WO1998038014A1 - Motor-driven hand unit - Google Patents
Motor-driven hand unit Download PDFInfo
- Publication number
- WO1998038014A1 WO1998038014A1 PCT/DE1998/000136 DE9800136W WO9838014A1 WO 1998038014 A1 WO1998038014 A1 WO 1998038014A1 DE 9800136 W DE9800136 W DE 9800136W WO 9838014 A1 WO9838014 A1 WO 9838014A1
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- WO
- WIPO (PCT)
- Prior art keywords
- bearing
- axial
- shaft
- sealing element
- hand unit
- 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.)
- Ceased
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Classifications
-
- 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
- B24B23/00—Portable grinding machines, e.g. hand-guided; Accessories therefor
- B24B23/04—Portable grinding machines, e.g. hand-guided; Accessories therefor with oscillating grinding tools; Accessories therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25F—COMBINATION OR MULTI-PURPOSE TOOLS NOT OTHERWISE PROVIDED FOR; DETAILS OR COMPONENTS OF PORTABLE POWER-DRIVEN TOOLS NOT PARTICULARLY RELATED TO THE OPERATIONS PERFORMED AND NOT OTHERWISE PROVIDED FOR
- B25F5/00—Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
- B25F5/008—Cooling means
Definitions
- the invention relates to a motor-driven hand unit according to the preamble of claim 1.
- the Invention motor-driven hand-held unit with the features of claim 1 has the following advantages.
- the circumferential axial sealing element seals the bearing from the dust chamber, so that neither dust can get into the bearing nor any bearing grease can escape from the bearing and get into the dust chamber. This considerably increases the life of the bearing.
- the bearing in particular deep groove ball bearing, has sealing disks that are integrated on both sides, touching or not touching, which are seated in particular on the outer ring and in relation to the axial end face of the inner ring further inside and at a distance from it.
- a disk rotating with it can be arranged on the shaft, which lies against the facing end face of the inner ring and the integrated sealing disk of the bearing with at least a small axial distance radially covered.
- the disk is formed from a thin sheet and if the disk and, via this, the inner ring of the bearing are secured axially on the shaft by means of a retaining ring. This results in a simple and cost-effective sealing of the bearing on the opposite axial side, where less dust is produced when the hand-held unit is designed as a grinding device.
- the shaft on the axial side of the fan wheel facing away from the axial sealing element has a z. B. carries eccentric sleeve on the - z. B. by means of an associated sleeve-shaped inner ring - a grinding plate is rotatably supported by a bearing.
- the bearing of the grinding plate can be formed from an open needle sleeve and can be axially sealed on the axial side which faces the fan wheel by means of at least one sealing element which is designed as a radial shaft sealing ring.
- the at least one sealing element of the bearing can be designed as a sealing ring corresponding in cross-section to a lying U and bearing two striving sealing lips. In this way, a dust seal of the bearing assigned to the grinding plate is achieved in a simple manner on the axial side facing the dust chamber. Drawing -.
- FIG. 2 shows an enlarged detail from FIG. 1.
- a motor-driven hand tool 1 in particular grinding device, for. B. Orbital sander, shown, which has a housing 2, in whose upper housing part 12 an electric motor 3 is contained, which drives a grinding plate 11 designed as an oscillating member via a coaxial shaft 10.
- the shaft 10 is supported in the housing part 12 by means of a bearing 13.
- the housing part 12 surrounds a fan wheel 14 which is located within a dust space 15 delimited by the housing part 12 and is arranged on the shaft 10 in a rotationally fixed manner by means of a sleeve 18, so that it rotates with the shaft 10.
- the bearing 13 is located outside the dust chamber 15 and is in an approximately cup-shaped receptacle 16 of the housing part 12 recorded in such a way that a bottom part 17 of the receptacle 16 covers the bearing 13 on the side facing the fan wheel 14, the bottom part 17 having a passage 19 through which the shaft 10 with the sleeve 18 extends.
- the bearing 13 is designed, for example, as a deep groove ball bearing, the outer ring 20 of which is held non-rotatably in the approximately cup-shaped receptacle 16 and can be axially supported on the bottom part 17 thereof.
- the inner ring 21 sits on the shaft 10 in a rotationally fixed manner.
- the bottom part 17 is dimensioned such that it extends radially approximately to the inner ring 21.
- the bearing 13, in particular in the form of a ball groove bearing, is sealed on the axial side which faces the fan wheel 14 with respect to the fan wheel 14 by means of an axial sealing element 30 which runs together with the shaft 10 and the sleeve 18.
- the sealing element 30 is formed from an annular, flexible and in particular rubber-elastic shaft seal and has a sealing body 31 and a flexible sealing lip 32, which are integral with one another.
