JPH05268743A - Bearing device of electric rotating machine - Google Patents

Abstract

PURPOSE:To improve the reliability by making a bearing easy to follow the inclination of a rotary shaft without increasing the frictional resistance between a bearing and a spherical supporting seat even if the weight of a rotor increases. CONSTITUTION:This bearing device is composed of a bearing base lower half 12 and a bearing base upper half 13, which are divided on an axial horizontal, and a bearing 21, and the periphery 21 a of a bearing 21 is nearly spherical, and the bearing base lower half 12 and the bearing base upper half 13 are provided with spherical supporting seats 22, which have inside peripheries 22a engaging with this outside periphery 21 a and are divided on the axial horizontal. This spherical supporting seat 22 is provided, at the inside periphery 22a, with a high-pressure oil circulating hole 23 for circulating high-pressure oil from a high-pressure oil feeder 4 and a supporting oil groove 24 in the shape of a circular recess leading to this high-pressure oil circulating hole 23, and the bearing hole 21 is provided with a high-pressure oil circulation hole 25 leading to this supporting seat oil groove 24 and bearing oil grooves 16 and 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device for a rotary electric machine in which high pressure oil is supplied between a bearing surface of a plain bearing and a journal surface to forcibly levitate a rotary shaft.

[0002]

2. Description of the Related Art In a large-sized rotating electric machine, when operating at a low speed, if the oil film formed between the bearing surface and the journal surface is small, in order to secure an oil film thickness for safe operation or start At times, high pressure is supplied to reduce the starting resistance, and a method of forcibly levitating the rotating shaft is adopted.

Generally, it is used when the bearing load / (shaft diameter × effective bearing length) = bearing surface pressure exceeds about 7 kg / cm ² or when it is difficult to form an oil film at a low speed.

FIG. 8 is a piping system diagram showing an example of a method of forcibly levitating the rotary shaft of a conventional rotary electric machine. 1 is a rotor, 2 is the rotary shaft of the rotor 1, and 3 is the rotary shaft. 2 is a bearing device that supports 2. The high-pressure oil supplied from the high-pressure oil supply device 4 through the high-pressure oil supply pipe 5 is flow-controlled by the flow control valve 6 and passes through the check valve 7 to the bearing device 3 which supports the rotating shaft 2 of the rotor 1. It is sent and the rotating shaft 2 is levitated. This high-pressure oil removes heat due to bearing loss, and oil site 8
It is configured to return to the high pressure oil supply device 4 through the.
In the high-pressure oil supply device 4, the pump 9 is driven by the motor 9 to pressurize the lubricating oil sucked from the tank 11, the flow rate is adjusted by the flow control valve 6 through the check valve 7, and the high-pressure oil supply pipe 5 is sent. Be done.

FIG. 9 shows a cross section of the bearing device 3, which is composed of a lower half 12 of the bearing stand, an upper half 13 of the bearing stand, and a slide bearing (hereinafter referred to as a bearing) 14 which are divided on a horizontal line of the shaft center.
Has a spherical outer surface 14a in order to provide self-centering property, and the outer half 14a and the upper half 13 of the bearing stand, which are opposed to the outer circumference 14a, have a divided structure, and the inner circumference 15a has a spherical surface. The support seat 15 is provided. Bearing oil groove 16 provided directly under the bearing 14 from the lower half 12 of the bearing base through high-pressure piping and a high-pressure hose
High pressure oil is supplied to the bearing surface and the journal surface of the rotary shaft 2 to which high pressure oil is added so that the rotary shaft 2 is levitated.

On the other hand, when a large thrust force is applied, a thrust collar 17 is provided on the rotary shaft 2 as in the bearing device 3 shown in FIG. 10, and the thrust force transmitted to the rotary shaft 2 is passed through the thrust collar 17. The structure is such that the end surface of the bearing 14 receives it. In this case, since the end surface of the bearing 14 and the thrust collar 17 are in direct contact, the lower part of the thrust collar 17 is immersed in the lubricating oil in the oil tank in the lower half 12 of the bearing stand so that it also has the function as an oil desk. , Thrust color 17
Lubricating oil adhered to the bearing 14 lubricates the end surface of the bearing 14. Reference numeral 18 in the figure indicates a lubricating oil surface.

