JPH0478358A - Ball screw mechanism - Google Patents

Abstract

PURPOSE:To perform uniform supply of fat without interruption so as to reduce fat feeding time and trouble by providing a return tube with an oil and fat storage part, and forming openings through which each ball passing the return tube is brought into direct contact with stored oil and fat. CONSTITUTION:When relative rotation is applied between a ball screw 1 and a nut 3, balls 2 move while rolling in ball grooves 5, 6, enter into a return tube 7 at one end of two cycles and a half and is circulated back into the ball grooves 5, 6 from the other end. The direction of circulation depends on the direction of relative rotation. In the meantime, when the balls pass through the return tube 7, each ball 2 comes in direct contact with sponge through an opening 8 in the position of a fat and oil storage pat 9 so as to receive fat and oil on the ball surface and continues its rolling. The fat is thereby fed automatically between the ball 2 and nut 3, and the ball 2 and ball screw 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a ball screw mechanism, which is one of the mechanisms for converting rotational motion into linear motion.

Conventional ball screw mechanisms are widely used as an excellent mechanism for converting rotational motion into linear motion. However, lubrication is performed through a grease nipple provided on a pole nut (hereinafter simply referred to as a nut) or through a ball screw mechanism. It is applied to the raceway surface of the screw by hand or with a brush.

Such greasing work is relatively troublesome, and there are also problems such as excessive grease supply, staining the surrounding area, and uneven lubrication.

Problems to be Solved by the Invention An object of the present invention is to provide a ball screw mechanism that can perform greasing uniformly and easily without waste.

Means for Solving the Problem An oil storage section is provided in the return tube provided in the nut of the ball screw mechanism.

An opening is provided in the return tube at that position, and the balls passing through the opening are brought into direct contact with the oil and fat in the oil storage section.

As the working ball circulates, oil and fat in the oil storage section is automatically applied to the ball surface, and the spaces between the ball and the nut and between the ball and the ball screw are lubricated.

Example FIG. 1 shows a first embodiment.

A nut 3 is attached to a ball screw 1 via a ball 2,
A normal ball screw mechanism 4 is configured.

A screw-shaped ball groove 5 is formed in the ball screw 1, in which the balls 2 roll.

The nut 3 has a hole groove 6 on the inside, and a half-circle return tube 7 is arranged every 2.5 turns of the ball groove 5, connecting both ends of the 2.5 turns of the ball groove to form a circulation path. is forming. In this embodiment, the return tube 7
It has two locations and two systems of circulation paths.

An opening 8 having a width of about 1/3 of the diameter of the ball 2 and a length of about 3 mm is formed in the part of the return tube 7 exposed to the outside from the nut 3. A storage section 9 is installed.

The oil storage section 9 is a box-shaped container 10 without a bottom, and a sealing material 11 is provided around the area in contact with the return tube 7, and a sponge or cotton 12 impregnated with oil (lubricating oil or grease) is provided inside. Being pushed. The oil and fat storage section 9 is mounted by being strongly pressed against the return tube 7 side by a simple lip 3. This embodiment is a disposable cassette type.

When relative rotation is applied between the ball screw 1 and the nut 3, the balls 2 move while rolling in the ball grooves 5 and 6.
It enters the return tube 7 at one end of the 2.5 rotations, returns to the ball grooves 5 and 6 again from the other end, and circulates. The direction of circulation depends on the direction of said relative rotation.

During this time, when the balls 2 pass through the return tube 7, each ball 2 directly contacts the sponge 12 through the opening 8 at the oil storage part 9, receives oil (stored oil) on the ball surface, and is transferred as it is. By continuing, the spaces between the ball 2 and the nut 3, and between the ball 2 and the ball screw 1 are automatically lubricated as described above.

FIG. 3 shows a second embodiment, which differs from the first embodiment in that the ball screw 1 is of a type that moves forward and backward while rotating with respect to a fixed nut 3.

Two return tubes 7 for circulating the balls 2 and an oil storage section 9 are provided under the nut 3, and the oil storage section 9 is attached to the surface of the nut so as to cover the exposed portions of the two return tubes 7. ing.

Reference numeral 14 denotes a nipple, which is used to supply oil to the oil storage section 9 fixedly attached to the nut 3.

The rest of the structure is the same as the first embodiment, and each return tube 7 is provided with an opening 8.

The oil storage section 9 is a type of oil tank with an open upper part, and the periphery of the open section is liquid-tightly fixed to the surface of the nut 3 via a packing 15, and the lubricating oil inside is almost below the return tube 7. It is filled to the extent that half of it is covered.

When the ball screw 1 rotates, the balls 2 roll and circulate. Each time the ball 2 passes through the return tube 7, it comes into direct contact with the lubricating oil and absorbs it into the ball grooves 5 and 6.
Since the ball 2 and the nut 3 and the ball 2 and the ball screw 1 are constantly lubricated as described above.

Note that the oil storage section 9 may be filled with grease. In this case, the nut 3 can also be rotated.

However, if the lubricating oil has good fluidity, it has a heat dissipation effect due to convection inside the oil storage section 9, and has the effect of cooling the threaded part between the ball screw 1 and the nut 3.

The above is an example.

The present invention can be similarly configured even when two or more ball grooves 5.6 are provided.

The return tube may be arranged at a distribution other than 2.5 times around the ball groove.

In the second embodiment, if the stored oil is a lubricating oil with good fluidity, the opening in the return tube should be made into a thin slit in order to prevent a large amount of lubricating oil from being carried away by the balls during high-speed rotation. There are things to do.

Effects of the invention Procedural amendment (method) in which oil and fat for lubrication are conveyed little by little but always uniformly by rolling and circulating balls % formula % Case description 1990 Patent Application No. 189520 2゜Name of the invention: Relationship with the case of the person making the 3° amendment to the ball screw mechanism

Claims (1)

[Claims] A structure is provided in which balls rolling in the thread groove of the ball screw are interposed between the ball screw and the ball nut, and both ends of the ball screw over a predetermined pitch are connected by a return tube to circulate the balls. A ball screw mechanism characterized in that an oil storage section is provided and an opening is formed in a return tube at that position so that a ball passing through the return tube can directly contact the stored oil and fat.