- the sealing lip 32 strives on an axial side from the sealing body 31 approximately in the shape of a truncated cone and is elastically movable relative to the sealing body 31.
- the sealing element 30 is tensioned on the shaft 10 or on the sleeve 18 and held in an elastically clamping manner.
- the radial dimensioning of the sealing element 30 is selected such that the sealing element 30 seals the passage 19 of the base part 17 with respect to the dust chamber 15.
- the sealing element 30 rests elastically on the bottom part 17 with its axial side facing the bottom part 17.
- the sealing lip 32 projects in the direction of the base part 17 and its surface 22, the sealing lip 32 preferably bears against the surface 22 of the base part 17 with a slight pretension. In this way, there is at least a slight contact pressure of the sealing lip 32. Due to the mobility of the sealing lip 32, tolerances, misalignments, angular deviations or the like, in particular of the base part 17, are compensated for by this.
- the sealing lip 32 provides a good seal in the axial direction, namely a sealing of the bearing 13 in relation to the dust chamber 15. When the shaft 10 rotates, the sealing lip 32 is relieved somewhat by the centrifugal force, as a result of which the friction at the contact point with the base part 17 and thus the wear of the sealing lip 32 is reduced.
- the housing part 12 is preferably made of light metal and in particular of die-cast aluminum.
- the surface 22 of the base part 17 which is in contact with the flexible sealing lip 32 is untreated, for example. machined cast iron. This surface 22 does not have to be polished. It is advantageous if the surface 22 is only greased, as a result of which the friction in the region of the contact surface with the sealing lip 32 is reduced.
- a good seal of the bearing 13 to the dust chamber 15 is achieved in the manner described by the axial sealing element 30, and this in a simple and inexpensive manner, in particular when axial sealing elements 30 as components in this form are already commercially available and available.
- the bearing 13, in particular deep groove ball bearing, has sealing disks 23 and 24 integrated therein on both sides, only schematically indicated in FIG. 2, which are seated, in particular, on the outer ring 20 and with respect to the axial end face 25 or 26 of the inner ring 21 further inside and at a distance run away.
- a disk 27, for example is made of thin sheet rotatably arranged, which rotates with the shaft 10.
- the disk 27 lies against the facing end face 26 of the inner ring 21 and radially covers the integrated sealing disk 24 with at least a small axial distance, so that there is no friction between the rotating disk 27 and the non-rotating sealing disk 24.
- the disk 27 acts as a centrifugal disk, which is sufficient for axially sealing the bearing 13 on this side.
- the shaft 10 On the axial side of the fan wheel 14 facing away from the axial sealing element 30, the shaft 10 carries, for example, an eccentric sleeve 40, on which the grinding plate 11 is rotatably mounted by means of an associated, sleeve-shaped inner ring 41 via a bearing 42.
- the bearing 42 of the grinding plate 11 is formed from an open needle sleeve and axially sealed on the axial side facing the fan wheel 14 by means of at least one sealing element 43, which is effective between the grinding plate 11 and the sleeve-shaped inner ring 41.
- the sealing element 43 is designed as a radial shaft sealing ring, two identical radial shaft sealing rings being provided in the exemplary embodiment shown, which are axial are arranged one behind the other.
- the at least one sealing element 43 is designed as a sealing ring with a cross-section that is approximately U-shaped and has two striving sealing lips, one of which functions as a sealing lip and the other as a dust lip.
- the bearing 42 is sealed in a simple manner by the at least one sealing element 43 at the area facing the fan wheel 14 in relation to the dust chamber 15 and the dust accumulating there.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Sealing Of Bearings (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
- Constituent Portions Of Griding Lathes, Driving, Sensing And Control (AREA)
- Grinding-Machine Dressing And Accessory Apparatuses (AREA)
Abstract
Description
Motorisch angetriebenes HandaggregatMotor-driven hand unit
Stand der TechnikState of the art
Die Erfindung geht aus von einem motorisch angetriebenen Handaggregat nach der Gattung des Anspruchs 1.The invention relates to a motor-driven hand unit according to the preamble of claim 1.
