JP2001208056A - Slide mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a maintenance free slide mechanism eliminating the necessity to deliver a lubricant periodically forming a lubricating oil film on the surface of a shaft by a bearing slide. SOLUTION: In the slide mechanism, the lubricating oil is filled within a hollow portion 46 of the shaft 12 and the through-holes 50, 52 are provided on the shaft 12 so that the lubricating oil can leak and spread out when the bearing 34 which support an exposure light head 10 through a support block 30 passes the holes 50, 52 on the surface 12S of the shaft 12 and forms a oil film 48F by the slide movement. Thus, it is not necessary to deliver the lubricating oil from outside periodically on the surface 12S of the shaft 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a slide mechanism for reciprocating a moving body along a hollow shaft.

[0002]

2. Description of the Related Art Various types of slide mechanisms for supplying a lubricant to a moving body that slides along a shaft are known. For example, Japanese Patent Application Laid-Open No. 6-241231 discloses a slide mechanism as shown in FIG. A mechanism 100 is disclosed.

In the slide mechanism 100, a shaft 104 is inserted through a slide-type bearing 102, and a lubricant 106 is periodically supplied to the surface 104S of the shaft 104 from the outside.
Is stretched on the surface 104S to form a lubricating oil film 106F. The supplied lubricant 106 is applied to the surface 10
As shown in FIG. 7, both ends of the bearing 102 are slightly tapered so as to easily enter between the 4S and the bearing 102.

However, a maintenance work of periodically supplying the lubricant 106 is required, and the lubricant 106 is often attached to a portion where the lubricant 106 is not desired to be attached during this supply. Conventionally, there has been such a problem that dirt is generated due to 106.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a slide mechanism which is maintenance-free by eliminating the need to periodically supply a lubricant in consideration of the above fact.

[0006]

According to the first aspect of the present invention, there is provided a hollow shaft having a hollow portion filled with a lubricant;
A bearing that is slidably guided by the hollow shaft and supports a moving body that moves along the hollow shaft.
And a lubricant supply hole penetrating from the surface of the hollow shaft to the hollow portion is formed in a moving section of the moving body.

[0007] Lubricants are usually oily. The diameter and number of the lubricant supply holes are determined in consideration of various parameters such as the viscosity of the lubricant.

When the temperature of the hollow shaft rises due to frictional heat generated by the movement of the moving body, the lubricant expands or the viscosity decreases, and the lubricant leaks from the lubricant supply hole. The leaked lubricant is stretched on the surface of the shaft by the slide of the bearing, and a lubricant film is formed.

This eliminates the need to periodically supply a lubricant from the outside, and implements a maintenance-free slide mechanism.

According to a second aspect of the present invention, the lubricant supply holes are formed at equal intervals in a circumferential direction of the hollow shaft.

Thus, the lubricant can be uniformly supplied to the surface of the hollow shaft in the circumferential direction.

According to a third aspect of the present invention, a lubricant holding member impregnated with a lubricant is loaded in the hollow portion.

Thus, it is not necessary to fill the entire hollow portion with the lubricant. Further, even if the diameter of the lubricant supply hole is large, the amount of leakage of the lubricant does not become excessive, so that when forming the lubricant supply hole, the lubricant supply hole can be formed with a margin in dimensional accuracy.

According to a fourth aspect of the present invention, a removable lid for sealing a lubricant into the hollow portion is attached to both ends of the hollow shaft.

This makes it possible to easily replenish the hollow portion of the shaft with the lubricant.

In the invention according to claim 5, the lid is
The volume of the hollow portion can be adjusted by moving forward and backward in the longitudinal direction of the hollow shaft.

This makes it possible for the lubricant to leak from the lubricant supply hole by moving the lid forward and backward in the longitudinal direction of the shaft to reduce the volume of the hollow portion.

According to a sixth aspect of the present invention, the moving body is an exposure head, and the lubricant supply hole is formed in a region of the moving section of the exposure head outside a scanning range. I do.

As a result, the vibration of the exposure head that occurs when passing through the lubricant supply hole does not occur during the exposure scanning. Further, since the shaft is hollow, the vibration frequency generated when the shaft bends can be made high.
For this reason, it is possible to suppress image unevenness that occurs during exposure scanning of the exposure head.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a slide mechanism 16 according to a first embodiment includes a cylindrical photosensitive drum 11 and
The present invention is applied to an exposure apparatus 18 having hollow shafts 12 and 14 arranged in parallel with the photosensitive drum 11 and an exposure head 10 for reciprocating along the shafts 12 and 14 to perform scanning exposure. I have.

