JP2014070719A - Bearing and cam device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing easy in pressurization adjustment work.SOLUTION: A bearing has an outer ring portion having an opposed circumferential groove opposed to an outer peripheral groove formed on an outer periphery of a rotatable rotating member, and a plurality of rolling elements disposed between the outer peripheral groove and the opposed circumferential groove and rolling while kept into contact with the outer peripheral groove and the opposed circumferential groove. The outer ring portion is divided into two members of an upper outer ring portion having an upper part of the opposed circumferential groove, and a lower outer ring portion having a lower part of the opposed circumferential groove, and a fastening member is further disposed to fasten the upper outer ring portion and the lower outer ring portion. The outer ring portion is provided with an adjustment screw for adjusting pressurization by the outer ring portion to the rolling elements, at an outer side with respect to the fastening member.

Description

  The present invention relates to a bearing and a cam device.

An outer ring portion formed with an opposed circumferential groove facing the outer circumferential groove provided on the outer circumference of the rotatable rotating member;
A bearing having a plurality of rolling elements provided between the outer circumferential groove and the opposed circumferential groove and rolling in contact with the outer circumferential groove and the opposed circumferential groove is already well known. Examples of such a bearing include a four-point contact ball bearing and a cross roller bearing.

JP 2005-186206 A

  By the way, in the bearing, the outer ring part includes two members, an upper outer ring part in which the upper part of the opposed circumferential groove is formed and a lower outer ring part in which the lower part of the opposed circumferential groove is formed. Some are divided.

  And in the said bearing, the pressurization adjustment operation | work which adjusts the pressurization which an outer ring part applies to a rolling element using the outer ring part being divided | segmented into two members was performed. For example, an annular spacer is inserted between the upper outer ring portion and the lower outer ring portion, and the pressure is adjusted by adjusting the thickness of the inserted spacer. Further, when the pressurization pressure is too low without inserting the spacer, the mating surfaces of the upper outer ring portion and the lower outer ring portion are directly cut to adjust the pressurization.

  However, in such a case, the following inconvenience occurred. In other words, both when adjusting using the spacer and when adjusting to cut the mating surface, when adjusting, there is a step of once removing the upper outer ring part and the lower outer ring part from the bearing and reassembling. It was necessary and the adjustment work was complicated.

  This invention is made | formed in view of this subject, The place made into the objective is to implement | achieve a bearing whose pressurization adjustment work is simple.

The main invention for achieving the above object is:
An outer ring portion formed with an opposed circumferential groove facing the outer circumferential groove provided on the outer circumference of the rotatable rotating member;
A plurality of rolling elements provided between the outer circumferential groove and the opposed circumferential groove and rolling in contact with the outer circumferential groove and the opposed circumferential groove;
The outer ring portion is divided into two members, an upper outer ring portion in which an upper portion of the opposed circumferential groove is formed and a lower outer ring portion in which a lower portion of the opposed circumferential groove is formed. A bearing further comprising a tightening member for tightening the portion and the lower outer ring portion,
The outer ring portion is provided with an adjustment screw for adjusting a pressure applied to the rolling element by the outer ring portion outside the tightening member in the radial direction of the rotating member. It is.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

2 is a schematic top view and a schematic side view of the cam device 10. FIG. It is the schematic diagram which showed a mode that the roller gear cam 20 which concerns on a prior art example is engaging with the cam follower 42. FIG. It is a timing diagram (schematic diagram) concerning a conventional example. It is the measurement data about the angle error of the rotary table 40 which concerns on a prior art example. It is the schematic diagram which showed a mode that the roller gear cam 20 which concerns on this Embodiment is engaging with the cam follower 42. FIG. It is a timing diagram (schematic diagram) concerning this embodiment. It is the schematic diagram which showed a mode that the roller gear cam 20 which concerns on the modification of this Embodiment is engaging with the cam follower. It is the schematic diagram which showed the four-point contact ball bearing 50 which concerns on a prior art example. It is a side surface schematic diagram of the four-point contact ball bearing 50 which concerns on this Embodiment. It is an explanatory schematic diagram for explaining pressurization adjustment by the pressurization adjustment screw 60 according to the present embodiment. It is an upper surface schematic diagram of the four-point contact ball bearing 50 which concerns on this Embodiment. It is the upper surface schematic diagram and side surface schematic diagram of the cam apparatus 10 which concern on 2nd embodiment. It is the schematic diagram which showed a mode that the barrel cam 21 which concerns on a prior art example is engaging with the cam follower 42. FIG. It is a timing diagram (schematic diagram) concerning a conventional example. It is the schematic diagram which showed a mode that the barrel cam 21 which concerns on 2nd embodiment was engaging with the cam follower 42. FIG. It is a timing diagram concerning a second embodiment. It is an explanatory schematic diagram for explaining pressurization adjustment by pressurization adjustment screw 60 concerning other embodiments. It is an explanatory schematic diagram for explaining pressurization adjustment by pressurization adjustment screw 60 concerning other embodiments. It is a side surface schematic diagram of the cross roller bearing 51 which concerns on other embodiment. It is an explanatory schematic diagram for explaining pressurization adjustment by pressurization adjustment screw 60 concerning other embodiments. It is an explanatory schematic diagram for explaining pressurization adjustment by pressurization adjustment screw 60 concerning other embodiments. It is an explanatory schematic diagram for explaining pressurization adjustment by pressurization adjustment screw 60 concerning other embodiments.

  At least the following matters will become clear from the description of the present specification and the accompanying drawings.

