JP2011001899A - Gear box internal pressure relaxation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear box internal pressure relaxation device capable of relaxing the internal pressure of a gear box by allowing only gas to escape from the gear box to the outside without leaking a liquid such as a lubricating oil and eliminating need to make a long hole to drastically reduce the cost.SOLUTION: The device includes a rotation plane 12 which is provided at the end of the rotary shaft 9 of a gear 2, rotates together with the rotary shaft and is perpendicular to the rotary shaft, a fixed plane 14 which is provided on a casing 3 and positioned spaced a certain distance from the rotation plane 12 for the gas positioned between the plane 12 and the plane 14 to rotate, and a ventilation hole 16 which is provided to the casing 3 and extended from the position opposite to the rotary shaft in the fixed plane 14 to the outside.

Description

  The present invention relates to an internal pressure relaxation device for a gear chamber having a plurality of gears therein.

In the present application, the “gear chamber” means a hollow space having a plurality of gears lubricated with lubricating oil therein and rotating while the gears mesh with each other and a casing thereof.
If such a gear chamber is a sealed space so that the internal lubricating oil does not leak to the outside, the temperature of the chamber rises due to the rotation of the gear, the pressure in the sealed space (internal pressure) rises, and the shaft seal This may cause oil leakage from etc.
Therefore, it is necessary to release only the internal gas to the outside without letting the lubricating oil in the gear chamber to the outside, and to reduce the pressure (internal pressure) in the sealed space.

  In order to achieve this object, various means have been conventionally proposed (for example, Patent Documents 1 to 3).

Patent document 1 aims at preventing interruption | blocking of the ventilation path | route by adhesion of grease, and suppressing spreading | diffusion of brush powder.
Therefore, as shown in FIG. 1, the apparatus includes a front housing 52 that forms a gear chamber that houses the speed reduction mechanism 51, and a center housing 53 that is combined with the front housing. The front housing 52 and the center housing 53 include: Meat stealing spaces 54 and 55 are formed on the mating surfaces of each other, and both meat stealing spaces are provided at positions shifted from each other in a partially overlapping state to form a labyrinth-like passage, The motor-side ventilation hole 56, the labyrinth-shaped passage, the communication chamber 57, and the switch-side ventilation hole 58 are configured.

Patent Document 2 aims at a crankcase ventilation passage in which lubricating oil hardly enters even when the lubricating oil violently splashes in the crankcase due to high vibration acceleration.
Therefore, as shown in FIG. 2, this device is a crankcase ventilation passage 62 formed in a camshaft 61 provided in the crankcase, and the opening of the passage links the camshaft with the crankshaft. The cam gear 63 is provided at the bottom of the recess formed on the side surface.

Patent Document 3 aims to relieve the internal pressure of the gear chamber by letting only gas to the outside without leaking liquid such as lubricating oil from the sealed gear chamber by adding a simple configuration to the turbocharger. And
Therefore, as shown in FIG. 3, this apparatus has a through hole from the gears 73 and 74 along the axial center line of the rotary shaft 72 on the rotary shaft 72 of the screw rotor 71 in the mechanically driven supercharger. 75, a ventilation hole 77 including an exhaust hole 76 that opens from the outer peripheral surface of the rotary shaft 72 toward the through hole 75 and continues to the outside through the through hole 75; And a filter 78 attached to the hole, and the centrifugal force of the rotating shaft 72 rotating at high speed blows off the liquid lubricating oil from the oil escape hole 76 in the through hole 75 and allows only the gas to pass through the ventilation hole 77. , To be discharged to the outside.

Japanese Patent No. 3794258, “Starter” Japanese Patent No. 3137868, “Crankcase ventilation passage” Japanese Patent Laid-Open No. 2001-323819, “Gas-Liquid Separation Mechanism of Rotating Shaft in Machine Driven Supercharger”

As in Patent Document 1, in the case of a ventilation hole in which an uneven baffle plate or a maze is provided in the casing, there is a problem that a small amount of oil is easily mixed with the gas and goes out and easily clogged.
In addition, as in Patent Documents 2 and 3, the structure in which the ventilation hole is provided in the rotation axis is more effective in preventing oil leakage than the case in which the concave and convex baffle plate is provided in the casing. There was a problem.

