JP2006090426A - Method for arranging ball forming ball bearing at equal intervals - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a method for securely and effectively arranging balls 3, 3 at equal intervals in the circumferential direction, etc. <P>SOLUTION: An inner ring 1 is rotated without imparting a contact angle on these ball 3, 3, revolving these balls 3, 3, and compressed air is blown toward an annular space 4 incorporating respective ball 3, 3 from these nozzles 7a, 7a. these causes an air flow flowing in the axial direction of the annular space 4 at circumferentially equal intervals of the annular space 4. In this state, the compressed air supplied into these nozzles 7a, 7a is gradually increased in pressure, these balls 3, 3 are trapped one by one in the air flow caused by each nozzle 7a, 7a, and these balls 3, 3 are arranged at circumferentially equal intervals. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is used to arrange a plurality of balls at equal intervals in the circumferential direction prior to the mounting operation of the cage when assembling a single row deep groove type ball bearing.

  When assembling the ball bearing, first, as shown in FIG. 2A, after a plurality of balls 3 and 3 are assembled between the inner ring raceway on the outer peripheral surface of the inner ring 1 and the outer ring raceway on the inner peripheral surface of the outer ring 2. As shown in FIG. 5B, the plurality of balls 3 and 3 are arranged at equal intervals along the circumferential direction. Next, an annular retainer (not shown) is pushed into the annular space 4 between the outer ring raceway and the inner ring raceway to hold the plurality of balls 3 and 3 so that they can roll.

  As shown in FIG. 2 (A), a device for arranging a plurality of balls 3 and 3 mounted at unequal intervals in the annular space 4 as shown in FIG. 2 (B). Conventionally, for example, there are those described in Patent Documents 1 to 3. Of these, the conventional device described in Patent Document 1 uses an annular comb-shaped arrangement arm having the same number of balls as each other and provided with recesses on each of which only one ball can be engaged. After holding the ball inside the recess, the array arm is pulled out. However, in the case of such a conventional device described in Patent Document 1, there is a risk that the surface of the ball may be damaged or foreign matter may be involved due to friction between the ball and the arrangement arm.

On the other hand, Patent Document 2 describes a technique for performing an operation of arranging a plurality of balls at equal intervals using a flow of compressed air in order to eliminate such inconvenience. FIG. 3 shows a second example of the prior art described in Patent Document 2 above. In the case of the second example of the prior art, a plurality of balls 3 and 3 are arranged at equal intervals in the circumferential direction using the flow of compressed air ejected from the nozzle device 5. Yes. In the nozzle device 5, the same number of nozzles 7, 7 as the balls 3, 3 are arranged at equal intervals in the circumferential direction on one axial surface of an annular manifold 6. When these balls 3 and 3 are arranged at equal intervals in the circumferential direction, the manifold 6 is reciprocally rotated in the circumferential direction while jetting compressed air from the nozzles 7 and 7. The balls 3 and 3 are captured one by one at the portions facing the nozzles 7 and 7, respectively.
Furthermore, in Patent Document 3, as shown in FIG. 4, a disturbance plate 8 is provided on the opposite side of the nozzle device 5 a across the annular space 4 in which the balls 3 and 3 are arranged. A technique for effecting separation is described.

  Among the methods for arranging the balls constituting the conventionally known ball bearing described in Patent Documents 2 and 3 as described above, in the case of the method described in Patent Document 2, 3 may not be arranged evenly in the circumferential direction. That is, when the number of balls 3 and 3 and the number of nozzles 7 and 7 are the same, for example, as shown in FIG. 5, one of the nozzles 7 captures two balls 3 and 3, There is a possibility that no ball is captured by another nozzle 7. In such a case, the balls 3 and 3 cannot be evenly arranged in the circumferential direction. When the relationship between the nozzles 7 and 7 and the balls 3 and 3 is as shown in FIG. 5, the nozzles 7 and 7 are moved back and forth in the circumferential direction vigorously. After disassembling the arrangement of the balls 3, 3, it is necessary to redo the arrangement work. For this reason, there is a problem that the efficiency of the arrangement work is deteriorated and the production efficiency of the ball bearing is deteriorated.