An outer ring portion formed with an opposed circumferential groove facing the outer circumferential groove provided on the outer circumference of the rotatable rotating member;
A plurality of rolling elements provided between the outer circumferential groove and the opposed circumferential groove and rolling in contact with the outer circumferential groove and the opposed circumferential groove;
The outer ring portion is divided into two members, an upper outer ring portion in which an upper portion of the opposed circumferential groove is formed and a lower outer ring portion in which a lower portion of the opposed circumferential groove is formed. A bearing further comprising a tightening member for tightening the portion and the lower outer ring portion,
The outer ring portion is provided with an adjustment screw for adjusting a pressure applied to the rolling element by the outer ring portion outside the tightening member in the radial direction of the rotating member. .
According to such a bearing, the pressurization adjustment work is simplified.

Next, a cam with a cam groove and rotatable,
A plurality of cam followers that engage with the cam groove, and a rotating member that rotates as the cam rotates;
An outer ring portion formed with an opposed circumferential groove facing an outer circumferential groove provided on an outer circumference of the rotating member, and provided between the outer circumferential groove and the opposed circumferential groove. A plurality of rolling elements that roll in contact with the groove, and the outer ring portion includes an upper outer ring portion in which an upper portion of the opposed circumferential groove is formed and a lower portion of the opposed circumferential groove. A bearing that is divided into two members of a formed lower outer ring portion, and further includes a tightening member for tightening the upper outer ring portion and the lower outer ring portion,
On the outer ring portion, a bearing provided with an adjusting screw for adjusting a pressure applied to the rolling element by the outer ring portion on the outer side of the tightening member in the radial direction of the rotating member;
A cam device comprising:
According to such a cam device, the pressurization adjustment work is simplified.

The cam groove includes a first groove portion in which at least one of the plurality of cam followers is in contact with one side surface of the cam groove, and at least one of the plurality of cam followers is the one of the cam grooves. A second groove portion that is in contact with the other side surface opposite to the side surface, and a third groove portion that connects the first groove portion and the second groove portion, and a cam follower positioned in the third groove portion includes the one side surface and the side surface A third groove that does not hit any of the other sides,
The cam groove is
In the timing diagram when the rotation angle of the cam is the horizontal axis and the angle position where the cam follower is located when viewed from the center of the rotation member is the vertical axis, it corresponds to the first groove portion and the second groove portion. It is good also as providing the shape where all a part becomes a linear area and the part corresponding to the said 3rd groove part becomes a curve area which connects two said linear areas.
In such a case, a cam device with high accuracy is realized.

=== About Configuration Example of Cam Device 10 ===
Here, a configuration example of the cam device 10 will be described with reference to FIG. FIG. 1 is a top view and a side view of the cam device 10.

  The cam device 10 includes a roller gear cam 20 as an example of a cam that is rotationally driven by a motor (not shown), and a rotary table 40 as an example of a rotating member.

  The roller gear cam 20 includes a cam groove 22 and is supported by a pair of rolling bearings 30 so as to be rotatable (rotatable) with respect to the housing 32. A motor (not shown) is fastened to the roller gear cam 20 at one end thereof, and the roller gear cam 20 is rotationally driven by the driving force of the motor. The roller gear cam 20 is integrally provided with an input shaft 34.

  The rotary table 40 has a role of holding a workpiece, for example. The rotary table 40 is supported so as to be rotatable (rotatable) with respect to the housing 32 by a four-point contact ball bearing 50 as an example of a bearing. A cylindrical turret 40a is suspended from the lower surface side of the rotary table 40, and a plurality of cam followers 42 arranged at equal intervals in the circumferential direction are provided at the lower part of the outer peripheral surface of the turret 40a ( That is, the rotary table 40 includes a plurality of cam followers 42 in a radial manner. The cam follower 42 is engaged with the cam groove 22 of the roller gear cam 20 described above (engaged with the cam groove 22), and the rotational force of the motor rotates via the roller gear cam 20 and the cam follower 42. It is transmitted to the table 40. That is, the rotary table 40 rotates as the roller gear cam 20 rotates.

=== About the shape of the cam groove 22 of the roller gear cam 20 according to the present embodiment ===
Next, the shape of the cam groove 22 of the roller gear cam 20 according to the present embodiment will be described.

  In the following, first, the shape of the cam groove 22 of the roller gear cam 20 according to the conventional example will be described with reference to FIGS. 2 and 3, and the problem of the roller gear cam 20 according to the conventional example will be described with reference to FIG. Will be described. Subsequently, the shape of the cam groove 22 of the roller gear cam 20 according to the present embodiment will be described with reference to FIGS. 5 to 7, and the effectiveness of the roller gear cam 20 according to the present embodiment will be described. To do.

  FIG. 2 is a view showing a state where the roller gear cam 20 according to the conventional example is engaged with the cam follower 42. The left figure (that is, the upper left figure and the lower left figure) is a state diagram showing the state of engagement in the design, and the right figure (that is, the upper right figure and the lower right figure) is after pressure adjustment (this will be described later). It is a state diagram showing the state of engagement of (explained).

  First, attention is paid to the left diagram showing the state of engagement in the design. In the left figure, five cam followers 42 (numbered 1 to 5 are assigned) are simultaneously engaged with the cam grooves 22 of the roller gear cam 20. Further, as shown in the lower left diagram, the cam follower diameter d of the cam follower 42 is smaller than the cam groove width D of the cam groove 22, and none of the five cam followers 42 is in contact with the side surface 24 of the cam groove 22. . That is, any of the five cam followers 42 has a gap 80 between the cam groove 22 and the side surface 24.

  FIG. 3 shows a conventional case where the rotation angle of the roller gear cam 20 is the horizontal axis (x axis) and the angular position where the cam follower 42 is located when viewed from the center 40b of the rotary table 40 is the vertical axis (y axis). FIG. 3 is a timing diagram according to an example (corresponding to FIG. 2).

