US20150306725A1 - Grinding machine for bearing rings and method for setting tangency conditions in such a machine - Google Patents
Grinding machine for bearing rings and method for setting tangency conditions in such a machine Download PDFInfo
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- US20150306725A1 US20150306725A1 US14/693,068 US201514693068A US2015306725A1 US 20150306725 A1 US20150306725 A1 US 20150306725A1 US 201514693068 A US201514693068 A US 201514693068A US 2015306725 A1 US2015306725 A1 US 2015306725A1
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- Prior art keywords
- rotation
- grinding wheel
- chuck
- rotation axis
- electric motor
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Classifications
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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
- B24B19/00—Single-purpose machines or devices for particular grinding operations not covered by any other main group
- B24B19/08—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding non-circular cross-sections, e.g. shafts of elliptical or polygonal cross-section
- B24B19/11—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding non-circular cross-sections, e.g. shafts of elliptical or polygonal cross-section for grinding the circumferential surface of rings, e.g. piston rings
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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
- B24B27/00—Other grinding machines or devices
- B24B27/0069—Other grinding machines or devices with means for feeding the work-pieces to the grinding tool, e.g. turntables, transfer means
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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
- B24B19/00—Single-purpose machines or devices for particular grinding operations not covered by any other main group
- B24B19/02—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding grooves, e.g. on shafts, in casings, in tubes, homokinetic joint elements
- B24B19/06—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding grooves, e.g. on shafts, in casings, in tubes, homokinetic joint elements for grinding races, e.g. roller races
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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
- B24B41/005—Feeding or manipulating devices specially adapted to grinding machines
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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
- B24B41/06—Work supports, e.g. adjustable steadies
- B24B41/061—Work supports, e.g. adjustable steadies axially supporting turning workpieces, e.g. magnetically, pneumatically
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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
- B24B49/00—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation
- B24B49/12—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation involving optical means
Definitions
- This invention relates to a grinding machine which can be used for grinding of bearing rings. This invention also relates to a method for setting tangency conditions between a grinding wheel of such a machine and its environment.
- This invention aims at solving these problems with a new grinding machine which is adapted for easily and automatically detecting the tangency conditions of the grinding wheel with its environment, in particular with a shaping tool and a chuck which belongs to holding means of the grinding machine.
- the invention concerns a grinding machine for bearing rings, this machine including a frame, a rotating grinding wheel movable in rotation around a first rotation axis, a working station where a bearing ring stands during a grinding operation of one of its surfaces, a chuck for holding a bearing ring in the working station, this chuck being movable in rotation along a second rotation axis.
- the machine also includes:
- first automatic means to set the position of a shaping tool with respect to an outer peripheral edge of the grinding wheel, these first automatic means including an electric motor, an encoder coupled to the electric motor to detect a rotation of an output shaft of this motor, a sensor of the position of the shaping tool along a translation axis and means to compare an output signal of the encoder and an output signal of the sensor,
- the first and second automatic means can be used one after the other, in any order, to set the tangency conditions between, on the one hand, the outer peripheral edge of the grinding wheel and the shaping tool and, on the other hand, a lateral surface of the grinding wheel and the chuck. In both cases, these settings can be obtained in a fast and reproducible way, since one does not need to rely on a human operator.
- the sensor of the first automatic means is advantageously an optical scale sensor.
- the machine includes means for moving the grinding wheel from a position offset with respect to the second rotation axis to a second position where a lateral face of the grinding wheel intersects the second rotation axis.
- the invention also relates to a method which can be implemented with a grinding machine as mentioned here-above and, more specifically, a method for setting the tangency conditions between a grinding wheel and its environment in a grinding machine for bearing rings, this machine including, in addition to the grinding wheel which rotates around a first rotation axis, a frame, a working station where a bearing ring stands during a grinding operation of one of its surfaces and a chuck for holding the bearing ring in the working station, this chuck being movable in rotation around a second rotation axis.
- this method includes at least the following steps consisting in:
- Steps a) to e) can be performed before or after steps f) to j).
- this invention also concerns methods for shaping an outer peripheral edge of a grinding wheel or an axial surface of a chuck of a grinding machine as mentioned hereabove, wherein one implements a method as mentioned here-above.
- step k For shaping of an outer peripheral edge of a grinding wheel, one uses an extra step k), implemented after step e), when it assessed that the shaping tool is tangent with the peripheral edge, and consisting in j) moving the shaping tool in translation along the transverse axis, towards the first rotation axis, over a given stroke.
- step l For shaping an axial surface of the chuck, one uses the following step l), implemented after step j), when it is assessed that the chuck is tangent with the lateral surface of the grinding wheel, and consisting in moving the chuck in translation along the second rotation axis, towards the grinding wheel, over a given stroke.
- FIG. 1 is a front view of a grinding machine according to the invention
- FIG. 2 is a partial perspective view corresponding to detail II on FIG. 1 ;
- FIG. 3 is a top schematic view of a portion of the grinding machine of FIGS. 1 and 2 where only some elements of the machine are represented;
- FIG. 4 is a top schematic view similar to FIG. 3 when the grinding machine is in another configuration.
