Patent Publication Number: US-2022226914-A1

Title: Rotary cutting tool having an energy harvesting arrangement

Description:
FIELD OF THE INVENTION 
     The subject matter of the present application relates to rotary cutting tools, and in particular to such rotary cutting tools having an energy harvesting arrangement, and further in particular to such energy harvesting arrangements having a turbine actuated by fluid. 
     BACKGROUND OF THE INVENTION 
     Cutting tool assemblies can include an energy harvesting arrangement having a turbine actuated by fluid. 
     EP 2 095 897 discloses a tool-holder assembly. A secondary pipe is derived from a main pipe that feeds the usual flow of pressurized lubricant-coolant in the machining area. A generator is located at the secondary pipe. In this way, a part of said flow, which is provided for lubrication/cooling in the machining area, is used for actuating the turbine that sets the generator in rotation. The fluid at output from the generator is conveyed through the secondary pipe to a discharge outlet. 
     US 2015/125230 discloses an apparatus comprising a spindle and a tool including a tool holder secured in mating relationship with an end of the spindle. The tool has a work-piece end wholly powered by an energy harvesting device. In a first embodiment (FIG. 2) a second fluid flow passage extends through the tool holder for delivery of fluid to the energy harvesting device. The energy harvesting device powers a sensor that may be used to inspect the work-piece as part of a machining process. In a second embodiment (FIG. 6) the work-piece end includes a device for inserting threaded inserts into a work-piece. The energy harvesting device harvests energy from the rotational motion of the spindle transmitted to a shaft of the tool and tool holder. 
     U.S. Pat. No. 4,716,657 discloses a machine having a movable member capable of releasable supporting a tool for performing an operation on a workpiece, and a supply of pressurized fluid. The tool includes an electric circuit which is provided with power from an electrical generator drivingly connected to a turbine driven by the machine&#39;s supply of pressurized fluid. In a first embodiment (FIG. 1) the machine includes a measuring probe. In a second embodiment (FIG. 2) the machine includes a boring bar having a cutter. The turbine in the form of a Pelton Wheel is provided around the outer periphery of the collar. 
     U.S. Pat. No. 6,840,723 discloses a working unit intended to be mounted on a movable machine operated tool support. The working unit includes a casing which is attached to the tool support and which supports a pneumatic turbine motor with a rotor, a shank end mill type machining tool with a cutter portion extending out of the casing and a shank portion rotatively journalled in the casing. The machining tool shank portion is rigidly integrated with a turbine wheel to form the turbine rotor. A flow control valve is arranged to deliver pressurized air to the turbine motor. 
     SUMMARY OF THE INVENTION 
     In accordance with a first aspect of the subject matter of the present application there is provided a rotary cutting tool having a tool central axis which defines opposite forward and rearward directions and about which the rotary cutting tool is rotatable, the rotary cutting tool comprising: 
     a tool holder comprising a mounting portion and a cutting portion receiving portion located at opposite rearward and forward ends of the tool holder, respectively; 
     a cutting portion releasably attached at the cutting portion receiving portion, the cutting portion comprising a cutting edge; 
     a fluid channel comprising:
         a) a channel inlet opening located at the mounting portion and configured to receive a supply of fluid;   b) a channel outlet opening in fluid communication with the channel inlet opening and configured to discharge fluid entering at the channel inlet opening; and   c) a channel turbine chamber located between the channel inlet and outlet openings; and       

     an energy harvesting arrangement comprising:
         a turbine located in the channel turbine chamber, the turbine configured to be rotated by fluid flowing from the channel inlet opening to the channel outlet opening, in a forward flow direction.       

     It is understood that the above-said is a summary, and that features described hereinafter may be applicable in any combination to the subject matter of the present application, for example, any of the following features may be applicable to the rotary cutting tool: 
     The rotary cutting tool can comprise a single fluid channel. 
     The rotary cutting tool can have only a single channel inlet opening and a single channel outlet opening, and the fluid channel may not branch between the channel inlet opening and the channel outlet opening. 
     The channel outlet opening can be located at either the cutting portion or at the forward end of the tool holder. 
     The channel outlet opening can be located at the cutting portion. 
     The channel outlet opening can be oriented to discharge fluid in the vicinity of the cutting edge. 
