Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
  • B23P13/00—Making metal objects by operations essentially involving machining but not covered by a single other subclass
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
  • B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
  • B23P15/14—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass gear parts, e.g. gear wheels

Definitions

• This invention relates to a method of manufacturing a shaft and forming a gear on the shaft. While the invention is not limited to any particular type of shaft or gear, the present method is particularly well suited for forming a spur gear or gear-type spline on one end portion of a shaft which is adapted for use as the drive shaft of a small electric motor.
• the general aim of the present invention is to provide a new and improved manufacturing method which enables the shaft and the gear to be made on a highly automated basis and with comparatively simple and compact apparatus for transferring and holding the shaft during the various steps of the manufacturing cycle.
• a more detailed object of the invention is to achieve the foregoing by advancing the shaft automatically through stations where pre-gear forming, gear forming and post-gear forming operations are performed on the shaft with each operation being performed while the shaft is held rotationally stationary so as to avoid the need of providing apparatus for rotating the shaft and to enable simplification of the apparatus for transferring the shaft between the stations.
• Still another object is to provide a method in which shafts are successively cut to length from the leading end portion of an elongated piece of intermittently movable bar stock and then are automatically advanced through the pre-forming, the forming and the post-forming stations.
• the invention also resides in the operations carried out in the various stations and in the unique manner by which the operations are performed.
• Fig. 1 is a perspective view of a typical shaft and gear adapted to be formed by the new and improved method of the present invention.
• Fig. 2 is a top plan view which schematically illustrates exemplary apparatus for carrying out the method of the invention.
• Fig. 3 is a front elevational view taken along the line 3-3 of Fig. 2 and shows the gear forming apparatus.
• Fig. 4 is a side elevational view of the gear forming apparatus as taken along the line 4-4 of Fig. 3.
• the present invention involves a method of manufacturing a shaft 10 and forming a gear 11 on the shaft.
• the shaft is cylindrical and is of relatively small diameter (e.g., 1/4 inch).
• the gear 11 is formed on one end portion of the shaft and is in the form of a straight spur gear or a gear-type spline.
• the outside diameter of the gear is approximately the same as the diameter of the shaft.
• a shaft of this type is commonly used as the drive shaft of a small electric motor.
• the shaft 10 and the gear 11 are formed by a unique method which enables the manufacture to be carried out on a virtually fully automated basis and with relatively simple and compact material handling and transfer apparatus.
• the invention is particularly characterized by the fact that the shaft 10 is held in a rotationally stationary position while pre-gear forming, gear forming and post-gear forming operations are performed on the shaft.
• transfer means 12 are provided for advancing successive shafts 10 step-by-step along a predetermined path and through several stations, where various operations are performed on the shafts while the latter dwell.
• the transfer means may take various forms such as a rotary index table having clamps for holding the shafts and adapted to advance the shafts around a circular path.
• the transfer means may be a reciprocating walking beam adapted to transfer the shafts along a straight path through the various stations and associated with means for clamping the shafts in the stations.
• the transfer means 12 has been shown schematically as being a conveyor adapted to be advanced with step-by-step motion along a straight path and having clamps for securely holding the shafts.
• the individual shafts 10 are cut to length from an elongated piece of bar stock 13.
• the bar stock extends transversely to the rear side of the conveyor 12 and is adapted to be advanced lengthwise and for wardly with a step-by-step motion.
• the leading end portion of the bar stock advances forwardly across the conveyor 12 and then its leading end is stopped by a transversely adjustable positive stopping device 14 .
• the conveyor 12 then clamps the shaft.
• a saw 15 moves toward and cuts through the bar stock 13 to sever the leading end portion therefrom and cut a shaft 10 to length .