The exposure head 10 is fixed to an endless timing belt 28 via a connecting plate 24 at the bottom of the casing 20. Support blocks 30 and 32 are attached to the casing 20. Support block 30,
32, bearings 34 and 36 are embedded, respectively, and the bearings 34 and 36 are
It is possible to slide along.

Both ends of the timing belt 28 are wound around sprockets 40 and 42 provided near both ends of the shafts 12 and 14, respectively.
The timing belt 28 rotates forward and reverse by the forward rotation and reverse rotation of 0 and 42, and the exposure head 10 reciprocates in the moving section area L along the shafts 12 and 14.

The exposure head 10 is connected to a flexible cable 44 for supplying electric power.

As shown in FIG. 2, the hollow portion 46 of the shaft 12 is filled with lubricating oil 48, and the shaft 12 is provided with a through hole 50 for supplying the lubricating oil 48 to the surface 12S of the shaft 12. , 52 are formed.

When the exposure head 10 passes over the through holes 50 and 52, the lubricating oil 48 is urged by surface tension to cause the through holes 50 and 52 to pass through.
Leaks from 52. In addition, the temperature of the shaft 12 increases due to the scanning of the exposure head 10, and the temperature of the lubricating oil also increases. Accordingly, the viscosity of the lubricating oil decreases, and the lubricating oil thermally expands.
2 easy to leak.

When the bearing 34 slides, the leaked lubricating oil is stretched on the surface 12S of the shaft 12, and a lubricating oil film 48F is formed.

The diameters of the through holes 50 and 52 are set so that the lubricating oil film 48F has an appropriate thickness.
It is determined in consideration of the viscosity and the coefficient of thermal expansion of the lubricating oil.
In the first embodiment, the inner diameter of the through holes 50 and 52 is 1.0 mmφ.
Has been. The outer diameter of the shaft 12 is 16 mmφ.
It is.

The through holes 50 and 52 are provided in the exposure head 1.
The two end areas B (see FIGS. 1 and 2) of the 0 moving section area L are formed respectively. The both end regions B are regions outside the scanning range of the exposure head 10.

As a result, the exposure head 10 is
Since there is no exposure scanning when passing over 0 and 52, the vibration of the exposure head 10 caused by passing over the through holes 50 and 52 does not occur during exposure scanning.

The through holes 50 are formed at symmetrical positions in an AA cross section orthogonal to the shaft 12 (see FIG. 2), and the same applies to the through holes 52. This allows
The unevenness of the thickness of the lubricating oil film 48F can be suppressed.

As shown in FIG. 2, detachable lids 60 and 62 (see also FIG. 3 for the lid 62) are attached to both ends of the shaft 12 by screw connection. In the coupled state, the lubricating oil 48 is sealed so as not to leak from the gap between the lids 60 and 62 and the shaft 12. Handles 66 and 68 are attached to the lids 60 and 62, respectively.

Thus, the lubricating oil 48 can be easily supplied to the hollow portion 46 of the shaft 12.

Since the cover 60 is screwed to the shaft 12, the handle 66 is manually rotated to move the cover 60 in the longitudinal direction of the shaft 12 to adjust the volume of the hollow portion 46. can do. Thereby, the volume of the hollow portion 46 is reduced, and the through-hole 50,
It is possible to allow the lubricating oil 48 to leak from the lubrication oil 52. The same applies to the lid 62.

The shaft 14 has the same structure as the shaft 12, has through holes 70 and 72, and has lids (not shown) attached to both ends.

In the first embodiment, the lubricating oil 48 leaks from the through holes 50, 52, 70, 72 when the exposure head 10 reaches the both end regions B in order to complete a series of exposure scans and wait. Therefore, there is no need to periodically supply lubricating oil to the surface 12S of the shaft 12 from outside the shaft. Also, by adjusting the diameter and number of these through holes,
The amount of the leakage of the lubricating oil 48 can be made appropriate.

Further, since the shaft 12 is a hollow shaft, the vibration frequency generated when the shaft 12 bends can be made high. For this reason, the exposure head 10
Image unevenness that occurs during the exposure scanning of the above.

