JPH09166284A - Rotary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a drag of a pump main body by providing a fin integrally and projectedly in radial direction in mid-course in the base line direction on the outer surface of the pump main body in a device in which lubricating oil is fed to the hollow part of the rotating shaft using the viscosity of the lubricating oil. SOLUTION: When a rotating shaft 1 is rotated at high speed so as to rotate a pump integrally with its main body 61 immersed in lubricating oil, lubricating oil in an oil sump 7 is pulled in the rotating direction, which initiates a rotating motion inside a tapered part 61b near a conical surface, acting a centrifugal force on the lubricating oil. Also, when the component of the centrifugal force in the conical base line direction overcomes the component of the gravity acting on the lubricating oil in the conical base line direction, the lubricating oil raises the conical surface, and is sprayed from an oil supply port so as to lubricating a bearing 2. In this case, a fin 63 is provided near the bottom outer end of the tapered part 61 of the pump main body 61 so as to prevent the lubricating oil from rising to the outer periphery of the upper tapered part 61, and remarkably reduce a drag of the rotating shaft 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary machine equipped with a self-suction pump which is useful when a self-contained bearing lubrication mechanism is constructed using a vertically placed rotary shaft. .

[0002]

2. Description of the Related Art When lubricating oil is fed to rolling bearings in various rotary machines, it is common practice to do this by interlocking a gear pump or the like. However,
For small high-speed turbomachines, from the viewpoint of reducing the number of parts and weight, omit the gear pump that sends lubricating oil to the rolling bearings, and introduce the lubricating oil into the shaft that rotates at high speed for rotation. It is often practiced to employ a self-contained bearing lubrication mechanism that itself generates a pressure by the accompanying centrifugal force to perform a lubricating oil transfer function equivalent to a gear pump or the like.
In such a case, a self-suction pump is additionally provided at the lower end of the rotary shaft. This pump is
The pump main body with a hollow shaft is attached to the lower end of the hollow rotary shaft so that it can rotate integrally, and part of it is immersed in the oil sump of the lubricating oil. It is configured to suck up lubricating oil by using it and send it to the hollow part of the rotating shaft, and its pump body has a simple cylindrical shape or a conical shape whose diameter gradually increases upward. There is.

[0003]

However, when the pump main body is constituted only by such a shape, a considerable amount of lubrication is carried out when the lubricating oil in the oil sump is dragged to the outer peripheral surface due to its viscosity and swung. Since the oil swirls in the same direction at a rotation speed lower than the rotation speed of the pump, drag resistance acts on the pump body. In particular, the viscosity of lubricating oil usually varies slightly depending on the temperature change due to seasonal changes or the temperature change with the time elapsed from the start, and the oil level in the oil sump increases depending on the usage condition. As the lubricating oil also changes, the lubricating oil forms a complicated flow at each time, and the drag resistance acting on the pump body also varies. Therefore, such a change in the viscosity of the lubricating oil and a change in the oil level are factors that cause a complicated vibration phenomenon that is difficult to analyze in the high-speed rotating shaft system. In addition, the drag resistance due to the viscosity of the lubricating oil increases the driving force for imparting the required number of rotations to the rotary shaft more than necessary, and is also a factor that reduces the operating efficiency of the rotary machine.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention has fins projecting from the outer circumference of a pump body, which allows lubrication to follow the outer circumference of the pump body. The oil is urged in the radial direction to be removed to reduce the drag resistance of the pump body.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A rotary machine according to the present invention is a self-sucking pump in which a fin is provided on the lower end side of the pump main body, preferably on the outer periphery near the lower end as much as possible, and the pump main body is a conical surface. In this case, it is particularly effective to use a fin having a rotationally symmetrical shape with the conical surface. In this way, by providing the fins on the part where the diameter of the cone is small, the lubricating oil in the vicinity can be swung away by the high-speed swiveling of the fins, so that the lubricating oil can be supplied to the outer peripheral conical surface of the pump body. Be cut off. Therefore, most of the outer peripheral surface of the pump main body can be a portion where there is no lubricating oil, and therefore there is no drag resistance, and it is possible to effectively avoid shaft system vibration involving complicated movement of the lubricating oil. .