[0007]

By the way, in the bearing device shown in FIG. 9 described above, both contact surfaces of the bearing and the spherical support seat are precisely machined in order to have self-aligning property.
Oil is applied to the contact surface to ensure smooth contact. However, when the bearing load is large, the surface pressure of the spherical surface becomes about 30 kg / cm ² , and the state becomes close to metal contact,
There is a drawback that the inclination of the bearing does not easily follow the inclination of the rotating shaft due to the weight of the rotor. If the inclination of the rotary shaft does not match the inclination of the bearing, high-pressure oil will flow more easily from one side, and the flow control valve will adjust the amount of oil supplied and the shape of the left and right bearing oil grooves will be adjusted to increase the pressure of high-pressure oil. Will need to be adjusted. Further, when the slip of the spherical surface portion is poor, the vibration in the axial direction tends to increase. As a method of reducing axial vibration, increasing the gap of the spherical surface is effective,
When the gap is increased, the spherical seat is hit by the impact from the machine (driven body) side and fretting corrosion is likely to occur.

Further, in the above-described bearing device shown in FIG. 10, the structure in which the bearing and the thrust collar are not forcibly lubricated, and therefore, when an excessive thrust force is applied, the oil film is cut off and heat-baking occurs. There is a fear.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks and provide a bearing device for a rotary electric machine with improved reliability.

[0010]

According to a first aspect of the present invention, a bearing for supporting a rotary shaft and a bearing stand for supporting the bearing via a contact sliding surface are provided, and the bearing is provided with a high pressure oil supply device and a high pressure. In a bearing device of a rotary electric machine in which oil is supplied to forcibly levitate a rotating shaft, an oil groove is provided on a contact sliding surface to supply high-pressure oil.

According to a second aspect of the present invention, there is provided a bearing for supporting a rotary shaft having a large diameter portion for transmitting thrust force,
It is equipped with a bearing stand that supports this bearing through the contact sliding surface,
A bearing device for a rotary electric machine, in which high pressure oil is supplied from a high pressure oil supply device to forcibly levitate the rotating shaft, and the side surface of the large diameter portion is brought into contact with the end surface of the bearing to bear the thrust force. A hole having an equal diameter portion and a truncated cone portion that communicate with an oil groove provided on the end surface of the bearing and extend along the axial direction of the rotating shaft,
A valve mechanism movably provided in the hole and having a cylindrical body and a truncated cone-shaped contact body having an intermediate portion connected through a rod, and a tip end portion of the contact body of the valve mechanism is always connected to an end surface of the bearing. Equipped with an elastic body that presses the back surface of the cylindrical body so as to project toward the large diameter part of the rotary shaft, and when the large diameter part of the rotary shaft presses the contact body of the valve mechanism, high-pressure oil is supplied to the oil groove. A flow path is formed.

[0012]

According to the invention described in claim 1, the energy possessed by the high-pressure oil is applied to the contact sliding surface between the bearing stand and the bearing, so that the slidability can be improved and the self-aligning property can be improved. ..

According to the second aspect of the present invention, the high pressure oil supply device is activated before the rotary electric machine is activated so that the rotary shaft is levitated. When the thrust force is applied to the rotary shaft, the contact body protruding from the bearing end face is pressed against the large diameter portion provided on the rotary shaft, and the valve mechanism retracts. Due to the retreat of the valve mechanism, high pressure oil is provided on the bearing end surface through the gap formed between the bypass flow path passing through the middle part of the hole and the bearing, and the contact body and the truncated cone hole part from the middle part of the hole. The oil is supplied to the oil groove, and the contact between the side surface of the large diameter portion and the end surface of the bearing can be well maintained.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a sectional view showing an embodiment of the present invention, FIG.
3 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a sectional view taken along the line BB of FIG. The same parts as those of the conventional bearing device shown in FIG. 5 described above are denoted by the same reference numerals, and duplicated description will be omitted.

1, 2 and 3, the bearing device
Reference numeral 20 is composed of a lower half 12 of the bearing stand, an upper half 13 of the bearing stand, and a bearing 21 which are divided on the horizontal axis. Similar to the bearing 14 described above, the bearing 21 has a self-centering property, and has an outer circumference 21a having a spherical shape so as to follow the inclination of the rotary shaft 2. Bearing lower half 12 and bearing upper half 13 facing the outer circumference 21a
Is provided with a spherical support seat 22 having a split structure and an inner circumference 22a engaging with the outer circumference 21a of the bearing 21 described above having a spherical shape.