Es ist ein motorisch angetriebenes Handaggregat dieser Art bekannt (DE-40 38 634 AI), bei dem das Lüfterrad in axialem Abstand oberhalb des Lagers der Welle angeordnet ist. Das Handaggregat ist z.B. als Schwingschleifer ausgebildet. Bei eingeschaltetem Motor und dadurch angetriebener umlaufender Welle wird mittels des umlaufenden Lüfterrades der bei der Oberflächenbearbeitung anfallende Schleifstaub durch Öffnungen in einer Schleifplatte und im daran gehaltenen Schleif- papier hindurch in einen Staubraum eingesaugt und aus diesem über eine Auslaßöffnung in einen angeschlossenen Behälter abgegeben. Dabei ist das Lager auf der dem Lüfterrad zugewandten Axialseite unmittelbar dem Staub im Staubraum ausgesetzt. Dadurch setzt sich das Lager relativ schnell mit Staub zu, wodurch die Lagerung unzulänglich wird und die Lebensdauer des Lagers erheblich reduziert wird. Vorteile der ErfindungThere is a motor-driven hand unit of this type known (DE-40 38 634 AI), in which the fan wheel is arranged at an axial distance above the bearing of the shaft. The hand-held unit is designed, for example, as an orbital sander. With the motor switched on and the rotating shaft driven thereby, the grinding dust generated during surface processing is sucked through openings in a grinding plate and in the sanding paper held thereon into a dust chamber and discharged from there via an outlet opening into a connected container. The bearing on the axial side facing the fan wheel is directly exposed to the dust in the dust chamber. As a result, the bearing becomes clogged with dust relatively quickly, which makes storage inadequate and considerably reduces the service life of the bearing. Advantages of the invention
Das erfindungsge äße motorisch angetriebene Handaggregat mit den Merkmalen des Anspruchs 1 hat demgegenüber folgende Vorteile. Durch das umlaufende axiale Dichtungselement wird das Lager zum Staubraum hin abgedichtet, so daß weder Staub in das Lager gelangen kann noch etwaiges Lagerfett aus dem Lager austreten und in den Staubraum gelangen kann. Die Lebensdauer des Lagers wird dadurch beträchtlich erhöht.The Invention motor-driven hand-held unit with the features of claim 1 has the following advantages. The circumferential axial sealing element seals the bearing from the dust chamber, so that neither dust can get into the bearing nor any bearing grease can escape from the bearing and get into the dust chamber. This considerably increases the life of the bearing.
Weitere vorteilhafte Ausgestaltungen der Erfindung ergeben sich aus den Unteransprüchen. Durch die Merkmale in den Ansprüchen 2 und 3 ergibt sich ein kostengünstiges, einfaches und gut abdichtendes axiales Dichtungselement. Durch die Merkmale in den Ansprüchen 7 bis 9 ist mit einfachen Mitteln eine gute Staubabdichtung des Lagers erreicht, wobei die elastische Dichtlippe Toleranzen, Winkelabweichungen, Fluchtungsfehler und auch Oberflächenungenauigkeiten der Oberfläche des Bodenteiles ausgleicht, so daß auch dann eine dauerhafte Dichtungsanlage gewährleistet ist. Aufgrund der Flexibilität der Dichtlippe kann der Gehäuseteil, insbesondere dessen Bodenteil, auf der Oberfläche, an der die Dichtlippe anliegt, unbehandelt, z.B. unbearbeitet bleiben, ohne die gute Abdichtungswirkung zu gefährden. Die Oberfläche muß also nicht etwa poliert werden. In vorteilhafter Weise kann die Reibwirkung durch Einfetten des Kontaktbereiches reduziert werden.Further advantageous embodiments of the invention result from the subclaims. The features in claims 2 and 3 result in an inexpensive, simple and well-sealing axial sealing element. The features in claims 7 to 9 achieve good dust sealing of the bearing with simple means, the elastic sealing lip compensating for tolerances, angular deviations, misalignment and also surface inaccuracies of the surface of the base part, so that a permanent sealing system is also guaranteed. Due to the flexibility of the sealing lip, the housing part, in particular its bottom part, can be left untreated on the surface on which the sealing lip rests, e.g. remain unprocessed without endangering the good sealing effect. So the surface does not have to be polished. The friction effect can advantageously be reduced by greasing the contact area.