  The present invention has been developed to solve the above-described problems. That is, the object of the present invention is to allow only gas to escape to the outside without leaking liquid such as lubricating oil from the gear chamber, to relieve the internal pressure of the gear chamber, and to eliminate the need for long hole machining, greatly increasing the cost. An object of the present invention is to provide an internal pressure relief device for a gear chamber that can be reduced.

According to the present invention, there is provided an internal pressure relief device for a gear chamber including a casing having a plurality of gears that are lubricated with lubricating oil and rotate while meshing with each other in a sealed state.
A rotation plane provided at an end of at least one rotation shaft of the plurality of gears, rotating with the rotation shaft and orthogonal to the rotation shaft;
A fixed plane that is provided in the casing and is located at a certain interval from which the gas positioned between the plane of rotation rotates.
An internal pressure relaxation device for a gear chamber is provided, comprising a ventilation hole provided in the casing and extending from a position facing the rotation axis of the fixed plane to the outside.

According to an embodiment of the present invention, the rotation plane is a circular end surface of the rotation axis,
The fixed plane is wider than the rotation plane and covers the entire surface.

According to another embodiment of the present invention, the rotating plane is provided on a rotating body that rotates together with the rotating shaft,
The rotating body has an axial hole extending partway along the rotation axis from the rotation plane, and a radial hole extending radially from the axial hole to the outer surface thereof.

  According to the configuration of the present invention, the rotation plane rotates at a high speed together with the rotation axis, and since this rotation plane is orthogonal to the rotation axis, a small air flow directed radially outward between the rotation plane and the fixed plane. Will occur. Due to this air flow, the lubricating oil near the center of the rotating plane moves outward in the radial direction, and only gas that does not contain lubricating oil exists near the center of the rotating plane. Accordingly, the ventilation hole provided in the casing and extending from the position facing the rotation axis of the fixed plane (that is, near the center of the rotation plane) to the outside allows only the gas near the center to escape to the outside and relieves the internal pressure of the gear chamber. it can.

Therefore, without providing an uneven baffle plate or labyrinth in the casing as in the prior art, it is possible to relieve pressure by letting only gas to the outside without leaking oil more than equivalently to providing a ventilation hole in the rotation axis.
In addition, this configuration eliminates the need for long hole processing and can greatly reduce the cost.

2 is a configuration diagram of an apparatus disclosed in Patent Document 1. FIG. It is a block diagram of the apparatus of patent document 2. FIG. It is a block diagram of the apparatus of patent document 3. FIG. It is a lineblock diagram of a machine drive supercharger provided with the internal pressure relaxation device of a 1st embodiment by the present invention. It is the elements on larger scale of FIG. It is a block diagram of the internal pressure relaxation apparatus of 2nd Embodiment by this invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best mode for carrying out the invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

FIG. 4 is a configuration diagram of a mechanically driven supercharger including the internal pressure relaxing device according to the first embodiment of the present invention. In this example, the mechanically driven supercharger is a compressor for automobiles (for fuel cell vehicles). In addition, a in the figure is the oil level at rest.
This mechanically driven supercharger is driven from a driving device such as a motor via gears 1 and 2 in a gear chamber 4 and is screwed together in an air chamber 6 adjacent to the gear chamber 4 via a partition wall 5. A pair of male and female screw rotors 7 and 8 are rotatably supported on the casing 3.