  As shown in FIG. 3, in the timing diagram, a portion corresponding to the cam groove 22 (specifically, a line connecting the median values in the y-axis direction of the two side surfaces 24 of the cam groove 22 in FIG. 3). ) Is one straight section. The median value in the y-axis direction of the two side surfaces 24 of the cam groove 22 will be described as an example. When the x-axis coordinate is x1, the y-coordinates of the two side surfaces 24 are y1 and y2. The median yc is (y1 + y2) / 2 (see the three coordinates shown in FIG. 3).

  In other words, the portion corresponding to each of the two side surfaces 24 of the cam groove 22 includes a portion corresponding to the one side surface 24a and a portion corresponding to the other side surface 24b opposite to the one side surface 24a. It is a straight section (the cam groove width D of the cam groove 22 is designed to be the same at any location of the cam groove 22, so that the one side surface 24a and the other side surface 24b are parallel to each other. )

  As is clear from FIG. 3, none of the cam followers 42 is in contact with either one side surface 24 a or the other side surface 24 b of the cam groove 22.

  It should be noted that the displacement associated with the cam groove 22 (that is, a schematic representation of the transition of the median yc relative to the transition of the value of the x-coordinate), its one-time differential value (that is, the speed associated with the cam groove 22), The single differential value (that is, the acceleration associated with the cam groove 22) is also shown in FIG. The so-called theoretical displacement is also shown in FIG. The theoretical displacement coincides with a line connecting the centers of the cam followers 42, and further coincides with a line connecting the center lines.

  As described above with reference to the left diagram of FIG. 2 and FIG. 3, the cam device 10 is conventionally designed so that the cam follower 42 does not contact the side surface 24 of the cam groove 22. However, since so-called backlash occurs in such a state, conventionally, when the cam device 10 is manufactured, the pressurization adjustment operation described below has been performed in order to prevent the occurrence of backlash.

  That is, as is apparent from a comparison between the left and right diagrams in FIG. 2, by pressing the roller gear cam 20 toward the rotary table 40 (upward in FIG. 2), as shown in the lower right diagram, 42 is brought into contact with the side surface 24 of the cam groove 22 so that an appropriate pressure is applied to the cam follower 42. That is, the pressurization is adjusted by reducing the distance between the axes of the roller gear cam 20 and the rotary table 40.

  However, since the roller gear cam 20 is forcibly moved from the design state of the cam device 10 shown in the left diagram of FIG. 2, the rotational accuracy of the rotary table 40 that rotates with the rotation of the roller gear cam 20 is adversely affected. (Refer to FIG. 4. Note that the deterioration of the rotation accuracy is very small and has not been considered as a problem in the past. However, there are very strict accuracy requirements for the recent cam device 10. In view of this, it can be said that the deterioration of the rotation accuracy has become a problem).

  This adverse effect will be described in more detail. When the roller gear cam 20 is pushed toward the rotary table 40 (upward in FIG. 2) from the design state of the cam device 10 shown in the left diagram of FIG. 2, the cam follower 42 eventually contacts the side surface 24 of the cam groove 22. However, as can be understood from FIG. 2, first, among the five cam followers 42, the first and fifth cam followers 42 come into contact with the side surface 24 (in this case, the second to fourth cam followers 42 are side surfaces). 24). That is, first, pressure is generated in the first and fifth cam followers 42.

Next, when the roller gear cam 20 is further pushed toward the rotary table 40 from this state, the second and fourth cam followers 42 eventually come into contact with the side surface 24, and the state shown in the right figure of FIG. That is, pressurization is generated also in the second and fourth cam followers 42, while the first and fifth cam followers 42 are pressed against the side surface 24 with a stronger force, and the pressurization of these cam followers 42 is increased. Is further increased (pressure applied by the first and fifth cam followers 42> pressure applied by the second and fourth cam followers 42)
That is, in the prior art, in order to appropriately prevent the occurrence of backlash, if pressure is applied to any of the first, second, fourth, and fifth cam followers 42, first and fifth The pressure applied to the cam follower 42 was excessively large (it was inevitable that the pressure was excessively large).

  And the excessive pressurization has produced the bad influence which concerns on the rotational accuracy mentioned above. That is, when the roller gear cam 20 rotates, the No. 5 cam follower 42 suddenly disengages from the cam groove 22 from a state where the pressurization is excessively applied (very high pressurization), and enters a state where the pressurization is free. On the other hand, the first cam follower 42 instantaneously changes from a pressure-free state to a state where the pressure is very high. These large state changes cause a rotation error of the rotary table 40.

  Therefore, in order to solve the problem, in the present embodiment, the shape of the cam groove 22 of the roller gear cam 20 is determined as follows.

  FIG. 5 is a view corresponding to FIG. 2, and shows a state where the roller gear cam 20 according to the present embodiment is engaged with the cam follower 42. In the present embodiment, the pressurization adjustment is not performed by moving the distance between the axes, so there is no difference between the left diagram and the right diagram as shown in FIG.

  Also in the present embodiment, as in the conventional example, five cam followers 42 (numbered 1 to 5) are simultaneously engaged with the cam grooves 22 of the roller gear cam 20. The cam follower diameter d is smaller than the cam groove width D of the cam groove 22. 2, the cam follower 42 is in contact with the cam groove 22 (as will be described later, the manner of contact is the same as in the conventional example after adjusting the pressure). is there).

  Specifically, the first and second cam followers 42 are in contact with the one side surface 24a of the cam groove 22 but are not in contact with the other side surface 24b (there is a gap 80 between the other side surface 24b). ing). On the other hand, the fourth and fifth cam followers 42 are in contact with the other side surface 24b but are not in contact with the one side surface 24a (there is a gap 80 between the one side surface 24a. The size of 80 is the same as the size of the gap 80 between the other side surface 24b). Accordingly, the rotational directions of the first and second cam followers 42 and the fourth and fifth cam followers 42 are reversed. On the other hand, the third cam follower 42 is not in contact with both the one side surface 24a and the other side surface 24b.

