The present disclosure relates to a shaft coupling for connecting a tool holder to the motor shaft of a machine tool.
Shaft couplings are used in a large number of machine tools (e.g. drills, lathes, grinders, etc.) in which a rotatable tool with the drive shaft (e.g., motor shaft or output shaft of a gearbox) is to be connected to a machine tool. The tool can be assembled to a short shaft, which is referred to as a tool holder. The drive shaft of a machine tool is often also referred to as a spindle and has a mechanism that can be used to mechanically couple the tool holder and tool to the motor shaft. This mechanism comprises, for example, a collet which is designed to grip a pull stud of the tool holder and to connect the tool holder to the motor shaft in a frictionally engaged manner.
The frictionally engaged connection between tool holder and motor shaft is usually realized with the help of a conical seat. Tool holders are therefore often referred to as tool cones. The collet can be actuated pneumatically, for example. In this case, a pneumatic actuator with the collet pulls the tool cone (on the pull stud) against a matching inner cone in the motor shaft (spindle), which creates a frictionally engaged coupling between the motor shaft and the tool cone.
In small, compactly designed machine tools, the space for the actuator that actuates the collet is comparatively small; and for this reason, the actuator force that can be generated and which is available to tension the tool cone in the spindle, is also relatively small. As a result, the conical seat between the tool cone and the spindle cannot transmit sufficient torque and there is a risk that the conical seat will start to slip.
One of the objects of the present disclosure can therefore be seen as providing a shaft coupling for machine tools which, with a relatively small size, enables problem-free torque transmission between the spindle and the tool holder.
A device is described below which, according to one exemplary embodiment, has a spindle for a machine tool, a driver ring and a tool holder. The driver ring is fixed on the spindle in such a way that it can be displaced along a rotational axis of the spindle. The spindle and the tool holder have matching faces which are designed to form a frictionally engaged connection when assembled (to one another). When assembled, opposing faces of the tool holder and the driver ring have matching contours, so that the driver ring can engage on the tool holder.
According to a further exemplary embodiment, the device has a spindle for a machine tool, a driver ring fixed on the spindle, and a tool holder. The spindle is designed as a hollow shaft with an inner cone. The driver ring can be displaced along a rotational axis of the spindle, and the tool holder has an outer cone that matches the inner cone, wherein, when assembled, the inner cone and outer cone form a conical seat, and wherein, when assembled, opposing faces of the tool holder and the driver ring have matching contours, so that the driver ring can engage on the tool holder.
In one exemplary embodiment, when assembled, the conical seat creates a frictionally engaged connection between the spindle and the tool holder, while the engaged driver ring additionally creates a form-fitting connection between the spindle and the tool holder. According to one exemplary embodiment, the tool holder can have a pull stud which is shaped in such a way that the tool holder on the pull stud can be pressed against the spindle by means of a collet.
According to one exemplary embodiment, the tool holder can have a plate which extends in a radial direction with respect to a rotational axis of the tool holder and which has a geometric structure (e.g. in the form of webs or the like) on a surface opposite the driver ring. The driver ring can have a geometric structure (e.g. in the form of grooves or the like) on its surface opposite the plate, with the geometric structure on the surface of the plate and the geometric structure on the surface of the driver ring having matching contours, so that the geometric structure on the surface of the driver ring can engage on the geometric structure on the surface of the plate.
In one exemplary embodiment, a spring element, which acts between the spindle and the driver ring, presses the driver ring against the tool holder. According to one exemplary embodiment, the driver ring can have sliding blocks which are arranged in a displaceable manner in matching guide grooves in the spindle. The spindle can have two end stops (e.g. in the guide grooves), which limit the movement of the driver ring in two directions.
Various exemplary embodiments are explained in more detail below using the examples shown in the figures. The illustrations are not necessarily to scale and the the present disclosure is not limited solely to the aspects illustrated. Rather, emphasis is placed on presenting the principles underlying the illustrated exemplary embodiments. In the figures,
In the central area of the tool cone 30, said tool cone 30 has a plate 32 which extends essentially at right angles to the rotational axis of the tool cone 30. The plate 32 can have a circular contour on the outside, but this does not necessarily have to be the case. On the side facing the spindle 10 (when assembled), the plate has webs 33 on its surface, which enable an engaging connection between the plate 32 and the driver ring 20.