  In order to arrange the balls 3, 3 installed in the annular space 4 at equal intervals in the circumferential direction by using the flow of compressed air ejected from the nozzles 7, 7, the nozzles 7, It is also conceivable that the balls 3 and 3 are caused to revolve while jetting compressed air from the nozzles 7 and 7 with the nozzle 7 fixed. This revolution motion is caused by rotating the inner ring 1 or the outer ring 2. In this case, the balls 3, 3 are captured one by one in the flow of compressed air ejected from the nozzles 7, 7. Thus, when these balls 3 and 3 are arranged at equal intervals in the circumferential direction, if the pressure (flow velocity) of the compressed air ejected from the nozzles 7 and 7 is regulated within an appropriate range, these nozzles 7 , 7 can be captured at the positions facing the tip surfaces of the balls 7, 3 respectively.

  However, when the pressure (flow velocity) of the compressed air ejected from the nozzles 7 and 7 is higher than the appropriate range, the two balls 3 and 3 are placed at positions facing the tip surfaces of any of the nozzles 7 and 7. The possibility of capturing arises. On the other hand, when the pressure (flow velocity) of the compressed air ejected from each of the nozzles 7 and 7 is lower than the appropriate range, the ball 3 is positioned at a position facing the tip surface of any or all of the nozzles 7 and 7. 3 may not be captured. In any case, these balls 3 and 3 cannot be arranged at equal intervals in the circumferential space 4 in the circumferential direction.

  By the way, irrespective of the rotation of the inner ring 1 or the outer ring 2, the force (stopping force) required to stop the revolving motion of the balls 3, 3 is slightly different depending on the individual rolling bearings. That is, even if the model number is the same (same bearing size), the above-mentioned restraining force differs depending on the roundness of the inner ring raceway surface, outer ring raceway surface, rolling surface, etc., and subtle undulations existing on these surfaces. . Therefore, when the pressure (flow velocity) of the compressed air ejected from the nozzles 7 and 7 is always the same, even if the ball bearings to be processed have the same model number, the tips of the nozzles 7 and 7 are the same. There is a possibility that the two balls 3 and 3 may be captured at a position facing the surface, or conversely, the balls 3 and 3 may not be captured at a position facing the tip surfaces of the nozzles 7 and 7. is there.

  As described in Patent Document 3, when the disturbance plate 8 is provided on the side opposite to the nozzle device 5a, the position facing the tip surfaces of the nozzles 7 and 7 as compared with the case where the disturbance plate 8 is not provided. It is easy to catch the balls 3 and 3 one by one. However, depending on the pressure of the compressed air ejected from each of these nozzles 7 and 7, a certain effect may not always be obtained. When the disturbance plate 8 is provided, a camera for confirming the arrangement state of the balls 3 and 3 in the annular space 4 cannot be installed. For this reason, it is necessary to take out the ball bearing from the device for arranging the balls 3 and 3 at equal intervals in the circumferential direction without confirming whether or not these balls 3 and 3 are arranged at equal intervals in the circumferential direction. There is. In this case, if it is determined that the arrangement of the balls 3 and 3 is defective after removal, the ball bearing must be set again in the device, and the work efficiency is deteriorated.

Japanese Examined Patent Publication No. 63-54503 Japanese Patent No. 3151882 Japanese Patent No. 3306602

  In view of the circumstances as described above, the present invention realizes a method of arranging balls constituting a ball bearing capable of performing the operation of arranging balls at equal intervals in the circumferential direction reliably and efficiently at equal intervals. Invented accordingly.

