JP2017155773A - Rolling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling device in which its productivity is high and a superior operativeness is attained at a low cost.SOLUTION: This invention relates to a rolling device 10 including a first member 1, a second member 2 and a roller body 5 arranged between the first member 1 and the second member 2 in which the second member 2 can be moved along the first member 1 through rolling action of the roller body 5. There are provided a rolling passage composed of a rolling groove 1a formed at the first member 1 and a rolling groove 3a formed at the second member 2 in opposition to the rolling groove 1a of the first member 1 and a circulation passage provided at the second member 2 to cause the rolling body 5 to communicate with the rolling passage and a speed control member 20 made of elastic material and contacted with the rolling body 5 to control speed of the rolling body 5 is installed in the circulation passage.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rolling device.

  Conventionally, a linear motion guide device (linear guide device) having a linear guide rail, a curved motion guide device having a curved guide rail, and a ball screw device are known as rolling devices.

  Among rolling devices, for example, a linear motion guide device connects a rolling path of a rolling element including a rolling groove provided on a guide rail and a rolling groove provided on a slider body, and a starting point and an end point of the rolling path. Thus, a circulation path for circulating the rolling elements is provided. The circulation path includes a return path provided in the slider body and a direction changing path provided in the end cap.

  In such a linear motion guide device, when the slider travels, the rolling elements that enter the rolling path from the circulation path are likely to be congested near the exit of the circulation path, that is, near the exit in the direction change path of the end cap. . When the rolling elements become overcrowded in the direction change path, a so-called ball slide occurs in which the rolling elements that have lost their refuge due to the pressing of the rolling elements roll along the direction change path. As a result, the frictional force between the rolling element and the direction change path suddenly increases, so that the operability of the linear motion guide device is deteriorated, or the direction change path and the rolling element are damaged and the linear motion guide device is damaged. There was a risk of failure.

  Under such a background, by designing the length of the rolling groove of the slider body and the shape of the tongue portion of the end cap to the optimum dimensions, by arranging the holding piece of the optimum dimension between the rolling elements, etc. A linear motion guide device has been proposed in which the ball sliding of the rolling element is suppressed to improve the operability (see, for example, Patent Document 1).

JP 2002-21848 A

  However, in the conventional linear motion guide device as described above, it is necessary to optimally design the dimensions and mounting positions of each component. For this reason, high component accuracy and high alignment accuracy of each component are required, which is disadvantageous in terms of productivity and cost.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a rolling device with high productivity, low cost and good operability.

In order to solve the above problems, the present invention
A first member; a second member; and a rolling element disposed between the first member and the second member. The second member is moved along the first member by rolling of the rolling element. In a movable rolling device,
A rolling path comprising a rolling groove formed in the first member and a rolling groove formed in the second member so as to face the rolling groove of the first member; and provided in the second member. A circulation path that circulates the rolling elements in communication with the rolling path,
There is provided a rolling device characterized in that a speed control member made of an elastic material and controlling the speed of the rolling element in contact with the rolling element is provided in the circulation path.

  According to the present invention, it is possible to provide a rolling device with high productivity, low cost, and good operability.

Fig.1 (a) is a figure which shows the linear motion guide apparatus which is a rolling device based on 1st Embodiment, FIG.1 (b) is a figure which shows the structure of an end cap. FIG. 2A is an enlarged cross-sectional view (a cross-sectional view taken along the line 1A-1A in FIG. 1B) showing the state of the direction change path in the linear guide apparatus of the first embodiment, and FIG. 2B is a speed control. It is a figure (2A-2A sectional view of Drawing 2 (a)) showing the composition of a member, and Drawing 2 (c) and Drawing 2 (d) are figures showing a different mode of a speed control member. FIG. 3A is a view showing a first modification of the linear motion guide device of the first embodiment, and FIG. 3B is a view showing the configuration of the speed control member (3A-3A in FIG. 3A). FIG. Fig.4 (a) is a figure which shows the 2nd modification of the linear guide apparatus of 1st Embodiment, FIG.4 (b) is a figure which shows the structure of a speed control member (4A-4A of Fig.4 (a)) FIG. Fig.5 (a) is a figure which shows the ball screw apparatus which is a rolling apparatus based on 2nd Embodiment, FIG.5 (b) is a figure which shows the structure of a piece member.

A rolling device according to an embodiment of the present invention will be described with reference to the accompanying drawings.
(First embodiment)
A linear motion guide device 10 that is a rolling device according to the present embodiment shown in FIG. 1A is used for a machine tool, a transport device, and other production equipment, and includes a linear guide rail 1 and a guide rail. 1 and a slider 2 movable along the line 1.

  The guide rail 1 is made of a substantially quadrangular prism-shaped metal member, and two rolling grooves 1a extending in the longitudinal direction are formed on both side surfaces thereof.