The twisted male and female screw rotors 7 and 8 are screwed so as to suck in air, and compress and discharge them by contraction of the volume of the screw threaded portion. The screw rotors 7 and 8 rotate at a high speed of, for example, 20,000 to 30,000 rpm.
This mechanically driven supercharger has little loss when the supercharging pressure is increased, but there is pressure fluctuation at the end faces (pressure increase side) of the screw rotors 7 and 8. The gear chamber 4 is sealed and filled with a liquid such as lubricating oil. However, in order to relieve the internal pressure of the gear chamber 4 that has become high temperature due to the rotation of the screw rotors 7 and 8, it is necessary to let only gas such as air escape to the outside without leaking liquid such as lubricating oil.

The present invention is an internal pressure relief device for the gear chamber 4, and the gear chamber 4 has a casing 3 as shown in FIG. The casing 3 holds a plurality (two in this example) of gears 1 and 2 that rotate while meshing with each other and a lubricating oil that lubricates the gears 1 and 2 in a sealed state.
In addition, this invention is not limited to the gear chamber of the mechanical drive supercharger mentioned above, The gear chamber of another machine apparatus may be sufficient.

  FIG. 5 is a partially enlarged view of FIG. In this figure, the internal pressure relaxation device 10 of the present invention includes a rotation plane 12, a fixed plane 14 and a ventilation hole 16.

In this example, the rotation plane 12 is provided at the end (left end) of the rotation shaft 9 of the gear 2, rotates with the rotation shaft 9, and is orthogonal to the rotation shaft 9.
In this example, the rotation plane 12 is a circular end surface of the rotation shaft 9 itself.

The fixed plane 14 is provided in the casing 3 and is located at a certain distance from the rotation plane 12. This interval is set to be sufficiently narrow (for example, 0.5 mm to 3 mm) so that the gas positioned between the rotation plane 12 and the rotation plane 12 rotates.
Moreover, in this example, the fixed plane 14 is provided integrally with the casing 3 itself, and has a size that covers the entire area wider than the rotation plane. The fixed plane 14 is at the tip of a columnar protrusion provided in the casing 3. Further, the fixed plane 14 is perpendicular to the rotation center axis (parallel to the rotation plane 12) in the illustrated example.

The ventilation hole 16 is provided in the casing 3 itself, and extends from a position facing the rotation shaft 9 of the fixed plane 14 to the outside.
In this example, the ventilation hole 16 is composed of two holes intersecting inside the casing 3, but the present invention is not limited to this, and may be one, three or more, or bent.
Further, the position of the opening end of the ventilation hole 16 in the fixed plane 14 is preferably on the rotation center of the rotating shaft 9, but the same effect can be obtained even if there is a slight deviation (even a slight deviation position). can get.

  According to the configuration of the present invention described above, the rotating plane 12 rotates at a high speed (for example, 20,000 to 30,000 rpm) together with the rotating shaft 9, and the rotating plane 12 is orthogonal to the rotating shaft 9. A small air flow is generated between the fixed planes 14 outward in the radial direction. Due to this air flow, the lubricating oil in the vicinity of the center of the rotating plane 12 moves outward in the radial direction, and only a gas not containing the lubricating oil exists in the vicinity of the center of the rotating plane 12. Therefore, only the gas in the vicinity of the center escapes to the outside by the ventilation hole 16 provided in the casing 3 and extending from the position facing the rotation axis of the fixed plane 14 (that is, near the center of the rotation plane 12) to the outside. Can be relaxed.

Therefore, without providing an uneven baffle plate or labyrinth in the casing as in the prior art, it is possible to relieve pressure by letting only gas to the outside without leaking oil more than equivalently to providing a ventilation hole in the rotation axis.
In addition, this configuration eliminates the need for long hole processing and can greatly reduce the cost.