     The fluid channel can be a through channel formed within the rotary cutting tool. 
     The cutting portion can be integrally formed to have unitary, one-piece construction. 
     The tool holder can be integrally formed to have unitary, one-piece construction. 
     The tool holder can comprise holder rear and forward surfaces and a holder peripheral surface extending therebetween about the tool central axis. The holder rear surface can be located at the rearward end of the rotary cutting tool. The channel inlet opening can be located at the holder rear surface. 
     The fluid channel can pass through the holder forward surface. 
     The rotary cutting tool can further comprise a fastening arrangement comprising a chucking nut and a collet. The cutting portion can be releasably attached to the tool holder by the chucking nut and the collet. 
     The fluid channel can comprise a channel turbine antechamber adjoining the channel turbine chamber and located rearward thereof with respect to the forward flow direction. In a radial cross-section taken in a plane perpendicular to the tool central axis through the fluid channel, a cross-sectional area of the fluid channel can be greater at the channel turbine chamber than at the channel turbine antechamber. 
     The fluid channel can include a channel turbine post-chamber adjoining the channel turbine chamber and located forward thereof with respect to the forward flow direction. The cutting portion can extend into the channel turbine post-chamber and is spaced apart from the turbine. 
     The channel turbine chamber can be aligned with the tool central axis. 
     The turbine can comprise a plurality of radially extending turbine blades. The plurality of radially extending turbine blades can be made of aluminum. 
     The energy harvesting arrangement can further comprise an electric generator which is located in the channel turbine chamber and is drivingly connected to the turbine. 
     The energy harvesting arrangement can further comprise two cables extending from the electric generator and terminating at two electrical connectors mounted on the tool holder. 
     A portion of each of the two cables can be located in the fluid channel. 
     The tool holder can comprise holder rear and forward surfaces and a holder peripheral surface extending therebetween about the tool central axis, the holder rear surface can be located at the rearward end of the rotary cutting tool. The holder peripheral surface can comprise a holder lateral recess recessed therein. The rotary cutting tool can comprise an electrical arrangement, the two electrical connectors being located thereat. The electrical arrangement can be located in the holder lateral recess. 
     The electrical arrangement can include a sensor configured to monitor the cutting tool and/or a cutting operation. 
     The electrical arrangement can further comprise a rechargeable battery configured to power the sensor, the rechargeable battery receiving power from the electric generator. 
     The fluid channel can contain the tool central axis for the entire of length the fluid channel, through the tool holder. 
     The fluid channel can contain the tool central axis for the entire length of the fluid channel, through both the tool holder and the cutting portion. 
     The rotary cutting tool can further comprise a turbine receptacle portion separatable from, and located within, the tool holder. The channel turbine chamber can be formed within the turbine receptacle portion. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       For a better understanding of the present application and to show how the same may be carried out in practice, reference will now be made to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a rotary cutting tool, partially cut-away, in accordance with the present application; 
         FIG. 2  is an exploded perspective view of the rotary cutting tool shown in  FIG. 1 ; 
         FIG. 3  is an axial cross-sectional view of the rotary cutting tool shown in  FIG. 1 ; and 
         FIG. 4  is a detail of  FIG. 3 . 
     
    
    
     It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity, or several physical components may be included in one functional block or element. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. 
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following description, various aspects of the subject matter of the present application will be described. For purposes of explanation, specific configurations and details are set forth in sufficient detail to provide a thorough understanding of the subject matter of the present application. However, it will also be apparent to one skilled in the art that the subject matter of the present application can be practiced without the specific configurations and details presented herein. 
     Attention is first drawn to  FIGS. 1 and 2 , showing a rotary cutting tool  20 , depicting an aspect of the present application. In this non-limiting example shown in the drawings, the rotary cutting tool  20  can form a drilling tool suitable for drilling cutting operations. The rotary cutting tool  20  has a tool central axis A. The tool central axis A defines opposite forward and rearward directions D F , D R . The tool central axis A forms an axis of rotation about which the rotary cutting tool  20  is rotatable in a rotational direction R. 
     It should be appreciated that in the following discussion with regard to the rotary cutting tool  20  use of the terms “forward” and “rearward” throughout the description and claims refer to a relative position in a direction of the tool central axis A to the right and left, respectively, in  FIGS. 3 and 4 . Moreover, the terms “axial” and “radial” are with respect to the tool central axis A, unless specified otherwise. 