In the method of arranging the balls constituting the ball bearing of the present invention at equal intervals, first, between the deep groove type inner ring raceway provided on the outer peripheral surface of the inner ring and the deep groove type outer ring raceway provided on the inner peripheral surface of the outer ring. Incorporate multiple balls.
Next, the inner ring and the outer ring are arranged concentrically with each other and with their central axes oriented in the vertical direction.
Further, a nozzle device in which the same number of nozzles as the balls are arranged at equal intervals in the circumferential direction is provided below the annular space in which the balls are arranged between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring. And the nozzles are opposed to the lower end opening of the annular space.
Then, by rotating the inner ring and the outer ring relative to each other in a state where no contact angle is given to each of the balls and revolving the balls, compressed air is blown out from the nozzles toward the annular space. The flow of air that flows in the axial direction of the annular space is caused at equal intervals in the circumferential direction of the annular space.
Further, the pressure of the compressed air supplied to the nozzles is gradually increased, and the balls are captured one by one in the air flow induced by the nozzles. Arrange at intervals.

  According to the method of arranging the balls constituting the ball bearing of the present invention configured as described above at equal intervals, the pressure (flow velocity) of the compressed air ejected from each nozzle is opposed to the tip surface of each nozzle. The value can be reliably adjusted so that each ball can be captured one by one. That is, if the pressure of the compressed air supplied to the nozzles is gradually increased while revolving the balls, the pressure (flow velocity) of the compressed air ejected from the nozzles is always increased during the increase process. The value is such that each of the balls can be captured at a position facing the tip surface of each nozzle. In this state, one of the balls is captured at a position facing the tip surfaces of the nozzles, and the balls are arranged at equal intervals in the circumferential direction. As a result, the operation of arranging these balls at equal intervals in the circumferential direction can be performed reliably and efficiently.

When implementing this invention, Preferably, as described in claim 2, the arrangement state of each ball is observed by an image processing apparatus including a camera provided above the annular space. Then, in a state in which these balls are arranged at equal intervals in the circumferential direction and it is determined that the revolving motion has stopped, the step of arranging these balls at equal intervals ends.
With this configuration, the pressure (flow velocity) of the compressed air ejected from each nozzle becomes an appropriate value, so that each of the balls is captured at a position facing the tip surface of each nozzle. , Automatically and reliably. Then, it is possible to immediately move to the next step in a state where the balls are arranged at equal intervals. In other words, it eliminates the waste of continuing to increase the pressure until the balls are arranged at equal intervals, shortens the work time required for arranging the balls at equal intervals, Increase efficiency.

  An embodiment of the present invention will be described with reference to an apparatus for arranging balls at equal intervals shown in FIG. A ball bearing 9 in which the balls 3 and 3 should be arranged at equal intervals in the circumferential direction includes a deep groove type inner ring raceway 10 provided on the outer peripheral surface of the inner ring 1 and a deep groove type outer ring raceway provided on the inner peripheral surface of the outer ring 2. 11, a plurality of balls 3 and 3 are incorporated. In the state immediately after being assembled, these balls 3 and 3 are arranged at unequal intervals in the circumferential direction as shown in FIG. In order to arrange such balls 3 and 3 at equal intervals in the circumferential direction as shown in FIG. 2 (B), the ball bearing 9 is connected to the outer peripheral surface of the inner ring holder 12 and the inner ring of the outer ring holder 13. Attach (set) to the circumference. An inner ring locking step 14 for abutting the lower end surface of the inner ring 1 is abutted on the lower portion of the outer ring surface of the inner ring holder 12, and a lower end surface of the outer ring 2 is disposed on the lower portion of the inner ring surface of the outer ring holder 13. Outer ring locking step portions 15 for abutting are provided respectively.

  In the state where the lower end surface of the inner ring 1 is abutted against the inner ring locking step portion 14 and the lower end surface of the outer ring 2 is abutted against the outer ring locking step portion 15, the balls 3 and 3 have a contact angle. Not granted. In other words, in this state, the bottom of the inner ring raceway 10 (the portion with the smallest outer diameter) and the bottom portion of the outer ring raceway 11 (the portion with the largest inner diameter) exist at the same height position. In this state, no preload is applied to the balls 3, 3, and the contact pressure between the rolling surfaces of the balls 3, 3 and the inner ring raceway 10 and the outer ring raceway 11 becomes zero or very small.