- the grinding machine 2 represented on FIGS. 1 to 4 includes a frame 4 and a rotating grinding wheel 6 which rotates around a first rotation axis X 6 .
- An electric motor 8 is used to drive wheel 6 in rotation around axis X 6 .
- D 6 denotes the outer diameter of grinding wheel 6 .
- auxiliary frame 9 which is movable with respect to frame 4 in two opposite directions perpendicular to axis X 6 , as shown by double arrow A 9 on FIG. 1 .
- Axis X 6 is fixed with respect to auxiliary frame 9 .
- the outer peripheral surface 10 of grinding wheel 6 is shaped by a knurl 12 when needed and is used to grind the outer surface of an inner ring 500 of a non-further represented bearing.
- Knurl 12 which is sometimes called “diamant roller”, is also supported by auxiliary frame 9 .
- outer surface 10 has a central bump 110 , so that it is used to grind the outer radial surface 502 of ring 500 with a concave groove 502 A.
- Grinding machine 2 is provided with a working station or zone 14 where each ring 500 is successively held in position with respect to grinding wheel 6 during a grinding operation.
- Working station 14 includes two support shoes 16 and 18 , each provided with a fitting 20 , respectively 22 .
- Fitting 20 is adapted to lie against the outer radial surface of a magnetic clamp 24
- fitting 22 is made of two parts and adapted to lie against the outer peripheral surface 502 of ring 500 .
- Each support shoe 16 and 18 is mounted on a slider 26 , respectively 28 .
- Another slider 30 is used to avoid escape of the ring 500 .
- each ring 500 When it is loaded in working station 14 , as shown on FIGS. 1 , 2 , and 3 , each ring 500 is centered around a central axis X 24 of magnetic clamp 24 parallel or substantially parallel to axis X 6 .
- the central bore 504 of ring 500 is empty and, because of the friction between surfaces 10 and 502 , ring 500 is driven in rotation around axis X 24 by the rotation movement of grinding wheel 6 around axis X 6 .
- Ring 500 is cut on FIG. 3 , in order to show central bore 504 .
- a multi-axis robot 100 belongs to the transfer means. It is mounted by its base 102 on the frame 4 of grinding machine 2 and includes a multi-articulated arm 104 whose free end is equipped with a clamp 106 adapted to grasp or grip different types of rings 500 , via a proper programming of robot 100 .
- a moving arm 200 also belongs to the transfer means. This moving arm 200 is rotatable around an axis X 200 which is fixed with respect to frame 4 and parallel to axis X 6 . Near its free end 204 opposite to axis X 200 moving arm 200 is provided with means for gripping a ring 500 to be moved away from working station 14 .
- Grinding machine 2 includes an inlet chute 300 where black rings 500 move by gravity in the direction of arrow A 300 .
- inlet chute 300 is close to robot 100 which can pick-up a ring 500 present in inlet chute 300 when needed.
- grinding machine 2 also includes an outlet chute 310 where ground rings 500 are dumped, one after the other.
- outlet chute 310 ground rings 500 move by gravity, in the direction of arrow A 310 .
- outlet chute 310 is equipped with a releaser 312 provided with a notch 314 of a size sufficient to accommodate the gripping means of moving arm 200 but with a transverse dimension, measured between two lateral edges of this notch, smaller than the outer diameter of the rings 500 .
- Knurl 12 is movable with respect to axis X 6 along an axis Y 12 which is radial with respect to axis X 6 . Such a movement is necessary in order for knurl 12 to be in contact with the outer peripheral surface or edge 10 of ring 6 when it is necessary to conform this edge 10 with a new shape, to be used for a new type of bearing ring 500 to be processed on machine 2 .
- the movements of knurl 12 along axis Y 12 are driven by an electric motor 702 whose output shaft 704 primes a ball screw mechanism 706 having an output slide rigidly connected to knurl 12 .
- an electric motor 702 whose output shaft 704 primes a ball screw mechanism 706 having an output slide rigidly connected to knurl 12 .
- An optical scale sensor 708 is arranged between ball screw mechanism 706 and knurl 12 . It includes a fixed graduation 708 A and a slide 708 B which moves along graduation 708 A and includes a sensing unit 708 C capable of reading graduations 708 A. Slide 708 B is rigidly connected to knurl 12 . Thus, optical scale sensor 708 is capable of delivering to an electronic control unit or ECU 800 a signal 5708 representative of the actual position of knurl 12 along axis Y 12 .
- knurl 12 itself is used as the “feeler” or “probe” of optical scale 708 .
- an encoder 710 is coupled to electric motor 702 and capable of delivering to ECU 800 an electric signal 5710 representative of the angular position or speed of the non represented rotor of electric motor 702 that is of output shaft 704 .
- electric motor 702 When it is needed to use knurl 12 in order to set a new shape on outer peripheral surface or edge 10 of grinding wheel 6 , electric motor 702 is actuated in order to move knurl 12 towards axis X 6 along axis Y 12 . During this movement and at regular time slots, e.g. every 100 ms, optical scale sensor 708 and encoder 710 provide ECU 800 with their respective output signals 5708 and 5710 .
- ECU 800 includes a microcontroller which is programmed to assess that, when signal S 708 is representative of a stop of slide 708 B and when signal 5710 is representative of a rotation of output shaft 704 , a tangency point has been reached, along axis Y 12 , between knurl 12 and outer peripheral edge 10 .
