JPH0427405B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an elastic spacer for a rolling bearing for infinite linear motion.

Conventional spacers for rolling bearings are inserted between rolling elements such as rollers to prevent them from coming into direct contact with each other and to maintain a constant distance between them. Since the number of certain moving and rolling elements is reduced, the load capacity is reduced, and the presence of spacers makes it impossible to downsize.

In order to eliminate this drawback, for example, as shown in Figs. 1 and 2, a large number of cylindrical rollers without a spacer that engages between the rollers are arranged directly adjacent to each other with their rotational axes 90 degrees apart, and are infinitely close to each other. A linear motion roller bearing has been developed that has so-called full-form cross rollers that circulate endlessly on a circulation path.At this time, the amount of rolling elements coming out and going in at both ends of the raceway surface is not constant, that is, there is a change in the amount of coming and going. Therefore, we focused on the occurrence of stake slip in bearings, and set the lengths of the load track and return path, as well as the length of the direction change path connecting both ends of both straight paths, to a predetermined multiple of the roller shaft diameter. Infinite circulation path for linear motion roller bearings (Patent application No. 58-101467)
No. 59-4875) was proposed. In the figure, 1
rollers, 2 is an endless circulation path, 3 is a linear load path,
4 is a straight return path, 5 is a semicircular direction change path, 6 is a track rail, and 7 is a casing.

However, as a practical matter, the structure of the endless circulation path after assembly is limited due to processing errors in the parts that make up the endless circulation path and the amount of play (backlash) between the endless circulation path and the rolling elements. It is not always the minimum condition, and even under the minimum condition, small status slips occur and are not zero.

Therefore, even in a bearing with an endless circulation path structure under conditions other than ideal conditions, where the amount of change in the opening and closing is large, if you take some measures to reduce the amount of change in the opening and closing, the status slip will be reduced and the ideal condition will be achieved. You can get close to the conditions.

In view of this point, the present invention uses an elastic spacer to allow a large number of rolling elements to circulate in an endless circulation path, thereby reducing the circumferential clearance, which is a behavior characteristic of the rolling elements of a linear motion rolling bearing. The first purpose is to absorb the amount of increase or decrease.

Further, the elastic spacer of the present invention exhibits its effect in a rolling bearing for infinite linear motion shown in FIG. In the figure, 11 is a track base, 12 is a guide plate attached to both sides of the track base, and 13 is a stepped roller that endlessly circulates around the track base while being guided by the guide plate. When this rolling bearing is rotated 180 degrees up and down in the state shown in Figure 3B, there is no gap between the rollers in the lower load area of the endless circulation path; Since it occurs at the upper part of the direction change path on the side entering the area, the roller and the roller come into direct contact with each other in the load area, and the direction of rotation is reversed at the contact area, generating a force that impedes rolling movement. The elastic spacer according to the invention can prevent such drawbacks.

The present invention replaces a plurality of elastic spacers with roller-like rolling elements between rolling elements such as rollers in an endless circulation path consisting of a linear load track, a linear return path, and a direction change path connecting both ends of the track. The structure is such that the rolling elements are inserted at equal intervals to absorb the gaps between the rolling elements.

Embodiments of the present invention will be described below with reference to the drawings.
In FIG. 4, structures of various elastic spacers are shown in A to E, and these will be explained as follows.

A Fit the split elastic ring _A2 to the fixed pin _A1 .

B Insert the fixing pin _B1 into the elastic ring _B2 , which has several slits in the circumferential direction to facilitate elastic deformation, and secure it by caulking both ends or one end.

C Wrap spring _D2 around fixing pin _D1 .

A fixing pin _E1 such as D A is divided into two parts in the circumferential direction, which are fixed by caulking with rivets _E3 , and the elastic ring _E2 may be integral.

This is an improved version of ED, in which the tapered part of the fixing pin _F1 supports the elastic ring _F2 to eliminate looseness and reduce acoustics, and _F3 is a rivet.