The slider 2 includes a slider body 3 and end caps 4 and 4 attached to both ends of the slider body 3 in the longitudinal direction.
The slider body 3 is made of a metal member that extends in the longitudinal direction of the guide rail 1 and has a substantially U-shaped cross section, and is straddled over the guide rail 1. Two rolling grooves 3 a extending in the longitudinal direction facing the rolling grooves 1 a of the guide rail 1 are provided on the portions of the slider body 3 facing the both sides of the guide rail 1, that is, the inner surfaces of the legs on both sides. Is formed.
The rolling groove 3 a of the slider body 3 and the rolling groove 1 a of the guide rail 1 constitute a rolling path (load rolling path) of the rolling element 5.
Two straight return paths 3b penetrating in the longitudinal direction of the slider body 3 are formed in parallel with the rolling grooves 3a on the legs on both sides of the slider body 3.

  The end cap 4 is made of a substantially U-shaped resin member. As shown also in FIG.1 (b), the direction change path 6 is formed in two places at the leg part of both sides in the surface at the side of the slider main body 3 of the end cap 4. As shown in FIG. As shown in FIGS. 1A and 2A, the direction changing path 6 communicates the rolling path and the return path 3b and has a semicircular arc shape. The direction change path 6 will be described in detail later. The end cap 4 is not limited to resin and may be made of metal.

  The return path 3b of the slider body 3 and the direction change path 6 of the end cap 4 constitute a circulation path for circulating the rolling elements 5 to the rolling path. As shown in FIG. 1A, a large number of metal balls are loaded as rolling elements 5 in the circulation path and the rolling path.

  With the above configuration, the slider 2 can linearly move on the guide rail 1 by the rolling element 5 rolling on the rolling path. In addition, the rolling element 5 that has rolled in the rolling path is guided to the rolling path again through the circulation path, and can circulate through the rolling path and the circulation path.

  As shown in FIG. 1B, on the surface of the end cap 4 on the slider body 3 side, two semicircular rolling grooves (upper rolling groove and lower rolling groove) 4a, 4b are formed on each leg portion. Are formed, and a semi-cylindrical recess 4c is further formed so as to intersect these. As shown in FIG. 2A, the recess 4c has a semi-cylindrical shape formed with two rolling grooves 7a and 7b (7a not shown) facing the upper rolling groove 4a and the lower rolling groove 4b. Return guide 7 is attached. The above-described direction change paths 6 and 6 are constituted by the upper rolling groove 4 a and the lower rolling groove 4 b of the end cap 4 and the two rolling grooves 7 a and 7 b of the return guide 7. In addition, as shown in FIG.1 (b), two tongue parts 8 for scooping up the rolling element 5 which rolled the rolling path and guide | inducing to the direction change path 6 are provided in the inner surface of each leg part of the end cap 4. As shown in FIG. Each is formed integrally.

  In this embodiment, the speed control member 20 is provided in the rolling groove 7b of the return guide 7 as shown in FIGS. 2 (a) and 2 (b). The speed control member 20 controls the speed of the rolling element 5 by directly contacting the rolling element 5 rolling on the direction change path 6. The speed control member 20 is a brush made of an elastic material, and extends inward in the radial direction of the direction change path 6 as shown in FIG. 2 (a), and the direction change path as shown in FIG. 2 (b). 6 as a whole, viewed from the direction of travel. The speed control member 20 is attached with an adhesive near the entrance / exit of the rolling path at the bottom of the rolling groove 7b.

  Note that the speed control member 20 is not limited to a brush, and may be a single thin plate shown in FIG. 2C or a plurality of thin plates arranged in a goodwill shape shown in FIG. The attachment of the speed control member 20 to the rolling groove 7b is not limited to an adhesive, and a configuration in which a concave portion is provided in the rolling groove 7b and the speed control member 20 is fitted, or the speed control member 20 and the return guide 7 are integrally formed. It is good also as a structure to perform.

It is desirable to use an elastic material having a flexural modulus of 80 to 1000 MPa for the speed control member 20. Examples of elastic materials that satisfy this requirement include thermoplastic elastomers, soft vinyl chloride, soft polyethylene, fluororesin, and synthetic rubber.
Specifically, polyamide elastomer (PA) 6, PA66, PA11, PA12, etc. as hard segments as thermoplastic elastomer (TPE), polybutylene terephthalate (PBT), polyethylene naphthalate (PBN), etc. are hard. Polyester elastomers, olefin elastomers, urethane elastomers, styrene elastomers, nitrile rubber elastomers, and the like are preferred as the segment.
Examples of fluororesins include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene (FEP), and ethylene-chlorotrifluoroethylene copolymer (ECTFE). In particular, PFA, FEP, and ECTFE, which can be injection molded, are particularly preferable.

