JP2000230549A - Linear motion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an increase in frictional force at a contact portion of a seal member and to improve abrasion resistance by preventing loss of lubricant at a contact portion of the seal member. Maintain dustproof performance over time. SOLUTION: A guide rail 11 having a ball rolling groove 13 and extending linearly, and a ball rolling groove 15 facing the ball rolling groove 13 of the guide rail 11, these ball rolling grooves are provided. A slider 12 which is guided by a guide rail 11 via a rolling motion of a large number of balls B inserted between the sliders 13 and 15 and moves linearly; a sealing member 19 which is attached to the slider 12 and protects the interior of the slider 12 from dust; In the linear guide bearing device having the seal members 19,
A baked film of a solid lubricant is formed on at least a portion of the first and second guide rails 20 and 21 which is in contact with the guide rail 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a seal member used for dust-proofing of a linear motion device such as a linear motion guide bearing device and a ball screw device.

[0002]

2. Description of the Related Art As a linear motion device, for example, as shown in FIG. 6, a guide rail (guide shaft) 1 extending in the axial direction is provided.
A linear guide bearing device including a slider (movable body) 2 movably straddled thereon. Guide rail 1
The ball rolling grooves 3 extending in the axial direction are formed on both side surfaces of the slider body 2.
Ball rolling grooves (not shown) facing the ball rolling grooves 3 are formed on the inner side surfaces of the ball rolling grooves 3, respectively.

[0003] A large number of balls as rolling elements are rotatably mounted between these opposed ball rolling grooves, and the slider 2 moves on the guide rail 1 through the rolling of the balls. It can be moved along the axial direction. With this movement, the ball interposed between the guide rail 1 and the slider 2 rolls and moves to the end of the slider body 2A of the slider 2. In order to continuously move the slider 2 in the axial direction, it is necessary to circulate these balls.

Therefore, a through hole (not shown) is formed in the sleeve portion 4 of the slider body 2A as a ball passage penetrating in the axial direction, and end caps 5 are provided at both front and rear ends of the slider body 2A. The ball circulation path is formed by forming a U-shaped curved ball circulation path connecting the two ball rolling grooves and the through hole as the ball passage. In the figure, reference numeral 7 denotes a nipple for supplying a lubricant to the ball circulation path.

The slider 2 is usually provided with a side seal member 6, an inner seal member, and an under seal member (both not shown) in order to protect the inside of the slider 2 from dust. The side seal member 6 is attached to the end cap 5 and scrapes foreign substances such as dirt and dust while sliding on the ball rolling grooves 3 of the guide rail 1 and the upper surface of the guide rail 1, and the foreign substances enter the slider 2. It is designed to prevent intrusions.

The inner seal member is attached to the inner surface of the slider body 2A in parallel with the ball row, and seals between the ball row and both sides of the upper surface of the guide rail 1,
The under seal member is attached to the lower surface of the sleeve portion 4 of the slider body 2A in parallel with the ball row, and seals between the ball row and the lower side surface of the ball rolling groove 3 of the guide rail 1. ing.

[0007]

The above-mentioned side seal member 6, inner seal member and under seal member are generally made of NBR (nitrile rubber), urethane, fluorine rubber or the like, and have high dustproofness. In order to improve the contact pressure, the contact pressure to the guide rail 1 is increased by increasing the interference.

However, if the contact pressure to the guide rail 1 is increased in this way, the frictional force between the seal member and the guide rail 1 naturally increases, which may cause an increase in the driving power of the linear guide bearing device. Become. Further, an increase in the contact pressure of the seal member against the guide rail 1 has a disadvantageous effect on the wear of the seal member, so that it is difficult to secure dustproof performance for a long period of time. When using the seal, there is a disadvantage that the lubricant is deprived of the foreign material, the surface of the guide rail 1 is dried, and the lubricant at the contact portion of the seal member is lost, thereby promoting the wear of the seal member.

SUMMARY OF THE INVENTION The present invention has been made to solve such inconvenience, and it is intended to suppress an increase in frictional force at a contact portion of a seal member and prevent wear of a lubricant at a contact portion of the seal member so as to prevent wear. To improve the performance,
It is an object of the present invention to provide a linear motion device capable of maintaining dustproof performance for a long period of time.

