KR101621968B1

KR101621968B1 - Bearing and cam apparatus

Info

Publication number: KR101621968B1
Application number: KR1020130081774A
Authority: KR
Inventors: 헤이자브로 카토
Original assignee: 주식회사 한즈모트롤
Priority date: 2012-10-01
Filing date: 2013-07-11
Publication date: 2016-05-17
Also published as: KR20140043271A; JP5929677B2; CN103711796B; JP2014070719A; CN103711796A

Abstract

[PROBLEM TO BE SOLVED] To realize a simple bearing with a pressure adjusting operation.
[MEANS FOR SOLVING PROBLEMS] An outer ring portion provided with an opposing circumferential groove facing an outer circumferential groove provided on the outer periphery of a rotatable rotary member, and an outer ring portion provided between the outer circumferential groove and the opposing circumferential groove, Wherein the outer ring portion is divided into two members, an upper outer ring portion on which an upper portion of the opposite circumferential groove is formed and a lower outer ring portion on which a lower portion of the opposite circumferential groove is formed, The outer ring portion is provided with an adjusting screw for adjusting the pressure applied to the rolling member by the outer ring portion on the outer side of the coupling member in the radial direction of the rotary member .

Description

[0001] Bearing and cam apparatus [0002]

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

An outer ring portion (outer ring portion) formed with an opposing circumferential groove facing the outer circumferential groove provided on the outer periphery of the rotatable rotary member, and a ring portion provided between the circumferential groove and the opposing circumferential groove, Bearings having a plurality of rolling elements rolling on are well known. As such a bearing, for example, a four-point contact ball bearing or a cross roller bearing can be enumerated.

Patent Document 1: Japanese Patent Application Laid-Open No. 2005-186206

Incidentally, among the bearings, the outer ring portion is divided into two members, that is, an upper outer ring portion on which an upper portion of the opposite circumferential groove is formed and a lower outer ring portion on which a lower portion of the opposite circumferential groove is formed.

Further, in the bearing, the pressure adjusting operation for adjusting the pressurization of the outer ring portion to the rolling member is performed by using the fact that the outer ring portion is divided into two members. For example, an annular spacer was inserted between the upper outer ring part and the lower outer ring part, and the thickness of the interposition to be inserted was adjusted to adjust the pressurizing force. Further, in the case where the pressurizing force was too low in the state without the insertion of the spigot, the contacting side between the upper outer ring part and the lower outer ring part was cut directly to adjust the pressure to be increased.

However, in this case, the following inconvenience occurred. That is, even in the case of performing the adjustment using the jogging, it is necessary to separate the upper outer ring part and the lower outer ring part from the one bearing at the time of adjustment and perform the assembly again, .

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to realize a bearing simple in pressure adjusting operation.

According to a first aspect of the present invention,

An outer ring portion formed with an opposing circumferential groove facing the outer circumferential groove provided on the outer periphery of the rotatable rotary member,

And a plurality of rolling elements provided between the outer circumferential grooves and the opposed circumferential grooves and contacting and rolling with the outer circumferential grooves and the opposed circumferential grooves,

Wherein the outer ring part is divided into an upper side outer ring part formed with an upper portion of the opposite circumferential groove and a lower side outer ring part formed with a lower portion of the opposite circumferential groove, A bearing further comprising a fastening member,

Wherein the outer ring portion is provided with an adjusting screw for adjusting the pressure applied to the rolling member by the outer ring portion on the outer side of the coupling member in the radial direction of the rotary member.

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

Fig. 1 is a schematic top view and a side view of the cam device 10. Fig.
Fig. 2 is a schematic view showing a state in which the roller gear cam 20 according to the conventional example is engaged with the cam follower 42. Fig.
3 is a timing diagram (schematic diagram) according to the conventional example.
FIG. 4 is measurement data on the angular error of the rotary table 40 according to the conventional example.
5 is a schematic view showing a state in which the roller gear cam 20 according to the present embodiment is engaged with the cam follower 42. Fig.
6 is a timing diagram (schematic diagram) according to the present embodiment.
7 is a schematic diagram showing a state in which the roller gear cam 20 according to the modification of this embodiment is engaged with the cam follower 42. As shown in Fig.
FIG. 8 is a schematic view showing a conventional four-point contact ball bearing 50. FIG.
9 is a side schematic view of the four-point contact ball bearing 50 according to the present embodiment.
10 is a schematic explanatory diagram for explaining the adjustment of the pressurizing force by the pressurizing adjusting screw 60 according to the present embodiment.
11 is an upper schematic diagram of the four-point contact ball bearing 50 according to the present embodiment.
12 is a top view and a side schematic view of the cam device 10 according to the second embodiment.
Fig. 13 is a schematic view showing a state in which the barrel cam 21 according to the conventional example is engaged with the cam follower 42. Fig.
14 is a timing diagram (schematic diagram) according to the conventional example.
15 is a schematic view showing a state in which the barrel cam 21 according to the second embodiment is engaged with the cam follower 42. Fig.
16 is a timing diagram according to the second embodiment.
17 is a schematic diagram for explaining the adjustment of the pressurizing force by the pressurizing adjusting screw 60 according to the other embodiment.
18 is a schematic diagram for explaining the adjustment of the pressurizing force by the pressurizing adjusting screw 60 according to the other embodiment.
19 is a side schematic view of a cross roller bearing 51 according to another embodiment.
20 is a schematic explanatory diagram for explaining adjustment of the pressurizing force by the pressurizing adjusting screw 60 according to the other embodiment.
21 is a schematic diagram for explaining adjustment of the pressurizing force by the pressurizing adjusting screw 60 according to another embodiment.
22 is a schematic diagram for explaining the adjustment of the pressurizing force by the pressurizing adjusting screw 60 according to the other embodiment.