It is desirable that the speed control member 20 satisfies the following conditional expression (1).
(1) E−d / 2 <D
However,
D: Length of the speed control member 20 in the radial direction of the direction change path 6 E: Diameter of the direction change path 6 d: Diameter of the rolling element 5

  Conditional expression (1) is a conditional expression that defines the length of the speed control member 20 in the radial direction of the direction change path 6. If the length of the speed control member 20 is less than the lower limit value of the conditional expression (1), the speed of the rolling element 5 that rolls on the direction change path 6 cannot be lowered sufficiently, which is not preferable.

  The speed control member 20 provided in the rolling groove 7b of the return guide 7 has been described above, but the speed control member 20 (not shown) is similarly provided in the rolling groove 7a of the return guide 7.

  By providing the speed control member 20 having the above configuration in the rolling grooves 7 a and 7 b of the return guide 7, the rolling element 5 that rolls the direction change path 6 toward the rolling path contacts the speed control member 20. The rolling element 5 in contact with the speed control member 20 rolls on the direction change path 6 while pushing and retracting the speed control member 20 to be elastically deformed, and is guided into the rolling path by the tongue portion 8. The elastically deformed speed control member 20 returns to its original shape after passing through the rolling element 5.

  When the rolling element 5 contacts the speed control member 20 as described above, the speed of the rolling element 5 is reduced to a substantially constant value. In this way, by controlling the speed of each rolling element 5 by the speed control member 20, the filling rate of the rolling element 5 in the space from the speed control member 20 in the direction change path 6 to the tip of the tongue portion 8 is set. It can always be kept substantially constant. Thereby, it can prevent that the rolling element 5 becomes an overcrowded state near the exit in the direction change path 6, and can suppress generation | occurrence | production of a ball slip. Therefore, since it is possible to prevent the frictional force between the rolling element 5 and the direction change path 6 from increasing suddenly, it is possible to prevent the linear motion guide device 10 from being broken due to the damage to the direction change path 6 or the rolling element 5. Good operability of the movement guide device 10 can be achieved.

The linear motion guide device 10 according to the present embodiment needs to optimally design the dimensions and mounting positions of each component as in the above-described conventional linear motion guide device, and has high component accuracy and high alignment of each component. Since no accuracy is required, high productivity and low cost can be achieved.
In addition, when the conventional linear motion guide device is provided with crowning at both ends in the longitudinal direction of the rolling groove of the slider body, in order to suppress fluctuations in the filling rate of the rolling elements around the crowning, it is adapted to the preload specification of the rolling path. It was necessary to determine the optimum crowning shape, which was further disadvantageous in terms of productivity and cost. Even in such a case, the linear motion guide device 10 according to the present embodiment does not need to strictly define the shape of the crowning, and thus can achieve high productivity and cost reduction.

  Here, in this embodiment, the speed control member 20 is provided in the rolling grooves 7a and 7b of the return guide 7 as described above. However, the position of the speed control member 20 is not limited to this, and the following first, It can also be configured as in the second modification.

(First modification)
As shown in FIGS. 3A and 3B, a speed control member 20 may be provided in the lower rolling groove 4 b of the end cap 4. Specifically, the speed control member 20 may be provided in the vicinity of the exit on the rolling road side at the groove bottom of the lower rolling groove 7b. In this case, a speed control member 20 (not shown) is similarly provided in the upper rolling groove 4a of the end cap 4. With such a configuration, the same effects as those of the first embodiment can be obtained.

(Second modification)
The first embodiment and the first modification may be combined. That is, as shown in FIGS. 4A and 4B, the speed control member 20 is provided so as to face both the rolling groove 7b of the return guide 7 and the lower rolling groove 4b of the end cap 4. May be. In this case, the speed control member 20 (not shown) is similarly provided in the rolling groove 7a of the return guide 7 and the upper rolling groove 4a of the end cap 4. With such a configuration, the same effects as those of the first embodiment can be obtained, and in particular, the speed of the rolling element 5 that rolls on the direction change path 6 can be controlled better.

  As described above, in the first embodiment, the linear motion guide device including the ball as the rolling element is shown. However, the present invention is not limited to this, and can also be applied to a linear guide device provided with rollers as rolling elements. Further, the present invention is not limited to a linear motion guide device, but can also be applied to a curved motion guide device.

(Second Embodiment)
A ball screw device 30 which is a rolling device according to the second embodiment shown in FIG. 5A includes a screw shaft 31 and a nut 32 screwed onto the screw shaft 31 via a rolling element 34.

The screw shaft 31 is made of an elongated cylindrical metal member. A rolling groove 31 a is spirally formed on the outer peripheral surface of the screw shaft 31.
The nut 32 is made of a substantially cylindrical metal member in which a circular through hole larger than the outer diameter of the screw shaft 31 is formed. A rolling groove 32 a is spirally formed on the inner peripheral surface of the nut 32 so as to correspond to the rolling groove 31 a of the screw shaft 31.
The screw shaft 31 is inserted into the through hole of the nut 32, and the rolling grooves 31a and 32a face each other to form a rolling path. A rolling element 34 is loaded on the rolling path, and the screw shaft 31 and the nut 32 are screwed together.