  Out of the inner ring holder 12 and the outer ring holder 13, the outer ring holder 13 does not move (does not rotate) while being supported in a horizontal direction by a frame or the like (not shown). On the other hand, the inner ring holder 12 is concentrically fixed to the rotating shaft 17 at the upper end portion of the rotating shaft 17 which is arranged in the vertical direction and is rotationally driven by a motor (electric motor or hydraulic motor) 16. The motor 16 is rotationally driven at a predetermined speed in a predetermined direction.

  Further, a nozzle device 5b is arranged around the upper portion of the rotating shaft 17. The nozzle device 5b is arranged around the rotating shaft 17 and supported and fixed to a frame or the like (not shown). The nozzle device 5b is vertically upright on the upper surface of the manifold 6a. It consists of the same number of nozzles 7a and 7a as the balls 3 and 3 arranged at equal intervals in the circumferential direction. The pitch circle diameters of the nozzles 7a and 7a are approximately the same as the pitch circle diameters of the balls 3 and 3, and the tip portions (upper end portions) of the nozzles 7a and 7a are connected to the outer peripheral surface of the inner ring 1. It is inserted into the lower part of the annular space 4 between the inner peripheral surface of the outer ring 2 so that the balls 3 and 3 can be opposed to each other (open at a position directly below the space through which the balls 3 and 3 pass). ing.

  Nozzle holes having the same inner diameter are provided in the tip surfaces (upper end surfaces) of the nozzles 7a and 7a, and the compressed air sent into the manifold 6a is introduced into the annular space 4 and the inner ring. 1 and the outer ring 2 can be ejected in the axial direction (upward in the vertical direction). Regarding all the nozzles 7a and 7a, the flow velocity and flow rate of the compressed air ejected from the nozzle holes are the same except for a slight difference based on the manufacturing error of the nozzle holes. The manifold 6a can be fed with compressed air adjusted by a pressure adjusting valve 18 at a predetermined pressure. The pressure of the compressed air sent from the pressure adjusting valve 18 to the manifold 6a can be adjusted by a controller 19. Further, the controller 19 receives a signal from an image processing device 21 that processes an image captured by the camera 20. The camera 20 is arranged above the ball bearing 9 to photograph the balls 3 and 3, and the image processing device 21 extracts information regarding the positions of the balls 3 and 3. Specifically, information indicating whether or not the positions of the balls 3 and 3 in the circumferential direction of the annular space 4 are equidistant from each other and whether or not they are revolving is taken out.

The operation for arranging the balls 3 and 3 constituting the ball bearing 9 at equal intervals in the circumferential direction of the annular space 4 by the apparatus for arranging the balls configured as described above at equal intervals ( (Equal distribution work) is performed as follows. If the ball bearing 9 is assembled between the inner ring holder 12 and the outer ring holder 13 as described above, the inner ring 1 is rotated by rotating the inner ring holder 12. The outer ring 2 remains stationary. The rotational speed of the inner ring 1 in this case is regulated in relation to the speed (pressure increase speed) for increasing the pressure of the compressed air ejected from the nozzles 7a and 7a, which will be described later (the rotational speed is The faster the speed, the faster the pressure rise rate). In order to ensure that the balls 3 and 3 are evenly distributed, it is preferable to slow down the rotation speed and the pressure increase speed. Time becomes long and the efficiency of the manufacturing operation of the ball bearing 9 is deteriorated. In consideration of these matters, when the outer diameter of the ball bearing 9 is about 25 to 30 mm, the rotational speed of the inner ring 1 is set to about 150 min ⁻¹ . As the outer diameter increases, the rotational speed is decreased in order to suppress the revolution speed (circumferential speed) of the balls 3 and 3 to the same extent.