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

The outer ring portion is divided into two members, an upper outer ring portion on which an upper portion of the opposite circumferential groove is formed and a lower outer ring portion on which a lower portion of the opposing circumferential groove is formed, and the upper outer ring portion and the lower outer ring portion are fastened The bearing according to claim 1,

Wherein the outer ring portion is provided with an adjusting screw for adjusting a pressure applied to the rolling member by the outer ring portion on the outer side of the coupling member in the radial direction of the rotary member.

According to these bearings, the pressure adjusting operation becomes simple.

A cam that is provided with a cam groove,

A rotating member having a plurality of cam followers engaged with the cam grooves and rotating in accordance with the rotation of the cam;

An outer ring portion having an opposite circumferential groove formed in an outer circumferential groove provided on an outer circumference of the rotary member; and a plurality of gear teeth arranged in contact with the outer circumferential groove and the opposed circumferential groove, Wherein the outer ring portion is divided into two members, an upper outer ring portion having an upper portion of the opposite circumferential groove and a lower outer ring portion having a lower portion of the opposite circumferential groove formed therein, and the upper outer ring portion and the lower outer ring portion And a fastening member for fastening the part,

Wherein the outer ring portion has a bearing provided with an adjusting screw for adjusting a pressure applied to the rolling member by the outer ring portion on the outer side of the coupling member in the radial direction of the rotating member.

According to such a cam device, the pressure adjusting operation becomes simple.

Wherein 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 face of the cam groove, and at least one cam follower of the plurality of cam followers faces the one side face of the cam groove And a third groove portion connected to the first groove portion and the second groove portion, and the cam follower positioned in the third groove portion is located on the one side surface and the other side surface And a third groove portion which is not in contact with any one of the first and second grooves,

The cam groove

And the cam follower is located at an angular position when viewed from the center of the rotary member is taken as a vertical axis, the timing chart of the first groove portion and the second groove portion corresponding to the first groove portion and the second groove portion And a portion corresponding to the third groove portion may have a shape that becomes a curve section connecting the two linear segments.

In this case, a highly accurate cam device is realized.

=== Regarding 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. Fig.

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

The roller gear cam 20 has a cam groove 22 and is rotatably (rotatably supported) with respect to the housing 32 by a pair of rolling bearings 30. 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. Further, the input shaft 34 is integrally provided in the roller gear cam 20.

The rotary table 40 has a role of, for example, holding the workpiece. The rotary table 40 is rotatably (rotatably supported) 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 downwardly disposed on the lower surface of the rotary table 40 and a plurality of cam followers 42 are disposed below the outer circumferential surface of the turret 40a at regular intervals along the circumferential direction And the rotation table 40 is provided with a plurality of cam followers 42 radially). The cam follower 42 is engaged with the cam groove 22 of the roller gear cam 20 (engaged with the cam groove 22), and the rotational force of the motor is transmitted to the rotary table 40 through the roller gear cam 20 and the cam follower 42 have. That is, the rotary table 40 rotates in accordance with the rotation of the roller gear cam 20.

=== Regarding 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.

2 and 3, the shape of the cam groove 22 of the roller gear cam 20 according to the conventional example will be described, and the problem of the roller gear cam 20 according to the conventional example will be described with reference to FIG. do. Next, 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 usefulness of the roller gear cam 20 according to the present embodiment will be described.

Fig. 2 is a view showing a state in which the roller gear cam 20 according to the conventional example is engaged with the cam follower 42. Fig. The left drawing (that is, the upper left drawing and the lower left drawing) is a state diagram showing the shape of the engagement in the design, and the right drawing (that is, the upper right drawing and the lower right drawing) Fig.