  FIG. 6 is a diagram corresponding to FIG. 3, in which the rotation angle of the roller gear cam 20 is the horizontal axis (x axis), and the angular position where the cam follower 42 is located when viewed from the center 40 b of the rotary table 40 is the vertical axis ( 6 is a timing diagram according to the present embodiment (corresponding to FIG. 5).

  As is clear from FIG. 6 and as described above, the first and second cam followers 42 contact only one side 24a of the two side surfaces 24, and the fourth and fifth cam followers 42 Only the other side surface 24b of the two side surfaces 24 is in contact, and the third cam follower 42 is not in contact with any of the side surfaces 24.

  In other words, in the cam groove 22 according to the present embodiment, at least one cam follower 42 (in the present embodiment, two cam followers 42) of the plurality of cam followers 42 hits one side surface 24 a of the cam groove 22. A first groove 22a, a second groove 22b in which at least one of the plurality of cam followers 42 (in this embodiment, two cam followers 42) is in contact with the other side surface 24b of the cam groove 22, and a first groove A third groove portion 22c connecting 22a and the second groove portion 22b, wherein the cam follower 42 located in the third groove portion 22c is not in contact with either the one side surface 24a or the other side surface 24b. I have.

  The cam groove 22 is different from the conventional example described above, and in the timing diagram, the portions corresponding to the first groove portion 22a and the second groove portion 22b (the line connecting the median values described above) are both linear sections. And the part corresponding to the 3rd groove part 22c is equipped with the shape which becomes a curve area which connects two said linear areas.

  That is, in the present embodiment, as is apparent from FIG. 6, the portion corresponding to the cam groove 22 is not entirely a straight section, but from the beginning (from the design state of the cam device 10), the one side surface 24a. A straight section prepared for applying pressure to the cam follower 42 to generate a pressurization (corresponding to the pressurizing section) and a straight section prepared for generating the pressurization by applying the cam follower 42 to the other side surface 24b. (Corresponding to the pressurizing section) and a curved section (cam follower) which is prepared to smoothly transfer the cam follower 42 to which the pressurization is applied from one straight section to the other straight section. This corresponds to the rotation direction switching section of the outer ring, that is, the buffer section).

  Therefore, it is not necessary to adjust the pressurization by moving the distance between the axes as in the conventional example, the problem of deterioration of the rotation accuracy of the rotary table 40 does not occur, and the occurrence of backlash is appropriately prevented.

  6, similarly to FIG. 3, the displacement relating to the cam groove 22, its one-time differential value (that is, the speed relating to the cam groove 22), and its one-time differential value (that is, relating to the cam groove 22). (Acceleration) is also shown together. As is apparent from the speed, the portion corresponding to the first groove portion 22a and the second groove portion 22b is a straight section, and the portion corresponding to the third groove portion 22c is a curved section (note that the shape of the curve is the example of FIG. It is not limited to this).

  The theoretical displacement is also shown in FIG. 6 as in FIG. As is apparent from FIG. 6, in the present embodiment, the theoretical displacement coincides with a line connecting the centers of the cam followers 42 despite the presence of the curve section (in other words, For example, the cam groove 22 is created so that the center position of the cam follower 42 does not deviate from the theoretical displacement).

  That is, in the first pressurizing section corresponding to the first and second cam followers 42, the center line of the cam groove 22 is offset from the theoretical displacement line by a dimension of (D−d) / 2 + a. (A represents the amount of pressurization). On the other hand, in the second pressurizing section corresponding to the No. 4 and No. 5 cam followers 42, the center line of the cam groove 22 is the dimension of (D−d) / 2 + a in the opposite direction from the theoretical displacement line. It is offset. In the buffer section, the first pressurizing section and the second pressurizing section are connected (connected) using a curve in consideration of the offset. In this way, the cam groove 22 is created so that the center position of the cam follower 42 matches the theoretical displacement in all sections.

  In this way, by preventing the center position of the cam follower 42 from deviating from the theoretical displacement, it is possible to reduce the cause of error and realize high rotational accuracy. This is in contrast to the above-described conventional example in which the roller gear cam 20 is pushed toward the rotary table 40 to adjust the pressure (in this example, backlash can be removed, but the center position of the cam follower 42 is different from the theoretical position. This causes an error in rotation transmission.

  In the above description, the cam groove 22 having the first groove portion 22a in which the two cam followers 42 are in contact with the one side surface 24a and the second groove portion 22b in which the two cam followers 42 are in contact with the other side surface 24b has been described as an example. As shown in FIG. 7, the cam groove 22 may include a first groove portion 22a in which one cam follower 42 contacts one side surface 24a and a second groove portion 22b in which one cam follower 42 contacts the other side surface 24b.

=== Regarding the Four-Point Contact Ball Bearing 50 According to the Present Embodiment ===
Next, the four-point contact ball bearing 50 according to the present embodiment will be described.
In the following, first, the four-point contact ball bearing 50 according to the conventional example will be described with reference to FIG. 8, and the problems of the four-point contact ball bearing 50 according to the conventional example will be described. Subsequently, the four-point contact ball bearing 50 according to the present embodiment will be described with reference to FIGS. 9 to 11 and the effectiveness of the four-point contact ball bearing 50 according to the present embodiment will be described.