- a control signal 5702 is sent to motor 702 in order to stop it, in case it has not already been stopped by a torque limitation module or any equivalent equipment.
- a shaping operation of edge 10 in predetermined conditions, in particular by machining edge 10 over a given depth along axis Y 12 .
- the fact that the tangency condition is determined prior to starting this machining operation guarantees that the machining operation is fully implemented, with a minimum decrease of the diameter of grinding wheel 6 , since machining of edge 10 occurs on a given stroke which is optimized.
- optical scale sensor 708 as a dedicated sensor of the position of knurl 12 along axis Y 12 is very convenient since such a sensor is reliable, simple to implement and economical.
- other types of sensors can be used, such as a magnetostrictive sensor.
- an optical scale sensor is by far preferred because of its high resolution capability, with an order of magnitude of one micrometer.
- Magnetic clamp 24 includes a solenoid activated clutch 242 and a chuck 244 made of a magnetic material, such as iron, which has a front annular face 244 A adapted to come into contact with a back axial surface 506 A of a bearing ring 500 present in working station 14 .
- Back axial surface 506 A is opposite to a front axial surface 506 B of this ring which is visible from outside machine 2 in the direction of FIG. 1 .
- a shaft 246 also belongs to magnetic clamp 24 and connects clutch 242 and chuck 244 .
- annular surface 244 A is correctly shaped in order to efficiently transfer a magnetic effort to a ring 500 present in working station 14 , via a surface/surface contact with axial surface 506 A of this ring.
- Such a correct geometry of surface 244 A can be obtained through a grinding operation of this surface via grinding wheel 6 .
- the success of such a grinding operation depends, amongst others, from its starting point where surface 244 A should be tangent with a lateral surface 62 of grinding wheel 6 .
- an electric motor 902 to drive magnetic clamp 24 in translation axially along axis X 24 .
- the output shaft 904 of electric motor 902 is connected to a ball screw mechanism 906 which transforms the rotational movement of output shaft 904 into a bidirectional translational movement as represented by arrow A 24 and A′ 24 on FIGS. 3 and 4 .
- An encoder 910 coupled to magnetic clamp 24 and capable of detecting a rotation of shaft 246 around axis X 24 , delivers to ECU 800 a signal 5910 representative of the rotation of shaft 246 .
- ECU 800 is capable of piloting electric motor 902 with an appropriate signal 5902 .
- ECU 800 controls electric motor 902 in order to move magnetic clamp backwards with respect to grinding wheel 6 , which is in the direction of arrow A 24 in FIG. 3 , whereas no ring 500 is mounted on chuck 244 .
- auxiliary frame 9 is moved towards axis X 24 , in the direction of arrow A′ 9 on FIG. 4 .
- This brings grinding wheel 6 in front of magnetic clamp 24 .
- the movement of auxiliary frame 9 in the direction of arrow A′ 9 induces that lateral surface 62 of grinding wheel 6 crosses axis X 24 .
- This movement can also be controlled via ECU 800 , via a non represented electric motor.
- ECU 800 also controls electric motor 8 in order to drive grinding wheel 6 in rotation around axis X 6 .
- Driving in rotation of grinding wheel 6 can start before or after the end of the translation movement of auxiliary frame in the direction of arrow A′ 9 .
- ECU 800 controls electric motor 902 in order for it to move magnetic clamp towards grinding wheel 6 , in the direction of arrow A′ 24 on FIG. 4 .
- annular surface 244 A of chuck 244 comes into contact with lateral surface 62 of grinding wheel 6 .
- the time moment when this occurs is detected via encoder 910 since, as soon as a contact exists between surfaces 244 A and 62 , chuck 244 is driven in rotation around axis X 24 , which also drives in rotation shaft 246 whose rotation is detected by encoder 910 .
- ECU 800 is informed via signal 5910 which is representative of the beginning of a rotational movement of shaft 246 around axis X 24 . As soon as it receives such a signal 5910 , ECU 800 stops electric motor 902 via signal 5902 .
- ECU 800 actuates electric motor 902 via signal 5902 in order to move magnetic clamp 24 , including chuck 244 , in the direction of arrow A′ 24 , that is towards grinding wheel 6 , on a given straw, between 0.01 and 10 mm, preferably about 0.1 mm.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Constituent Portions Of Griding Lathes, Driving, Sensing And Control (AREA)
- Grinding And Polishing Of Tertiary Curved Surfaces And Surfaces With Complex Shapes (AREA)
Abstract
A grinding machine for bearing rings includes a frame, a rotating grinding wheel rotationally movable around a first rotation axis, a working station where a bearing ring stands during a surface grinding operation, a chuck for holding a bearing ring, the chuck being rotationally movable around a second rotation axis. The machine includes a first automatic mechanism to set the position of a shaping tool with respect to an outer peripheral edge of the grinding wheel, these first automatic mechanism includes an electric motor, an encoder coupled to the electric motor to detect a rotation of an output shaft of the motor, a sensor of the position of the shaping tool along a translation axis and a comparator to compare output signals from each of the encoder and the sensor. The machine also includes second automatic mechanism to set the axial position of the chuck along the second rotation axis.
