JPH0225998Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a device for recovering bearing oil supplied to a bearing that supports a rotating shaft of a machine tool.

<Conventional technology> The grinding wheel head of a grinding machine is generally installed on the bed. An oil drain hole is provided at the bottom of the oil sump, and the oil in the oil sump is collected by gravity through the drain hole and piping into a tank located at a lower level than the oil sump.

<Problems to be solved by the invention> In cases where the grinding wheel head is installed above the bed, the bearing oil collected in the oil pool can be discharged into the tank using the above-mentioned natural fall method. When hoisting the rail so that it can move horizontally and vertically and installing piping for collecting bearing oil along the overhead rail, it is necessary to raise the bearing oil to the same position as the overhead rail, which is higher than the oil sump. With the natural fall method, bearing oil cannot be collected into a tank.

<Means for Solving the Problems> The present invention has been made to solve the above problems, and the gist of the invention is to rotatably support a rotating shaft and to which bearing oil is supplied. A bearing body including a radial bearing includes an oil reservoir having a sealed structure arranged between the pair of radial bearings, a discharge passage through which bearing oil from the radial bearing flows into the oil reservoir, and an inner peripheral surface of the radial bearing. Utilizing the gap passage formed by the clearance between the outer peripheral surface of the rotating shaft and the outer peripheral surface of the rotating shaft, an air groove is provided to allow air to flow between the outer side of the bearing body and the discharge passage, and bearing oil is supplied to the pair of radial bearings. A bearing oil supply piping, an air supply piping that supplies air higher than atmospheric pressure to the air groove, and a bearing oil recovery system that discharges the bearing oil in the oil reservoir to a tank or the like after passing through a position higher than the oil reservoir. The piping for this purpose is connected to the bearing body.

<Operation> The present invention increases the internal pressure of the oil sump by introducing air into the oil sump, drains the bearing oil in the oil sump to a place higher than the oil drain hole and collects it in a tank, etc. The coolant is led out to the outside of the bearing body to prevent coolant from entering the bearing body.

<Example> Hereinafter, an example of the present invention will be described based on the drawings. In FIG. 1, 1 is an overhead rail (hereinafter referred to as rail). A horizontal movable table 2 is guided on this rail 1. Reference numeral 3 denotes a vertically movable table, which is guided through an unillustrated guide hole provided at the center of the horizontally movable table 2 so as to be movable in the vertical direction. Reference numeral 4 denotes a whetstone stand fixed to the lower part of the vertical movable stand 3, on which a whetstone shaft 13 (described later) is supported along an axis parallel to the moving direction of the horizontal movable stand 2, and a whetstone 5 is fixed to the tip thereof. ing. Therefore, the grindstone head 4 is suspended below the rail 1 via the vertical movable base 3 and the horizontal movable base 2, and is movable horizontally and vertically by a servo motor and a ball screw (not shown) to perform processing. It is.

Reference numeral 6 denotes an oil tank, which is supplied to the bearing of the grindstone shaft 13 by a pump 7, and also collects the bearing oil supplied to the bearing. This tank 6 and pump 7 are installed on the ground. Therefore, the tank 6 is located at a lower position than the oil reservoir 25 in the grindstone head 4, which will be described later.

8 is a bearing oil supply pipe, 9 is a bearing oil recovery pipe, and 10 is an air supply pipe, all of which are arranged along the rail 1. 11 is an air source to which the air supply pipe 10 is connected. 12
is an expandable pipe provided in each of the pipes 8, 9, and 10, and allows the vertical movable base 3 to move up and down with respect to the horizontal movable base 2.

The specific configuration will be explained with reference to FIGS. 2 and 3. The grindstone shaft (rotary shaft) 13 is rotatably supported by a first bearing metal 15 and a second bearing metal 16 fixed to a grindstone head main body (bearing main body) 14. The bearings of this grinding wheel shaft 13 are provided on both sides of static pressure radial bearings 17 and 18 provided in the first and second bearing metals 15 and 16, and a circular flange 19 formed on the grinding wheel shaft 13. The bearing oil is supplied from the bearing oil supply pipe 8 to the static pressure radial bearings 15, 16 and the static pressure thrust bearing 20.

21 is a motor housing, and the grindstone head main body 1
It is fixed at 4. This motor housing 21
A stator 23 is fixedly installed inside the grindstone shaft 13, and a rotor 24 that faces the stator 23 with a gap is fixedly installed at the end of the grindstone shaft 13 to constitute a built-in type grindstone shaft driving motor.