FIG. 8 is a view showing a general four-point contact ball bearing 50 according to a conventional example.
The four-point contact ball bearing 50 includes an annular inner ring portion 100 in which an inner ring groove 102 as an example of an outer circumferential groove is formed on the outer periphery, and an outer ring portion as an example of a counter circumferential groove facing the inner ring groove 102. An annular outer ring portion 52 in which a groove 54 is formed, and an inner ring portion groove 102 and an outer ring portion groove 54 are provided between the inner ring portion groove 102 and the outer ring portion groove 54 (that is, two inner ring contact points 102a). , 102b and the two outer ring contacts 54a, 54b), and a plurality of ball-shaped rolling elements 56 that roll in contact with each other, and a retainer 58 for holding the rolling elements 56. The outer ring portion 52 is divided into two members, an upper outer ring portion 52a and a lower outer ring portion 52b.

  In the four-point contact ball bearing 50, a pressurizing operation for adjusting the pressurizing force applied to the rolling element 56 by the outer ring portion 52 is performed using the fact that the outer ring portion 52 is divided into two members. It was. For example, as shown in FIG. 8, an annular spacer 104 (that is, a spacer) is inserted between the upper outer ring portion 52a and the lower outer ring portion 52b, and the thickness of the inserted spacer 104 is adjusted. Therefore, the pressure was adjusted. Further, when the pressurization pressure is too low without inserting the spacer 104, the mating surfaces of the upper outer ring portion 52a and the lower outer ring portion 52b are directly cut to adjust the pressurization.

  However, in such a case, the following inconvenience occurred. In other words, both when adjusting using the spacer 104 and when adjusting the mating surface, the upper outer ring portion 52a and the lower outer ring portion 52b are once removed from the four-point contact ball bearing 50 when adjusting. The process of removing and reassembling is required, and the adjustment work is complicated. In addition, since re-realization after reassembly varies, there is a problem in accuracy control.

  Therefore, in order to solve the problem, in the present embodiment, the configuration of the four-point contact ball bearing 50 is determined as follows.

FIG. 9 is a schematic side view of the four-point contact ball bearing 50 according to the present embodiment.
Similar to the four-point contact ball bearing 50 according to the conventional example, the four-point contact ball bearing 50 includes an annular outer ring portion 52 formed with an outer ring portion groove 54 as an example of an opposed circumferential groove facing the outer circumferential groove 44. , Provided between the outer circumferential groove 44 and the outer ring groove 54, and in contact with the outer circumferential groove 44 and the outer ring groove 54 at four points (that is, two outer circumferential groove contacts 44a and 44b and two outer ring contacts 54a and 54b). And a plurality of ball-shaped rolling elements 56 that roll, and a retainer 58 for holding the rolling elements 56. However, unlike the four-point contact ball bearing 50 according to the conventional example, the inner ring portion is not provided, and the outer peripheral groove 44 is provided on the outer periphery of the rotary table 40 (formed directly on the outer periphery). .

  The outer ring portion 52 is divided into two members: an upper outer ring portion 52a where the upper portion 54c of the outer ring portion groove 54 is formed, and a lower outer ring portion 52b where the lower portion 54d of the outer ring portion groove 54 is formed. Yes. These two members are tightened by a tightening bolt 62 as an example of a tightening member provided across both members so as to extend in the vertical direction.

  Further, a mounting bolt 64 and a pressurizing adjusting screw 60 as an example of an adjusting screw are provided outside the tightening bolt 62 in the radial direction of the rotary table 40.

  The attachment bolt 64 is for attaching the four-point contact ball bearing 50 to the housing 32. The mounting bolt 64 is provided across the outer ring portion 52 and the housing 32 along the vertical direction, and fixes the outer ring portion 52 to the housing 32.

  The pressurizing adjustment screw 60 is for adjusting the pressurizing force applied to the rolling element 56 by the outer ring portion 52. The pressurizing adjustment screw 60 is provided across the upper outer ring portion 52a and the lower outer ring portion 52b so as to extend in the vertical direction.

FIG. 10 is an explanatory schematic diagram for explaining pressurization adjustment by the pressurization adjustment screw 60.
When the pressurizing adjustment screw 60 is tightened, the upper outer ring portion 52a is slightly displaced with the joint surface 62a formed by the tightening bolt 62 as a fulcrum (in FIG. 10, the displaced upper outer ring portion 52a is indicated by a dotted line). That is, while the outer upper portion 52c of the upper outer ring portion 52a is lifted, the groove forming surface 52d that forms the outer ring portion groove 54 is inclined toward the rolling element 56 (that is, the outer periphery of the upper outer ring portion 52a is pulled to the outer periphery). The stress is applied and the groove forming surface 52d is reduced in diameter while the shape of the upper outer ring portion 52a is deformed). And the pressurization given to rolling element 56 becomes large by such stress deformation of upper outside ring part 52a. On the other hand, when the pressurization adjusting screw 60 is loosened, the movement of the upper outer ring portion 52a is reversed and the pressurization is reduced. Note that the behavior of these deformations is similar to the behavior of stress accompanying the deformation of the diaphragm spring. The deformation with respect to the tightening force of the pressurizing adjustment screw 60 is not a linear shape like a coil spring but a so-called non-linear deformation.

  In the above-described conventional example, when adjusting, the upper outer ring portion 52a and the lower outer ring portion 52b are once removed from the four-point contact ball bearing 50, and the process of reassembling is required, which makes the adjustment work complicated. However, according to the pressurization adjustment screw 60 according to the present embodiment, the pressurization adjustment work can be performed without removing the upper outer ring portion 52a and the lower outer ring portion 52b. Therefore, the pressurization adjustment work becomes simple.

