JP5772158B2 - Linear motion device - Google Patents

Description

The present invention relates to a linear motion apparatus provided with a lubricant feed member (ball screw apparatus and goods carrier device, etc.).

  Conventionally, linear motion bearing devices (linear guides), ball screw devices, and monocarrier devices have been proposed as linear motion devices. The linear motion guide bearing device moves the slider linearly along the guide rail by rolling the ball, which is a rolling element, on a raceway formed by both ball grooves provided on the guide rail and the slider. It is a device to do. On the other hand, in the ball screw device, the ball, which is a rolling element, rolls in a loaded state on a track formed by both ball grooves provided on the screw shaft and the nut, so that the nut moves linearly along the screw shaft. Device. Furthermore, the monocarrier device is a uniaxial actuator in which the linear motion guide bearing device and the ball screw device are combined. These linear motion guide bearing devices and ball screw devices have a circulation portion that moves the ball from the end point of the track to the start point, and the circulation portion and the track constitute a ball circulation path.

  As a lubricant supply body used in such a linear motion guide device, for example, there is one described in Patent Document 1. As shown in FIG. 6, the lubricant supply body described in Patent Document 1 includes a lubricant holder 101 made of needle felt containing grease, and the lubricant holder 101. And a support 102 to be supported. The grease contains 2 to 95% by mass of the total amount of grease in which the base oil is contained in the warm capsule at a content of 10% by mass or more of the total amount of the capsule.

JP 2008-274122 A

  However, since the lubricant supply body described in Patent Document 1 employs a needle felt as the lubricant holder 101, there is room for improvement in long-term lubricant holding performance. In addition, the warm capsule contained in the lubricant supplier described in Patent Document 1 does not release the lubricant from the capsule unless a certain amount of heat is transmitted to the capsule itself, so there is room for improvement in its release controllability. there were.

Therefore, the present invention has been made paying attention to the above-mentioned problems, and its purpose is to provide a lubricant supply body that has a long-term lubricant retention performance and is excellent in lubricant release controllability , An object of the present invention is to provide a linear motion device in which a stable lubrication state is maintained for a long time.

Engaging Ru linear guide device in Claim 1 of the present invention to solve the above problem, a guide member extending in a straight line, and the linear motion member relatively move linearly arranged outside of the guide member, A rolling element that rolls in a loaded state a raceway constituted by rolling surfaces provided at opposite positions of both members, and a circulation part that moves the rolling element from the end point to the start point of the raceway. And the raceway constitutes a circulation path of the rolling elements ,
At least one linear movement direction end of the linear motion member is disposed between and in contact with an end cap and a side seal constituting the linear motion member, and has the same outer shape as the end cap. A lubricant supplier that contacts the guide member is provided;
The lubricant supply body is made of a synthetic resin containing a lubricant, contains the lubricant, and the portion contracts as the lubricant decreases in the portion close to the guide rail due to contact with the guide rail. , being crushed by the contraction pressure sensitive microcapsules to sequentially release the lubricant is characterized by a Turkey contained therein.

According to the present invention, it has a long-term lubricant retention performance, with excellent lubricant supplying member to the controlled release of the lubricant, provides a linear motion device stable lubrication over is maintained in the long term can do.

It is a perspective view which shows the structure in one Embodiment of the linear motion apparatus (linear motion guide bearing apparatus) which concerns on this invention. It is a front view which shows the structure of the lubricant supply body which concerns on this invention. It is a disassembled perspective view which shows the structure of the slider in one Embodiment of the linear motion apparatus (linear motion guide bearing apparatus) which concerns on this invention. It is a perspective view which shows the structure in one Embodiment of the linear motion apparatus (ball screw apparatus) which concerns on this invention. It is a perspective view which shows the structure in one Embodiment of the linear motion apparatus (monocarrier apparatus) based on this invention. It is a front view which shows the structure of the conventional lubricant supply body.

