JPH04244368A - Lap method - Google Patents

Abstract

PURPOSE:To provide a lap method for high accurately lapping opposed surfaces between a pair of members sliding each other, relating to the method of lapping a sliding surface between a rotary shaft and its bearing or a linearly guided member. CONSTITUTION:In the case of lapping while sliding an opposed surface 32S of a pair of members, the lapping is performed while adjusting both opposed surface clearances in a size of lapping abrasive grains 36.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of lapping a rotating shaft and its bearing, or a sliding surface between linearly guided members. Therefore, it can be used for wrapping ultra-precision air bearings, etc.

0002

[Prior Art] Conventionally, in order to wrap the sliding surfaces of a cylindrical member and a cylindrical member, the gap size between the two members is generally achieved by machining, and the gap is the size of the abrasive grains for lapping. is sufficiently large compared to For example, even in ultra-precision air bearings, the size of the abrasive grains is one-fifth or less compared to the gap size between the members in relation to the size of lap abrasive grains suitable for the bearing. Therefore, as shown in FIG. 4, during lapping, it is necessary to rotate the center-side cylindrical member 10 while pressing it in a certain radial direction of the outer ring-side cylindrical member 12, and sequentially change the pressing direction.

Furthermore, in the lap between the sliding surfaces between the linearly moving member 20 having a rectangular cross section and its guide member 22 as shown in FIG. 5, it is not possible to press each surface at the same time.
Each side needs to be wrapped.

0004

[Problems to be Solved by the Invention] However, in the case shown in FIG. 4, only the pressed portion is wrapped, so the outer periphery of the cylindrical member 10 is finished in a polygonal shape, which makes it difficult to obtain an ultra-precise bearing structure. cannot be adopted. In addition, in the case shown in Fig. 5, since the gap between the opposing sliding surfaces is small, it is not always possible to wrap only between the ideally pressed surfaces, and the two members may be placed in a relatively straight line. During sliding, it comes into contact with other surfaces randomly, making it impossible to wrap it evenly.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lapping method for lapping, with high precision, opposing surfaces between a pair of members that slide against each other.

[0006]

[Means for Solving the Problems] In view of the above object, the present invention provides a method for lapping while sliding the opposing surfaces of a pair of members, while adjusting the gap between the opposing surfaces to the size of the abrasive grains for lapping. To provide a wrapping method characterized by:

[0007]

[Effect] Regardless of the set gap size between both members, pressure is applied uniformly to all opposing surfaces only during lapping by adjusting the abrasive grain size for lapping. Opposite surfaces are lapped at the same time. Therefore, a desired perfect circle or flat surface can be obtained, and the gaps can be made uniform. Furthermore, if necessary, it is also possible to obtain a very narrow gap that is as close to zero as possible.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in more detail below based on embodiments shown in the accompanying drawings. First of all, referring to FIG. 1, this figure shows how to wrap the opposing surfaces 30S and 32S of a rotating shaft 30 that rotates around a central axis CL and a cylindrical member 32 that supports the rotating shaft 30 via air. FIG. 3 is a diagram illustrating a method according to the invention.

A housing member 38 having a heating or cooling function is provided on the outer periphery of the cylindrical member 32.
A gap 40 between both members 32 and 38 may be filled with a heat transfer fluid as required. That is, in this embodiment, the temperature of the cylindrical member 32, which is a stationary body, is controlled to cause the member 32 to thermally expand or contract, thereby creating a gap between the facing surfaces 30S and 32S where the lapping abrasive grains 36 are generally layered. Adjust to size.

As a method for this adjustment, when the rotating shaft 30 is rotated and its torque is measured while controlling the temperature of the cylindrical member 32, the torque suddenly increases at a certain temperature to as shown in FIG. As schematically shown in FIG. 1, the gap between the opposing surfaces becomes the size of one layer of lapping abrasive grains 36, and
This shows that the rotating shaft 30 is now pressed from all radial directions. Therefore, with a sudden increase in torque value,
It turns out that a state is reached in which uniform pressure is applied between the opposing surfaces 30S and 32S of the rotating shaft 30 and the cylindrical member 32. Moreover, when the state shown in FIG. 1 is reached, the opposing surface 30S
, 32S, the lapping liquid becomes black and cloudy, and this can be visually determined.

[0011] Thus, as described above, since pressure acts over the entire circumference between the surfaces to be lapped, lapping can be performed simply by rotating the rotary shaft 30. As a result, the rotation axis 30
Both the outer peripheral surface 30S of the cylinder member 32 and the inner peripheral surface 32S of the cylindrical member 32 are wrapped in a perfect circle. Note that, if necessary, as the wrapping progresses and the gap between the opposing surfaces 30S and 32S widens and the torque becomes smaller, the temperature of the cylindrical member 32 may be controlled again so that a uniform pressure is applied. .

Although the gap between the opposing surfaces to be lapped has been adjusted by thermal expansion and contraction in the above example, there is also a method of applying pressure. That is, the cylindrical member 32 may be contracted from the outer periphery by allowing pressure fluid to flow into the gap 40 described above. The pressure of the fluid is gradually increased.

Unlike the above, the above method is possible even if the rotating shaft 30 described above is a stationary body and the cylindrical member 32 is a rotating body. However, if the shaft 30 has a center hole 30b as shown in FIG. 1, the shaft 30 can be expanded by applying pressure fluid or inserting a heater into the center hole 30b. The same effect as above can be achieved.

FIG. 2 shows a case where the cross section is rectangular, and the opposing surfaces 30S' and 32S' between a member 30' that moves linearly in a direction perpendicular to the paper and a guide member 32' that guides it are lapped. This is an example of a case where In this case as well, by expanding or contracting the member 30' or 32' using the outer housing member 38' or the center hole 30b' of the linearly movable member 30' to adjust the gap between the opposing surfaces to be lapped, flat surfaces can be formed. Opposing surfaces are obtained and the gaps are also made equal.

[0015]

As is clear from the above description, according to the present invention, the opposing surfaces, which are sliding surfaces, can be lapped with high precision between members that slide on each other.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one application example of the wrapping method according to the present invention.

FIG. 2 is a diagram showing another application example of the wrapping method according to the present invention.

FIG. 3 is a diagram illustrating a gap adjustment method in the wrapping method according to the present invention.

FIG. 4 is a diagram showing an example of a conventional wrapping method.

FIG. 5 is a diagram showing another example of a conventional wrapping method.

[Explanation of symbols]

30...Rotation axis 30b...center hole 30S...Opposing surface 32...Cylindrical member 32S...Opposing surface 36...Abrasive grain for lapping 38...Housing member

Claims (5)

[Claims] 1. A lapping method characterized in that when lapping is performed while sliding the opposing surfaces of a pair of members, the gap between the opposing surfaces is adjusted to the size of the abrasive grains for lapping. 2. The wrapping method according to claim 1, wherein the gap between the opposing surfaces is adjusted by controlling the temperature of at least one of the pair of members. 3. The wrapping method according to claim 1, wherein the gap between the opposing surfaces is adjusted by applying pressure to at least one of the pair of members. 4. The wrapping method according to claim 1, wherein one of the pair of members is a rotating member. 5. The wrapping method according to claim 1, wherein one of the pair of members is a linearly moving member having a rectangular cross section.