First, notice the left drawing showing the shape of the engagement in the design. In the left figure, five cam followers 42 (numbered 1 to 5) are engaged with the cam grooves 22 of the roller gear cam 20 at the same time. The cam follower diameter d of the cam follower 42 becomes smaller than the cam groove width D of the cam groove 22 and none of the five cam followers 42 contact the side surface 24 of the cam groove 22 as shown in the lower left figure. In other words, it has a gap 80 between the side surfaces 24 of the cam groove 22 for any of the five cam followers 42.

3 is a cross-sectional view of the roller gear cam 20 according to the conventional example when the rotational angle of the roller gear cam 20 is represented by the horizontal axis (x-axis) and the angular position at which the cam follower 42 is positioned when viewed from the center 40b of the rotary table 40, (Corresponding to Fig. 2).

3, a portion corresponding to the cam groove 22 in the timing diagram (concretely, a line connecting the center values of the two side surfaces 24 of the cam groove 22 in the y-axis direction in Fig. 3) Section. For example, when the y-coordinates of the two side surfaces 24 when the x-axis coordinate is x1 are y1 and y2, the median yc of the two side surfaces 24 of the cam groove 22 is (y1 + y2) / 2 (see 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 is formed as one straight section, which corresponds to one side surface 24a and the other side surface 24b opposite to the one side surface 24a (The cam groove width D of the cam groove 22 is designed to be the same at any position of the cam groove 22, one side face 24a is parallel to the other side face 24b).

3, neither of the cam followers 42 contact any of the side surface 24a and the other side surface 24b of the cam groove 22. [

(I.e., the change in the median value yc with respect to the change in the x coordinate value), the one-time derivative value thereof (i.e., the velocity along the cam groove 22) (I.e., the acceleration along the cam groove 22) is also shown in Fig. 3 (lower part). The so-called theoretical displacement is also shown in Fig. The theoretical displacement coincides with a line connecting the center of each cam follower 42 and further coincides with a line connecting the center line.

2, the cam device 10 is designed so that the cam follower 42 does not come into contact with the side surface 24 of the cam groove 22, as described above. However, in this state, so-called backlash occurs. Therefore, in order to prevent the occurrence of backlash at the time of manufacturing the conventional cam device 10, the pressure adjusting operation described below has been performed.

2, the roller gear cam 20 is urged toward the rotary table 40 (upward in FIG. 2) to apply the pressure to the cam follower 42 as shown in the lower right figure, So as to be brought into contact with the side surface 24 of the groove 22 so that a suitable pressure is applied to the cam follower 42. That is, by adjusting the distance between the axes of the roller gear cam 20 and the rotary table 40 to be close to each other.

However, since the roller gear cam 20 is semi-forcibly moved in the designed state of the cam gear ratio 10 shown in the left drawing of FIG. 2, the rotational accuracy of the rotating table 40 rotating in accordance with the rotation of the roller gear cam 20 is adversely affected The deterioration of the rotation accuracy is very small and has not been a problem in the prior art. However, considering the very strict accuracy requirement for the cam device 10, it is said that the deterioration of the rotation precision has become a problem .

These adverse effects will be described in more detail. When the roller gear cam 20 is pressed toward the rotary table 40 (upward in Fig. 2) in the left side view of Fig. 2 and the designed state of the cam device 10, the cam follower 42 contacts the side surface 24 of the cam groove 22 immediately. As can be understood, the first and fifth cam followers 42 of the five cam followers 42 first make contact with the side surfaces 24 (and the cam followers 42 of the second to fourth cam followers 42 are not in contact with the side surfaces 24 at this time). In other words, the first and fifth cam followers 42 generate the pressurization first.

Next, in this state, the roller gear cam 20 is further pressed toward the rotary table 40, and the cam followers 42 of the second and fourth cam followers come into contact with the side surface 24, and the state shown in the right drawing of Fig. In other words, the second and fourth cam followers 42 pressurize, while the first and fifth cam followers 42 are pressed against the side surface 24 with a stronger force, and the pressure of these cam followers 42 is further increased Pressurization of the cam follower 42 of No. 5 > pressure of the cam follower 42 of No. 2 and 4)

That is, conventionally, in order to appropriately prevent the occurrence of backlash, when it is attempted to generate the pressurizing force in any of the first, second, fourth, fifth cam followers 42, the pressures of the first and fifth cam followers 42 are excessive It became large (it was inevitable to grow excessively).

And the excessive pressurization has an adverse effect according to the rotation accuracy described above. That is, when the roller gear cam 20 rotates, the fifth cam follower 42 suddenly separates from the cam groove 22 in the state where the excessive pressure is excessively caught (the pressure is greatly increased), and the pressure is released. Conversely, the first cam follower 42 instantly changes in a state in which the pressurization is free, and a state in which the pressurization is great. These large changes in the state have caused rotation errors of the rotary table 40.

