JPS6235943Y2 - - Google Patents

Description

[Detailed description of the invention] Field of industrial application This invention forms a thin steel plate into a U-shaped cross section to make a table or bed, and a raceway groove is formed in the longitudinal direction on a part of the side wall surface of the table or bed. This relates to a ball bearing for finite linear motion in which the raceway grooves of the bearings face each other and are connected via balls.

Prior Art Figure 7 shows an example of a conventional ball bearing of this type.
1 is a table, 2 is a bed, 3 is a ball, 4' is a plate-shaped retainer that engages the ball in a hole, 5' is an upper plate fixed to the table, and 6' is a lower plate fixed to the bed. be. The conventional side plates 5', 6' are formed perpendicularly to the mounting surface of the table or bed and restrict the position of the retainer 4' so that it does not fly out.

Problems to be Solved by the Invention However, the actual relationship between both raceway members and the cage is complicated as shown in FIG. In the figure, the solid line of cage 4' is the normal position, and the dotted line is the most common position (5
゜）It is in a rolling state.

The movements of the cage can be roughly classified as follows.

(1) Side-to-side rocking of the cage around the ball center C (rolling), (2) Parallel movement due to the gap between the ball and the cage (yawing), (3) Back and forth movement due to the gap between the ball and the cage Shaking pitting, in which the behaviors (1) and (2) are large, the conventional side plate cannot stop the cage, which has the disadvantage of causing the cage to jump out of the table or bed. In particular, the lower plate was disadvantageous in terms of its structure because its area in contact with the cage was smaller than that of the upper plate.

Furthermore, the conventional cage had the following drawbacks.

(1) The amount of rolling was large, and the degree of freedom of the cage during movement was large and unstable.

(2) If the gap between the balls and the cage was large, the cage would come into close contact with either the bed or the table, and the sliding resistance would increase due to the surface tension of the lubricant.

(3) There were problems with stable supply of lubricant because there were few oil pockets.

(4) Due to the unstable behavior of the cage, it was prone to wear and its lifespan was shortened.

The present invention solves these drawbacks, and provides a cage for this type of bearing that is inexpensive, lightweight, securely holds the balls, and has a large oil pocket. The purpose is to provide

Means for Solving the Problems The present invention has the following configuration to achieve the above object.

As for the side plates, the lower plates attached to both longitudinal ends of the bed are trapezoidal in shape, and their tapered surfaces are located on the ball side, with one end being closer to the bed than the center of the ball, and the other end being attached to the center of the ball. The upper plate attached to both longitudinal ends of the table has the same shape as the lower plate, leaving a certain gap in the shape of the inner peripheral surface. As for the cage, the cross-sectional shape of the cage is approximately I-shaped in order to keep the balls separated, and a window for holding the balls is formed approximately in the center of the I-shape. The ball is held by intermittent annular protrusions, such as half-moon shapes, formed on the left and right sides.

Function As mentioned above, in the conventional rectangular side plate, the surface in contact with the cage was rectangular and did not touch the cross-sectional center line of the cage, so when the cage moved toward the table side, it could sometimes climb over the side plate. Ta. The present invention improves on this point, and by forming the side plate into a trapezoidal shape, it can partially cross the cross-sectional center line of the cage and come into contact with the cage. The stopping force is increased, and the cage stopping force of the side plate as a whole can also be increased. Furthermore, as a result of the above structure of the cage, pitting and rolling can be prevented and a large amount of lubricant can be retained.

Embodiment Figures 1 to 5 show an example of implementing the present invention, in which 1 is a table, 2 is a bed, 3 is a ball, and 4 is a table.
5 is an upper plate fixed to the table, and 6 is a trapezoidal lower plate fixed to the bed. Further, 1a and 2a are ball raceway grooves. These side plates 5, 6 are made of plastic and are fixed to each track member by heat caulking (FIG. 5). The cage 4 has an I-shaped cross section and is reinforced at both upper and lower ends. Furthermore, in order to increase the amount of balls held, protrusions 4b around the windows 4a are formed on both sides in a half-moon shape, as shown in FIG. The reason for the half-moon shape is to facilitate the removal of the core from injection molding. Of course, the protruding portion 4b does not have to be half-moon-shaped; for example, a modification in which the protruding portion is separated at four locations is also possible.

FIG. 6 shows a second embodiment of the present invention, in which the trapezoidal shape of the lower plate 6 is the opposite of that of the first embodiment, and the shape of the upper plate 5 is also changed accordingly. Compared to the first embodiment, since the cage can be stopped closer to the bed 2, the side plates are less deformed when the cage collides, but the contact area is somewhat smaller.

The present invention can also be used for the side plates of this type of bearings that use thick-walled beds and tables other than those made of thin-walled steel plates, and the material of the side plates can also be made from materials other than plastic depending on the mating member. can also be applied.

In both of the above embodiments, the tapered surfaces of the upper and lower plates are formed symmetrically with respect to a line passing through the center of the ball, but the structural contact area between the upper plate and the retainer or the contact area between the lower plate and the retainer is Since there are obviously more contact areas than others, the tapered surface can be moved beyond the center of the ball to balance the contact area of each. In practice, the taper angle of the side plate may be approximately 5 degrees at the maximum angle of inclination of the cage.

Effects of the invention (1) The practical contact area between the side plate and the cage is increased,
The cage can be stopped reliably.

(2) A wide recess is formed on the side surface of the cage by the I-shaped cross section and the protruding part of the window, and a large amount of lubricant can be held.

(3) The flanges at both ends of the I-shaped cross section not only reinforce the cage, but also prevent pitting and rolling.

(4) The cage is formed by injection molding of plastic, but when the cage is pulled out from the mold after injection molding (forcibly removed), the holding part has an intermittent annular protruding shape, so the core inside the window is easily pulled out of the window, thereby avoiding plastic deformation of the window protrusion. Therefore, the ball is held accurately.

(5) During operation, the movement of the cage, such as rolling, is stable, so the stopping effect of the side plates is more effectively achieved.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view showing the first embodiment of the present invention, Fig. 2 is a partially cross-sectional side view, Fig. 3 is an enlarged side view of the main part, and Fig. 4 is a sectional view of the cage. and FIG. 5 is a partially longitudinal front view. FIG. 6 is a partially cross-sectional side view showing a second embodiment of the present invention, FIG. 7 is a partially cut-away perspective view showing a conventional example, and FIG. 8 is an enlarged side view of the main part. The symbols in the drawings indicate the following members, respectively. 1: table, 2: bed, 3: ball, 4, 4': retainer, 5, 5': upper plate, 6, 6': lower plate.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. Raceway grooves are formed in the longitudinal direction on a part of the side wall surface of a table or bed formed by making a thin steel plate into a U-shaped cross section, and the raceway grooves of the table and bed face each other. The lower plate attached to both longitudinal ends of the bed is formed into a trapezoidal shape, and its tapered surface is located on the ball side, and one end is connected to the ball through a ball having a retainer. It is located on the bed side from the center, and the other end is on the table side beyond the center of the ball, and the upper plate attached to both longitudinal ends of the table leaves a nearly constant gap in the shape of the inner peripheral surface. A ball bearing for linear motion made of a thin steel plate, characterized in that the ball bearing is shaped to fit the lower plate. 2. The retainer of the ball has an I-shaped cross section, and a window for retaining the ball is formed approximately in the center of the I-shape, and an intermittent annular protrusion such as a semicircle is formed at the periphery of the window. A ball bearing for linear motion made of a thin steel plate according to claim 1, characterized in that the ball bearing is made of a thin steel plate and is adapted to hold balls.