  FIG. 11 is a schematic top view of the four-point contact ball bearing 50 according to the present embodiment. As shown in FIG. 11, a plurality of pressurizing adjustment screws 60, tightening bolts 62, and mounting bolts 64 are provided at equal pitches along the circumferential direction of the outer ring portion 52. As described above, the mounting bolt 64 and the pressurizing adjustment screw 60 are located outside the tightening bolt 62 in the radial direction, and the mounting bolt 64 and the pressurizing adjusting screw 60 are in the radial direction. Located at approximately the same position.

  Further, the pressurization adjusting screw 60 has not only a pressurization adjusting function but also a function of correcting a shift of the axis (center 40b) of the rotary table 40. For example, in FIG. 11, if the tightening force of the pressurizing adjustment screw 60 above the line L is made larger than the tightening force of the pressurizing adjustment screw 60 below the line L (a difference is intentionally made in tightening). In other words, due to the difference in the degree of stress deformation between the upper side and the lower side, the axial center moves slightly downward. Therefore, when the shaft center is slightly deviated from the design position, the shaft center can be brought to the design position using the pressurizing adjustment screw 60.

=== Regarding Cam Device 10 According to Second Embodiment ===
In the above description, the cam device 10 including the roller gear cam 20 is taken as an example of the cam device 10, and the characteristic shape of the cam groove 22 and the characteristic four-point contact ball bearing 50 have been described. However, the shape of the characteristic cam groove 22 and the characteristic four-point contact ball bearing 50 are not limited to the cam device 10 including the roller gear cam 20. Here, the cam apparatus 10 provided with the barrel cam 21 will be described as an example of the cam apparatus 10 according to the second embodiment.

  FIG. 12 is a top view and a side view of the cam device 10 according to the second embodiment.

  The cam device 10 includes a barrel cam 21 as an example of a cam that is rotationally driven by a motor (not shown), and a rotary table 40 as an example of a rotating member.

  The barrel cam 21 includes a cam groove 22 and is supported by a pair of rolling bearings 30 so as to be rotatable (rotatable) with respect to the housing 32. A motor (not shown) is fastened to the barrel cam 21 at one end side, and the barrel cam 21 is rotationally driven by the driving force of the motor. The barrel cam 21 is integrally provided with an input shaft 34.

  The rotary table 40 has a role of holding a workpiece, for example. The rotary table 40 is supported so as to be rotatable (rotatable) with respect to the housing 32 by a four-point contact ball bearing 50 as an example of a bearing. A cylindrical turret 40a is suspended from the lower surface side of the rotary table 40, and a plurality of cam followers 42 arranged at equal intervals in the circumferential direction are provided on the lower surface of the turret 40a (that is, cam followers). 42 are arranged at equal intervals along the circumferential direction so that the rotation axis direction thereof is parallel to the rotation axis direction of the turntable 40). The cam follower 42 is engaged with the cam groove 22 of the barrel cam 21 described above (engaged with the cam groove 22), and the rotational force of the motor is transmitted to the rotary table 40 via the barrel cam 21 and the cam follower 42. It is like that. That is, the rotary table 40 rotates as the barrel cam 21 rotates.

<<< About the shape of the cam groove 22 of the barrel cam 21 according to the second embodiment >>>
Next, the shape of the cam groove 22 of the barrel cam 21 according to the second embodiment will be described.
In the following, first, the shape of the cam groove 22 of the barrel cam 21 according to the conventional example will be described with reference to FIGS. 13 and 14, and problems of the barrel cam 21 according to the conventional example will be described. Subsequently, the shape of the cam groove 22 of the barrel cam 21 according to the present embodiment will be described with reference to FIGS. 15 and 16, and the effectiveness of the barrel cam 21 according to the present embodiment will be described.

  FIG. 13 is a view showing a state in which the barrel cam 21 according to the conventional example is engaged with the cam follower 42, and the left view of FIG. 13 is a state diagram showing the state of engagement in the design. In the left figure, three cam followers 42 (numbered 1 to 3) are simultaneously engaged with the cam groove 22 of the barrel cam 21. The cam follower diameter d of the cam follower 42 is smaller than the cam groove width D of the cam groove 22, and none of the three cam followers 42 is in contact with the side surface 24 of the cam groove 22. In other words, any of the three cam followers 42 has a gap 80 between the cam groove 22 and the side surface 24.

  FIG. 14 shows a conventional example in which the rotational angle of the barrel cam 21 is the horizontal axis (x axis) and the angular position where the cam follower 42 is located when viewed from the center 40b of the rotary table 40 is the vertical axis (y axis). FIG. 14 is a timing diagram (corresponding to FIG. 13).

  As shown in FIG. 14, in the timing diagram, a portion corresponding to the cam groove 22 (specifically, a line connecting the median values in the y-axis direction of the two side surfaces 24 of the cam groove 22 in FIG. ) Is one straight section.

  In other words, the portion corresponding to each of the two side surfaces 24 of the cam groove 22 includes a portion corresponding to the one side surface 24a and a portion corresponding to the other side surface 24b opposite to the one side surface 24a. It is a straight section (the cam groove width D of the cam groove 22 is designed to be the same at any location of the cam groove 22, so that the one side surface 24a and the other side surface 24b are parallel to each other. )

  As is clear from FIG. 14, none of the cam followers 42 is in contact with either the one side surface 24 a or the other side surface 24 b of the cam groove 22.

  Here, in the above-described embodiment (also referred to as the first embodiment) of the cam device 10 provided with the roller gear cam 20, the roller gear cam 20 is pressed against the rotary table 40 in order to prevent the occurrence of backlash. Although it has been described that the pressurization adjustment work has been performed, in the cam device 10 provided with the barrel cam 21, even if the barrel cam 21 is pressed against the rotary table 40, the occurrence of backlash cannot be prevented. (This is different from the first embodiment). That is, as shown in the right side of FIG. 13, even if the barrel cam 21 is pressed against the rotary table 40 and the cam follower 42 contacts the side surface 24 of the cam groove 22, all three cam followers 42 are on the same side. Since it contacts the side surface 24, the occurrence of backlash cannot be prevented as in the first embodiment. Therefore, the problem of the conventional example in 2nd embodiment (cam apparatus 10 provided with the barrel cam 21) is that the said backlash generate | occur | produces.