In Fig. 4, (F) and (G) are elastic spacers different from those of the present invention, which have the same length as the rolling elements and a contact portion with a shape compatible with the rolling elements and an axial notch. By intervening between moving bodies, it exerts an elastic action and produces the same effect as the elastic spacer of the present invention.

Figures 5A and 5B show an example using both of the two types of elastic spacers described above. A is a longitudinal front view, and (B) is an explanatory view seen in the AA direction. FIG. 5B shows the case in which γ=45° in FIG. 5A, and FIGS. 1 and 2 show the case in which 0≪γ′<45°. Reference numeral 1 denotes cylindrical rollers having approximately the same diameter and length, which are arranged directly adjacent to each other and alternately on an endless circulation path with their rotation axes 90 degrees apart, and the endless circulation path is linear and long. It consists of a load track 3 of length L, a linear return path 4 of length L, and semicircular directional rotation paths 5, 5 connecting both ends of both paths 3, 4. An A-type elastic spacer is inserted in place of the cylindrical rollers 1 at positions divided into three equal pitches with substantially the same pitch as the length L of the raceway. As a result, there is one in the load area 3 and two in the no-load areas 4 and 5, and the amount of absorption is stabilized. In this case, one F-type spacer is used and inserted into the circumferential gap.

Figure 6A is a curve showing actual measured values of sliding resistance when a roller bearing of the type shown in Figures 1 and 2 with γ' = 18° is placed in a horizontal position, filled with grease, and the sliding resistance is measured at a moving speed of 10 mm/sec. The thick line is the conventional bearing, and the curved line is the case with one C-shaped elastic spacer, as shown in Figure 6B.
This is an example in which the same condition is used, but sometimes the stake slip is artificially generated (the rollers are tilted and set to fall within the load range).

The effects of the present invention are as follows.

(1) As is clear from the measured curve in Figure 6, the sliding resistance is clearly reduced by inserting the elastic spacer. The characteristic of this reduction is that it smooths out the intermittent rapid decrease in sliding resistance, which is called stake slip, by buffering it.

(2) In the case of vertical use in which linear movement is performed in the vertical direction, particularly large stick slips were noticeable when moving from top to bottom, but with the implementation of the present invention, this decrease has been eliminated and vertical Even using a mold can be effective.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view showing one embodiment of a roller bearing for linear motion, Fig. 2 is a partially cutaway side view of the same, and Figs. 3A, B, and C are other embodiments of a roller bearing for linear motion. A perspective view showing an example, a partially cut-away front view, and a perspective view of essential parts; FIGS. 4A to 4E are respectively perspective views or partially cut-away front views showing an example of implementing the present invention; F and G are those of the present invention. 5A and 5B are partial cross-sectional views of a linear motion roller bearing embodying the present invention, and explanatory views as seen in the A-A direction. FIGS. 6A and 6B are curve diagrams showing actual measurement results. The symbols in the drawings indicate the following members, respectively. 1: Roller, 2: Endless circulation path, 3: Load track,
4: return road, 5: direction change road, 6: track rail, 7: casing, 11: track base, 12:
Guide plate, 13: stepped roller, A to G: elastic spacer.

Claims (1)

[Claims] 1. An elastic spacer used in place of a roller-shaped rolling element in a linear motion rolling bearing having an endless circulation path consisting of a linear load track, a return path, and a direction change path connecting both ends of the spacer, the elastic spacer The spacer is formed by attaching a circumferential member slightly smaller than the outer diameter of the rolling element to the outer periphery of a fixed pin having the same length as the roller-shaped rolling element, and the elastic spacer has a circumferential member that is slightly smaller than the outer diameter of the rolling element. A straight line characterized in that the circumferential member of the surface and the fixing pin of the core are formed separately, and the circumferential member is formed to have a much thinner cross section than the fixing pin so that it is easily elastically deformed. Elastic spacer for motion rolling bearings.