2, three through-holes 80 may be formed at equal intervals D in the circumferential direction of the surface 12S of the shaft 12, as shown in FIG. Thereby, the supply amount of the lubricating oil in the circumferential direction can be made uniform. The number of through holes may be larger as long as the above-mentioned interval D is even.

Next, a second embodiment will be described. Less than,
The same components and members as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the second embodiment, as shown in FIG. 5, a felt 88 in which the hollow portion 46 of the shaft 12 is impregnated with lubricating oil is used.
Is loaded, and the impregnated lubricating oil leaks from the through holes 90 and 92 formed in both end regions B of the shaft 12 to form a lubricating oil film 94F.

Accordingly, even if the entirety of the hollow portion 46 is not filled with lubricating oil, the felt 88 may be impregnated with lubricating oil, and the amount of lubricating oil filled can be reduced. Further, even if the diameters of the through holes 90 and 92 are somewhat large, the lubricating oil does not leak too much, so that the formation of the through holes 90 and 92 is easy.

In the above description, the exposure apparatus has been described as an example, but it goes without saying that the present invention is not limited to the exposure apparatus.

[0042]

According to the present invention having the above-described configuration, the following effects can be obtained.

According to the first aspect of the present invention, there is no need to periodically supply a lubricant from the outside.

According to the second aspect of the invention, the lubricant can be uniformly supplied to the surface of the hollow shaft in the circumferential direction.

According to the third aspect of the present invention, it is not necessary to fill the entire hollow portion with the lubricant. Further, even if the diameter of the lubricant supply hole is large, the amount of leakage of the lubricant does not become excessive, so that when forming the lubricant supply hole, the lubricant supply hole can be formed with a margin in dimensional accuracy.

According to the fourth aspect of the invention, the lubricant can be easily replenished to the hollow portion of the shaft.

According to the fifth aspect of the present invention, it is possible to cause the lubricant to leak from the lubricant supply hole by moving the lid forward and backward in the longitudinal direction of the shaft to reduce the volume of the hollow portion.

According to the sixth aspect of the invention, the vibration of the exposure head that occurs when the exposure head passes through the lubricant supply hole does not occur during the exposure scanning. Also, since the shaft is hollow,
The vibration frequency generated when the shaft flexes can be made high. For this reason, it is possible to suppress image unevenness that occurs during exposure scanning of the exposure head.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a slide mechanism according to a first embodiment.

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a side view of the shaft taken along line 3-3 in FIG. 2;

FIG. 4 is a shaft side view showing another example of the slide mechanism in the first embodiment.

FIG. 5 is a sectional view showing a slide mechanism according to a second embodiment.

FIG. 6 is a sectional view showing a conventional slide mechanism.

FIG. 7 is a partially enlarged view of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Exposure head (moving body) 12 Shaft (hollow shaft) 14 Shaft (hollow shaft) 16 Slide mechanism 34 Bearing 36 Bearing 46 Hollow part 48 Lubricant (lubricant) 12S Surface 50 Through-hole (lubricant supply hole) 52 Through-hole (Lubricant supply hole) 60 Lid 62 Lid 70 Through hole (lubricant supply hole) 72 Through hole (lubricant supply hole) 80 Through hole (lubricant supply hole) 90 Through hole (lubricant supply hole) 92 through Hole (lubricant supply hole) 100 Slide mechanism 102 Bearing 104 Shaft 104S Surface 106 Lubricant

Claims (6)

[Claims] A hollow shaft having a hollow portion filled with a lubricant; a bearing slidably guided by the hollow shaft and supporting a moving body moving along the hollow shaft;
And a lubricant supply hole penetrating from a surface of the hollow shaft to the hollow portion in a moving section of the moving body. 2. The slide mechanism according to claim 1, wherein the lubricant supply holes are formed at equal intervals in a circumferential direction of the hollow shaft. 3. The slide mechanism according to claim 1, wherein a lubricant holding member impregnated with a lubricant is loaded in the hollow portion. 4. The hollow shaft according to claim 1, wherein a detachable lid for enclosing a lubricant in the hollow portion is attached to both ends of the hollow shaft. The slide mechanism as described. 5. The slide mechanism according to claim 4, wherein the lid is capable of adjusting a volume of the hollow portion by moving forward and backward in a longitudinal direction of the hollow shaft. 6. The apparatus according to claim 1, wherein the moving body is an exposure head, and the lubricant supply hole is formed in a region outside a scanning range in a moving section of the exposure head. 6. The slide mechanism according to claim 5, wherein