  And in order to solve the said problem, in 2nd embodiment, the shape of the cam groove 22 of the barrel cam 21 is made into the shape similar to 1st embodiment.

  FIG. 15 is a view corresponding to FIG. 13 and shows a state in which the barrel cam 21 according to the second embodiment is engaged with the cam follower 42.

  Also in the second embodiment, as in the conventional example, three cam followers 42 (numbered 1 to 3) are simultaneously engaged with the cam groove 22 of the barrel cam 21, and the cam follower diameter of the cam follower 42 is the same. d is smaller than the cam groove width D of the cam groove 22.

  The cam follower 42 is in contact with the cam groove 22. Specifically, the first cam follower 42 contacts the one side surface 24a of the cam groove 22 but does not contact the other side surface 24b (having a gap 80 between the other side surface 24b). . On the other hand, the third cam follower 42 contacts the other side surface 24b but does not contact the one side surface 24a (has a gap 80 between the one side surface 24a). Therefore, the rotation direction of the first cam follower 42 and the third cam follower 42 are reversed. On the other hand, the second cam follower 42 is not in contact with both the one side surface 24a and the other side surface 24b.

  FIG. 16 is a diagram corresponding to FIG. 14, wherein the rotational angle of the barrel cam 21 is the horizontal axis (x axis), and the angular position where the cam follower 42 is located when viewed from the center 40 b of the rotary table 40 is the vertical axis (y axis). FIG. 16 is a timing diagram according to the second embodiment (corresponding to FIG. 15).

  As is clear from FIG. 16 and as described above, the first cam follower 42 contacts only one side 24 a of the two side surfaces 24, and the third cam follower 42 is out of the two side surfaces 24. Only the other side surface 24 b is in contact, and the second cam follower 42 is not in contact with any side surface 24.

  In other words, in the cam groove 22 according to the present embodiment, at least one cam follower 42 (in the present embodiment, one cam follower 42) of the plurality of cam followers 42 hits one side surface 24a of the cam groove 22. A first groove 22a, a second groove 22b in which at least one cam follower 42 (in this embodiment, one cam follower 42) of the plurality of cam followers 42 contacts the other side surface 24b of the cam groove 22, and a first groove A third groove portion 22c connecting 22a and the second groove portion 22b, wherein the cam follower 42 located in the third groove portion 22c is not in contact with either the one side surface 24a or the other side surface 24b. I have.

  The cam groove 22 is different from the conventional example described above, and in the timing diagram, the portions corresponding to the first groove portion 22a and the second groove portion 22b (the line connecting the median values described above) are both linear sections. And the part corresponding to the 3rd groove part 22c is equipped with the shape which becomes a curve area which connects two said linear areas.

  That is, in the present embodiment, as is apparent from FIG. 16, not all the portions corresponding to the cam grooves 22 are straight sections, but the cam follower 42 is applied to the one side surface 24a to generate the pressurization. A straight section (corresponding to the pressurizing section) prepared in order to generate a pressurization by applying the cam follower 42 to the other side surface 24b. A curve section (a rotation section for changing the rotational direction of the outer ring of the cam follower, that is, a buffer section) prepared for smoothly transferring the cam follower 42 under pressure from one straight section to the other straight section. ).

  Therefore, the occurrence of backlash that has been a problem in the conventional example is appropriately prevented.

<<< Regarding the Four-Point Contact Ball Bearing 50 in the Cam Device 10 According to the Second Embodiment >>>
As shown in the lower part of FIG. 12, the cam device 10 including the barrel cam 21 according to the second embodiment may be provided with a four-point contact ball bearing 50 similar to that of the first embodiment (FIG. 1). it can. Therefore, also in the cam apparatus 10 provided with the barrel cam 21 which concerns on 2nd embodiment, it becomes possible to enjoy the merit mentioned above by providing the pressurization adjustment screw 60. FIG.

=== Effectiveness of Cam Groove Shape of Cam Device 10 According to the Embodiment (First and Second Embodiments) ===
The cam device 10 according to the embodiment includes a cam groove 22, a rotatable cam, a plurality of cam followers 42 that engage with the cam groove 22, and a rotating table 40 that rotates as the cam rotates. doing. The cam groove 22 includes a first groove portion 22a in which at least one cam follower 42 of the plurality of cam followers 42 contacts one side surface 24a of the cam groove 22, and at least one cam follower 42 in the plurality of cam followers 42. 22 is a second groove portion 22b that contacts the other side surface 24b opposite to the one side surface 24a, and a third groove portion 22c that connects the first groove portion 22a and the second groove portion 22b, and is located in the third groove portion 22c. The cam follower 42 includes a third groove portion 22c that is not in contact with either the side surface 24a or the other side surface 24b. The cam groove 22 is a cam follower when the cam rotation angle is viewed from the horizontal axis and the center of the rotary table 40. In the timing diagram when the angle position where 42 is located is the vertical axis, the parts corresponding to the first groove 22a and the second groove 22b There either be straight section, and the portion corresponding to the third groove portion 22c is provided with a shape such that the curved section connecting two of said straight section.

  Therefore, as described above, it is not necessary to adjust the pressurization by moving the distance between the axes, and there is no problem of deterioration of the rotation accuracy of the rotary table 40 (first embodiment). Further, occurrence of backlash is also prevented appropriately (first embodiment and second embodiment). That is, the accuracy of the cam device 10 is improved.