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

Fig. 5 is a view corresponding to Fig. 2, showing a state in which the roller gear cam 20 according to the present embodiment is engaged with the cam follower 42. Fig. In the present embodiment, since the pressure adjustment can not be performed by moving the inter-shaft distance, there is no difference between the left drawing and the right drawing as shown in Fig.

In this embodiment, similarly to the conventional example, five cam followers 42 (numbered 1 to 5) are engaged with the cam grooves 22 of the roller gear cam 20 at the same time, and the cam follower diameter d of the cam follower 42 22 of the cam groove width D. 2, the cam follower 42 is in contact with the cam groove 22 (the method of contact is also the same as that of the conventional example after pressure adjustment), as described later.

Specifically, the first and second cam followers 42 are in contact with the one side surface 24a of the cam groove 22 and do not contact with the other side surface 24b (they have a gap 80 between the other side surface 24b and the other side surface 24b). The cam follower 42 of No. 4 and No. 5, on the contrary, is in contact with the other side surface 24b and has a gap 80 between the side surface 24a and the side surface 24a. The size of the gap 80 is larger than the gap between the other side surfaces 24b 80 < / RTI > size). Therefore, the cam followers 42 of No. 1 and No. 2, and the Cam Follower 42 of No. 4 and No. 5 are opposite in the direction of rotation. 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 view corresponding to Fig. 3, in which the angular position at which the cam follower 42 is positioned when the rotation angle of the roller gear cam 20 is viewed on the horizontal axis (x axis) and the center 40b of the rotary table 40 is shown on the vertical axis (Corresponding to Fig. 5) according to the present embodiment.

6, the first and second cam followers 42 contact only one side 24a of the two side faces 24, and the fourth and fifth cam followers 42 contact the other side face 24b of the two side faces 24 And does not contact the side surface 24 of any of the three cam followers 42. [

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

Unlike the conventional example described above, in the cam groove 22, the portions corresponding to the first groove portion 22a and the second groove portion 22b (the line connecting the median values described above) in the timing diagram become a linear section, And 22c are curved sections connecting the two linear sections.

That is, in this embodiment, as shown in Fig. 6, not all of the portions corresponding to the cam grooves 22 are formed as rectilinear sections, but on the side 24a (from the design state of the cam device 10) (Corresponding to the pressurization section) and a straight section (corresponding to the pressurization section) prepared to generate the pressurization by aligning the cam follower 42 on the other side 24b with the straight section (corresponding to the pressurization section) (A rotation direction switching period of the cam follower outer ring, that is, corresponding to the buffer section) in which no pressure is applied to smoothly move the cam follower 42 from one linear section to the other linear section.

Therefore, it is not necessary to adjust the pressurization by moving the inter-shaft distance as in the conventional example, and there is no problem of deterioration of the rotation accuracy of the rotary table 40 and occurrence of backlash is appropriately prevented.

6, the displacement along the cam groove 22, its one-time differential value (i.e., the velocity along the cam groove 22) and its one-time derivative value (i.e., the acceleration relating to the cam groove 22) Respectively. As can be seen from the speed, the portion corresponding to the first groove portion 22a and the portion corresponding to the second groove portion 22b are arranged in a straight section, the portion corresponding to the third groove portion 22c is formed in a curved section (the curved shape is limited to the example shown in Fig. 6 .

The theoretical displacement is also shown in Fig. 6 as in Fig. 6, in this embodiment, the theoretical displacement coincides with the line connecting the center of each cam follower 42 (in other words, the center position of the cam follower 42 is The cam groove 22 is formed so as not to deviate from the theoretical displacement).

That is, in the first pressurization section corresponding to the first and second cam followers 42, the center line of the cam groove 22 is offset by a dimension of (Dd) / 2 + a from the theoretical displacement line Lt; / RTI > On the other hand, in the second pressurizing section corresponding to the fourth and fifth cam followers 42, the center line of the cam groove 22 is offset by a dimension of (D-d) / 2 + a in the opposite direction on the line of theoretical displacement. In the buffer section, the first and second pressure-pressure sections are connected by using curves in consideration of the offset. In this manner, the cam groove 22 is formed so that the center position of the cam follower 42 coincides with the theoretical displacement in all sections.

As described above, by preventing the center position of the cam follower 42 from deviating from the theoretical displacement, the error factor can be reduced, and high rotation accuracy can be realized. This is in contrast to the above-described conventional example in which the roller gear cam 20 is pressed against the rotary table 40 to perform pressure adjustment (in this example, backlash can be removed, but since the center position of the cam follower 42 deviates from the theoretical position, Resulting in an error in transmission).

In the above description, the two cam followers 42 have been described by taking as an example the cam groove 22 having the first groove portion 22a in contact with the one side face 24a and the second groove portion 22b in which the two cam followers 42 are in contact with the other side face 24b. As shown, one cam follower 42 may be a cam groove 22 having a first groove portion 22a in contact with one side face 24a and a second groove portion 22b in which one cam follower 42 is in contact with the other side face 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.