Von Vorteil kann es sein, wenn die mit dem axialen Dich- tungselement , insbesondere der flexiblen mindestens einenIt can be advantageous if the with the axial sealing element, in particular the flexible at least one
Dichtlippe, in Berührung stehende Oberfläche des Bodenteils unbehandelt, z. B. unbearbeitet, vorzugsweise eingefettet ist. Vorteilhaft kann es ferner sein, wenn das Lager, insbesondere Rillenkugellager, beidseitig darin berührend oder nicht berührend integrierte Dichtscheiben aufweist, die insbesondere am Außenring sitzen und in Bezug auf die axiale Stirnfläche des Innenringes weiter innen und mit Abstand davon verlaufen. Auf der Axialseite des Lagers, insbesondere des Rillenkugellagers , die dem axialen Dich- tungselement abgewandt ist, kann auf der Welle eine mit dieser umlaufende Scheibe angeordnet sein, die an der zugewandten Stirnfläche des Innenringes anliegt und die integrierte Dichtscheibe des Lagers mit zumindest geringem Axialabstand radial überdeckt. Von Vorteil kann es sein, wenn die Scheibe aus einem dünnen Blech gebildet ist und wenn die Scheibe und über diese der Innenring des Lagers mittels eines Sicherungsringes axial auf der Welle gesichert ist. Hierdurch ergibt sich in einfacher und kostengünstiger Weise eine Abdichtung des Lagers auf der gegenüberliegenden Axialseite, wo bei der Gestaltung des Handaggregats als Schleifgerät weniger Staub anfällt.Sealing lip, contacting surface of the bottom part untreated, e.g. B. unprocessed, preferably greased. It can furthermore be advantageous if the bearing, in particular deep groove ball bearing, has sealing disks that are integrated on both sides, touching or not touching, which are seated in particular on the outer ring and in relation to the axial end face of the inner ring further inside and at a distance from it. On the axial side of the bearing, in particular of the deep groove ball bearing, which faces away from the axial sealing element, a disk rotating with it can be arranged on the shaft, which lies against the facing end face of the inner ring and the integrated sealing disk of the bearing with at least a small axial distance radially covered. It can be advantageous if the disk is formed from a thin sheet and if the disk and, via this, the inner ring of the bearing are secured axially on the shaft by means of a retaining ring. This results in a simple and cost-effective sealing of the bearing on the opposite axial side, where less dust is produced when the hand-held unit is designed as a grinding device.
Vorteilhaft kann es ferner sein, wenn die Welle auf der dem axialen Dichtungselement abgewandten Axialseite des Lüfterrades eine z. B. exzentrische Hülse trägt, auf der - z. B. mittels eines zugeordneten hülsenfδrmigen Innenringes - über ein Lager eine Schleifplatte drehbar gelagert ist. Das Lager der Schleifplatte kann aus einer offenen Nadelhülse gebildet sein und auf der Axialseite, die dem Lüfterrad zugewandt ist, mittels zumindest eines Dichtungselements axial abgedichtet sein, das als Radialwellendichtring ausgebildet ist. VonIt may also be advantageous if the shaft on the axial side of the fan wheel facing away from the axial sealing element has a z. B. carries eccentric sleeve on the - z. B. by means of an associated sleeve-shaped inner ring - a grinding plate is rotatably supported by a bearing. The bearing of the grinding plate can be formed from an open needle sleeve and can be axially sealed on the axial side which faces the fan wheel by means of at least one sealing element which is designed as a radial shaft sealing ring. Of
Vorteil kann es auch sein, wenn zwei Radialwellendichtringe vorgesehen sind, die axial hintereinander angeordnet sind. Das mindestens eine Dichtungselements des Lagers kann als im Querschnitt etwa einem liegenden U entsprechender, zwei abstrebende Dichtlippen tragender Dichtungsring ausgebildet sein. Hierdurch ist in einfacher Weise eine Staubabdichtung des der Schleifplatte zugeordneten Lagers auf der dem Staubraum zugewandten Axialseite erreicht. Zeichnung -.It can also be advantageous if two radial shaft sealing rings are provided, which are arranged axially one behind the other. The at least one sealing element of the bearing can be designed as a sealing ring corresponding in cross-section to a lying U and bearing two striving sealing lips. In this way, a dust seal of the bearing assigned to the grinding plate is achieved in a simple manner on the axial side facing the dust chamber. Drawing -.
In der nachfolgenden Beschreibung ist ein Ausführungsbeispiel der Erfindung anhand der zugehörigen Zeichnung näher erläutert. Es zeigen:In the following description, an embodiment of the invention is explained in more detail with reference to the accompanying drawing. Show it:
Fig. 1 einen schematischen axialen Längsschnitt eines Schwingschleifers ,1 is a schematic axial longitudinal section of an orbital sander,
Fig. 2 einen vergrößerten Ausschnitt aus Fig. 1.FIG. 2 shows an enlarged detail from FIG. 1.
