JPS6116046Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a small amount lubricating device for a bearing, in which lubricating oil is supplied to the bearing from an oil reservoir area through an oil amount adjusting member provided in an oil passage.

Generally, grease lubrication, which is easy to maintain, is often used as a lubrication method for bearings. However, one of the requirements for bearings used in the main spindles of machine tools is high speed and low temperature rise, so efforts are being made to reduce the amount of grease and reduce temperature rise. At high speeds, it was difficult to maintain stable lubrication conditions due to lack of grease, causing damage such as seizure.
For this reason, jet lubrication is used as a lubrication method for high-speed bearings, but jet lubrication requires more lubricant than is necessary, and in order to supply a large amount of lubricant to the bearing, the lubricant must be stirred. It requires a large driving force due to resistance, making it unsuitable for machine tools, etc., and further requires the provision of an oil drain hole and a device for collecting lubricating oil.

Therefore, it is desirable to supply oil to this type of bearing continuously in extremely small amounts over a long period of time while controlling the flow rate.

This invention solves the above-mentioned problems, and the details of this invention will be explained below with reference to the embodiments shown in the drawings.

This idea installs an oil amount adjustment member designed according to the required oil amount in the oil flow path to the bearing that requires lubrication, and uses the centrifugal force generated by the rotation around the bearing to provide lubrication. To provide a device that controls the amount of oil to a minute amount without requiring specific power or equipment.

The embodiment shown in the drawings is an example of application to a high-speed thrust bearing of a machine tool, and the spindle shaft 1 of the machine tool,
It consists of a main shaft cylinder 2, an intermediate shaft cylinder 3, a bearing 4, and an axle box 5.

The spindle shaft 1 is provided with a plurality of oil supply holes 6 on the circumference at positions corresponding to the width centers of the bearings 4, each penetrating through a center hole 1a formed at the end thereof. The leak-prevention sleeve 7 and the bearing 8 are inserted and positioned and fixed by the lid 9, and further supported by the inner ring of the bearing 9, the oil supply pipe 1
0 is inserted. The main shaft cylinder 2 is fitted onto the spindle 1 axis with a tight fit, and an annular groove 11 with a semicircular cross section is provided on the inner peripheral surface corresponding to the width center of the bearing 4. A plurality of oil introduction holes 13 penetrating the lubricating oil receiving hole 12 of the bearing 4 are provided. The intermediate shaft cylinder 3 is fitted onto the main shaft cylinder 2 and fixed to the main shaft cylinder 2 with a collar 14 and a nut 15, and has an arc-shaped notch at a symmetrical position on the circumference of the inner peripheral surface corresponding to the bearing 4. A lubricating oil receiving hole 12 is provided,
A plurality of screw holes 16 passing through the outer peripheral surface are provided in the outer peripheral portion of the lubricating oil receiving hole 12, and an oil amount adjusting screw 17 is screwed into each screw hole 16. The bearing 4 is fixed with a preload adjustment spacer 26 between a collar 18 and a nut 19 to apply preload to the main shaft cylinder 2 and intermediate shaft cylinder 3 to fix the inner rings 21 and 21 to the main shaft cylinder 2 and the intermediate shaft cylinder 3, and to fix the outer ring 22 in the shaft box 5. The inner ring 2 is positioned and fixed with the cover body 23.
Rolling elements 25, 25 held by retainers 24, 24 are arranged between 1, 21 and the outer ring 22, and oil supply grooves 26 are provided on both end surfaces of the preload adjustment spacer 20 in correspondence with the screw holes 26 of the intermediate shaft cylinder 3. is installed. As shown in the drawing, the oil supply hole 6, oil introduction hole 13, screw hole 16, and oil supply groove 26 communicate with each other via the annular groove 11 and the lubricating oil receiving hole 12, and are located on the rotation axis of the spindle shaft 1. An oil passage is formed that extends generally in the radial direction from the central hole 10 toward the bearing 4.

In the above structure, the lubricating oil supplied from the oiler 27 through the oil supply pipe 10 into the center hole 1a of the spindle shaft 1 is affected by the centrifugal force caused by the rotation of the spindle shaft 1, main shaft cylinder 2, intermediate shaft cylinder 3, and bearing 4. , the main spindle cylinder 2 passes through the oil supply hole 6 of the spindle shaft 1.
The lubricating oil reaches the annular groove 11 of the main shaft cylinder 2, passes through the oil introduction hole 13 of the main shaft cylinder 2, and collects in the lubricating oil receiving hole 12 of the intermediate shaft cylinder 3. The lubricating oil accumulated in the lubricating oil receiving hole 12 is transferred to the screw hole 16.
The oil is introduced into the screw hole 16 and flows out onto the outer circumferential surface of the intermediate shaft cylinder 3 through a small gap between the oil amount adjustment screw 17 screwed into the screw hole 16 and the preload adjustment. The oil is supplied into the bearing 4 through the oil supply groove 26 of the spacer 20. The amount of lubricating oil supplied into the bearing 4 at this time can be set according to the purpose by changing the rotation speed of the spindle shaft 1, the outer diameter and length of the oil amount adjusting screw 17, etc.

As a result of conducting a bearing temperature rise test using a small amount oil supply lubrication device based on this invention, it was found that 10 hours of operation was possible with 8 c.c. of lubricating oil supplied to the center hole 1a of the spindle shaft 1, and the temperature was lower than that of the small amount grease lubrication. The increase was as low as 2 degrees Celsius (max).

As explained above, this invention consists of a central hole that is located on the axis of rotation of a rotating member fitted with a bearing and receives oil from the outside, and an oil path that extends approximately radially from the central hole toward the bearing. and a screw screwed in the middle of the oil path, and by using centrifugal force, oil is supplied to the bearing in minute amounts through the screw hole and the gap between the screws, so in minute amounts at a time. It is possible to supply oil continuously over a long period of time while controlling the flow rate, making it suitable as a lubricating device for bearings used in the main shafts of machine tools and the like.

[Brief explanation of the drawing]

The drawing is a sectional view showing an embodiment of the bearing micro-oil lubrication device according to the invention. DESCRIPTION OF SYMBOLS 1... Spindle shaft, 2... Main shaft cylinder, 3... Intermediate shaft cylinder, 4... Bearing, 5... Axle box, 6... Oil supply hole, 10... Oil supply pipe, 11... Annular groove, 12
... Lubricating oil receiving hole, 13 ... Oil introduction hole, 16 ... Screw hole, 17 ... Oil amount adjustment member, 20 ... Preload adjustment member, 26 ... Oil supply groove.

Claims (1)

[Scope of utility model registration request] A central hole located on the rotational axis of a rotating member fitted with a bearing and receiving oil supply from the outside, an oil path extending approximately radially from the center hole toward the bearing, and a screw inserted in the middle of the oil path. What is claimed is: 1. A micro-oil lubricating device for a bearing, characterized in that the device includes a screw having a screw hole and a screw, and is configured to supply lubricant in minute amounts to the bearing through a gap between the screw hole and the screw using centrifugal force.