Hereinafter, embodiments of a lubricant supply body and a linear motion guide bearing device according to the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a configuration in an embodiment of a linear motion device (linear motion guide bearing device) according to the present invention. FIG. 2 is a front view showing the configuration of the lubricant supply body according to the present invention. FIG. 3 is an exploded perspective view showing the configuration of the slider in one embodiment of the linear motion device (linear motion guide bearing device) according to the present invention.

<Configuration of linear motion device>
As shown in FIG. 1, the linear motion device of the present embodiment includes a guide rail 10, a slider 20, and a ball (not shown) as a rolling element. The slider 20 includes a main body 21, an end cap 22, a lubricant supply body 23, and a side seal 24. Further, the ball grooves (rolling surfaces) 10A and 11B of the guide rail 10 and the ball grooves (rolling surfaces) (not shown) of the slider 20 form a track on which a ball (not shown) rolls under load. A circulation part for moving the ball from the end point of the track to the start point is formed in the end cap 22. A lubricant supply body 23 is disposed between the end cap 22 and the side seal 24.

<Lubricant supplier>
[Constitution]
As shown in FIGS. 1 to 3, the lubricant supply body 23 has a substantially U-shaped outer shape that is substantially the same as the end cap 22. The lubricant supply body 23 is made of a synthetic resin containing a lubricating oil described later. The lubricant supply body 23 is opposed to the ball groove 10b on the side surface of the guide rail 10 and the portion 23a arranged to face the ball groove 10a at the corner of the guide rail 10 as the portion positioned around the guide rail 10. And a portion 23 c disposed opposite to the upper surface 10 c of the guide rail 10. All of these portions are formed such that a slight gap is formed between the guide rail 10 and the guide rail 10 when attached.

In addition, the lubricant supply body 23 is formed with through holes 23d through which the bolts 40 are passed at positions on both sides of the guide rail 10 (see FIG. 2).
Further, the lubricant supply body 23 contains a plurality of pressure-sensitive microcapsules (hereinafter referred to as microcapsules) 30. The microcapsule 30 contains a lubricant, and the lubricant in the microcapsule 30 is released by contraction of the lubricant supply body 23.
As a method for incorporating the microcapsules 30 into the lubricant supply body 23, the microcapsules are put into the material of the lubricant supply body before molding, and the resulting mixture is molded.

[material]
Next, the material of the lubricant supply body 23 will be described in detail. The lubricant supplier 23 is made of a synthetic resin selected from the group of polyolefin resins having basically the same chemical structure, such as polyethylene, polypropylene, polybutylene, and polymethylpentene. Examples of the lubricant contained in the lubricant supplier 23 include paraffinic hydrocarbon oils such as poly α-olefin oils, naphthenic hydrocarbon oils, mineral oils, ether oils such as dialkyldiphenyl ether oils, and phthalates. A raw material prepared by mixing one of ester oils or the like in the form of a single or mixed oil is molded by injection molding. Various additives such as antioxidants, rust inhibitors, anti-friction agents, antifoaming agents, extreme pressure agents and the like may be added in advance to the lubricant.

  The composition ratio of the lubricant supply body 23 is preferably 20 to 80% by mass, more preferably 20 to 50% by mass, and 80 to 20% by mass of the lubricant with respect to the total mass. More preferably, it is particularly preferably 80 to 50% by mass. When the polyolefin resin is less than 20% by mass, it is difficult to obtain hardness and strength exceeding a certain level. Further, when the polyolefin resin exceeds 80% by mass (that is, when the lubricant is less than 20% by mass), the supply of the lubricant is reduced, and it becomes difficult to make the linear guide device maintenance-free. Practically, 50 to 80% by mass of the lubricant (50 to 20% by mass of the polyolefin resin) is preferable because the supply of the lubricant is abundant and the supply capability can be maintained for a long time.