On the spherical support seat 22 of the lower half 12 of the bearing stand, from the high pressure oil supply device 4, the high pressure oil supply pipe 5, the flow control valve 6, and the check valve 7 are provided.
High-pressure oil circulation hole 23 for circulating high-pressure oil supplied via
And a support seat oil groove 24, which is an arcuate recess for supplying high-pressure oil, is provided on the inner circumference 22a of the spherical support seat 22.

Further, the bearing 21 is provided with a high-pressure oil circulation hole 25 for circulating high-pressure oil at a position opposite to the support seat oil groove 24 provided in the spherical support seat 22 of the lower half 12 of the bearing stand. This high pressure oil circulation hole
25 is branched in the bearing 21, and is connected to bearing oil grooves 16 and 16 provided at two locations along the axial direction of the rotary shaft 2.

Next, the operation of the embodiment having the above construction will be described. The high-pressure oil supplied from the high-pressure oil supply device 4 flows through the high-pressure oil supply pipe 5, the flow control valve 6, and the check valve 7 into the high-pressure oil circulation hole 23 provided in the spherical support seat 22 of the lower half 12 of the bearing stand. ,
It flows into the support seat oil groove 24 on the inner circumference 22a of the spherical support seat 22. Further, it flows into the high pressure oil circulation hole 25 of the bearing 21, and flows from the high pressure oil circulation hole 25 to the journal surface 2 a of the rotary shaft 2.
The high-pressure oil that flows in this manner first comes into contact with the bearing oil groove 16 of the bearing 21.
Is added to the bearing surface and the journal surface of the rotary shaft 2, and then to the support seat oil groove 24 portion of the inner circumference 22a of the spherical support seat 22.

Therefore, the rotating shaft 2
And the inner periphery 22a of the spherical support seat 22 receives the energy of the high-pressure oil, so that contact is made through the oil, the slidability is improved, and the self-centering property of the bearing 21 can be improved. Moreover, since the high-pressure oil is applied to the portion directly below the inner circumference 22a of the spherical support seat 22, it is effective against the phenomenon that the spherical seat is hit by the impact from the machine (driven body) side, and the occurrence of fretting corrosion is prevented. Can be suppressed.

FIG. 4 is a sectional view showing another embodiment of the present invention, and FIG. 5 is an enlarged sectional view showing an essential part of another embodiment shown in FIG. In FIGS. 4 and 5, the bearing device 30 is composed of a lower half 12 of the bearing stand, an upper half 13 of the bearing stand, a bearing 31, and a valve mechanism 32 provided on the bearing 31, which are divided on the horizontal axis. There is.

In the above structure, the bearing 31 has the spherical outer periphery 31a so as to have the self-centering property and follow the inclination of the rotary shaft 2 like the bearing 14 described above. This perimeter
In contrast to 31a, the lower half 12 and the upper half 13 of the bearing stand, which are opposed to each other, have a divided structure, and a spherical support seat 33 having a spherical inner surface 33a that engages with the outer circumference 31a of the bearing 31 is provided. ..

A plurality of oil pockets 34 are provided on both end faces of the lower half portion of the above-mentioned bearing 31, a truncated cone-shaped through hole 35 is connected to the central portion thereof, and the through hole 35 is coaxially connected. The cylinder 36 thus configured is provided. This cylinder 36
The end opposite to the through hole 35 is connected to a high pressure oil circulation hole 38 connected to the shaft levitation oil pipe 37. The high-pressure oil circulation hole 38 extends upward and is connected to the bearing oil groove 16. Axial levitation oil pipe 37
A branch oil pipe 39 is connected to the downstream side of the check valve 7, and the branch oil pipe 39 is connected to an intermediate portion of the cylinder 36 via a relief valve 40. On the outlet side of the relief valve 40,
The oil pressure detector 41 is connected. The relief valve 40 is
The hydraulic pressure of the cylinder 36 is controlled by the hydraulic pressure detector 41 and opens when the hydraulic pressure applied to the hydraulic pressure detector 41 decreases to reduce the hydraulic pressure of the cylinder 36 to the set pressure.