  In any case, as a result of the rotation of the inner ring 1, the balls 3 and 3 revolve due to rolling friction between the respective rolling surfaces and the inner ring raceway 10. However, as described above, the frictional force acting between these rolling surfaces and the inner ring raceway 10 is small. In particular, since the flow of compressed air ejected from the nozzles 7a and 7a acts in the direction in which the balls 3 and 3 are lifted, the frictional force is considerably reduced. For this reason, when the force that hinders the revolving motion of the balls 3 and 3 is increased to some extent, the balls 3 and 3 are stopped (revolution motion is stopped) regardless of the rotation of the inner ring 1. On the other hand, as is clear from Bernoulli's theorem, the object existing in the portion where the dynamic pressure exists along the flow of the compressed air ejected from the nozzles 7a, 7a is higher than the static pressure of this portion. Based on the static pressure, it is sucked (pressed) into this flow. In other words, a force for capturing the balls 3 and 3 is applied based on the flow of compressed air ejected from the nozzles 7a and 7a. This force increases as the pressure of the compressed air fed into the manifold 6a increases and the flow velocity (dynamic pressure) of the compressed air ejected from the nozzles 7a, 7a increases.

  When the pressure of the compressed air fed into the manifold 6a is low and the flow velocity (dynamic pressure) of the compressed air ejected from the nozzles 7a and 7a is low, the force that hinders the revolving motion of the balls 3 and 3 However, the balls 3 and 3 cannot be captured at positions facing the tip surfaces of the nozzles 7a and 7a. On the other hand, when the pressure of the compressed air fed into the manifold 6a is high and the flow velocity (dynamic pressure) of the compressed air ejected from the nozzles 7a and 7a is high, the balls 3 and 3 flow through the balls 3 and 3. As a result, the two balls 3 and 3 are captured at a position facing the tip surface of one of the nozzles 7a. In any case, these balls 3 and 3 cannot be arranged at equal intervals in the circumferential direction of the annular space 4.

  Therefore, in the case of the present invention, the pressure of the compressed air fed into the manifold 6a is gradually increased by the pressure adjusting valve 18. Then, in the course of this pressure increase, the flow velocity (dynamic pressure) of the compressed air ejected from each of the nozzles 7a, 7a is set so that the balls 3, 3 1 It is set to a value that can be captured one by one (not so low that one cannot be captured and not high enough to capture two). In the case of the present embodiment, the pressure rise speed of the compressed air is appropriately regulated in relation to the rotational speed of the inner ring 1, so that the nozzle 7a, 7a is always ejected during the pressure rise process. The pressure (flow velocity) of the compressed air becomes such a value that each of the balls 3 and 3 can be captured at a position facing the tip surfaces of the nozzles 7a and 7a. And in the state which became this value, each said balls 3 and 3 will try to pass the position which opposes the front end surface of each of these nozzles 7a and 7a. Then, with each of these balls 3 and 3 reaching a position facing the tip surface of each of the nozzles 7a and 7a, one each of these balls 3 and 3 is captured at that position. In this state, these balls 3 and 3 are arranged at equal intervals in the circumferential direction. As a result, the operation of arranging the balls 3 and 3 at equal intervals in the circumferential direction can be performed reliably and efficiently.

  As described above, the state in which the balls 3 and 3 are arranged in the circumferential direction of the annular space 4 is observed by the image processing device 21 that has processed the image signal captured by the camera 20. Then, in a state where it is determined that the balls 3 and 3 are arranged at equal intervals in the circumferential direction and the revolving motion is stopped, the process of arranging the balls 3 and 3 at equal intervals is completed. Specifically, the operation of sending compressed air into the manifold 6a is stopped. In this case, the balls 3 and 3 are prevented from inadvertently moving in the circumferential direction of the annular space 4 until the ball bearing 9 is taken out (opposite the tip surfaces of the nozzles 7a and 7a). It is also possible to supply low-pressure compressed air to the extent that the balls 3 and 3 are held at the positions where they are to be held.