Description
- This is a Non-Provisional Patent Application, filed under the Paris Convention, claims the benefit of European Patent (EP) Application Number 14305618.2 filed on 25 Apr. 2014 (25 Apr. 2014), which is incorporated herein by reference in its entirety.
- This invention relates to a grinding machine which can be used for grinding of bearing rings. This invention also relates to a method for setting tangency conditions between a grinding wheel of such a machine and its environment.
- In the field of bearings manufacturing, it is known, e.g. from WO-A-2008 082 140, to use a grinding machine provided with a rotating grinding wheel movable in rotation around an axis. It is known that such a grinding wheel must interact, on the one hand, with a shaping tool, in order to conform its outer peripheral edge to the actual geometry of a bearing wheel to be processed, and, on the other hand, with bearing rings successively installed within a working station of the grinding machine and held in this working station by a chuck. Because of these interactions, it is important to assess when the grinding wheel is tangent with the shaping tool and with the chuck, during setting of the grinding machine for a new type of bearing ring to be processed. Up to now the detection of the tangency positions of these elements is done manually, which requires a qualified manpower and a high level of concentration of the operator. This is time consuming and expensive.
- This invention aims at solving these problems with a new grinding machine which is adapted for easily and automatically detecting the tangency conditions of the grinding wheel with its environment, in particular with a shaping tool and a chuck which belongs to holding means of the grinding machine.
- To this end, the invention concerns a grinding machine for bearing rings, this machine including a frame, a rotating grinding wheel movable in rotation around a first rotation axis, a working station where a bearing ring stands during a grinding operation of one of its surfaces, a chuck for holding a bearing ring in the working station, this chuck being movable in rotation along a second rotation axis. According to the invention, the machine also includes:
- first automatic means to set the position of a shaping tool with respect to an outer peripheral edge of the grinding wheel, these first automatic means including an electric motor, an encoder coupled to the electric motor to detect a rotation of an output shaft of this motor, a sensor of the position of the shaping tool along a translation axis and means to compare an output signal of the encoder and an output signal of the sensor,
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- second automatic means to set the axial position of the chuck along the second rotation axis, these second automatic means including an electric motor for driving the chuck in translation along the second rotation axis and means to detect a rotation of the chuck around the second rotation axis.
- Thanks to the invention, the first and second automatic means can be used one after the other, in any order, to set the tangency conditions between, on the one hand, the outer peripheral edge of the grinding wheel and the shaping tool and, on the other hand, a lateral surface of the grinding wheel and the chuck. In both cases, these settings can be obtained in a fast and reproducible way, since one does not need to rely on a human operator.
- The sensor of the first automatic means is advantageously an optical scale sensor. Preferably, the machine includes means for moving the grinding wheel from a position offset with respect to the second rotation axis to a second position where a lateral face of the grinding wheel intersects the second rotation axis.
- The invention also relates to a method which can be implemented with a grinding machine as mentioned here-above and, more specifically, a method for setting the tangency conditions between a grinding wheel and its environment in a grinding machine for bearing rings, this machine including, in addition to the grinding wheel which rotates around a first rotation axis, a frame, a working station where a bearing ring stands during a grinding operation of one of its surfaces and a chuck for holding the bearing ring in the working station, this chuck being movable in rotation around a second rotation axis. According to the invention, this method includes at least the following steps consisting in:
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- a) moving a shaping tool, to be used for shaping an outer peripheral edge of the grinding machine, in translation along a transverse axis, towards the first rotation axis by actuation of a first electric motor,
- b) detecting a rotation of an output shaft of the electric motor via an encoder coupled to the electric motor,
- c) detecting a position of the shaping tool along the transverse axis via a dedicated sensor,
- d) comparing a first output signal of the encoder with a second output signal of the dedicated sensor,
- e) assessing that the shaping tool is tangent with the outer peripheral edge of the grinding wheel when the first output signal is representative of a rotation of the output shaft and the second output signal is representative of a stop of the shaping tool along the transverse axis,
- f) moving the grinding wheel to a position where a lateral surface of the grinding wheel intersects the second rotation axis,
- g) moving the grinding wheel in rotation around the first rotation axis,
- h) moving the chuck in translation along the second rotation axis, towards the lateral surface of the grinding wheel by actuation of a second electric motor,
- i) detecting a rotation of the shaft integral in rotation with the chuck via a dedicated rotation sensor,
- j) assessing that the chuck is tangent with the lateral surface of the grinding wheel as soon as the dedicated rotation sensor detects a rotation of the shaft.
- Steps a) to e) can be performed before or after steps f) to j).
- According to further aspects of the invention which are advantageous but not compulsory, one can provide that:
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- when it is assessed in step e) that the shaping tool is tangent with the outer peripheral edge of the grinding wheel, the first electric motor is stopped, and/or
- when it is assessed in step j) that the chuck is tangent with the lateral surface of the grinding wheel, the second electric motor is stopped.
- Moreover, this invention also concerns methods for shaping an outer peripheral edge of a grinding wheel or an axial surface of a chuck of a grinding machine as mentioned hereabove, wherein one implements a method as mentioned here-above.
