Linear motion device

Abstract

To provide a liner motion device capable of detecting foreign matter such as abrasion powder and peeling pieces with a simple configuration.SOLUTION: A linear motion device includes a long guide member, a movable body that can move on the guide member relative to the guide member, and an adsorption member that is provided on the guide member at a position facing the movable body and has magnetism that allows it to adsorb metallic foreign matter.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a linear motion device such as a linear guide or a ball screw. [Background technology]

[0002] In general industrial conveying devices, robots, and the like, linear motion devices are often incorporated to convey objects and perform precise positioning. Such linear motion devices include, for example, guide mechanisms and feed mechanisms in conveying devices, robots, and the like. Specific examples of linear motion devices include, for example, linear guides, ball screws, and the like.

[0003] In order to efficiently maintain and manage the accuracy and function, there is an increasing need for abnormality detection and condition monitoring of linear motion devices. For example, Patent Document 1 discloses a screw device capable of detecting the iron powder concentration of a lubricant supplied into a nut and the oil content of the lubricant. In this screw device, a lubricant discharge hole is provided in the nut or the seal cap, and the oil content and iron powder concentration of the lubricant discharged from the lubricant discharge hole to the outside of the nut are measured by an oil content meter and an iron powder concentration meter.

[0004] Moreover, Patent Document 2 discloses a detection device that detects the amount of iron powder in a liquid that contains fine iron powder, such as from a cylinder drain, to detect the wear state of engine parts. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-180380 A [Patent Document 2] JP 2008-190963 A Summary of the Invention [Problem to be solved by the invention]

[0006] The devices disclosed in Patent Documents 1 and 2 both require piping connecting a lubricant supply inlet and a lubricant discharge outlet, a lubricant pressure-feed pump that pressure-feeds the lubricant into the piping, and measuring instruments such as an iron powder concentration meter and an oil content meter, which increases costs and increases the size of the device.

[0007] The present invention provides a linear motion device capable of detecting foreign matter such as wear powder and flaking debris with a simple configuration. [Means for solving the problem]

[0008] The above object of the present invention can be achieved by the following configuration. (1) an elongated guide member; a movable body that is movable on the guide member relative to the guide member; an attraction member that is provided on the guide member at a position facing the movable body and has magnetism capable of attracting metallic foreign objects; A linear motion device comprising: (2) The adsorption member contains magnetic metal powder. The linear motion device described in (1). (3) The attraction member is obtained by molding a mixture of the magnetic metal powder and a resin or rubber. A linear motion device as described in (2). (4) The color of the adsorption member is different from that of the foreign matter. A linear motion device according to any one of (1) to (3). (5) The magnetic force of the attraction member is BHMax: 1.6 to 111 [KJ / m 3 ], A linear motion device according to any one of (1) to (4). (6) The moving body includes a magnetic sensor disposed opposite the attraction member and capable of detecting a change in a magnetic field. A linear motion device according to any one of (1) to (5). Effect of the Invention

[0009] According to the present invention, it is possible to detect foreign matter with a simple configuration, and by capturing wear powder generated by magnetic force with an adsorption member, it is possible to slow the progression of wear and tear, thereby making it possible to extend the life of the linear motion device. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view of a linear guide that is a specific example of a linear motion device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of a linear guide as a specific example of a linear motion device according to a second embodiment of the present invention. [Diagram 3] FIG. 3 is a side view of a ball screw as a specific example of a linear motion device according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A linear motion device according to an embodiment of the present invention will now be described in detail with reference to the drawings. Fig. 1 is a cross-sectional view of a linear guide 100 which is a specific example of a linear motion device according to a first embodiment of the present invention.

[0012] The linear guide 100 includes a long rail 10, a bearing 20 movable relative to the rail 10, and an adsorption member 30 capable of adsorbing foreign matter generated by the relative movement between the rail 10 and the bearing 20.

[0013] The rail 10 is an elongated guide member, and extends in the depth direction relative to the plane of FIG.

[0014] The bearing 20 is a movable body that is movable on the rail 10 relatively to the rail 10, and moves in the depth direction relative to the plane of the paper in FIG.

[0015] The rail 10 and the bearing 20 are formed with rolling grooves 11 and 21, respectively, facing each other. Between these rolling grooves 11 and 21, rolling elements 40 such as steel balls are disposed, thereby reducing the frictional force generated between the rail 10 and the bearing 20.

[0016] The attraction member 30 is provided at a position on the rail 10 facing the bearing 20. The attraction member 30 is disposed at a location other than the load-bearing portion of the rail 10 that moves relative to the rail 10, i.e., a location other than the rolling groove 11. In this embodiment, the attraction member 30 is provided between adjacent rolling grooves 11, 11 on both side surfaces of the rail 10, facing both legs of the bearing 20 that straddles the rail 10.