FIG. 6 is a configuration diagram of an internal pressure relaxing device according to a second embodiment of the present invention.
In this example, the rotating plane 12 is provided on a rotating body 18 that rotates together with the rotating shaft 9. The rotating body 18 has an axial hole 19 that extends partway from the rotation plane 12 along the rotation axis 9 and a radial hole 20 that extends radially from the axial hole 19 to the outer surface thereof. Further, in this example, the portion of the axial hole 19 that faces the fixed plane 14 is a tapered hole that spreads outward (left side in this figure), and its maximum diameter is set larger than the ventilation hole 16 of the fixed plane 14. ing.
When the rotating body 18 is a bolt (screw form), it is preferable that the rotating body 18 is a reverse screw (a screw that is tightened when the rotating shaft 9 rotates). With this configuration, it is possible to prevent the rotating body 18 from being loosened.
The rotating body 18 may be attached by caulking, press fitting or the like instead of screw fastening.
An integral form may be sufficient. That is, you may process the rotary body 18 and the rotating shaft 9 as an integral member instead of a separate member. In other words, the axial hole 19 may be formed at the tip of the rotating shaft 9.
The position of the opening end of the axial hole 19 in the rotation plane is preferably on the rotation center of the rotation shaft 9, but the same effect can be obtained even if there is a slight shift (even a slightly shifted position). .
Other configurations are the same as those in the first embodiment.

According to the configuration of the second embodiment described above, the rotating plane 12 rotates at a high speed (for example, 20,000 to 30,000 rpm) together with the rotating shaft 9, and the radial hole 20 also rotates at a high speed. The lubricating oil is separated by centrifugal force, and the gas flowing into the axial hole 19 through the radial hole 20 contains almost no lubricating oil.
The axial hole 19 also rotates at a high speed, and the portion facing the fixed plane 14 of the axial hole 19 is a tapered hole extending outward (left side in this figure). Is centrifuged, proceeds outward along the tapered hole, and is returned to the inside of the casing 3 through the gap between the rotating plane 12 and the fixed plane 14.
Therefore, only gas that does not contain lubricating oil exists in the vicinity of the center of the rotation plane 12, and the ventilation hole 16 extending from the position facing the rotation axis of the fixed plane 14 (ie, near the center of the rotation plane 12) to the outside, Only the gas near the center can escape to the outside, and the internal pressure of the gear chamber 4 can be relaxed.

Therefore, as in the first embodiment, without providing an uneven baffle plate or labyrinth in the casing as in the prior art, and only leaking gas to the outside without leaking oil more than equivalent to providing a ventilation hole in the rotation axis. The relief pressure can be relieved.
In addition, this configuration eliminates the need for long hole processing and can greatly reduce the cost.

  In addition, this invention is not limited to embodiment mentioned above, Of course, a various change can be added in the range which does not deviate from the summary of this invention.

1, 2 gears, 3 casing,
4 gear chamber, 5 partition, 6 air chamber,
7,8 Screw rotor, 9 Rotating shaft,
10 Internal pressure relief device,
12 rotation planes, 14 fixed planes,
16 ventilation holes, 18 rotating bodies,
19 axial holes, 20 radial holes

Claims (3)

An internal pressure relaxation device for a gear chamber comprising a casing having a plurality of gears that are lubricated with lubricating oil and rotated while meshing with each other in a sealed state,
A rotation plane provided at an end of at least one rotation shaft of the plurality of gears, rotating with the rotation shaft and orthogonal to the rotation shaft;
A fixed plane that is provided in the casing and is located at a certain interval from which the gas positioned between the plane of rotation rotates.
An internal pressure relaxation device for a gear chamber, comprising a ventilation hole provided in the casing and extending from a position of the fixed plane facing the rotation shaft to the outside. The rotation plane is a circular end surface of a rotation axis,
2. The gear chamber internal pressure relaxation device according to claim 1, wherein the fixed plane is wider than the rotation plane and covers the entire surface. The rotating plane is provided on a rotating body that rotates together with the rotating shaft,
2. The rotary body according to claim 1, wherein the rotary body has an axial hole extending partway along the rotation axis from the rotation plane and a radial hole extending radially from the axial hole to the outer surface thereof. The internal pressure relaxation device for a gear chamber as described.

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