[0006]

An embodiment of the present invention will be described below with reference to the drawings.

This embodiment exemplifies a turbo blower, which is a kind of small high-speed turbomachine, as a rotary machine. In this turbo blower, as shown in FIG. 1, a rotary shaft 1 is arranged vertically, and a turbine (not shown) located at an upper end position is rotated at high speed to perform pressure feeding of gas and the like. The rotary shaft 1 is supported by a rolling bearing 2 arranged on the outer periphery near the lower end, and a self-contained bearing lubrication mechanism 3 is constructed for the rolling bearing 2. In this bearing lubrication mechanism 3, the shaft center portion of the rotary shaft 1 is hollow and this hollow portion is used as an oil passage 4, and a radial oil supply port 5 is bored at two locations above the oil passage 4, The lubricating oil sucked up from the oil sump 7 by the self-sucking pump 6 configured at the lower end of the shaft is guided upward along the oil passage 4 and then led to the outside of the rotary shaft 1 via the oil supply port 5 to perform this lubrication. After the oil is supplied to the gap between the outer ring 2a and the inner ring 2b of the rolling bearing 2, it is spontaneously dropped to be collected again in the oil sump 7.

The self-wicking pump 6 in this embodiment, however, has a pump body 61 fitted to the lower end of the rotary shaft 1 by a seal structure, and the pump body 6
1 is provided with an upward cup-shaped fastening member 62 fitted on the outer periphery of the rotary shaft 1. A female screw portion 62a screwed on the inner periphery of the fastening device 62 is attached to the lower end shaft portion of the rotary shaft 1. The pump main body 61 is attached to the lower end shaft portion of the rotary shaft 1 with its axis aligned by being screwed onto the male screw portion 1a which is threaded on the outer periphery.

In the pump body 61, a lower portion of a cylindrical portion 61a fitted in the rotary shaft 1 in a seal state is a tapered portion 61b whose diameter gradually decreases toward the lower end, and the tapered portion 61b is formed inside and outside. The circumference is tapered.
In this embodiment, the taper portion 6 of the pump body 61 is used.
Fins 63 are integrally provided on the outer periphery of 1b in the radial direction. The fin 61c includes a substantially conical lower surface 63a whose diameter gradually increases upward and a lower surface 63a.
It has an axially symmetric shape with respect to a, that is, a substantially conical upper surface 63b whose diameter is gradually reduced upward. Further, as another component of the pump 6, a cylindrical partition or a stationary partition 8 close to the cylindrical surface is provided in the oil sump 7 concentrically with the rotation axis of the pump main body 61, and the partition 8 provides the pump main body. A part of the circumference of 61 is surrounded. In the vicinity of the bottom of the partition wall 8, a baffle plate 9 that appropriately suppresses the swirling flow of the lubricating oil generated when the pump body 61 rotates is arranged in the radial direction. And in the oil sump 7,
Lubricating oil is filled up to a position almost the same as or slightly lower than the partition wall 8.

In such a structure, when a driving force is applied to the rotary shaft 1 and the rotary shaft 1 starts to rotate at high speed, the pump main body 61 attached to the lower end portion of the rotary shaft 1 moves its lower end side. Since it rotates integrally while being immersed in the lubricating oil, the lubricating oil in the oil sump 7 can be transferred to the tapered portion 61 b of the pump body 61.
In a portion near the conical surface that expands upward in the inside of, the oil is dragged in the rotational direction due to the viscosity of the lubricating oil to start a rotational motion, and the centrifugal force accompanying the rotation acts on the lubricating oil. In a situation where the conical generatrix component of this centrifugal force overcomes the conical generatrix component of gravity acting on the lubricating oil, the lubricating oil rises upward on the conical surface as indicated by the arrow in FIG. It functions as a self-pumping pump.
Then, the lubricating oil rises along the inner wall of the oil passage 4 of the rotating shaft 1 and is ejected from the oil supply port 5 by the centrifugal force associated with the rotation to lubricate the space between the inner ring 2a and the outer ring 2b of the bearing 2 and then the gravity. By the action of, the water drops downward and returns to the oil sump 7 again.