=== Other Embodiments ===
The bearing and cam device according to the present invention have been described above based on the above embodiment. However, the above embodiment of the present invention is for facilitating the understanding of the present invention and limits the present invention. is not. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

  In the above embodiment, as shown in FIG. 11, the mounting bolt 64 and the pressurizing adjustment screw 60 are located at substantially the same position in the radial direction. However, the present invention is not limited to this. Absent. For example, as shown in FIG. 17, the attachment bolt 64 may be positioned outside the pressurizing adjustment screw 60 in the radial direction.

  In the example of FIG. 17, the mounting bolt 64 fixes the lower outer ring portion 52b to the housing 32. However, the present invention is not limited to this, and as shown in FIG. 18, the upper outer ring portion 52a. This may be fixed to the housing 32. In the example of FIG. 18, unlike the example of FIG. 17, the lower outer ring portion 52b is displaced by the pressure adjustment by the pressure adjusting screw 60, as indicated by the dotted line in the figure. And the magnitude | size of the pressurization given to the rolling element 56 can be changed also by displacing such a lower side outer ring | wheel part 52b.

  Moreover, in the said embodiment, although the four-point contact ball bearing 50 was mentioned as an example and demonstrated as a bearing, it is not limited to this, It can apply to all other bearings, such as a rolling bearing. For example, as shown in FIGS. 19 to 22, a cross roller bearing 51 may be used. FIG. 19 corresponds to FIG. 9 and is a side view of the cross roller bearing 51. FIG. 20 is a diagram corresponding to FIG. 10, and is an explanatory diagram for explaining the pressurization adjustment by the pressurization adjustment screw 60. FIG. 21 is a diagram corresponding to FIG. 17, and is an explanatory diagram for explaining the pressurization adjustment by the pressurization adjustment screw 60. FIG. 22 is a diagram corresponding to FIG. 18, and is an explanatory diagram for explaining the pressurization adjustment by the pressurization adjustment screw 60.

  Moreover, in the said embodiment, although the bearing provided in the cam apparatus 10 was mentioned as an example and demonstrated, it is not limited to this. The present invention can also be applied to a bearing provided in a device other than the cam device 10.

DESCRIPTION OF SYMBOLS 10 Cam apparatus 20 Roller gear cam 21 Barrel cam 22 Cam groove 22a First groove part 22b Second groove part 22c Third groove part 24 Side surface 24a One side surface 24b Other side surface 30 Rolling bearing 32 Housing 34 Input shaft 40 Rotary table 40a Turret 40b Center 42 Cam follower 44 Peripheral groove 44a Peripheral groove contact 44b Peripheral groove contact
50 Four-point contact ball bearing 51 Cross roller bearing 52 Outer ring part 52a Upper outer ring part 52b Lower outer ring part 52c Outer upper part 52d Groove forming surface 54 Outer ring part groove 54a Outer ring contact 54b Outer ring contact 54c Upper part 54d Lower part 56 Rolling element 58 Cage 60 Pressure adjusting screw 62 Tightening bolt 62a Joint surface 64 Mounting bolt 80 Clearance 100 Inner ring portion 102 Inner ring portion groove 102a Outer ring contact 102b Outer ring contact 104 Spacer

Claims (3)

An outer ring portion formed with an opposed circumferential groove facing the outer circumferential groove provided on the outer circumference of the rotatable rotating member;
A plurality of rolling elements provided between the outer circumferential groove and the opposed circumferential groove and rolling in contact with the outer circumferential groove and the opposed circumferential groove;
The outer ring portion is divided into two members, an upper outer ring portion in which an upper portion of the opposed circumferential groove is formed and a lower outer ring portion in which a lower portion of the opposed circumferential groove is formed. A bearing further comprising a tightening member for tightening the portion and the lower outer ring portion,
The outer ring portion is provided with an adjustment screw for adjusting a pressure applied to the rolling element by the outer ring portion outside the tightening member in the radial direction of the rotating member. . A cam with a cam groove and rotatable;
A plurality of cam followers that engage with the cam groove, and a rotating member that rotates as the cam rotates;
An outer ring portion formed with an opposed circumferential groove facing an outer circumferential groove provided on an outer circumference of the rotating member, and provided between the outer circumferential groove and the opposed circumferential groove. A plurality of rolling elements that roll in contact with the groove, and the outer ring portion includes an upper outer ring portion in which an upper portion of the opposed circumferential groove is formed and a lower portion of the opposed circumferential groove. A bearing that is divided into two members of a formed lower outer ring portion, and further includes a tightening member for tightening the upper outer ring portion and the lower outer ring portion,
On the outer ring portion, a bearing provided with an adjusting screw for adjusting a pressure applied to the rolling element by the outer ring portion on the outer side of the tightening member in the radial direction of the rotating member;
A cam device comprising: The cam apparatus according to claim 2,
The cam groove includes a first groove portion in which at least one cam follower of the plurality of cam followers is in contact with one side surface of the cam groove, and at least one cam follower of the plurality of cam followers is formed on the one side surface of the cam groove. Is a second groove portion that is in contact with the other side surface on the opposite side, and a third groove portion that connects the first groove portion and the second groove portion, and the cam follower located in the third groove portion includes the one side surface and the other side surface. A third groove portion that does not hit any of the
The cam groove is
In the timing diagram when the rotation angle of the cam is the horizontal axis and the angle position where the cam follower is located when viewed from the center of the rotation member is the vertical axis, it corresponds to the first groove portion and the second groove portion. A cam device comprising a shape in which all of the portions are straight sections, and a portion corresponding to the third groove is a curved section connecting the two straight sections.