[0010]

In order to achieve the above object, a linear motion device according to the present invention comprises a linearly extending guide shaft having rolling element rolling grooves, and the rolling element of the guide shaft. A movable body that has rolling element rolling grooves opposed to the rolling grooves, is guided by the guide shaft through the rolling of a number of rolling elements inserted between these rolling element rolling grooves, and moves linearly; A linear motion device having a seal member attached to the movable body to prevent dust inside the movable body, wherein a fired film of a solid lubricant is formed on at least a portion of the seal member that contacts the guide shaft. It is characterized by.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway view of a linear motion guide bearing device according to an embodiment of the present invention viewed from an axial end. FIG. 2 is an exploded perspective view of a slider constituting the linear motion guide bearing device. FIG. 3 is a diagram showing a wiper seal member constituting a ball screw device according to another embodiment of the present invention,
4 is a sectional view taken along line IV-IV in FIG. 3, and FIG. 5 is a graph showing the relationship between the number of reciprocations of the slider and the amount of change in the frictional force of the seal member.

This linear motion guide bearing device includes a guide rail (guide shaft) 11 extending in the axial direction, similarly to the conventional example,
A slider (movable body) 12 movably straddled thereon.
And Ball rolling grooves 13 extending in the axial direction are formed on both side surfaces of the guide rail 11, and the ball rolling surfaces opposing the ball rolling grooves 13 are formed on the inner surfaces of both sleeve portions 14 of the slider body 12 </ b> A of the slider 12. The moving grooves 15 are respectively formed.

A large number of balls B as rolling elements are rotatably mounted between the opposed ball rolling grooves 13 and 15, and the slider 12 is moved through the rolling of the balls B. It can move on the guide rail 11 along the axial direction. As in the conventional case, the ball circulation path is formed by penetrating in the axial direction in the sleeve portion 14 of the slider body 12A to form a through hole 16 as a ball passage, and providing end caps 17 at both front and rear ends of the slider body 12A. The two ball rolling grooves 13 and 15 and the through hole 1
6 is formed by forming a U-shaped curved ball circulation path (not shown) which communicates with the ball 6. In FIG. 1, reference numeral 18 denotes a nipple for supplying a lubricant to the ball circulation path.

To prevent dust in the slider 12, a side seal member 19, an inner seal member 20, and an under seal member 21 integrally formed of rubber such as nitrile rubber are attached around the sheet metal in order to prevent dust in the slider 12. ing. The side seal member 19 is an end cap 17
And the ball rolling groove 13 of the guide rail 11
While sliding on the side surfaces including the upper surface and the upper surface of the guide rail 11, foreign matters such as dust and dust are scraped off, and the foreign matters are prevented from entering the inside of the slider 12.

The inner seal member 20 is mounted on the inner surface of the slider body 12A facing the upper surface of the guide rail 11 so as to be parallel to the ball row, and seals between the ball row and both sides of the upper surface of the guide rail 11. Slider 12
Prevents foreign matter from entering the inside of the under seal member 2
Numeral 1 is attached to the lower surface of the sleeve portion 14 of the slider body 12A in parallel with the ball row, seals between the ball row and the lower side surface of the ball rolling groove 13 of the guide rail 11, and It prevents foreign substances from entering the space.

In this embodiment, a baked film of a solid lubricant is formed on the side seal member 19, the inner seal member 20, and the under seal member 21 at and around the portions contacting the guide rails 11. Examples of the type of the solid lubricant include sulfides such as MoS ₂ , WS ₂ , and SbS ₂ , fluorides of (CFx) n, graphite, mica and S
oxides such as b ₂ O ₃ , extreme pressure agents such as MoDTC, BN
Such as nitrides, fluorine resins such as PTFE,
These are used alone or in combination of two or more kinds, and are fired at a low temperature using a thermosetting resin as a binder.