Beschreibung des AusführungsbeispielsDescription of the embodiment
In Fig. 1 und 2 ist ein motorisch angetriebenes Handwerkzeug 1, insbesondere Schleifgerät, z. B. Schwingschleifer, ge- zeigt, das ein Gehäuse 2 aufweist, in dessen oberem Gehäuseteil 12 ein Elektromotor 3 enthalten ist, der über eine dazu koaxiale Welle 10 eine als Schwingglied ausgebildete Schleifplatte 11 antreibt. Die Welle 10 ist in dem Gehäuseteil 12 mittels eines Lagers 13 gelagert. Der Gehäuseteil 12 umgibt bei diesem Handwεrkzeug ein Lüfterrad 14, das sich innerhalb eines vom Gehäuseteil 12 begrenzten Staubraumes 15 befindet und mittels einer Hülse 18 drehfest auf der Welle 10 angeordnet ist, so daß es mit der Welle 10 umläuft. Das Lager 13 befindet sich außerhalb des Staubraumes 15 und ist in einer etwa napfför igen Aufnahme 16 des Gehäuseteils 12 derart aufgenommen, daß ein Bodenteil 17 der Aufnahme 16 das Lager 13 auf der Seite überdeckt, die dem Lüfterrad 14 zugewandt ist, wobei der Bodenteil 17 einen Durchlaß 19 aufweist, durch den sich die Welle 10 mit der Hülse 18 erstreckt.1 and 2, a motor-driven hand tool 1, in particular grinding device, for. B. Orbital sander, shown, which has a housing 2, in whose upper housing part 12 an electric motor 3 is contained, which drives a grinding plate 11 designed as an oscillating member via a coaxial shaft 10. The shaft 10 is supported in the housing part 12 by means of a bearing 13. In this hand tool, the housing part 12 surrounds a fan wheel 14 which is located within a dust space 15 delimited by the housing part 12 and is arranged on the shaft 10 in a rotationally fixed manner by means of a sleeve 18, so that it rotates with the shaft 10. The bearing 13 is located outside the dust chamber 15 and is in an approximately cup-shaped receptacle 16 of the housing part 12 recorded in such a way that a bottom part 17 of the receptacle 16 covers the bearing 13 on the side facing the fan wheel 14, the bottom part 17 having a passage 19 through which the shaft 10 with the sleeve 18 extends.
Das Lager 13 ist beispielsweise als Rillenkugellager ausgebildet, dessen Außenring 20 in der etwa napfförmigen Aufnahme 16 undrehbar gehalten ist und an deren Bodenteil 17 axial abgestützt sein kann. Der Innenring 21 sitzt drehfest auf der Welle 10. Der Bodenteil 17 ist so bemessen, daß er sich radial etwa bis zum Innenring 21 erstreckt. Das Lager 13, insbesondere in der Ausbildung als Kugelrillenlager, ist auf der Axialseite, die dem Lüfterrad 14 zugewandt ist, in Bezug auf das Lüfterrad 14 mittels eines axialen Dichtungselements 30 abgedichtet, das zusammen mit der Welle 10 und der Hülse 18 läuft. Das Dichtungselement 30 ist aus einer ringförmigen, flexiblen und hierbei insbesondere gummielastischen Wellendichtung gebildet und weist einen Dichtungskörper 31 und eine flexible Dichtlippe 32 auf, die miteinander einstückig sind. Die Dichtlippe 32 strebt auf einer Axialseite vom Dichtungskörper 31 etwa umgekehrt kegelstumpfförmig ab und ist relativ zum Dichtungskörper 31 elastisch bewegbar. Das Dichtungselement 30 ist auf der Welle 10 bzw. auf der Hülse 18 mit Vorspannung aufgezogen und elastisch klemmend gehalten. Die radiale Bemessung des Dichtungselements 30 ist so gewählt, daß das Dichtungselement 30 den Durchlaß 19 des Bodenteils 17 gegenüber dem Staubraum 15 abdichtet. Das Dichtungselement 30 liegt mit seiner dem Bodenteil 17 zugewandten Axialseite am Bodenteil 17 elastisch an. Dadurch ist der Durchlaß 19 dicht verschlossen, ohne daß ein etwaiger Luftspalt verbleibt. Aufgrund der Anlage reibt das mit der Welle 10 umlaufende Dichtungselement 30 auf der zugewandten Oberfläche 22 des Bodenteils 17. Die Dichtlippe 32 steht in Richtung zum Bodenteil 17 und dessen Oberfläche 22 über, wobei die Dichtlippe 32 vorzugsweise mit geringer Vorspannung an der Oberfläche 22 des Bodenteils 17 anliegt. Auf diese Weise herrscht ein zumindest geringer Anpressdruck der Dichtlippe 32. Aufgrund der Beweglichkeit der Dichtlippe 32 werden von dieser Tole- ranzen, Fluchtungsfehler, Winkelabweichungen od dgl., insbesondere des Bodenteils 17, ausgeglichen. Die Dichtlippe 32 bewirkt eine gute Abdichtung in axialer Richtung, und zwar eine Abdichtung des Lagers 13 in Eezug auf den Staubraum 15. Bei umlaufender Welle 10 wird die Dichtlippe 32 durch die Fliehkraft etwas entlastet, wodurch die Reibung an der Kontaktstelle zum Bodenteil 17 und damit der Verschleiß der Dichtlippe 32 reduziert wird.The bearing 13 is designed, for example, as a deep groove ball bearing, the outer ring 20 of which is held non-rotatably in the approximately cup-shaped receptacle 16 and can be axially supported on the bottom part 17 thereof. The inner ring 21 sits on the shaft 10 in a rotationally fixed manner. The bottom part 17 is dimensioned such that it extends radially approximately to the inner ring 21. The bearing 13, in particular in the form of a ball groove bearing, is sealed on the axial side which faces the fan wheel 14 with respect to the fan wheel 14 by means of an axial sealing element 30 which runs together with the shaft 10 and the sleeve 18. The sealing element 30 is formed from an annular, flexible and in particular rubber-elastic shaft seal and has a sealing body 31 and a flexible sealing lip 32, which are integral with one another. The sealing lip 32 strives on an axial side from the sealing body 31 approximately