Hereinafter, a conventional four-point contact ball bearing 50 will be described with reference to FIG. 8, and a problem of the conventional four-point contact ball bearing 50 will be described. Next, 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.

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 has an annular inner ring portion 100 formed on the outer periphery of an inner ring portion groove 102 as an example of an outer circumferential groove, and an annular outer ring portion groove 54 formed as an example of an opposing circumferential groove facing the inner ring portion groove 102. (That is, two inner ring contact points 102a and 102b and two outer ring contact points 54a and 54b) provided between the inner ring portion groove 102 and the outer ring portion groove 54, A plurality of bead-shaped rolling elements 56 which are brought into contact with the rolling elements 56, and a retainer 58 for holding the rolling elements 56. And 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, the outer ring portion 52 is divided into two members, and the pressure adjusting operation for adjusting the pressure applied to the rolling member 56 by the outer ring portion 52 is performed. For example, as shown in Fig. 8, an annular gap 104 (i.e., a spacer) is inserted between the upper outer ring portion 52a and the lower outer ring portion 52b, and the thickness of the interposer 104 to be inserted is adjusted, Respectively. When the pressure is too low in a state where the spigot 104 is not inserted, the mounting surface of the upper outer ring part 52a and the lower outer ring part 52b is directly cut to adjust the pressure to be increased.

However, in this case, the following inconvenience occurred. Even in the case of making adjustments using the spacer 104, the step of separating the upper-side outer ring portion 52a and the lower-side outer ring portion 52b from the four-point contact ball bearing 50 once at the time of adjustment, And the adjustment work has become complicated. In addition, since re-realization after reassembly has changed, problems in precision management have also arisen.

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

9 is a side schematic view of the four-point contact ball bearing 50 according to the present embodiment.

The four-point contact ball bearing 50 has an annular outer ring portion 52 having an outer ring groove 54 as an example of an opposing circumferential groove facing the outer circumferential groove 44, an outer circumferential groove 44, Shaped rolling members 54 that are in contact with the outer peripheral groove 44 and the outer ring groove 54 and contact four points (that is, two outer peripheral contact points 44a and 44b and two outer ring contact points 54a and 54b) 56, and a retainer 58 for retaining the rolling member 56. [ However, unlike the conventional four-point contact ball bearing 50, the inner ring portion is not provided, and the outer circumferential groove 44 is provided on the outer periphery of the rotary table 40 (formed directly on the outer circumference).

The outer ring portion 52 is divided into two members, an upper outer ring portion 52a on which an upper portion 54c of the outer ring groove 54 is formed and a lower outer ring portion 52b on which a lower portion 54d of the outer ring groove 54 is formed. These two members are fastened by fastening bolts 62 as an example of fastening members formed on both members so as to follow the vertical direction.

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

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

The pressure adjusting screw 60 is for adjusting the pressure applied to the rolling member 56 by the outer ring portion 52. The pressure adjusting screw 60 is provided so as to extend along the upper and lower outer ring portions 52a and the lower outer ring portion 52b.

10 is a schematic explanatory diagram for explaining the adjustment of the pressurizing force by the pressurizing adjusting screw 60. As shown in FIG.

When the pressure adjusting screw 60 is fastened, the upper outer ring portion 52a is slightly displaced from the joint surface 62a formed by the fastening bolt 62 as a point (in FIG. 10, the upper outer ring portion 52a after displacement is indicated by a dotted line). That is, the outer upper portion 52c of the upper outer ring portion 52a floats, while the groove forming surface 52d forming the outer ring portion groove 54 is inclined toward the rolling body 56 (that is, tensile stress acts on the outer periphery of the upper outer ring portion 52a, The shape of the portion 52a is deformed, and the diameter of the groove forming surface 52d is reduced). By this stress deformation of the upper outer ring portion 52a, the pressure applied to the rolling member 56 is increased. On the other hand, when the pressure adjusting screw 60 is loosened, the motion of the upper side outer ring part 52a is reversed, and the pressurizing force is reduced. Also, their deformation behavior is similar to that of the diaphragm spring. The deformation with respect to the tightening force of the pressure adjusting screw 60 is not linear like the coil spring but is called nonlinear deformation.

In the above-described conventional example, at the time of adjustment, a process of separating the upper outer ring portion 52a or the lower outer ring portion 52b from the four-point contact ball bearing 50 once and then reassembling is necessary and the adjustment work is troublesome. According to the screw 60, the pressure adjusting operation can be performed without removing the upper outer ring portion 52a or the lower outer ring portion 52b. Therefore, the pressure adjusting operation becomes simple.