On the other hand, since fins 63 are present on the outer periphery of the taper portion 61b of the pump body 61 near the lower end thereof, when the pump body 61 rotates, the lubricating oil flows along the outer periphery of the fins 63 as shown by the arrow in FIG. After reaching the tip (outermost peripheral portion) of the conical lower surface 63, it is shaken off by centrifugal force. Therefore, the fin 63 blocks the lubricating oil from rising to the outer periphery of the tapered portion 61b above the fin 63. Then, the lubricating oil shaken off by the centrifugal force from the fins 63 makes a circular motion in the cylindrical partition wall 8 along the inner surface of the partition wall 8. At that time, the centrifugal force acts on the lubricating oil, and the lubricating oil The outer peripheral side becomes bulky with respect to the central portion, and the outer periphery of the tapered portion 61b above the fin 63 becomes a hollow region S where no lubricating oil exists.
Due to the cooperative action of the fins 63 and the partition wall 8 as described above, an environment where lubricating oil does not follow is generated in most of the outer periphery of the tapered portion 61b of the pump body 61, and drag resistance acting on the rotary shaft 1 through the pump body 61. Will be drastically reduced compared to the past. Therefore, according to the present embodiment, the generation of a complicated flow of lubricating oil that causes harmful vibration of the shaft system is prevented, and the viscosity change due to the oil temperature and the oil level height of the oil sump according to the usage situation The rotating shaft 1 can be stably rotated at high speed without being affected by the above. In particular, in this embodiment, the baffle plate 9 is radially arranged at the bottom portion of the oil sump 7, and the lubricating oil is dragged in the rotational direction to cause a circular motion, so that the oil level in the central portion is extremely lowered. Since it is avoided, it is possible to ensure proper suction characteristics without making suction into the pump body 61 difficult. Further, since the unnecessary stirring of the lubricating oil is eliminated in this way, unnecessary load does not act on the rotary shaft 1, and the operating efficiency of the rotary machine can be improved by saving the driving force.

Although the pump main body has a tapered shape in the above embodiment, it may have a cylindrical shape as long as the condition that causes the suction phenomenon is satisfied. Further, the shape of the fin projecting from the pump body can be modified in various ways as long as it has a function to scatter the lubricating oil, which is going to rise along the outer periphery and is going to rise, by the centrifugal force.

[0013]

The rotary machine according to the present invention has the above-described structure to eliminate the lubricating oil that has been a factor of vibration of the rotating shaft attached to the outer peripheral surface of the pump body of the self-priming pump, thereby reducing drag resistance. Since it can be reduced, stable rotation can be imparted to the rotating shaft regardless of the season and operating conditions, while at the same time the driving power is saved by reducing the stirrer loss, which in turn makes the operating efficiency of the rotating machine effective. The excellent effect that it can be improved is exhibited.

[Brief description of the drawings]

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

FIG. 2 is an enlarged cross-sectional view showing a main part of FIG. 1 together with an operation.

[Explanation of symbols]

 1 ... Rotary shaft 6 ... Self-pumping pump 7 ... Oil sump 61 ... Pump body 63 ... Fin

Claims (1)

[Claims] 1. A pump main body having a hollow shaft center portion is attached to a shaft lower end portion of a hollow rotary shaft so as to be integrally rotatable, and the lower end side thereof is arranged so as to be immersed in an oil sump of lubricating oil, In the case where the pump is equipped with a self-suction type pump configured to send the lubricating oil into the hollow portion of the rotating shaft by utilizing the viscosity of the lubricating oil, in the radial direction at the midway of the bus body direction on the outer peripheral surface of the pump body. A rotary machine characterized in that fins are integrally projected toward the.