[0017] The attraction member 30 is made of resin or rubber etc. that is molded by mixing magnetic metal powder, and has a magnetic property that allows it to attract metallic foreign matter such as wear powder and peeling debris. The attraction member 30 has, for example, a thin tape-like shape and extends along the direction of relative movement between the rail 10 and the bearing 20 (the depth direction of the paper in FIG. 1). In this embodiment, it is attached to the rail 10 using an adhesive over the entire length of the rail 10. In this way, it is preferable from the viewpoint of improving the foreign matter attraction function that the attraction member 30 is arranged without any gaps in the direction of relative movement between the rail 10 and the bearing 20 (the depth direction of the paper in FIG. 1).

[0018] The attraction member 30 is provided in an area of ​​the side surface of the rail 10 where the rolling groove 11 is not formed, and is also separated from the bearing 20. Therefore, the attraction member 30 is prevented from contacting the rolling elements 40 and the bearing 20, and peeling off from the rail 10 is suppressed.

[0019] In general, the rail 10, the bearing 20, the rolling element 40, and other components constituting a linear motion device such as the linear guide 100 are made of steel. The linear guide 100 may be used in harsh environments. For example, the linear guide 100 may be used for a long period of time, continuously under an excessive load, or in the presence of foreign matter. In such harsh environments, foreign matter such as metallic wear powder and peeling pieces may be generated from the steel rolling elements 40, rolling grooves 11, 21, and other components. The generated foreign matter may cause a decrease in the functionality of the linear guide 100, and in general industrial conveyance devices, robots, and the like incorporating the linear guide 100 (deterioration in mounting accuracy, generation of abnormal noise and vibration, etc.).

[0020] In the linear guide 100 of the first embodiment, the attraction member 30 can attract and hold foreign matter such as metallic wear powder and peeling pieces by its magnetic force. The foreign matter holding function of the attraction member 30 suppresses the occurrence of foreign matter coming into contact with the components of the linear guide 100, making it possible to slow down the progress of wear of the components and to slow down the shortening of the lifespan of the linear guide 100. Because the attraction member 30 is a simple component, it is possible to extend the lifespan of the linear guide 100 while suppressing increases in costs.

[0021] In addition, the user of the linear guide 100 can visually check the adhering amount of foreign matter on the adsorption member 30. This allows the user to determine the degree of abnormality, such as the degree of wear, of the linear guide 100, with a simple configuration. Furthermore, the user can perform effective maintenance, such as replacing components, before the accuracy of the linear guide 100 deteriorates or significant wear occurs that would hinder smooth operation.

[0022] The color of the attraction member 30 can be set to be different from the color of foreign matter such as wear powder and peeled off pieces. In this case, the color of the attraction member 30 is set to be white, for example. This allows the user to more easily distinguish the foreign matter adhering to the attraction member 30 when visually checking the attraction member 30.

[0023] FIG. 2 is a cross-sectional view of a portion of a linear guide 110, which is a specific example of a linear motion device according to a second embodiment of the present invention, to which a detection unit 23 is attached. In the linear guide 110, a bearing (not shown), which is a moving body, is disposed facing an attraction member 30. The detection unit 23 can be attached between an end cap (not shown) attached to an end (in the depth direction or forward direction of the paper surface of FIG. 2) of the bearing (not shown) and a side seal, and includes a magnetic sensor 22 capable of detecting a change in a magnetic field. The magnetic sensor 22 is disposed at a position corresponding to both legs of the bearing (not shown) so as to face the attraction member 30. The magnetic sensor 22 can detect a change in a magnetic field (magnetic field, magnetic lines of force) generated from the attraction member 30 and a foreign object attracted to the attraction member 30, and therefore can detect the degree of occurrence of foreign objects more accurately and quantitatively than by a user's visual inspection alone. As a result, parts can be replaced in an appropriate cycle that suppresses waste, which is more advantageous in terms of cost and maintenance.

[0024] FIG. 3 is a side view of a ball screw 200, which is a specific example of a linear motion device according to a third embodiment of the present invention. The ball screw 200 includes a long screw shaft 50, a nut 60 that is movable relative to the screw shaft 50, and an adsorption member 70 that can adsorb foreign matter generated by the relative movement of the screw shaft 50 and the nut 60. The screw shaft 50 is a long guide member, and a helical screw groove 52 is formed on its surface. The nut 60 is a moving body that can move relatively on the screw shaft 50 along the longitudinal direction of the screw shaft 50. In addition, rolling bodies (not shown) such as steel balls are arranged in rolling grooves formed between the screw groove 52 of the screw shaft 50 and the inner groove (not shown) of the nut 60, thereby reducing the frictional force generated in the screw shaft 50 and the nut 60.