11 is a schematic top view of the four-point contact ball bearing 50 according to the present embodiment. 11, a plurality of pressure adjusting screws 60, fastening bolts 62, and mounting bolts 64 are provided at regular intervals along the circumferential direction of the outer ring part 52, respectively. As described above, the mounting bolt 64 and the pressure adjusting screw 60 are located radially outward of the fastening bolt 62, and the mounting bolt 64 and the pressure adjusting screw 60 are located at substantially the same positions in the radial direction.

The pressure adjusting screw 60 also has a function of correcting the difference in the axial center (the center 40b) of the rotary table 40 as well as the pressure adjusting function. For example, if the tightening force of the pressure adjusting screw 60 on the upper side of the line L in FIG. 11 is made larger than the tightening force of the lower side pressure adjusting screw 60 (if intentionally made different from the tightening), the upper and lower stress- The axis moves slightly downward due to the difference. Therefore, when the shaft center is slightly deviated from the designed position, the shaft center can be moved to the designed position using the pressure adjusting screw 60. [

=== Regarding the cam device 10 according to the second embodiment ===

In the above description, as the cam device 10, the cam device 10 having the roller gear cam 20 is taken as an example and the characteristic of the cam groove 22 and the characteristic four-point contact ball bearing 50 have been described. However, the configuration of the characteristic cam groove 22 and the characteristic four-point contact ball bearing 50 are not limited to the cam device 10 having the roller gear cam 20. Here, the cam device 10 having the barrel cam 21 as the cam device 10 according to the second embodiment will be described.

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 rotationally driven by a motor (not shown) and a rotary table 40 as an example of a rotary member.

The barrel cam 21 is provided with a cam groove 22 and is rotatably (rotatably) supported by the pair of rolling bearings 30 with respect to the housing 32. A motor (not shown) is fastened to the barrel cam 21 at one end thereof, and the barrel cam 21 is rotationally driven by the driving force of the motor. In addition, the barrel cam 21 is integrally provided with the input shaft 34.

The rotary table 40 has a role of, for example, holding a workpiece. The rotary table 40 is rotatably (rotatably) supported by the housing 32 by a four-point contact ball bearing 50 as an example of a bearing. A plurality of cam followers 42 are provided on the lower surface of the turntable 40 so as to be downwardly disposed on the lower surface of the turret 40a. The cam followers 42 are disposed at regular intervals along the circumferential direction of the turret 40a Are arranged at regular intervals along the circumferential direction so as to be parallel to the rotation axis direction of the rotary table 40). The cam follower 42 is engaged with the cam groove 22 of the barrel cam 21 (engaged with the cam groove 22), and the rotational force of the motor is transmitted to the rotary table 40 through the barrel cam 21 and the cam follower 42. That is, the rotary table 40 rotates in accordance with the rotation of the barrel cam 21.

<<< Regarding 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.

13 and 14, the shape of the cam groove 22 of the barrel cam 21 according to the conventional example will be described below, and the problem of the barrel cam 21 according to the conventional example will be described. Next, 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 Fig. 13 is a state diagram showing the shape of engagement in the design. In the left figure, three cam followers 42 (numbered 1 to 3) are engaged with the cam groove 22 of the barrel cam 21 at the same time. Further, 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 contact the side surface 24 of the cam groove 22. That is, the gap 80 between the side surfaces 24 of the cam groove 22 with respect to any of the three cam followers 42.

14 is a graph showing the relationship between the horizontal axis (x axis) of the barrel cam 21 and the vertical position (y axis) of the angular position at which the cam follower 42 is located when viewed from the center 40b of the rotary table 40 13). &Lt; / RTI >

As shown in Fig. 14, the portions corresponding to the cam grooves 22 in the timing diagram (concretely, lines connecting the median values in the y-axis direction of both sides 24 of the cam groove 22 in Fig. 14) It is a straight line section.

In other words, a portion corresponding to each of the two side surfaces 24 of the cam groove 22 has a portion corresponding to one side surface 24a and a portion corresponding to the other side surface 24b opposite to the side surface 24a, (One side surface 24a and the other side surface 24b are parallel to each other since the cam groove width D of the cam groove 22 is designed to be the same at any position of the cam groove 22).

14, no cam follower 42 is in contact with any of the side surface 24a and the other side surface 24b of the cam groove 22.

In the above-described embodiment (also referred to as the first embodiment) of the cam device 10 provided with the roller gear cam 20 here, in order to prevent the occurrence of backlash, pressure is applied to the rotary table 40 side by the roller gear cam 20, However, in the cam device 10 provided with the barrel cam 21, backlash can not be prevented from occurring even if the barrel cam 21 applies pressure to the rotating table 40 side (in this respect, in the first embodiment . 13, even if the cam follower 42 comes into contact with the side surface 24 of the cam groove 22 by applying the pressure to the rotary table 40 side of the barrel cam 21, any of the three cam followers 42 The back side lash can not be prevented from occurring as in the first embodiment. Therefore, the problem of the conventional example in the second embodiment (cam device 10 provided with the barrel cam 21) is that backlash occurs.