• the saw 15 then retracts , and the conveyor advances the shaft laterally away from the bar stock and into the first operating station 16.
• a pre-gear forming operation is performed on the shaft 10 .
• the pre-gear forming operation consis ts of chamfering both ends of the shaft 10 as indicated at 17 in order to remove burrs and sharp edges from the ends .
• the chamfering is performed by two transversely movable heads 18 each having a chamfering tool 19 adapted to be advanced into engagement with the end of the shaft and adapted to be advanced into engagement with the end of the shaft and adapted to be rotated to form the chamfer 17 on the rotationally stationary shaft.
• another pre-gear forming operation e . g .
• keyway cutting may be performed on the shaft at the station 16 or at a station immediately downstream of the station 16.
• the shaft 10 is advanced by the conveyor 12 into a gear forming station 20 .
• the gear 11 is formed on the shaft 10 while the latter is held in a rotationally stationary position .
• the gear may be formed by different ones of the machines disclosed in our co-pending application Serial No . 041,680, filed May 23, 1979, entitled Shape Generation By Orbiting A Rotating Cutter and assigned to the assignee of the present invention.
• the gear forming machine which has been illustrated is a hobbing machine 21 having a transversely movable slide 22.
• a head 23 is mounted to rotate on the slide about an axis which is aligned with the axis of the shaft 10.
• a hob 24 is supported on the head at a location offset from the axis of the head and is adapted to be rotated about its own axis.
• the slide 22 is moved transversely while the head 23 and the hob 24 are rotated around their respective axes. This causes the hob 24 to move along and orbit around the shaft 10 and, at the same time, to turn about its own axis to form the gear 11 on the rotationally stationary shaft.
• Another hobbing machine 21 ' may be located in a station downstream of the hobbing machine 21.
• the hobbing machine 21 ' may be used if the machine 21 is down for repair or if a gear of a different type or size is to be formed on the shaft 10.
• One or more post-gear forming operations are performed after the gear 11 has been hobbed.
• the first post operation involves heat treating the gear 11 at a station 25 downstream from the hobbing machine 21' .
• the heat treating is effected by a transversely movable induction heater 26 having a coil 27 which is adapted to telescope over and inductively heat the gear 11 when the shaft 10 dwells in the station 25 and the heater is moved forwardly.
• Means also may be provided in the station 25 for quenching the gear after the heater has been retracted. Consistent with the invention, the shaft 10 is held in a rota tionally stationary position during the heating and quenching steps .
• the newly formed gear 11 is checked to determine if the gear meets designated standards .
• the checking is effected by apparatus 29 which is disclosed in our co-pending application Serial No . 153 , 599 , filed May 27 , 1980 , entitled Method And Apparatus For Checking a Gear (Attorney ' s Docket No . 08129 ) and assigned to the assignee of the present invention.
• apparatus 29 includes a master gear 30 which is adapted to be brought into meshing engagement with the gear 11 while the shaft 10 is held ro tationally .
• the master gear 30 orbits around the gear 11 much in the same manner as the hob 24 and, at the same time, rotates freely around its own axis so as to roll around the stationary gear 11.
• the center distance between the gear 11 and the master gear 30 is gauged by an electrical detecting device (not shown) which produces a signal indicative as to whether the gear is acceptable .
• an electrical detecting device (not shown) which produces a signal indicative as to whether the gear is acceptable .
• Our last-mentioned application may be referred to for a more detailed disclosure of the construction and operation of the gear checking apparatus 29 .
• the shaft 10 is removed from the conveyor 13 by a transversely movable ejection mechanism 32 which pushes the shaft into a downwardly inclined chute 33.
• a shaft with an acceptable gear 11 proceeds down the chute to a collection area while a shaft with a non-acceptable gear falls out of the chute through a trap door 34 .

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Gear Processing (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=22547818

Family Applications (1)

Country Status (2)

Family Cites Families (7)

• 1981
  • 1981-04-30 EP EP19810901272 patent/EP0052616A1/de not_active Withdrawn
  • 1981-04-30 WO PCT/US1981/000596 patent/WO1981003444A1/en not_active Ceased

Non-Patent Citations (1)

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