- For shaping of an outer peripheral edge of a grinding wheel, one uses an extra step k), implemented after step e), when it assessed that the shaping tool is tangent with the peripheral edge, and consisting in j) moving the shaping tool in translation along the transverse axis, towards the first rotation axis, over a given stroke.
- For shaping an axial surface of the chuck, one uses the following step l), implemented after step j), when it is assessed that the chuck is tangent with the lateral surface of the grinding wheel, and consisting in moving the chuck in translation along the second rotation axis, towards the grinding wheel, over a given stroke.
- The invention will be better understood on the basis of the following description which is given in correspondence with the annexed figures and as an illustrative example, without restricting the object of the invention. In the annexed figures:
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FIG. 1 is a front view of a grinding machine according to the invention; -
FIG. 2 is a partial perspective view corresponding to detail II onFIG. 1 ; -
FIG. 3 is a top schematic view of a portion of the grinding machine ofFIGS. 1 and 2 where only some elements of the machine are represented; and -
FIG. 4 is a top schematic view similar toFIG. 3 when the grinding machine is in another configuration. - The grinding machine 2 represented on
FIGS. 1 to 4 includes aframe 4 and a rotatinggrinding wheel 6 which rotates around a first rotation axis X6. Anelectric motor 8 is used to drivewheel 6 in rotation around axis X6. D6 denotes the outer diameter ofgrinding wheel 6. - Grinding
wheel 6 andmotor 8 are supported by anauxiliary frame 9 which is movable with respect toframe 4 in two opposite directions perpendicular to axis X6, as shown by double arrow A9 onFIG. 1 . Axis X6 is fixed with respect toauxiliary frame 9. - The outer
peripheral surface 10 ofgrinding wheel 6 is shaped by aknurl 12 when needed and is used to grind the outer surface of aninner ring 500 of a non-further represented bearing.Knurl 12, which is sometimes called “diamant roller”, is also supported byauxiliary frame 9. In the example of the figures,outer surface 10 has acentral bump 110, so that it is used to grind the outerradial surface 502 ofring 500 with aconcave groove 502A. - Grinding machine 2 is provided with a working station or
zone 14 where eachring 500 is successively held in position with respect to grindingwheel 6 during a grinding operation. -
Working station 14 includes two support shoes 16 and 18, each provided with a fitting 20, respectively 22. Fitting 20 is adapted to lie against the outer radial surface of amagnetic clamp 24, whereas fitting 22 is made of two parts and adapted to lie against the outerperipheral surface 502 ofring 500. Each support shoe 16 and 18 is mounted on a slider 26, respectively 28. Another slider 30 is used to avoid escape of thering 500. - When it is loaded in
working station 14, as shown onFIGS. 1 , 2, and 3, eachring 500 is centered around a central axis X24 ofmagnetic clamp 24 parallel or substantially parallel to axis X6. In this configuration, thecentral bore 504 ofring 500 is empty and, because of the friction betweensurfaces ring 500 is driven in rotation around axis X24 by the rotation movement of grindingwheel 6 around axis X6. Ring 500 is cut onFIG. 3 , in order to showcentral bore 504. - Two types of equipment are used to feed
working station 14 withrings 500 and to evacuate the rings from this working station, once they have been processed. In this description, a ring which is not yet processed is called a “black ring”, whereas a ring which has been processed by grindingwheel 6 is called a “ground ring”. - A
multi-axis robot 100, with 6 degrees of freedom, belongs to the transfer means. It is mounted by itsbase 102 on theframe 4 of grinding machine 2 and includes amulti-articulated arm 104 whose free end is equipped with aclamp 106 adapted to grasp or grip different types ofrings 500, via a proper programming ofrobot 100. - A moving
arm 200 also belongs to the transfer means. This movingarm 200 is rotatable around an axis X200 which is fixed with respect toframe 4 and parallel to axis X6. Near its free end 204 opposite to axisX200 moving arm 200 is provided with means for gripping aring 500 to be moved away from workingstation 14. - Grinding machine 2 includes an
inlet chute 300 whereblack rings 500 move by gravity in the direction of arrow A300. For the sake of simplicity, only onering 500 is represented ininlet chute 300 onFIG. 2 .Inlet chute 300 is close torobot 100 which can pick-up aring 500 present ininlet chute 300 when needed. - On the other hand, grinding machine 2 also includes an
outlet chute 310 where ground rings 500 are dumped, one after the other. Inoutlet chute 310, ground rings 500 move by gravity, in the direction of arrow A310. On its side oriented towardsarm 200,outlet chute 310 is equipped with areleaser 312 provided with anotch 314 of a size sufficient to accommodate the gripping means of movingarm 200 but with a transverse dimension, measured between two lateral edges of this notch, smaller than the outer diameter of therings 500. -
Knurl 12 is movable with respect to axis X6 along an axis Y12 which is radial with respect to axis X6. Such a movement is necessary in order forknurl 12 to be in contact with the outer peripheral surface or edge 10 ofring 6 when it is necessary to conform thisedge 10 with a new shape, to be used for a new type ofbearing ring 500 to be processed on machine 2. The movements ofknurl 12 along axis Y12 are driven by anelectric motor 702 whoseoutput shaft 704 primes aball screw mechanism 706 having an output slide rigidly connected toknurl 12. Thus, depending on the electriccurrent feeding motor 702, it is possible to move knurl in translation along axis Y12, in the directions of double arrow A12. - An