     Referring in particular to  FIGS. 2 and 3 , the rotary cutting tool  20  has a tool holder  22 . The tool holder  22  includes a rearward end  24  and a forward end  26  located opposite the rearward end  24 . In accordance with some embodiments of the subject matter of the present application, the tool holder  22  can be made from steel. The tool holder  22  can be integrally formed to have unitary, one-piece construction. The tool holder  22  can include holder rear and forward surfaces  28 ,  30  and a holder peripheral surface  32  which extends between the holder rear and forward surfaces  28 ,  30 . The holder peripheral surface  32  can extend about the tool central axis A. The holder rear surface  28  can be located at the rearward end  24  of the rotary cutting tool  20 . 
     The tool holder  22  includes a mounting portion  34  located at the rearward end  24  of the tool holder  22 . The mounting portion  34  is designed to be attached to a spindle (not shown) which provides a driving means in order to rotate the cutting tool  20 . 
     As best seen in  FIG. 2 , the tool holder  22  includes a cutting portion receiving portion  35  located at the forward end  24  of the tool holder  22 . The cutting portion receiving portion  35  is designed to receive a cutting portion. The cutting portion receiving portion  35  is located axially opposite the mounting portion  34 . 
     The rotary cutting tool  20  has a cutting portion  36 . The cutting portion  36  is releasably attached to the tool holder  22 . Specifically, the cutting portion  36  is attached to the tool holder  22  at the tool holder&#39;s cutting portion receiving portion  35 . The cutting portion  36  includes a cutting edge  38 , for cutting of a workpiece. In accordance with some embodiments of the subject matter of the present application, the cutting portion  36  can be integrally formed to have unitary, one-piece construction. In such a configuration, the cutting portion  36  can be made of cemented carbide. Alternatively, the cutting portion  36  can include a shank portion having at least one cutting insert releasably attached thereto at a forward end of the shank portion. In such a configuration, the cutting insert can be made of cemented carbide and the shank portion made from steel. 
     In accordance with some embodiments of the subject matter of the present application, the rotary cutting tool  20  can include a fastening arrangement. In this non-limiting example shown in the drawings, the fastening arrangement  40  can include a chucking nut  42  and a collet  44 . The cutting portion  36  can be releasably attached to the tool holder  22  by the chucking nut  42  and the collet  44 . The cutting portion receiving portion  35  can include a conical recess  45  for receiving the collet  44 . Specifically, the conical recess  45  can be formed in the holder forward surface  30 . 
     The rotary cutting tool  20  includes a fluid channel  46 . The fluid channel  46  serves to convey fluid for actuation of a turbine, as described later in the description. In accordance with some embodiments of the subject matter of the present application, the fluid can be, for example, oil, water, emulsion. The fluid channel  46  can be a through channel formed within the rotary cutting tool  20 . 
     The fluid channel  46  may contain the tool central axis A for the entire length of the fluid channel through the tool holder  22 . The fluid channel  46  may contain the tool central axis A for the entire length of the fluid channel through both the tool holder  22  and the cutting portion  36 . Alternatively, the fluid channel  46  may contain tool central axis A for a partial length of the fluid channel through the tool holder  22 . The fluid channel  46  may contain the tool central axis A for a partial length of the fluid channel through both the tool holder  22  and the cutting portion  36   
     The fluid channel  46  includes a channel inlet opening  48  located at the mounting portion  34 . The channel inlet opening  48  is configured to receive a supply of fluid. In accordance with some embodiments of the subject matter of the present application, the channel inlet opening  48  can be located at the rearward end  24  of the tool holder  22 . Specifically, the channel inlet opening  48  can be located at the holder rear surface  28 . That is to say, the fluid channel  46  can open out to the holder rear surface  28  at the channel inlet opening  48 . 