In this embodiment, a case where a fired film of a solid lubricant is formed on all of the side seal member 19, the inner seal member 20, and the under seal member 21 is taken as an example. No need,
The fired film of the solid lubricant may be formed on any one of the side seal member 19, the inner seal member 20, and the under seal member 21 or a combination thereof.

Further, in this embodiment, a case where a fired film of a solid lubricant is formed on and around the portion of the seal member that contacts the guide rail 11 is not necessarily required. , Guide rail 1 for sealing member
A fired film of a solid lubricant may be formed only on the portion in contact with 1 or on the entire sealing member for the sake of processing.

As is clear from the above description, in this embodiment, since the sintering film of the solid lubricant is formed on at least the portion of the seal member which comes into contact with the guide rail 11, the seal member is formed on the guide rail 11 thereof. Even when the contact pressure of the seal member increases, the frictional coefficient of the contact portion of the seal member can be kept low to suppress the increase in the frictional force. Even if the surface is deprived and the surface becomes dry, the lubricant at the contact portion of the seal member is not lost due to the action of the solid lubricant possessed as a film by itself, so that the wear resistance can be improved. The dustproof performance can be maintained for a long time.

FIG. 5 shows a side seal member having a sintering film of a solid lubricant formed on a portion in contact with the guide rail and the periphery thereof, attached to one side of the slider with a predetermined interference, and a sintering process of the solid lubricant. The number of reciprocations of the slider (stroke 300 mm) with a side seal member with no coating formed attached to one side of the slider with a specified interference
7 shows the result of comparing the relationship between the frictional force and the amount of change in the frictional force of the side seal member.

The solid lubricating film treatment is performed by ESTEST Corporation SOLVEST (registered trademark) 392DRYCOA.
80 ° C using MoS ₂ and PTFE with binder at T
For 30 minutes. Further, a comparative test was performed by intentionally degreasing a lubricant in a portion of the guide rail where the side seal member contacts. As can be seen from FIG. 5, the side seal member having no solid lubricant fired film does not have the initial interference given by the abrasion, and the frictional force is reduced. It can be seen that the side seal member having the coating formed thereon maintains a constant frictional force and has excellent wear resistance.

As shown in FIGS. 3 and 4, the present invention may be applied to a wiper seal member 22 attached to a nut (movable body: not shown) of a ball screw device. That is, by forming a fired film of the solid lubricant on at least a portion of the wiper seal 22 that comes into contact with the screw shaft (guide shaft: not shown), it is possible to obtain the same operation and effect as in the above-described embodiment. An increase in friction torque, heat generation, and a decrease in positioning accuracy can be effectively suppressed.

[0023]

As is apparent from the above description, according to the present invention, it is possible to suppress an increase in the frictional force at the contact portion of the seal member and to prevent the lubricant at the contact portion of the seal member from being lost. Therefore, the effect of maintaining dustproof performance for a long period of time in a specification under a foreign substance environment can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially cutaway view of a linear motion guide bearing device as an example of an embodiment of the present invention as viewed from an axial end.

FIG. 2 is an exploded perspective view of a slider constituting the linear motion guide bearing device.

FIG. 3 is a view showing a wiper seal member constituting a ball screw device according to another embodiment of the present invention.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a graph showing the relationship between the number of reciprocations of the slider and the amount of change in the frictional force of the seal member.

FIG. 6 is an overall perspective view of a linear motion guide bearing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Guide rail (guide shaft) 12 ... Slider (movable body) 13 ... Ball rolling groove (rolling body rolling groove) 15 ... Ball rolling groove (rolling body rolling groove) 19 ... Side seal member 20 ... Inner seal Member 21: Under seal member B: Ball (rolling element)

Claims (1)

[Claims] 1. A guide shaft having a rolling element rolling groove and extending linearly, and a rolling element rolling groove opposed to the rolling element rolling groove of the guide shaft, and these rolling element rolling grooves are provided. A movable member that is guided by the guide shaft and linearly moves through the rolling of a number of rolling members inserted between the grooves, and a seal member that is attached to the movable member and that prevents dust inside the movable member. A linear motion device, wherein a baked film of a solid lubricant is formed on at least a portion of the seal member that contacts the guide shaft.