optical scale sensor 708 is arranged betweenball screw mechanism 706 andknurl 12. It includes a fixedgraduation 708A and aslide 708B which moves alonggraduation 708A and includes asensing unit 708C capable of readinggraduations 708A.Slide 708B is rigidly connected toknurl 12. Thus,optical scale sensor 708 is capable of delivering to an electronic control unit or ECU 800 a signal 5708 representative of the actual position ofknurl 12 along axis Y12. - In other words, knurl 12 itself is used as the “feeler” or “probe” of
optical scale 708. - On the other hand, an
encoder 710 is coupled toelectric motor 702 and capable of delivering toECU 800 an electric signal 5710 representative of the angular position or speed of the non represented rotor ofelectric motor 702 that is ofoutput shaft 704. - When it is needed to use
knurl 12 in order to set a new shape on outer peripheral surface or edge 10 of grindingwheel 6,electric motor 702 is actuated in order to moveknurl 12 towards axis X6 along axis Y12. During this movement and at regular time slots, e.g. every 100 ms,optical scale sensor 708 andencoder 710 provideECU 800 with their respective output signals 5708 and 5710. - When knurl 12 becomes tangent to outer
peripheral surface 10,slide 708B is blocked alonggraduation 708A and signal 5708 is representative of a stop ofslide 708B. On the other hand, at the same moment,encoder 710 still detects thatoutput shaft 704 rotates because the rotation ofball screw mechanism 706 has not yet been blocked by the reaction ofknurl 12. Thus, the output signal 5710 ofencoder 710 is representative of a rotation ofoutput shaft 704. -
ECU 800 includes a microcontroller which is programmed to assess that, when signal S708 is representative of a stop ofslide 708B and when signal 5710 is representative of a rotation ofoutput shaft 704, a tangency point has been reached, along axis Y12, betweenknurl 12 and outerperipheral edge 10. - Then, a control signal 5702 is sent to
motor 702 in order to stop it, in case it has not already been stopped by a torque limitation module or any equivalent equipment. - Once a tangency condition has been detected between
knurl 12 and outer peripheral surface or edge 10 of grindingwheel 6, it is possible to implement with knurl 10 a shaping operation ofedge 10 in predetermined conditions, in particular by machiningedge 10 over a given depth along axis Y12. The fact that the tangency condition is determined prior to starting this machining operation guarantees that the machining operation is fully implemented, with a minimum decrease of the diameter ofgrinding wheel 6, since machining ofedge 10 occurs on a given stroke which is optimized. - The use of
optical scale sensor 708 as a dedicated sensor of the position ofknurl 12 along axis Y12 is very convenient since such a sensor is reliable, simple to implement and economical. However, other types of sensors can be used, such as a magnetostrictive sensor. However an optical scale sensor is by far preferred because of its high resolution capability, with an order of magnitude of one micrometer. -
Magnetic clamp 24 includes a solenoid activated clutch 242 and achuck 244 made of a magnetic material, such as iron, which has a frontannular face 244A adapted to come into contact with a backaxial surface 506A of abearing ring 500 present in workingstation 14. Backaxial surface 506A is opposite to a frontaxial surface 506B of this ring which is visible from outside machine 2 in the direction ofFIG. 1 . - A
shaft 246 also belongs tomagnetic clamp 24 and connects clutch 242 andchuck 244. - It is essential that
annular surface 244A is correctly shaped in order to efficiently transfer a magnetic effort to aring 500 present in workingstation 14, via a surface/surface contact withaxial surface 506A of this ring. Such a correct geometry ofsurface 244A can be obtained through a grinding operation of this surface via grindingwheel 6. The success of such a grinding operation depends, amongst others, from its starting point wheresurface 244A should be tangent with alateral surface 62 of grindingwheel 6. - In order to obtain such a tangency configuration, one uses an
electric motor 902 to drivemagnetic clamp 24 in translation axially along axis X24. Theoutput shaft 904 ofelectric motor 902 is connected to aball screw mechanism 906 which transforms the rotational movement ofoutput shaft 904 into a bidirectional translational movement as represented by arrow A24 and A′24 onFIGS. 3 and 4 . - An
encoder 910, coupled tomagnetic clamp 24 and capable of detecting a rotation ofshaft 246 around axis X24, delivers to ECU 800 asignal 5910 representative of the rotation ofshaft 246. - On the other hand,
ECU 800 is capable of pilotingelectric motor 902 with anappropriate signal 5902. - When it is needed to re-shape or re-conform
annular surface 244A,ECU 800 controlselectric motor 902 in order to move magnetic clamp backwards with respect to grindingwheel 6, which is in the direction of arrow A24 inFIG. 3 , whereas noring 500 is mounted onchuck 244. - Then,
auxiliary frame 9 is moved towards axis X24, in the direction of arrow A′9 onFIG. 4 . This brings grindingwheel 6 in front ofmagnetic clamp 24. In other words, the movement ofauxiliary frame 9 in the direction of arrow A′9 induces thatlateral surface 62 of grindingwheel 6 crosses axis X24. - This movement can also be controlled via