So that the driver ring 20 reliably engages into the webs 33 of the plate 32, the driver ring 20 is pressed against the plate 32 by means of a spring element (see
In the situation shown in
In
In the situation shown in
If during operation of the machine tool (e.g. grinding, polishing, milling, etc.) the frictional connection in the cone seat is not sufficient to transmit the required torque, the tool cone 30 will start to slip in the spindle, whereby the tool cone 30 will rotate relative to the spindle 10. That is to say, the angle ϕ changes. The tool cone 30 will rotate until an angular position ϕ is reached, which allows the driver ring to engage in the webs 33.
Terms such as “first”, “second”, and the like, are used to describe various elements, regions, sections, etc. and are also not intended to be limiting. Like terms refer to like elements throughout the description.
As used herein, the terms “having”, “containing”, “including”, “comprising” and the like are open ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features. The articles “a”, “an” and “the” are intended to include the plural as well as the singular, unless the context clearly indicates otherwise.
It is to be understood that the features of the various embodiments described herein may be combined with each other, unless specifically noted otherwise.
Although various embodiments have been illustrated and described with respect to one or more specific implementations, alterations and/or modifications may be made to the illustrated examples without departing from the spirit and scope of the appended claims. With particular regard to the various functions performed by the above described components or structures (units, assemblies, devices, circuits, systems, etc.), the terms (including a reference to a “means”) used to describe such components are intended to correspond-unless otherwise indicated—to any component or structure that performs the specified function of the described component (e.g., that is functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs the function in the herein illustrated exemplary implementations of the invention.
It will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.
Number | Date | Country | Kind |
---|---|---|---|
202019107127.3 | Dec 2019 | DE | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/EP2020/086748 | 12/17/2020 | WO |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2021/122977 | 6/24/2021 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
3395927 | Hammond | Aug 1968 | A |
4436463 | Rea | Mar 1984 | A |
4583890 | Ewing | Apr 1986 | A |
4604010 | Reeves | Aug 1986 | A |
4607989 | Kitamura | Aug 1986 | A |
4714389 | Johne | Dec 1987 | A |
4726721 | Heel | Feb 1988 | A |
4818161 | Cook | Apr 1989 | A |
5074723 | Massa | Dec 1991 | A |
5125777 | Osawa | Jun 1992 | A |
5352073 | Kitaguchi | Oct 1994 | A |
5368421 | Head | Nov 1994 | A |
5407308 | Takayoshi | Apr 1995 | A |
5593258 | Matsumoto | Jan 1997 | A |
5964556 | Toyomoto | Oct 1999 | A |
5975816 | Cook | Nov 1999 | A |
5997226 | Tagami | Dec 1999 | A |
6071219 | Cook | Jun 2000 | A |
6077003 | Laube | Jun 2000 | A |
6109842 | Cook | Aug 2000 | A |
6135684 | Senzaki | Oct 2000 | A |
6224306 | Hiroumi | May 2001 | B1 |
6382888 | Cook | May 2002 | B2 |
6409439 | Riviere | Jun 2002 | B1 |
6467381 | Frecska | Oct 2002 | B1 |
6923451 | Taguchi | Aug 2005 | B2 |
7131797 | Kai | Nov 2006 | B2 |
7284938 | Miyazawa | Oct 2007 | B1 |
7331585 | Lindstrom | Feb 2008 | B2 |
8043036 | Cook | Oct 2011 | B2 |
8607435 | Yeh | Dec 2013 | B2 |
9004498 | Haimer | Apr 2015 | B2 |
9475139 | Mikado | Oct 2016 | B2 |
10259049 | Jansen | Apr 2019 | B2 |
10335911 | Huang | Jul 2019 | B1 |
11135657 | Fautz | Oct 2021 | B2 |
20030223837 | Komine | Dec 2003 | A1 |
20030228199 | Matsumoto | Dec 2003 | A1 |
20050175425 | Watanabe | Aug 2005 | A1 |
20050214087 | Agapiou | Sep 2005 | A1 |
20080260483 | Cook | Oct 2008 | A1 |
20090116912 | Jansen | May 2009 | A1 |
20090155010 | Cook | Jun 2009 | A1 |
20140044497 | Mikado | Feb 2014 | A1 |
20150030407 | Chen | Jan 2015 | A1 |
20220040808 | Chen | Feb 2022 | A1 |
Number | Date | Country |
---|---|---|
578974 | Jun 1933 | DE |
3916315 | Nov 1990 | DE |
102017119524 | Feb 2019 | DE |
Number | Date | Country | |
---|---|---|---|
20230030445 A1 | Feb 2023 | US |