kann sowohl aus der Bohrung 9 austreten (Rücktransport zum Kühlmittelbehälter, gereinigt) oder aber über die Bohrungen 14 und 15 und die Radialbohrung 16 in den Arbeitsbereich des Werkzeugeskopfes 11 eintreten. Über das Zuführteil 4 tritt der Hauptteil des Kühlmittels aus.The same applies to tool heads that are inseparably connected to the shank by gluing or welding. However, these must then be dressed using the bearing points of the shaft.
The tool head is driven together with the shaft 1 by the drive motor 5, which is fixed in the spindle housing 6. When changing the tool, the tool is changed with the shank; if necessary, the fixed bearing sleeve 2 can also be replaced. In hydrostatic bearings, changes in tolerance can be compensated for by changes in the pressure of the cooling medium. Appropriate quantity metering allows storage temperatures to be set to the desired values. The particularly critical bearing point on the processing side is formed by a coolant film, which is created by a hydrostatic pressure as it emerges from the feed bores 7, 8 and in the pocket 3. The pressure medium is subject to a specific flow which can be influenced by the groove arrangement 12. As a result of the shaft rotation, the coolant is transported in the direction of the bore 9. The coolant can either emerge from the bore 9 (return transport to the coolant container, cleaned) or else enter the working area of the tool head 11 via the bores 14 and 15 and the radial bore 16. The main part of the coolant emerges via the feed part 4.

Claims (2)

  1. Grinding and polishing spindle with a hydrostatic bearing, in particular for grinding and polishing turbine and compressor blades whose machining is possible only with small tool dimensions, which comprises a spindle housing (6), a shaft (1) and a tool head (11) as well as means for supplying a pressurized fluid through bores (7, 8) in said spindle housing (6) and in at least one bearing sleeve (2) towards at least one point of bearing support (3), characterized in that said shaft (1) is integrally combined with said tool head (11), and that the discharge of at least one part of said pressurized fluid from bearing points into the machining zone of said tool head (11) is realized through an annulus (13) between said shaft (1) and said bearing sleeve (2) as well as through axial and radial bores (14, 15, 16) in the shaft (1) and said tool head (11) so as to assist the cooling of the tool head and the workpiece.
  2. Grinding and polishing spindle according to Claim 1, characterized in that another share of said pressurized fluid may be returned from said annulus (13) through bores (17, 9) in said bearing sleeve (2) and in said spindle housing (6) into a pressurized fluid reservoir.
EP89202054A 1988-08-19 1989-08-02 Grinding or polishing spindle with a hydrostatic bearing Expired - Lifetime EP0355904B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT89202054T ATE88402T1 (en) 1988-08-19 1989-08-02 GRINDING AND POLISHING SPINDLE WITH HYDROSTATIC BEARING.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3828225 1988-08-19
DE3828225 1988-08-19

Publications (3)

Publication Number Publication Date
EP0355904A2 EP0355904A2 (en) 1990-02-28
EP0355904A3 EP0355904A3 (en) 1991-04-17
EP0355904B1 true EP0355904B1 (en) 1993-04-21

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ID=6361215

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89202054A Expired - Lifetime EP0355904B1 (en) 1988-08-19 1989-08-02 Grinding or polishing spindle with a hydrostatic bearing

Country Status (2)

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EP (1) EP0355904B1 (en)
AT (1) ATE88402T1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6390907B1 (en) * 1998-02-09 2002-05-21 Joel Kym Metzler Machine tool and machine tool spindle and workpiece mounting-apparatus and grinding process
DE19826519C2 (en) * 1998-06-15 2000-05-18 Freundeskreis Des Lehrstuhles Hydrostatic guidance

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2475791A (en) * 1941-04-04 1949-07-12 Lesueur Jules Marcel Internal grinding apparatus
DE884003C (en) * 1950-11-08 1953-07-23 Mario Coppier Rotating grindstone, especially for high speeds, and method for its manufacture
US3183632A (en) * 1962-07-09 1965-05-18 Gen Motors Corp Grinding tool
US3609931A (en) * 1970-02-16 1971-10-05 Gen Motors Corp Coolant system for high speed spindles

Also Published As

Publication number Publication date
ATE88402T1 (en) 1993-05-15
EP0355904A3 (en) 1991-04-17
EP0355904A2 (en) 1990-02-28

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