     The fluid channel  46  also includes a channel outlet opening  50 . The channel outlet opening  50  is in fluid communication with the channel inlet opening  48 . Fluid flows in the fluid channel  46  from the channel inlet opening  48  to the channel outlet opening  50  defining a forward flow direction F F . The channel outlet opening  50  is configured to discharge fluid entering at the channel inlet opening  48 . The forward flow direction F F  extends in a direction along the fluid channel  46  from the channel inlet opening  48  to the channel outlet opening  50 . A rearward flow direction F R  is a direction opposite the forward flow direction F F . That is to say, the rearward flow direction F R  extends in a direction along the fluid channel  46  from the channel outlet opening  50  to the channel inlet opening  48 . In accordance with some embodiments of the subject matter of the present application, notwithstanding the fluid flow through the turbine, the forward and rearward flow directions F F , F R  may be generally linear. The channel outlet opening  50  can be located at either the cutting portion  36  or at the forward end  24  of the tool holder  22 . 
     Making reference in particular to  FIGS. 3 and 4 , the fluid channel  46  includes a channel turbine chamber  52 . That is to say, the channel turbine chamber  52  is located in, and forms part of, the fluid channel  46 . The channel turbine chamber  52  is designed for housing at least a turbine as described later in the description. The channel turbine chamber  52  is located between the channel inlet and outlet openings  48 ,  50 . In accordance with some embodiments of the subject matter of the present application, the rotary cutting tool  20  can include a turbine receptacle portion  53  separatable from, and located within, the tool holder  22 . The channel turbine chamber  52  can be formed within the turbine receptacle portion  53 . The channel turbine chamber  52  can be located between the rearward end  24  of the tool holder  22  and the cutting portion receiving portion  35 . The channel turbine chamber  52  can be aligned with the tool central axis A. Stated differently, the channel turbine chamber  52  can be centered about and intersected by the tool central axis A. Thus, a turbine located in the channel turbine chamber  52  is also aligned with the tool central axis A allowing the rotary cutting tool  20  to be balanced. 
     In accordance with some embodiments of the subject matter of the present application, the fluid channel  46  can include a channel turbine antechamber  54  which adjoins the channel turbine chamber  52  and which is located rearward thereof with respect to the forward flow direction F R . That is to say, the channel turbine antechamber  54  precedes the channel turbine chamber  52  with respect to the forward flow direction F F . In a radial cross-section taken in a plane perpendicular to the tool central axis A through the fluid channel  46 , a cross-sectional area of the fluid channel  46  can be greater at the channel turbine chamber  52  than at the channel turbine antechamber  54 . Like the channel turbine chamber  52 , the channel turbine antechamber  54  can be aligned with the tool central axis A. Stated differently, the channel turbine antechamber  54  can be centered about and intersected by the tool central axis A. The channel turbine chamber  52 , and the channel turbine antechamber  54  are preferably cylindrical, though at least the channel turbine antechamber  54  can be conical with a taper in the forward flow direction F F . 
     In accordance with some embodiments of the subject matter of the present application, the fluid channel  46  can include a channel turbine post-chamber  56  which adjoins the channel turbine chamber  52  and which is located forward thereof with respect to the forward flow direction F F . The channel turbine post-chamber  56  can be separated from the channel turbine chamber  52  by an annular groove  57 . In a radial cross-section taken in a plane perpendicular to the tool central axis A through the fluid channel  46 , the cross-sectional area of the fluid channel  46  can be smaller at the forwardmost portion of the channel turbine chamber  52  than at the channel turbine post-chamber  56 . The cutting portion receiving portion  35  and/or the conical recess  45  can extend in the rearward direction D R  to the channel turbine post-chamber  56 . The cutting portion  36  can extend into the channel turbine chamber  52 . The cutting portion  36  can be spaced apart from the turbine  60 . 
     The rotary cutting tool  20  includes an energy harvesting arrangement  58 . The energy harvesting arrangement  58  is configured to harvest electrical energy. Such energy harvesting can be used, for example, for powering an electrical arrangement, such as sensor and/or a rechargeable battery (optionally configured to power such a sensor). In the case of the latter, this avoids the need to replace batteries, which can only be performed by stopping the cutting operation. 