Further, the valve mechanism 32 is connected to the piston 42 movably inserted in the cylinder 36 described above and the piston 42 via the rod 43, and the cone corresponding to the truncated cone-shaped through hole 35 described above. A trapezoidal tip with an arcuate shape, and a mover 44 movably inserted into the through hole 35 and a piston 42.
It is composed of a spring 45 that presses from the back side.
Here, the piston 42 is provided with a seal member that operates similarly to the piston ring.

On the other hand, the cylinder 36 has a high-pressure oil circulation hole 46 which is closed when the piston 42 is moving forward (moving to the through hole 35 side) and opened when the piston 42 is moving backward (moving to the opposite side). The relief valve 40 is connected on the upper side, and the lower side of the intermediate portion of the piston 42 and the mover 44 is connected to the relief valve 40. 6 shows a piping system diagram in the case of this embodiment.

Next, the operation of the embodiment having the above configuration will be described. First, before operating the rotating electric machine, the high-pressure oil supply device 4
To drive. The amount of high-pressure oil is adjusted by the bearing base flow control valve 6 via the high-pressure oil supply pipe 5, and flows into the shaft levitation oil pipe 37 via the check valve 7. Piston 42 of valve mechanism 32
Is moved forward as shown in FIG. 5 by being pressed by the spring 45, so that a high-pressure oil passage is formed on the back surface of the piston 42. Therefore, the high-pressure oil that has flowed into the shaft levitation oil pipe 37 flows into the bearing oil groove 16 and is stored there, so that the rotary shaft 2 is levitated. The moving element 44 of the valve mechanism 32 is in a state in which its tip portion projects from the end surface of the bearing 31 as shown in FIG.

When the rotating electric machine is operated and the thrust force in the left direction in FIG.
17 contacts the end surface of the bearing 31, simultaneously presses the mover 44,
The mover 44 and the piston 42 are retracted as shown in FIG. By this retreat, the high-pressure oil circulation hole 38 is closed and the high-pressure oil circulation hole 46 is opened, and the mover 44 and the truncated cone-shaped through hole are formed.
A gap is formed with 35. Therefore, the high pressure oil is
As shown by the arrow in the figure, the oil pipe 37 for branching from the shaft is branched to the oil pipe 3
9, supplied to the cylinder 36 via the relief valve 40,
The oil is supplied to and stored in the bearing oil groove 16 through the high-pressure oil circulation hole 46, and the rotating shaft 2 is continuously levitated, and is also supplied from the frustoconical through hole 35 to the oil pocket 34 on the end surface of the bearing 31.
A sufficient oil film is formed between the thrust collar 17 and the end surface of the bearing 31. As a result, a large thrust force can be received by the bearing 31 without causing oil film breakage.

When the thrust force no longer acts on the rotating shaft 2 in operation and the original state (state shown in FIG. 5) is restored, the amount of oil flowing through the gap between the through hole 35 and the moving element 44 increases. Since the hydraulic pressure is reduced accordingly, the hydraulic pressure detector 41 detects the hydraulic pressure and opens the relief valve 40 to reduce the hydraulic pressure to the set pressure. Due to this decrease in oil pressure, the force of the spring 45 acting on the rear surface of the piston 42 becomes larger, so that the piston 42 is pushed forward by the spring 45, and the mover 44 also moves forward to inscribe in the through hole 35. The tip portion thereof projects from the end surface of the bearing 31. By the advance of the piston 42,
The flow of the high-pressure oil in the branch oil pipe 39 is shut off, and the high-pressure oil again flows only to the original shaft floating oil pipe 37.

The pump 10 of the high-pressure oil supply device 4 does not have to have a large capacity as compared with the pump 10 dedicated to the shaft levitation. This supplies high-pressure oil to levitate the rotary shaft 2 before operating the rotary shaft 2, but the characteristics of the pump 10 depend on the high pressure required at that time. After that, the required hydraulic pressure is reduced, and the thrust force is received after the operation. Therefore, the hydraulic pressure required to supply the lubricating oil to the end faces of the thrust collar 17 and the bearing 31 is increased by the reduced pressure difference. Therefore, the capacity of the pump 10 is increased. No need. Therefore, the conventional pump can perform the forced lubrication when the rotary shaft is levitated and the thrust force is applied.