ECU 800, via a non represented electric motor. -
ECU 800 also controlselectric motor 8 in order to drive grindingwheel 6 in rotation around axis X6. Driving in rotation of grindingwheel 6 can start before or after the end of the translation movement of auxiliary frame in the direction of arrow A′9. - Thereafter,
ECU 800 controlselectric motor 902 in order for it to move magnetic clamp towardsgrinding wheel 6, in the direction of arrow A′24 onFIG. 4 . The consequence is thatannular surface 244A ofchuck 244 comes into contact withlateral surface 62 of grindingwheel 6. The time moment when this occurs is detected viaencoder 910 since, as soon as a contact exists betweensurfaces chuck 244 is driven in rotation around axis X24, which also drives inrotation shaft 246 whose rotation is detected byencoder 910. Thus, as soon assurface 244A comes tangent to surface 62,ECU 800 is informed viasignal 5910 which is representative of the beginning of a rotational movement ofshaft 246 around axis X24. As soon as it receives such asignal 5910,ECU 800 stopselectric motor 902 viasignal 5902. - One is then in the configuration represented on
FIG. 4 . - Starting from this configuration,
ECU 800 actuateselectric motor 902 viasignal 5902 in order to movemagnetic clamp 24, includingchuck 244, in the direction of arrow A′24, that is towardsgrinding wheel 6, on a given straw, between 0.01 and 10 mm, preferably about 0.1 mm. This induces thatsurface 244A is ground bylateral surface 62 of grindingwheel 6, on a predetermined depth, so thatsurface 244A becomes fully effective to cooperate withsurface 506A of a bearing ring presenting workingstation 14.
Claims (7)
1. A grinding machine for bearing rings, the grinding machine including:
a frame;
a rotating grinding wheel movable in rotation around a first rotation axis;
a working station where a bearing ring stands during a grinding operation of one of its surfaces;
a chuck for holding a bearing ring in the working station, this chuck being movable in rotation around a second rotation axis;
a first automatic mechanism to set a position of a shaping tool with respect to an outer peripheral edge of the grinding wheel, the first automatic mechanism includes an electric motor, an encoder coupled to the electric motor to detect a rotation of an output shaft of the motor, a sensor of the position of the shaping tool along a translation axis and a comparator to compare an output signal of the encoder and an output signal of the sensor; and
a second automatic mechanism to set the axial position of the chuck along the second rotation axis, these second automatic mechanism including an electric motor for driving the chuck in translation along the second rotation axis and a sensor to detect a rotation of the chuck around the second rotation axis.
2. The machine according to claim 1 , wherein the sensor of the first automatic mechanism is an optical scale sensor.
3. The machine according to claim 1 , further comprising a movement mechanism for moving the grinding wheel from a first position offset with respect to the second rotation axis to a second position where a lateral face of the grinding wheel intersects the second rotation axis.
4. A method for setting the tangency conditions between a grinding wheel and its environment in a grinding machine for bearing rings, the machine including:
in addition to the grinding wheel which rotates around a first rotation axis;
a frame;
a working station where a bearing ring stands during a grinding operation of one of its surfaces;
a chuck for holding a bearing ring in the working station, this chuck being movable in rotation along a second rotation axis;
the method comprising steps of:
a) moving a shaping tool, to be used for shaping an outer peripheral edge of the grinding machine, in translation along a transverse axis, towards the first rotation axis by actuation of a first electric motor,
b) detecting a rotation of an output shaft of the electric motor via an encoder coupled to the electric motor,
c) detecting a position of the shaping tool along the transverse axis via a dedicated sensor,
d) comparing a first output signal of the encoder with a second output signal of the dedicated sensor,
e) assessing that the shaping tool is tangent with the outer peripheral edge of the grinding wheel when the first output signal is representative of a rotation of the output shaft and the second output signal is representative of a stop of the shaping tool along the transverse axis,
f) moving the grinding wheel to a position where a lateral surface of the grinding wheel intersects the second rotation axis,
g) moving the grinding wheel in rotation around the first rotation axis,
h) moving the chuck in translation along the second rotation axis, towards the lateral surface of the grinding wheel, by actuation of a second electric motor,
i) detecting a rotation of a shaft integral in rotation with the chuck via a dedicated rotation sensor, and
j) assessing that the chuck is tangent with the lateral surface of the grinding wheel as soon as the dedicated rotation sensor detects a rotation of the shaft.
5. The method according to claim 4 , wherein when assessed in step e) that the shaping tool is tangent with the outer peripheral edge of the grinding wheel, the first electric motor is stopped.
6. The method according to claim 4 , wherein when assessed in step j) that the clutch is tangent with the lateral surface of the grinding wheel, the second electric motor is stopped.