[0025] The attraction member 70 is provided at a position on the screw shaft 50 at which the nut 60 faces in the radial direction. The attraction member 70 is disposed at a location other than the load-bearing portion of the screw shaft 50 and the nut 60, which move relative to each other, i.e., a location other than the rolling groove. In this embodiment, the attraction member 70 is provided in a spiral shape on the surface of the screw shaft 50 in an area where the screw groove 52 is not formed.

[0026] As in the first embodiment, the attraction member 70 has magnetism that allows it to attract metallic foreign matter such as wear powder and peeling debris. The attraction member 70 is, for example, in the form of a thin tape, and is attached to the entire axial length of the screw shaft 50 using an adhesive. In this way, it is preferable from the viewpoint of improving the foreign matter attraction function that the attraction member 70 is arranged without any gaps in the relative movement direction of the screw shaft 50 and the nut 60 (the left-right direction in FIG. 3).

[0027] The attraction member 70 is provided in an area of ​​the surface of the screw shaft 50 where the screw groove 52 in which the rolling elements are arranged is not formed, and is also separated from the nut 60. Therefore, the attraction member 70 is prevented from coming into contact with the rolling elements and the nut 60, and detachment from the screw shaft 50 is suppressed.

[0028] In the ball screw 200 of the embodiment, the attraction member 70 can attract and hold foreign matter such as wear powder and peeled off pieces by its magnetic force. The attraction member 70 holds the foreign matter, thereby preventing the foreign matter from coming into contact with the components of the ball screw 200, and therefore, it is possible to slow down the progress of wear of the components and prevent a decrease in the lifespan of the ball screw 200. Because the attraction member 70 is a simple component, it is possible to extend the lifespan of the ball screw 200 while preventing an increase in costs.

[0029] Moreover, a user of the ball screw 200 can visually check the attraction member 70 to ascertain the level of foreign matter adhering to the attraction member 70. This allows the user to determine the degree of abnormality, such as the degree of wear of the members of the ball screw 200, with a simple configuration. Furthermore, the user can perform effective maintenance, such as replacing members, before the accuracy of the ball screw 200 deteriorates or significant wear occurs that would hinder smooth operation.

[0030] The attraction member 70 of the ball screw 200 can be configured similarly to the attraction member 30 of the linear guide 100. In addition, the nut 60 of the ball screw 200 can be provided with a magnetic sensor 22, similar to the bearing 20 of the linear guide 100.

[0031] The attraction members 30 and 70 can be easily formed by containing magnetic metal powder. In particular, the attraction members 30 and 70 can be easily obtained by molding a mixture of magnetic metal powder and resin or rubber.

[0032] The magnetic force of the attraction members 30 and 70 is, for example, BHMax (maximum energy product): 1.6 to 111 [KJ / m 3 If the magnetic force is in this range, it is advantageous in terms of functionality and availability. BHMax is 1.6KJ / m 3 If the magnetic force is less than 111KJ / m, the magnetic force is too low to attract foreign matter. 3 If it is too high, the magnetic force will be too strong and the components constituting the linear motion device will be magnetized, possibly adversely affecting industrial equipment incorporating the linear motion device.

[0033] The shape, arrangement position, fixing method, etc. of the attraction members 30, 70 may be appropriately set in accordance with the linear motion device in which they are incorporated.

[0034] Furthermore, the present invention is not limited to the above-described embodiment, and can be appropriately modified, improved, etc. In addition, the material, shape, size, numerical value, form, number, arrangement location, etc. of each component in the above-described embodiment are arbitrary as long as they can achieve the present invention, and are not limited. [Explanation of symbols]

[0035] 10 Rail (Guide member) 11 Rolling groove 20 Bearing (moving body) 21 Rolling groove 22 Magnetic Sensor 23 Detection Unit 30 Adsorption member 40 Rolling elements 50 Screw shaft (guiding member) 52 Thread groove 60 Nut (moving body) 70 Adsorption material 100 Linear guide (linear motion device) 110 Linear guide (linear motion device) 200 Ball screw (linear motion device)

Claims

1. An elongated guide member; a movable body that is movable on the guide member relative to the guide member; an attraction member that is provided on the guide member at a position facing the movable body and has magnetism capable of attracting metallic foreign objects; A linear motion device comprising:

2. The adsorption member contains magnetic metal powder. The linear motion device according to claim 1 .

3. The adsorption member is obtained by molding a mixture of the magnetic metal powder and a resin or rubber. The linear motion device according to claim 2.

4. The attraction member has a hue different from that of the foreign matter. The linear motion device according to any one of claims 1 to 3.

5. The magnetic force of the attraction member is BHMax: 1.6 to 111 [KJ / m ３ ], The linear motion device according to any one of claims 1 to 3.

6. the movable body includes a magnetic sensor disposed opposite the attraction member and capable of detecting a change in a magnetic field; The linear motion device according to any one of claims 1 to 3.

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