The nut 32 is formed with a linear return path 32b penetrating in the axial direction. The top members 35 are embedded in both end portions of the nut 32 in the axial direction.
As shown in FIG. 5B, the top member 35 is made of a substantially triangular prism-shaped resin member, and a direction changing path 35a is formed. As shown in FIG. 5A, the direction changing path 35a communicates the rolling path and the return path 32b and has a substantially arc shape. The top member 35 is not limited to resin but may be metal.

  The return path 32b of the nut 32 and the direction changing path 35a of the top member 35 constitute a circulation path for circulating the rolling elements 34 to the rolling path. A large number of metal balls are loaded as rolling elements 34 in the circulation path and the rolling path.

  With the above configuration, by rotating one of the screw shaft 31 and the nut 32, the rolling element 34 rolls in the rolling path, and the other can be linearly moved in the axial direction. In addition, the rolling element 34 that has rolled in the rolling path is guided again to the rolling path through the circulation path, and can circulate through the rolling path and the circulation path.

  In the present embodiment, the speed control member 21 is provided in the direction change path 35a of the top member 35 as shown in FIG. The speed control member 21 controls the speed of the rolling element 34 by contacting the rolling element 34 rolling on the direction changing path 35a, and is composed of an elastically deformable brush extending toward the center of the direction changing path 35a. . The speed control member 21 is attached with an adhesive near the entrance / exit on the rolling road side, that is, near the tongue 35b at the groove bottom of the direction changing path 35a. The configuration of the speed control member 21 is the same as that of the speed control member 20 in the first embodiment.

  With this configuration, the ball screw device 30 according to the present embodiment can achieve the same effects as those of the first embodiment. The present invention is not limited to the ball screw device 30 including the piece member 35 as in the present embodiment, but includes a ball screw including other circulation members (for example, a return tube and a guide plate) for circulating the rolling elements 34. It is also possible to apply to an apparatus.

  As described above, according to each embodiment, it is possible to realize a rolling device with high productivity, low cost, and good operability.

DESCRIPTION OF SYMBOLS 1 Guide rail 1a Rolling groove 2 of a guide rail 2 Slider 3 Slider main body 3a Rolling groove 3b of a slider main body Return path 4 of a slider main body 5 End caps 5, 34 Rolling body 6 End cap direction change path 10 Linear motion guide device (linear Guide device)
20, 21 Speed control member 30 Ball screw device 31 Screw shaft 31a Rolling groove 32 of screw shaft Nut 32a Rolling groove 32b of nut Nut return path 35 Top member 35a Direction change path of top member

Claims (7)

A first member; a second member; and a rolling element disposed between the first member and the second member. The second member is moved along the first member by rolling of the rolling element. In a movable rolling device,
A rolling path comprising a rolling groove formed in the first member and a rolling groove formed in the second member so as to face the rolling groove of the first member; and provided in the second member. A circulation path that circulates the rolling elements in communication with the rolling path,
A rolling device comprising a speed control member made of an elastic material and controlling the speed of the rolling element in contact with the rolling element in the circulation path.   The rolling device according to claim 1, wherein the speed control member is disposed at an entrance / exit of the circulation path.   The rolling device according to claim 1, wherein the speed control member extends inward in the radial direction of the circulation path, and includes a brush, a thin plate, or a plurality of thin plates having a goodwill shape. The rolling device according to any one of claims 1 to 3, wherein the speed control member extends inward in the radial direction of the circulation path and satisfies the following conditional expression.
E−d / 2 <D
However,
D: Length of the speed control member in the radial direction of the circulation path E: Diameter of the circulation path d: Diameter of the rolling element   The rolling device according to any one of claims 1 to 4, wherein the speed control member is made of a thermoplastic elastomer, soft vinyl chloride, soft polyethylene, a fluororesin, or a synthetic rubber. The first member comprises a guide rail;
The second member has a slider body, an end cap, and a return guide,
The circulation path includes a return path formed in the slider body, a rolling groove formed in the end cap, and a rolling groove formed in the return guide so as to face the rolling groove of the end cap. It consists of a turning path
The rolling device according to any one of claims 1 to 5, wherein the speed control member is arranged in at least one of a rolling groove of the end cap and a rolling groove of the return guide. . The first member comprises a screw shaft;
The second member has a nut and a circulation member for circulating the rolling element,
The circulation path includes a direction changing path formed in the circulation member,
The rolling device according to any one of claims 1 to 5, wherein the speed control member is disposed in the direction change path.

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