In order to solve the above problem, in the second embodiment, the cam groove 22 of the barrel cam 21 has the same shape as that of the first embodiment.

Fig. 15 is a view corresponding to Fig. 13, showing a state in which the barrel cam 21 according to the second embodiment is engaged with the cam follower 42. Fig.

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

The cam follower 42 is in contact with the cam groove 22. Specifically, the first cam follower 42 is in contact with the one side surface 24a of the cam groove 22 and does not contact the other side surface 24b (it has a gap 80 with the other side surface 24b). The third cam follower 42, on the other hand, is in contact with the other side 24b and does not come in contact with one side 24a (it has a gap 80 between one side 24a). Therefore, the rotation directions 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 of the side surface 24a and the other side surface 24b.

Fig. 16 is a view corresponding to Fig. 14, in which the horizontal axis (x axis) of the rotation angle of the barrel cam 21 and the angular position at which the cam follower 42 is positioned when viewed from the center 40b of the rotary table 40 is taken as the vertical axis (Corresponding to Fig. 15) according to the second embodiment.

16, as described above, the first cam follower 42 contacts only one side surface 24a of the two side surfaces 24, the third cam follower 42 contacts only the other side surface 24b of the two side surfaces 24, The cam follower 42 does not contact any side surface 24.

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

Unlike the conventional example described above, in the cam groove 22, the portions corresponding to the first groove portion 22a and the second groove portion 22b (the line connecting the above-mentioned median values) in the timing diagram become a straight line section, And a portion corresponding to the groove portion 22c has a shape such that it becomes a curve section connecting the two linear segments.

That is, in the present embodiment, as shown in Fig. 16, not all of the portions corresponding to the cam grooves 22 are formed as rectilinear sections, but a rectilinear section that is prepared for aligning the cam followers 42 on one side surface 24a and generating a pressurization (Corresponding to the pressure section) and the cam follower 42 to which the pressurized pressure is applied, in the other straight section to the other straight section (Corresponding to the rotation direction switching period of the outer ring of the cam follower, that is, the buffering period) in which the pressurizing pressure prepared for smooth transition is not applied.

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

<< Four-Point Contact Ball Bearing 50 in Cam Device 10 according to Second Embodiment >>>

12, the cam device 10 having the barrel cam 21 according to the second embodiment can also be provided with the same four-point contact ball bearing 50 as in the first embodiment (Fig. 1). Therefore, even in the cam device 10 provided with the barrel cam 21 according to the second embodiment, it is possible to enjoy the above-mentioned advantages by installing the pressure adjusting screw 60. [

=== Effectiveness of cam groove shape of cam device 10 according to the above-described embodiment (first and second embodiment) ===

The cam device 10 according to the above embodiment has the cam groove 22 and has a rotatable cam 40 and a plurality of cam followers 42 for engaging the cam grooves 22 and has a rotary table 40 that rotates in accordance with the rotation of the cam. The cam groove 22 has a first groove portion 22a in which at least one cam follower 42 of the plurality of cam followers 42 is in contact with the side surface 24a of the cam groove 22 and at least one cam follower 42 of the plurality of cam followers 42, A second groove portion 22b contacting the other side surface 24b opposite to the one side surface 24a and a third groove portion 22c connecting with the second groove portion 22a and the second groove portion 22b, and the cam follower 42 positioned in the third groove portion 22c And the third groove portion 22c which does not contact either one of the side surface 24a and the other side surface 24b. The cam groove 22 has an axis of rotation of the cam in the horizontal axis and an angular position in which the cam follower 42 is located when viewed from the center of the rotation table 40 All of the portions corresponding to the first groove portion 22a and the second groove portion 22b are in the linear section and the portion corresponding to the third groove portion 22c is formed in the two straight sections To which the S-curve, which is equipped with the same shape.

Therefore, as described above, there is no need to adjust the pressurization by moving the inter-shaft distance and there is no problem that the rotation accuracy of the rotary table 40 is deteriorated (first embodiment). Also, occurrence of backlash is appropriately prevented (the first embodiment and the 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 based on the above embodiment has been described above. However, the above-mentioned embodiments of the invention are for the purpose of facilitating understanding of the present invention, and the present invention is not limited thereto. It is to be understood that the present invention may be changed and modified without departing from the spirit and scope of the present invention.

In the above-described embodiment, as shown in Fig. 11, the mounting bolt 64 and the pressure adjusting screw 60 are located at almost the same positions in the radial direction, but the present invention is not limited thereto. For example, as shown in Fig. 17, the mounting bolt 64 may be positioned radially outward of the pressure adjusting screw 60.