in the shape of a truncated cone and is elastically movable relative to the sealing body 31. The sealing element 30 is tensioned on the shaft 10 or on the sleeve 18 and held in an elastically clamping manner. The radial dimensioning of the sealing element 30 is selected such that the sealing element 30 seals the passage 19 of the base part 17 with respect to the dust chamber 15. The sealing element 30 rests elastically on the bottom part 17 with its axial side facing the bottom part 17. As a result, the passage 19 is tightly closed without any air gap remaining. Due to the system, the sealing element 30 rotating with the shaft 10 rubs on the facing surface 22 of the base part 17. The sealing lip 32 projects in the direction of the base part 17 and its surface 22, the sealing lip 32 preferably bears against the surface 22 of the base part 17 with a slight pretension. In this way, there is at least a slight contact pressure of the sealing lip 32. Due to the mobility of the sealing lip 32, tolerances, misalignments, angular deviations or the like, in particular of the base part 17, are compensated for by this. The sealing lip 32 provides a good seal in the axial direction, namely a sealing of the bearing 13 in relation to the dust chamber 15. When the shaft 10 rotates, the sealing lip 32 is relieved somewhat by the centrifugal force, as a result of which the friction at the contact point with the base part 17 and thus the wear of the sealing lip 32 is reduced.
Der Gehäuseteil 12 besteht vorzugsweise aus Leichtmetall und hierbei insbesondere aus Aluminium-Druckguß. Die mit der flexiblen Dichtlippe 32 in Berührung stehende Oberfläche 22 des Bodenteils 17 ist unbehandelt, z .B. nbearbeitet gußrauh. Diese Oberfläche 22 muß also nicht poliert sein. Von Vorteil ist es, wenn die Oberfläche 22 lediglich eingefettet ist, wodurch die Reibung im Bereich der Kontaktfläche mit der Dichtlippe 32 reduziert wird.The housing part 12 is preferably made of light metal and in particular of die-cast aluminum. The surface 22 of the base part 17 which is in contact with the flexible sealing lip 32 is untreated, for example. machined cast iron. This surface 22 does not have to be polished. It is advantageous if the surface 22 is only greased, as a result of which the friction in the region of the contact surface with the sealing lip 32 is reduced.
Durch das axiale Dichtungselement 30 wird in beschriebener Weise eine gute Abdichtung des Lagers 13 zum Staubraum 15 erreicht, und dies auf einfache und kostengünstige Weise, insbesondere dann, wenn axiale Dichtungselemente 30 als Bauteile in dieser Form bereits handelsüblich und verfügbar sind.A good seal of the bearing 13 to the dust chamber 15 is achieved in the manner described by the axial sealing element 30, and this in a simple and inexpensive manner, in particular when axial sealing elements 30 as components in this form are already commercially available and available.
Das Lager 13, insbesondere Rillenkugellager, weist beidseitig darin integrierte, in Fig. 2 nur schematisch angedeutete Dichtscheiben 23 und 24 auf, die insbesondere am Außenring 20 sitzen und in Bezug auf die axiale Stirnfläche 25 bzw. 26 des Innenringes 21 weiter innen und mit Abstand davon verlaufen. Auf der Welle 10 ist auf der Axialseite des Lagers 13, die dem axialen Dichtungselement 30 abgewandt ist, in der Zeichnung also oben, eine Scheibe 27 z.B. aus dünnem Blech drehfest angeordnet, die mit der Welle 10 umläuft. Die Scheibe 27 liegt an der zugewandten Stirnfläche 26 des Innenringes 21 an und überdeckt radial die integrierte Dichtscheibe 24 mit zumindest geringem Axialabstand, so daß zwischen der umlaufenden Scheibe 27 und der nicht umlaufenden Dichtscheibe 24 keine Reibung herrscht. Diese Abdichtung mittels der nicht schleifenden, dünnen Scheibe 27 ist einfach montierbar und kostengünstig. Hierbei wird die Tatsache nutzbar gemacht, daß der Innenring 21 axial mit seiner Stirnfläche 26 etwas über die integrierte Dichtscheibe 24 übersteht, so daß zwischen der Scheibe 27 und der Dichtscheibe 24 sich ein enger Spalt ergibt, der in vorteilhafter Weise mit Schmiermittel, z.B. Fett, gefüllt werden kann.The bearing 13, in particular deep groove ball bearing, has sealing disks 23 and 24 integrated therein on both sides, only schematically indicated in FIG. 2, which are seated, in particular, on the outer ring 20 and with respect to the axial end face 25 or 26 of the inner ring 21 further inside and at a distance run away. On the shaft 10 on the axial side of the bearing 13, which faces away from the axial sealing element 30, that is to say in the drawing above, a disk 27, for example, is made of thin sheet rotatably arranged, which rotates with the shaft 10. The disk 27 lies against the facing end face 26 of the inner ring 21 and radially covers the integrated sealing disk 24 with at least a small axial distance, so that there is no friction between the rotating disk 27 and the non-rotating sealing disk 24. This seal by means of the non-grinding, thin disc 27 is easy to install and inexpensive. This makes use of the fact that the inner ring 21 protrudes axially with its end face 26 somewhat beyond the integrated sealing washer 24, so that there is a narrow gap between the washer 27 and the sealing washer 24, which is advantageously coated with lubricant, eg grease, can be filled.