7. A method for shaping an outer peripheral edge of a grinding wheel of a grinding machine, the grinding machine comprising:
a frame;
a rotating grinding wheel movable in rotation around a first rotation axis;
a working station where a bearing ring stands during a grinding operation of one of its surfaces;
a chuck for holding a bearing ring in the working station, this chuck being movable in rotation around a second rotation axis;
a first automatic mechanism to set a position of a shaping tool with respect to an outer peripheral edge of the grinding wheel, the first automatic mechanism includes an electric motor, an encoder coupled to the electric motor to detect a rotation of an output shaft of the motor, a sensor of the position of the shaping tool along a translation axis and a comparator to compare an output signal of the encoder and an output signal of the sensor, a second automatic mechanism to set the axial position of the chuck along the second rotation axis, these second automatic mechanism including an electric motor for driving the chuck in translation along the second rotation axis and a sensor to detect a rotation of the chuck around the second rotation axis;
the method comprising steps of:
a) moving a shaping tool, to be used for shaping an outer peripheral edge of the grinding machine, in translation along a transverse axis, towards the first rotation axis by actuation of a first electric motor,
b) detecting a rotation of an output shaft of the electric motor via an encoder coupled to the electric motor,
c) detecting a position of the shaping tool along the transverse axis via a dedicated sensor,
d) comparing a first output signal of the encoder with a second output signal of the dedicated sensor,
e) assessing that the shaping tool is tangent with the outer peripheral edge of the grinding wheel when the first output signal is representative of a rotation of the output shaft and the second output signal is representative of a stop of the shaping tool along the transverse axis,
f) moving the grinding wheel to a position where a lateral surface of the grinding wheel intersects the second rotation axis,
g) moving the grinding wheel in rotation around the first rotation axis,
h) moving the chuck in translation along the second rotation axis, towards the lateral surface of the grinding wheel, by actuation of a second electric motor,
i) detecting a rotation of a shaft integral in rotation with the chuck via a dedicated rotation sensor, and
j) assessing that the chuck is tangent with the lateral surface of the grinding wheel as soon as the dedicated rotation sensor detects a rotation of the shaft.
k) moving the shaping tool in translation along the transverse axis, towards the first rotation axis, over a given stroke, wherein step k is implemented after at least one of:
step e) when it is assessed that the shaping tool is tangent with the outer peripheral edge, and
step j) when it is assessed that the chuck is tangent with the lateral surface of the grinding wheel.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP14305618.2 | 2014-04-25 | ||
EP14305618.2A EP2937175A1 (en) | 2014-04-25 | 2014-04-25 | Grinding machine for bearing rings and method for setting tangency conditions in such a machine |
Publications (1)
Publication Number | Publication Date |
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US20150306725A1 true US20150306725A1 (en) | 2015-10-29 |
Family
ID=50630734
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/693,068 Abandoned US20150306725A1 (en) | 2014-04-25 | 2015-04-22 | Grinding machine for bearing rings and method for setting tangency conditions in such a machine |
Country Status (4)
Country | Link |
---|---|
US (1) | US20150306725A1 (en) |
EP (1) | EP2937175A1 (en) |
JP (1) | JP2015208852A (en) |
CN (1) | CN105033819A (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
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CN105751042A (en) * | 2016-03-11 | 2016-07-13 | 温州智元知识产权管理有限公司 | Stability-adjustable bearing seat surface grinding equipment |
JP6694310B2 (en) * | 2016-03-31 | 2020-05-13 | Ntn株式会社 | Bearing ring forming method |
CN106002505A (en) * | 2016-07-07 | 2016-10-12 | 浙江宏恩智能装备技术有限公司 | Synchromesh spiral grinding wheel grinding device and method for automatic tool compensation |
CN106217145A (en) * | 2016-08-28 | 2016-12-14 | 浙江宏恩智能装备技术有限公司 | A kind of cutter grinding machine |
CN106271955B (en) * | 2016-08-30 | 2017-07-28 | 江苏同庆车辆配件有限公司 | A kind of annular workpieces lapping device in railway freight-car |
CN110802476B (en) * | 2019-11-27 | 2021-06-01 | 芜湖佳先传动轴有限公司 | Outer ring grinding device is used in processing of drive shaft assembly |
CN112676985B (en) * | 2020-12-23 | 2022-08-19 | 嘉兴津田精密机械制造有限公司 | Bearing processing stable and efficient grinding device |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
IT1116326B (en) * | 1977-04-13 | 1986-02-10 | Famir Int Spa | GRINDING MACHINE FOR ANNULAR PIECES TO BE WORKED EXTERNALLY PARTICULARLY FOR BEARING RINGS |
EP0499685A1 (en) * | 1991-02-16 | 1992-08-26 | Ernst Thielenhaus Kg | Grinding machine, especially finish grinding machine, for ring shaped workpieces |
KR20080062886A (en) | 2006-12-29 | 2008-07-03 | 삼성전자주식회사 | Method and apparatus for transmission of reverse-link control-channel acknowledgement channel for forward-link shared control channel in mobile communication systems using orthogonal frequency division multiplexing access |
-
2014
- 2014-04-25 EP EP14305618.2A patent/EP2937175A1/en not_active Withdrawn
-
2015
- 2015-04-22 US US14/693,068 patent/US20150306725A1/en not_active Abandoned
- 2015-04-24 JP JP2015089065A patent/JP2015208852A/en active Pending
- 2015-04-24 CN CN201510201511.4A patent/CN105033819A/en active Pending
Also Published As
Publication number | Publication date |
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JP2015208852A (en) | 2015-11-24 |
CN105033819A (en) | 2015-11-11 |
EP2937175A1 (en) | 2015-10-28 |
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