  In the case of the present embodiment, as described above, it is automatically detected that the equal distribution work of the balls 3 and 3 has been completed, and the feeding of compressed air to the manifold 6a is stopped. Evenly distributed work can be performed automatically. Then, it is possible to immediately move to the next step in a state where the balls 3 and 3 are arranged at equal intervals. In other words, the working time required to arrange the balls 3 and 3 at equal intervals without increasing the pressure sent to the manifold 6a until the balls 3 and 3 are arranged at equal intervals. The efficiency of the assembly work of the ball bearing 9 can be improved. The operation for increasing the pressure may not be continuous, but may be performed step by step while gradually increasing the pressure. In this case, the operation of revolving the balls 3 and 3 while performing the jet of compressed air at a certain pressure is performed for a predetermined time (a short time of 1 second or less), and the balls 3 and 3 are arranged at equal intervals. If it is determined that the balls 3 and 3 are revolved by slightly raising the pressure, the balls 3 and 3 are equally spaced in the circumferential direction of the annular space 4. Repeat until they are arranged.

  It should be noted that at the start of the equalizing operation, the pressure of the compressed air first fed into the manifold 6a is such that none of the balls 3, 3 can be captured at a position facing the tip surfaces of the nozzles 7a, 7a. Set to a low value. However, when the pressure is gradually increased from 0, the time required for the uniform work becomes long. Therefore, the minimum value of the low value is experimentally determined according to the model number of the ball bearings 9 to be evenly distributed, and the minimum value or a value slightly lower than the minimum value is used as the starting pressure. It is preferable to gradually increase the pressure. This pressure increase operation is performed once for each equal distribution operation related to one ball bearing 9. However, it was determined that evenly distributed work was not completed even if the pressure increased sufficiently for some reason (for example, it was determined that two balls 3, 3 were captured with respect to one nozzle 7a). ), Once the pressure fed to the manifold 6a is reduced, the pressure is increased again.

The block diagram of the apparatus for arranging the ball | bowl used for implementation of this invention at equal intervals. The front view which shows the state in the middle of the assembly of a ball bearing in the state before and behind arrange | positioning a ball | bowl at equal intervals. The perspective view which shows the 1st example of the conventional method. The longitudinal cross-sectional view which shows the 2nd example of the conventional method. The perspective view which shows the state which cannot arrange | position a ball | bowl at equal intervals.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner ring 2 Outer ring 3 Ball 4 Toroidal space 5, 5a, 5b Nozzle device 6, 6a Manifold 7, 7a Nozzle 8 Disturbing plate 9 Ball bearing 10 Inner ring raceway 11 Outer ring raceway 12 Inner ring holder 13 Outer ring holder 14 Inner ring locking step 15 Outer ring locking step 16 Motor 17 Rotating shaft 18 Pressure adjustment valve 19 Controller 20 Camera 21 Image processing device

Claims (2)

  After incorporating a plurality of balls between the deep groove type inner ring raceway provided on the outer peripheral surface of the inner ring and the deep groove type outer ring raceway provided on the inner peripheral surface of the outer ring, the inner ring and the outer ring are concentric with each other. In addition, a nozzle device in which the respective center axes are arranged in the vertical direction and the same number of nozzles as the balls are arranged at equal intervals in the circumferential direction is provided with an outer peripheral surface of the inner ring and an inner periphery of the outer ring. It is installed below the annular space in which each ball is arranged between the surface, the nozzles are opposed to the lower end opening of the annular space, and the inner ring and the inner ring are not provided with a contact angle. By rotating the outer ring relative to each other and revolving the balls, the compressed air is blown out from the nozzles toward the annular space. Air flowing in the axial direction of this annular space In addition to causing the flow, the pressure of the compressed air supplied to the nozzles is gradually increased, and each of the balls is captured one by one in the air flow caused by the nozzles. A method of arranging balls constituting a ball bearing at equal intervals in the circumferential direction. With the image processing device including a camera provided above the annular space, the arrangement state of each ball is observed, and when these balls are arranged at equal intervals in the circumferential direction and determined that the revolving motion has stopped, The method of arranging the balls constituting the ball bearing according to claim 1, wherein the step of arranging the balls at regular intervals is finished.

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