[0029]

As described above, according to the present invention, the high pressure oil is supplied to the sliding contact surfaces of the bearing and the bearing stand, so that the frictional resistance between the levitation of the rotating shaft and the sliding contact surface is significantly increased. The sliding property is improved and the self-centering property is improved.
This improvement in self-alignment makes it easier to follow the shaft tilt, shortens the work time for adjusting the amount of oil supply, etc., facilitates the operation and maintenance of the rotating electrical machine, and also reduces the impact on the driven body side of the rotating electrical machine. It is possible to suppress the occurrence of fretting corrosion on the sliding contact surface due to and improve the reliability. Further, the bearing is provided with a hole having an equal diameter portion and a truncated cone portion along the axial direction,
A valve mechanism consisting of a movable columnar body and a contact body is provided in this hole, and this valve mechanism is pressed when a thrust force acts on the rotating shaft to supply high pressure oil to the bearing and the bearing end surface. A good contact state is maintained without causing oil film breakage between the bearing end surface and the large-diameter side surface of the rotating shaft during levitation and thrust force operation, which facilitates operation and maintenance of the rotating electrical machine and improves reliability. To do.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

3 is a sectional view taken along line BB of FIG.

FIG. 4 is a sectional view showing another embodiment of the present invention.

5 is a cross-sectional view of the essential parts of another embodiment of the present invention shown in FIG.

FIG. 6 is a piping system diagram of another embodiment of the present invention shown in FIG.

7 is an explanatory view showing the operation of another embodiment of the present invention shown in FIG.

FIG. 8 is a piping system diagram of a bearing device of a rotary electric machine in which a conventional rotary shaft is levitated.

9 is a cross-sectional view of the bearing device in the piping system diagram shown in FIG.

FIG. 10 is a cross-sectional view of a conventional bearing device for a rotary electric machine that levitates a rotary shaft and carries thrust force.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotor, 2 ... Rotating shaft, 4 ... High pressure oil supply device, 6 ... Flow control valve, 7 ... Check valve, 12 ... Lower half of bearing stand, 13 ... Upper half of bearing stand, 16 ... Bearing oil groove, 21 ... Bearing, 22, 33 ... Spherical support seat, 2
3, 25 ... High-pressure oil circulation hole, 24 ... Support seat oil groove, 32 ... Valve mechanism, 34 ... Oil pocket, 35 ... Frustum-shaped through hole, 36 ...
Cylinder, 40 ... Relief valve, 41 ... Oil pressure detector, 42 ...
Piston, 44 ... mover, 45 ... spring.

Claims (2)

[Claims] 1. A slide bearing for supporting a rotating shaft, and a bearing stand for supporting the slide bearing via a contact sliding surface,
In a bearing device of a rotating electric machine, wherein high pressure oil is supplied from a high pressure oil supply device to the slide bearing to forcibly levitate the rotary shaft, an oil groove is provided on the contact sliding surface, and the high pressure oil is supplied. A bearing device for a rotary electric machine characterized by the above. 2. A high pressure oil supply to the slide bearing, comprising a slide bearing for supporting a rotary shaft having a large diameter portion for transmitting a thrust force, and a bearing stand for supporting the slide bearing via a contact sliding surface. Bearing device of a rotary electric machine, in which high pressure oil is supplied from a device to forcibly levitate the rotary shaft, and a side surface of the large diameter portion is brought into contact with an end face of the slide bearing to bear the thrust force. In, a hole having an equal diameter portion and a truncated cone-shaped portion communicated with an oil groove provided on the end surface of the plain bearing along the axial direction of the rotating shaft, and a hole movably provided in the hole and an intermediate portion A valve mechanism consisting of a cylindrical body and a truncated cone-shaped contact body connected via a rod, and the tip of the contact body of this valve mechanism always projects from the end face of the slide bearing to the large diameter side of the rotary shaft. Elasticity to press the back of the cylinder so that A rotary electric machine comprising a body, wherein when the large-diameter portion of the rotary shaft presses the contact body of the valve mechanism, a passage for supplying the high-pressure oil is formed in the oil groove. Bearing device.