The group of synthetic resins described above has the same basic structure but different average molecular weights, ranging from 700 to 5 × 10 ⁶ . Among them, waxes an average molecular weight 700-1 × 10 ⁴ (e.g., polyethylene wax) and those classified to, those of relatively low molecular weight an average molecular weight ^{1 × 10 4 ~1 × 10 6} , 1 × 10 Those having an ultrahigh molecular weight of ^{6 to} 5 × 10 ⁶ are used alone or mixed as necessary. A combination of a relatively low molecular weight material and a lubricant provides a lubricant-containing polymer member having a certain level of mechanical strength, lubricant supply capability, and oil retention. Replacing some of those with a relatively low molecular weight with those classified as wax increases the affinity with the lubricating oil because the molecular weight between the wax and the lubricating oil is small. As a result, the oil retention is increased, and the lubricant supply capability is reduced (thereby, the lubricant can be supplied for a longer period of time). On the other hand, the mechanical strength decreases. As the wax, in addition to a polyolefin resin such as polyethylene wax, any hydrocarbon-based material (for example, paraffin-based synthetic wax) having a melting point of 100 to 130 ° C. or higher can be used. On the other hand, if it is replaced with a super-molecular weight, the difference in molecular weight between the ultra-high molecular weight and the lubricating oil is large, so the affinity with the lubricating oil is reduced, resulting in poor oil retention and lubrication. The agent supply capacity increases (thereby supplying the lubricant in a relatively short time). Also, the mechanical strength increases.

  Considering the balance of injection moldability, mechanical strength, lubricant supply capability, and oil retention, the composition ratio of the synthetic resin (polymer) in the lubricant supply body 23 is 0 to 5% by mass classified as wax. 5 to 48% by mass of a low molecular weight, 2 to 10% by mass of an ultra high molecular weight, and the total of the three resins is 20 to 50% by mass (the remainder is 80 to 50% by mass of lubricant). Such a range is preferable.

  In order to achieve long-term maintenance-free operation of the linear guide device, at least two lubricant supply bodies 23 provided on the end face of the slider 20 are provided on one or both end faces of the slider 20, At least one lubricant supply body 23 containing wax may be used. By using the lubricant supply body 23 containing wax, the lubricant supply period becomes longer, and maintenance such as replenishment of lubricating oil can be omitted for a long period of time.

[Other materials]
In order to improve the mechanical strength of the lubricant supply body 23, the following thermoplastic resin and thermosetting resin may be added to the above-described polyolefin resin.
As the thermoplastic resin, resins such as polyamide, polycarbonate, polybutylene terephthalate, polyphenylene sulfide, polyethersulfone, polyetheretherketone, polyamideimide, polystyrene, and ABS resin can be used.
As the thermosetting resin, each resin such as unsaturated polyester resin, urea resin, melamine resin, phenol resin, polyimide resin, and epoxy resin can be used. These resins may be used alone or in combination.

[Additives, etc.]
Furthermore, in order to disperse the polyolefin resin and other resins in a more uniform state, an appropriate compatibilizing agent may be added as necessary.
Moreover, in order to improve mechanical strength, you may add a filler. For example, inorganic whiskers such as calcium carbonate, magnesium carbonate, potassium titanate whisker and aluminum borate whisker, or inorganic fibers such as glass fiber, asbestos and metal fiber, and those braided into a cloth, or organic compounds Then, carbon black, graphite powder, carbon fiber, aramid fiber, polyester fiber, or the like may be added.

  Further, for the purpose of preventing deterioration of the polyolefin resin due to heat, an anti-aging agent such as N, N′-diphenyl-P-phenylenediamine, 2,2′-methylenebis (4-ethyl-6-t-butylphenol), For the purpose of preventing deterioration due to light, 2-hydroxy-4-n-octoxybenzophenone, 2- (2′-hydroxy-3′-tert-butyl-5′-methyl-phenyl) -5-chlorobenzo You may add ultraviolet absorbers, such as a triazole.