An oil reservoir 25 sealed inside the grindstone head main body 14
is provided. This oil reservoir 25 is communicated with the discharge grooves of the hydrostatic radial bearings 17, 18 of the first and second bearing metals 15, 16 via discharge passages 26, 27, and the bottom of the oil reservoir 25 is An oil drain hole 34 communicating with the oil recovery pipe 9 is provided.

Furthermore, the first and second bearing metals 15 and 16 include an air passage 28 that communicates with the air supply pipe 10;
29 are provided. This one air passage 28
is the cap 3 fixed to the first bearing metal 15.
The other air passage 29 communicates with an air groove 31 provided in a cap 32 fixed to the second bearing 16. The air from these air grooves 31 and 33 flows into the first and second air grooves.
Utilizing the gap passage formed by the clearance between the inner circumferential surface of the bearing metals 15 and 16 and the outer circumferential surface of the rotating shaft 13, the outer side of the grindstone main body 14 and the discharge groove of the hydrostatic radial bearings 17 and 18 are connected. The oil is then led to the oil reservoir 25 via the discharge passages 26 and 27.

Since the present invention has the above-mentioned configuration, the bearing oil pumped from the tank 6 by the pump 7 is supplied to the hydrostatic thrust bearing 20 and the hydrostatic radial bearing of the first bearing metal 15 through the bearing oil supply piping 8. 17 and also the hydrostatic radial bearing 1 of the second bearing metal 16
Supply to 8.

The bearing oil supplied to the hydrostatic radial bearings 17 and 18 is passed through the discharge passages 26 and 27 to the oil reservoir 25.
are collected in.

On the other hand, air supplied from the air supply piping 10 is introduced into the oil sump 25 from the air passages 28 and 29 via the air grooves 31 and 33 and the discharge passages 26 and 27, thereby increasing the internal pressure in the sealed oil sump 25. generate. As a result, the bearing oil 35 collected in the oil sump 25 is pushed out from the oil drain hole 34 to the bearing oil recovery pipe 9, raised to a position higher than the oil sump 25, and collected in the tank 6.

The air in the air grooves 31 and 33 is fed to the cap 3.
Coolant flows according to the throttling resistance of the respective gap passages to the outside of the caps 30 and 32 and to the discharge passages 26 and 27, and the coolant that flows out to the outside of the caps 30 and 32 is supplied to the part processed by the grinding wheel 5 on the workpiece. Prevent the inconvenience of intrusion.

Although the above embodiment uses a grindstone head, it can also be applied to a spindle head.

<Effects of the invention> As described above, according to the invention, air from the air supply piping is transferred from the air groove to the gap passage formed by the clearance between the inner peripheral surface of the radial bearing and the outer peripheral surface of the rotating shaft. However, since the coolant is allowed to flow out to the outside of the bearing body, it is possible to prevent coolant from entering the bearing body, and the air from the air supply piping is allowed to flow through the air groove, the gap passage, the discharge groove, and the discharge passage. Since the bearing oil is allowed to flow into the oil sump and the pressure within the oil sump is increased, the bearing oil can be collected into the tank via a position higher than the oil sump.
In this way, it is possible to obtain the advantage that coolant intrusion can be prevented and bearing oil can be recovered with a small number of air supply piping without complicating the structure.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, with Figure 1 being a front view, Figure 2 being a sectional view showing details of the bearing part, and Figure 3 being a sectional view showing details of the bearing part.
The figure is a sectional view taken along the line -- in FIG. 2. 4... Grindstone head, 6... Tank, 7... Pump,
8... Piping for bearing oil supply, 9... Piping for bearing oil recovery, 10... Piping for air supply, 11... Air source,
13... Grinding wheel shaft, 14... Grinding wheel stand body, 15...
First bearing metal, 16...Second bearing metal, 17,1
8...Static pressure radial bearing, 25...Oil sump, 2
6, 27...Drain passage, 28, 29...Air passage, 34...Oil drain hole.

Claims (1)

[Scope of utility model registration request] A bearing body including a pair of radial bearings that rotatably supports a rotating shaft and is supplied with bearing oil includes an oil reservoir with a sealed structure arranged between the pair of radial bearings, and a bearing oil reservoir from the radial bearings. Using a discharge passageway that flows into the oil reservoir and a gap passage formed by the clearance between the inner circumferential surface of the radial bearing and the outer circumferential surface of the rotating shaft, air is circulated between the outer side of the bearing body and the discharge passageway. a bearing oil supply pipe that supplies bearing oil to the pair of radial bearings; an air supply pipe that supplies air at a pressure higher than atmospheric pressure to the air groove; and a bearing oil supply pipe that supplies bearing oil to the pair of radial bearings; A bearing oil recovery device characterized in that a bearing oil recovery piping for discharging oil to a tank or the like through a position higher than an oil reservoir is connected to a bearing body.