Auf der Welle 10 sitzt ein Sicherungsring 28, über den die Scheibe 27 und über letztere der Innenring 21 des Lagers 13 axial auf der Welle 10 gesichert ist. Bei umlaufender Welle 10 wirkt die Scheibe 27 als Schleuderscheibε, die zur axialen Abdichtung des Lagers 13 auf dieser Seite ausreichend ist.On the shaft 10 is a locking ring 28, via which the disc 27 and the latter, the inner ring 21 of the bearing 13 is axially secured on the shaft 10. With the shaft 10 rotating, the disk 27 acts as a centrifugal disk, which is sufficient for axially sealing the bearing 13 on this side.
Die Welle 10 trägt auf der dem axialen Dichtungselement 30 abgewandten Axialseite des Lüfterrades 14 eine z.B. exzentrische Hülse 40, auf der mittels eines zugeordneten, hülsen- förmigen Innenringes 41 über ein Lager 42 die Schleifplatte 11 drehbar gelagert ist. Das Lager 42 der Schleifplatte 11 ist beim gezeigten Ausführungsbeispiel aus einer offenen Nadelhülse gebildet und auf der Axialseite, die dem Lüfterrad 14 zugewandt ist, mittels zumindest eines Dichtungselements 43 axial abgedichtet, das zwischen der Schleifplatte 11 und dem hülsenförmigen Innenring 41 wirksam ist. Das Dichtungselement 43 ist als Radialwellendichtring ausgebildet, wobei beim gezeigten Ausführungsbeispiel zwei gleichartige Radialwellendichtringe vorgesehen sind, die axial hintereinander angeordnet sind. Bei einem anderen, nicht gezeigten Ausführungsbeispiel ist das mindestens eine Dichtungselement 43 als im Querschnitt etwa U-förmiger, zwei abstrebende_ Dichtlippen tragender Dichtungsring ausgebildet, von denen die eine Dichtlippe als abdichtende Dichtungslippe fungiert und die andere Dichtlippe als Staublippe fungiert. Durch das mindestens eine Dichtungselement 43 ist das Lager 42 am zum Lüfterrad 14 hin weisenden Bereich in Bezug auf den Staubraum 15 und dort anfallenden Staub in einfacher Weise abgedichtet. On the axial side of the fan wheel 14 facing away from the axial sealing element 30, the shaft 10 carries, for example, an eccentric sleeve 40, on which the grinding plate 11 is rotatably mounted by means of an associated, sleeve-shaped inner ring 41 via a bearing 42. In the exemplary embodiment shown, the bearing 42 of the grinding plate 11 is formed from an open needle sleeve and axially sealed on the axial side facing the fan wheel 14 by means of at least one sealing element 43, which is effective between the grinding plate 11 and the sleeve-shaped inner ring 41. The sealing element 43 is designed as a radial shaft sealing ring, two identical radial shaft sealing rings being provided in the exemplary embodiment shown, which are axial are arranged one behind the other. In another exemplary embodiment, not shown, the at least one sealing element 43 is designed as a sealing ring with a cross-section that is approximately U-shaped and has two striving sealing lips, one of which functions as a sealing lip and the other as a dust lip. The bearing 42 is sealed in a simple manner by the at least one sealing element 43 at the area facing the fan wheel 14 in relation to the dust chamber 15 and the dust accumulating there.