The addition amount of all the above additives (excluding polyolefin + oil) is preferably 20% by mass or less of the total weight of the molding raw material as a whole in terms of maintaining the supply capability of the lubricant.
A sealing device in which a rubber material such as nitrile rubber and a core metal are integrated may be provided outside the lubricant supply body 23 disposed on the end face of the slider 20. The lubricant supplied from the lubricant supply body 23 is used not only for lubricating the linear motion guide bearing device itself but also for lubricating the rubber lip portion of the seal device, thereby reducing the wear of the rubber lip portion and maintaining the sealing performance. It also works.

[Lubricant]
Lubricating oil contained in the lubricant supply body 23 is composed of the same base oil (base oil or base oil and additive), thickener, and various additives (extreme pressure agent, antioxidant, etc.) as before. .
[Microcapsule]
The microcapsule 30 contains a base oil (base oil or base oil and additive) made of mineral oil, synthetic oil, or the like. Note that the lubricating oil contained in the microcapsule 30 is preferably 10 to 60 mass% of the total amount of the lubricating oil contained in the lubricant supply body 23. When the lubricating oil contained in the microcapsule 30 is less than 10% by mass of the total amount of lubricating oil contained in the lubricant supplier 23, there is a problem that there are few microcapsules and the effect of releasing the lubricant by the microcapsules is low, When it exceeds 60 mass%, the problem that it is difficult to form a lubricant supply body arises.
Moreover, it is preferable that the particle size of the microcapsule 30 is a primary particle size of 1-1000 micrometers.

[Installation of lubricant supply body]
Thus, the lubricant supply body 23 in which the microcapsules 30 are formed is disposed between the end cap 22 and the side seal 24 and is inserted from the outside of the side seal 24 as shown in FIG. The bolt 40 is used to attach to the main body 21 together with the side seal 24 and the end cap 22.

  As a procedure, first, a ball was put into a ball circulation path formed by the guide rail 10, the main body 21 and the end cap 22 by the guide rail 10, the main body 21, the end cap 22 and the ball (not shown). State. Next, in this state, the lubricant supply body 23 and the side seal 24 are arranged outside the end cap 22, and the bolt 40 is attached to the attachment hole 24a of the side seal 24, the attachment hole 23 of the lubricant supply body 23, and The tip of the end cap 22 is passed through the mounting hole 22 a and the tip of the end cap 22 is screwed into the female screw of the main body 21.

  In this manner, the seal portions of the lubricant supply body 23 and the side seal 24 are attached in contact with the guide rail 10. Then, lubricant is supplied from the lubricant supply body 23 to the ball grooves 10 a and 10 b and the upper surface 10 c of the guide rail 10. As a result of the lubricant oil contained in the lubricant supply body 23 itself being released for a long period of time, the lubricant supply body 23 contracts, so that the microcapsules 30 in the lubricant supply body 23 are crushed, and the microcapsules 30 Supplied with lubricating oil.

  In particular, the portion of the lubricant supply body 23 close to the guide rail 10 has a large supply amount of lubricant, so that the lubricant directly contained in the lubricant supply body 23 is quickly reduced, and the lubricant supply body 23 itself contracts quickly. . That is, almost all the microcapsules 30 included in the lubricant supply body 23 are not broken at a time. As a result, the microcapsule 30 in the portion where the lubricant is rapidly reduced (for example, the portion close to the guide rail 10) breaks early and the lubricant is sequentially supplied from the microcapsule 30, so that the lubricant is constantly supplied. Is done. Therefore, a stable lubrication state is maintained over a long period of time as compared with the case where the lubricant supply body including the lubricating oil is not included and the microcapsule 30 is not included.