17, the mounting bolt 64 fixes the lower outer ring portion 52b to the housing 32, but the present invention is not limited to this, and the upper outer ring portion 52a may be fixed to the housing 32 as shown in Fig. 18 . In the example of FIG. 18, as shown by the dotted line in the drawing, the lower outer ring portion 52b is displaced by the pressure adjustment by the pressure adjusting screw 60, unlike the example of FIG. Also, by displacing the lower outer ring portion 52b, the magnitude of the applied pressure given to the rolling member 56 can be changed.

In the above embodiment, the four-point contact ball bearing 50 has been described as an example of the bearing. However, the present invention is not limited to this and can be applied to all other bearings such as a rolling bearing. For example, as shown in Figs. 19 to 22, a cross roller bearing 51 is also preferable. FIG. 19 is a view corresponding to FIG. 9, and is a side view of the cross roller bearing 51. FIG. Fig. 20 is a view corresponding to Fig. 10 and is an explanatory view for explaining the adjustment of the pressurizing force of the pressurization adjusting screw 60. Fig. Fig. 21 is a view corresponding to Fig. 17 and is an explanatory view for explaining the adjustment of the pressurizing force of the pressurizing adjusting screw 60. Fig. Fig. 22 is a view corresponding to Fig. 18 and is an explanatory view for explaining the adjustment of the pressurizing force of the pressurizing adjusting screw 60. Fig.

In the above-described embodiment, bearings provided in the cam device 10 have been described as an example, but the present invention is not limited thereto. The present invention is also applicable to a bearing installed in a device other than the cam device 10. [

10 cam device
20 Roller gear cam
21 barrel cam
22 Cam home
22a First groove
22b Second groove
22c Third groove
24 side
24a one side
24b the other side
30 Rolling bearings
32 housing
34 Input shaft
40 Rotating Table
40a Tillet
40b center
42 Cam Follower
44 Outer Home
44a outer peripheral groove contact
44b Outer groove contact
50 4 point contact ball bearing
51 Crossed roller bearings
52 outer ring part
52a upper ring portion
52b Lower outer ring part
52c outer upper portion
52d groove forming surface
54 Outer ring groove
54a outer ring contact
54b outer ring contact
54c upper portion
54d lower portion
56 rolling body
58 viewers
60 Pressure adjusting screw
62 fastening bolt
62a joint surface
64 mounting bolts
80 niche
100 inner ring portion
102 inner ring groove
102a outer ring contact
102b outer ring contact
104 interstate

Claims

An outer ring portion formed with an opposing circumferential groove facing the outer circumferential groove provided on the outer periphery of the rotatable rotary member,
And a plurality of rolling elements provided between the outer circumferential grooves and the opposed circumferential grooves and contacting and rolling with the outer circumferential grooves and the opposed circumferential grooves,
The outer ring portion is divided into two members, an upper outer ring portion having an upper end portion of the opposite circumferential groove and a lower outer ring portion having a lower portion of the opposite circumferential groove formed therein, and the upper outer ring portion and the lower outer ring portion And further comprising a fastening member,
And the outer ring portion is provided on the outer side of the upper outer ring portion and the lower outer ring portion on the outer side of the coupling member in the radial direction of the rotary member and has an adjusting screw for allowing the outer ring portion to adjust the pressurizing force applied to the rolling member. Bearing.

A cam having a cam groove, a rotatable cam,
A rotating member having a plurality of cam followers engaging with the cam groove and rotating in accordance with rotation of the cam;
An outer ring portion having an opposite circumferential groove formed in an outer circumferential groove provided on an outer circumference of the rotary member; and a plurality of teeth arranged in contact with the outer circumferential groove and the opposed circumferential groove, Wherein the outer ring portion is divided into two members, an upper outer ring portion on which an upper portion of the opposite circumferential groove is formed and a lower outer ring portion on which a lower portion of the opposite circumferential groove is formed, And a bearing having a coupling member for coupling the outer ring part,
The outer ring portion of the bearing has an adjusting screw which is provided on the outer side of the upper outer ring portion and the lower outer ring portion on the outer side of the fastening member in the radial direction of the rotary member so that the outer ring portion adjusts the pressurizing force applied to the rolling body Characterized by a cam device.

The cam device according to claim 2,
Wherein the cam groove includes a first groove portion in which at least one of the plurality of cam followers is in contact with a side surface of the cam groove, and at least one cam follower of the plurality of cam followers And a third groove portion connecting the first groove portion and the second groove portion, wherein the cam follower positioned in the third groove portion is a groove portion connecting the one side surface and the other side surface And a second groove part
The cam groove
Wherein the camshaft has a horizontal axis, and the camshow is located at an angular position on the vertical axis, the portion corresponding to the first groove portion and the second groove portion Wherein the first groove portion and the second groove portion have a shape in which a straight line section is formed and a portion corresponding to the third groove section is a curve section connecting the two straight line sections.