     Referring to  FIG. 4 , the energy harvesting arrangement  58  includes a turbine  60 . The turbine  60  is located in the fluid channel  46  at the channel turbine chamber  52 . Stated differently, the turbine  60  is located in the channel turbine chamber  52 . The turbine  60  is configured to be rotated in response to fluid flow from the channel inlet opening  48  to the channel outlet opening  50 , in the forward flow direction F F . In accordance with some embodiments of the subject matter of the present application, the turbine  60  can include a plurality of radially extending turbine blades  62 . The plurality of radially extending turbine blades  62  can be made of a metal, in particular the plurality of radially extending turbine blades  62  can be made of aluminum. Advantageously, this configuration provides sufficient strength and rigidity for the turbine blades  62  not to break or bend. 
     In accordance with some embodiments of the subject matter of the present application, the energy harvesting arrangement  58  can also include an electric generator  64  drivingly connected to the turbine  60 . The electric generator  64  can be located in the channel turbine chamber  52 . The electric generator  64  can be used to power an electrical arrangement. 
     In accordance with some embodiments of the subject matter of the present application, the energy harvesting arrangement  58  can include two cables  66  which extend from the electric generator  64  and terminate at two electrical connectors  70 , mounted on the tool holder  22 . A portion of each of the two cables  66  can be located in the fluid channel  46 . In particular, a portion of each of the two cables  66  that extend immediately (i.e. adjoins) from the turbine  60  can be located in the fluid channel  46 . It is understood that a single electric cable carrying two wires and extending from the generator to a single electrical connector having two terminals may also be used. 
     In accordance with some embodiments of the subject matter of the present application, the rotary cutting tool  20  can include an electrical arrangement  72 . The two electrical connectors  70  can be located at the electrical arrangement  72 . When the turbine  62  rotates, the electric generator  64  outputs electrical energy via the two cables  66  to power the electrical arrangement  72 . Stated differently, the electric generator  64  can be in electrical communication with the electrical arrangement  72 . The electrical arrangement  72  can be a sensor designed to monitor the condition of the cutting tool and/or the cutting operation. For example, the sensor can determine axial pull-out of the cutting portion  36  from the cutting portion receiving portion  35 . Alternatively, or in addition, the electrical arrangement  72  can include a rechargeable battery designed to power, for example, the sensor. Advantageously, such a configuration avoids the user having to stop the tool for battery replacement when such a sensor is powered by a non-rechargeable battery. 
     In accordance with some embodiments of the subject matter of the present application, the holder peripheral surface  32  can include a holder lateral recess  68  recessed therein. The electrical arrangement  72  can be located in the holder lateral recess  68 , thereby protecting the electrical arrangement  72  from impact by, for example, cut away chips. 
     Referring to  FIGS. 3 and 4 , in accordance with some embodiments of the subject matter of the present application, the fluid channel  46  can extend into the cutting portion  36 . Thus, the channel outlet opening  50  can be located at the cutting portion  36 . Specifically, the channel outlet opening  50  can be located at a forwardmost cutting portion surface  76  of the cutting portion  36 . That is to say, the fluid channel  46  can open out to the forwardmost cutting portion surface  76  at the channel outlet opening  50 . The channel outlet opening  50  can be oriented to discharge fluid in the vicinity of the cutting edge  38 . The channel outlet opening  50  can be located adjacent the cutting edge  36 . The channel outlet opening  50  can face in the forward direction D F . That is to say, a normal which is perpendicular to a plane defined by the channel outlet opening  50  can extend generally parallel to the tool central axis A. In the configuration including the chucking nut  42  and collet  44 , the fluid channel  46  can pass through the holder forward surface  30  at the conical recess  45 . The channel outlet opening  50  can be located at the collet  44  and/or chucking nut  42  (not shown). 
     In accordance with some embodiments of the subject matter of the present application, the rotary cutting tool  20  is devoid of a secondary channel with its own inlet and outlet. That is to say, the rotary cutting tool  20  has only a single channel inlet opening  48  and a single channel outlet opening  50  (i.e. the rotary cutting tool  20  includes a single (i.e. exactly one) fluid channel  46 . Moreover, the fluid channel  46  may not branch between the channel inlet opening  48  and the channel outlet opening  50  (so as to open out to another outlet), as shown for example in EP 2 095 897. Thus, advantageously, a single fluid channel  46  is used for conveying coolant to the cutting edge  38  and also conveying fluid to actuate the turbine  60 . 
     Although the subject matter of the present application has been described to a certain degree of particularity, it should be understood that various alterations and modifications could be made without departing from the spirit or scope of the invention as hereinafter claimed.