  As described above, in the present invention, the lubricant contracts by the amount of the lubricant released from the lubricant supplier, whereby the microcapsules are broken and the lubricant therein is replenished. The configuration of the present invention solves the conventional problem that the supply of the lubricant is not sufficient when the environmental temperature is low, and the release of the lubricant is accelerated more than necessary and may be exhausted when the environmental temperature is high. To do. As a result, it is possible to provide a linear motion guide bearing device that can retain a sufficient amount of lubricant in the lubricant supply body without being affected by the environmental temperature and maintain a stable lubrication state for a long period of time.

(Other embodiments)
In the above-described embodiment, the linear motion device in which the lubricant supply body of the present invention is applied to the linear motion guide bearing device has been described. However, as the linear motion device according to the present invention, the lubricant supply body of the present invention is a ball screw. Even if it is applied to the apparatus, the same effect is obtained.
FIG. 4 is a perspective view showing a configuration in one embodiment of a linear motion device (ball screw device) according to the present invention. As shown in FIG. 4, the ball screw device includes a rod-like screw shaft 50 having a helical screw groove 51 on the surface of which a plurality of balls (not shown) roll, and the screw shaft 50 is screwed. And a nut 60 penetrating therethrough. A lubricant supply body 23 of the present invention is attached to the end surface of the nut 60 in order to seal the gap between the screw shaft 50 and the nut 60 and supply lubricating oil to the gap.
As described above, according to the ball screw device including the lubricant supply body 23 of the present invention, the lubricant supply body 23 having excellent lubricant release controllability is used, so that a stable lubrication state can be obtained over a long period of time. A maintained linear motion device can be provided.

  Moreover, as a linear motion apparatus according to the present invention, the same effect can be obtained even if the lubricant supply body of the present invention is applied to a monocarrier apparatus. FIG. 5 is a perspective view showing a configuration in one embodiment of a linear motion device (monocarrier device) according to the present invention. As shown in FIG. 5, the monocarrier device has a linear guide mechanism and a feed screw mechanism. The linear guide mechanism includes a guide rail 70 having a U-shaped cross section, a slider 80 disposed in a U-shaped concave portion of the guide rail 70, and a plurality of disposed between the guide rail 70 and the slider 80. It is comprised with the rolling element B piece. Then, the rolling element B rolls on a rolling path formed by rolling surfaces arranged at positions where the guide rail 70 and the slider 80 face each other.

On the other hand, the feed screw mechanism includes a female screw hole 81 formed in the slider 80 in parallel with the guide rail 70, and a screw shaft 90 that penetrates the female screw hole 81. Then, by the operation of the screw shaft 90, the slider 80 moves linearly relative to the guide rail 70 via the feed screw mechanism and the linear guide mechanism.
The lubricant supply body 23 of the present invention is attached to the end face of the slider 80 in order to seal the gap between the female screw hole 81 and the screw shaft 90 and supply lubricating oil to this gap portion.
Thus, according to the monocarrier device provided with the lubricant supply body 23 of the present invention, the lubricant supply body 23 having excellent lubricant release controllability is used, so that a stable lubrication state can be obtained over a long period of time. A maintained linear motion device can be provided.

10 Guide rail 20 Slider (linear motion member)
23 Lubricant supply body 30 Microcapsule

Claims (1)

A track composed of a linearly extending guide member, a linearly moving member arranged on the outside of the guide member and relatively moving linearly, and a rolling surface provided at a position where both the members are opposed to each other is rolled in a loaded state. A rolling element that moves, and a circulation unit that moves the rolling element from an end point of the track to a start point, and the circulation path of the rolling element is configured by the circulation unit and the track ,
At least one linear movement direction end of the linear motion member is disposed between and in contact with an end cap and a side seal constituting the linear motion member, and has the same outer shape as the end cap. A lubricant supplier that contacts the guide member is provided;
The lubricant supplying member is Ri Do a synthetic resin impregnated with lubricating oil, or lubricants is contained, reduces that portion with the lubricant at a portion closer to the guide rail due to contact with the guide rail contracts and, it is crushed by the contraction, linear motion and wherein the pressure sensitive microcapsules to sequentially release the lubricant contained therein.

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