Claims
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP53714498A JP2001513032A (en) | 1997-02-28 | 1998-01-16 | Hand-held unit driven by motor |
| DE59801955T DE59801955D1 (en) | 1997-02-28 | 1998-01-16 | MOTORIZED DRIVE UNIT |
| EP98906813A EP0963278B1 (en) | 1997-02-28 | 1998-01-16 | Motor-driven hand unit |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19708072 | 1997-02-28 | ||
| DE19800046A DE19800046A1 (en) | 1997-02-28 | 1998-01-02 | Motor-driven hand unit |
| DE19708072.3 | 1998-01-02 | ||
| DE19800046.4 | 1998-01-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1998038014A1 true WO1998038014A1 (en) | 1998-09-03 |
Family
ID=26034371
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/DE1998/000136 Ceased WO1998038014A1 (en) | 1997-02-28 | 1998-01-16 | Motor-driven hand unit |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0963278B1 (en) |
| JP (1) | JP2001513032A (en) |
| CN (1) | CN1077833C (en) |
| WO (1) | WO1998038014A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2422931A1 (en) * | 2010-08-31 | 2012-02-29 | Jöst GmbH | Universal grinding plate unit with suction hood for a rotating grinding machine |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5012661B2 (en) * | 2008-05-26 | 2012-08-29 | マックス株式会社 | Driving tool |
| JP5728303B2 (en) * | 2011-06-15 | 2015-06-03 | 株式会社マキタ | Impact tool |
| JP2017502526A (en) | 2013-10-04 | 2017-01-19 | キング アブドゥラー ユニバーシティ オブ サイエンス アンド テクノロジー | System and Method for Producing Quantum Dots <Priority Claim from Related Applications> This application was filed on Oct. 4, 2013, application number 61 / 886,837, “To make quantum dots” And claims priority from a co-pending US provisional application entitled “Systems and Methods”, which is incorporated herein by reference in its entirety. This application claims priority from a co-pending US provisional application filed Oct. 14, 2013 and having an application number of 61 / 890,536 entitled “Systems and Methods for Making Quantum Dots”. All of which are hereby incorporated by reference in their entirety. This application is filed with priority from a co-pending US provisional application filed July 15, 2014, filed 62 / 024,490 entitled "Systems and Methods for Making Quantum Dots". All of which are hereby incorporated by reference in their entirety. |
| DE102015121305A1 (en) * | 2015-12-08 | 2017-06-08 | Festool Gmbh | The handheld machine tool |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1951105A (en) * | 1933-02-03 | 1934-03-13 | American Floor Surfacing Mach | Rotary disk edging machine |
| US2893174A (en) * | 1956-03-07 | 1959-07-07 | Sunbeam Corp | Surface treating machine |
| GB1226062A (en) * | 1968-04-08 | 1971-03-24 | ||
| US4612734A (en) * | 1985-04-23 | 1986-09-23 | Shinko Electric Co., Ltd. | Grinding machine |
| US5251406A (en) * | 1989-05-20 | 1993-10-12 | Robert Bosch Gmbh | Power hand tool with a gearbox casing with sealing washer |
| DE19513279A1 (en) * | 1994-08-22 | 1996-02-29 | Ryobi Ltd | Dust collection system for a machine-driven tool |
-
1998
- 1998-01-16 JP JP53714498A patent/JP2001513032A/en active Pending
- 1998-01-16 CN CN98802866A patent/CN1077833C/en not_active Expired - Lifetime
- 1998-01-16 EP EP98906813A patent/EP0963278B1/en not_active Expired - Lifetime
- 1998-01-16 WO PCT/DE1998/000136 patent/WO1998038014A1/en not_active Ceased
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1951105A (en) * | 1933-02-03 | 1934-03-13 | American Floor Surfacing Mach | Rotary disk edging machine |
| US2893174A (en) * | 1956-03-07 | 1959-07-07 | Sunbeam Corp | Surface treating machine |
| GB1226062A (en) * | 1968-04-08 | 1971-03-24 | ||
| US4612734A (en) * | 1985-04-23 | 1986-09-23 | Shinko Electric Co., Ltd. | Grinding machine |
| US5251406A (en) * | 1989-05-20 | 1993-10-12 | Robert Bosch Gmbh | Power hand tool with a gearbox casing with sealing washer |
| DE19513279A1 (en) * | 1994-08-22 | 1996-02-29 | Ryobi Ltd | Dust collection system for a machine-driven tool |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2422931A1 (en) * | 2010-08-31 | 2012-02-29 | Jöst GmbH | Universal grinding plate unit with suction hood for a rotating grinding machine |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0963278A1 (en) | 1999-12-15 |
| CN1248934A (en) | 2000-03-29 |
| CN1077833C (en) | 2002-01-16 |
| EP0963278B1 (en) | 2001-10-31 |
| JP2001513032A (en) | 2001-08-28 |
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