JPH0725239U - Lubrication structure of mechanical turbocharger - Google Patents

Abstract

(57) [Summary] [Purpose] The objective is to supply a sufficient amount of oil to the mechanical seal and maintain good mechanical sealability. An air vent hole 11 for letting out a pressure in a space S formed between a bearing that rotatably supports the rotor shaft 2 and a mechanical seal that is externally fitted to the outer periphery of the rotor shaft 2 is provided. 20 to 45
Formed within the housing 1 at an angular position of degrees.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a lubricating structure for a mechanical supercharger.

[0002]

[Prior art and its problems]

 Conventionally, as shown in FIG. 4, a rotor shaft 52 is rotatably disposed in a housing 51 of a mechanical supercharger through a bearing 53, and the rotor shaft 52 and the rotor shaft 52 slide inside the bearing 53. A mechanical seal 54 is provided in order to achieve oil tight contact, a timing gear 56 is fixed to the shaft end of the rotor shaft 52, and an oil chamber formed below the timing gear 56. The oil in 58 is scraped upward by the rotation of the timing gear 56, and the scraped oil is supplied to the mechanical seal 54 through the supply hole 60 formed in the housing 51. The oil is returned to the oil chamber 58 through the discharge hole 61. In such a conventional lubrication structure, the oil supplied to the mechanical seal 54 is the oil scraped up by the timing gear 56, and unlike the structure in which the oil is forcedly pumped from the outside for lubrication. In the case of refueling, the amount of oil supplied to the mechanical seal 54 is small, and when the sliding contact surface of the mechanical seal 54 with respect to the rotor shaft 52 generates heat, the pressure in the space S between the bearing 53 and the mechanical seal 54 rises, Due to the increase in pressure, the amount of oil dripped from the oil supply hole 60 to the mechanical seal 54 side deteriorates, and the amount of oil supplied to the mechanical seal 54 decreases, which further increases heat generation on the sliding contact surface. However, there is a problem that the oil on the sliding contact surface is carbonized and the sealing performance of the mechanical seal 54 deteriorates. Was Tsu.

[0003]

[Means for Solving the Problems]

 The present invention has been devised in view of the above conventional problems, and an object thereof is not to provide a lubricating structure that can secure a sufficient amount of oil supplied to the mechanical seal and improve the sealing performance of the mechanical seal. The first gist of the invention is that a timing gear is fixed to the shaft end of a rotor shaft rotatably arranged in a housing through a bearing, and the rotation of the timing gear scratches the oil in the oil chamber upward. In the mechanical supercharger configured to supply the lifted and lifted oil through the supply hole formed in the housing to the space between the bearing and the mechanical seal arranged inside thereof, That is, an air vent hole for releasing the pressure of the portion is formed in the housing at an angle position of 20 to 45 degrees with respect to the supply hole. The second gist is that the discharge hole for returning the oil in the space to the oil chamber is formed at a height position below the axial center of the sliding surface of the mechanical seal with respect to the rotor shaft. is there.

[0004]

[Action]

 In the first aspect, the air vent hole for letting out the pressure in the space between the bearing and the mechanical seal is formed at an angle of 20 to 45 degrees with respect to the oil supply hole, which is generated in the space. The internal pressure can be satisfactorily released through the air vent hole, the blowback to the supply hole side can be reduced, and the amount of oil dripped from the supply hole to the mechanical seal can be increased to make the mechanical seal function properly. it can. Further, in the second aspect, since the oil discharge hole is formed at a height position below the axial center of the sliding surface of the mechanical seal, the oil is properly returned to the oil chamber, and the oil is not collected in the space. It is possible to prevent the rise of internal pressure due to the agitation of oil in the space.

[0005]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional configuration diagram of a main part of a mechanical supercharger, in which a pair of rotor shafts are arranged, and a cross section of the rotor shaft 2 on one side is shown on the axial end side. As shown in FIG. On the outer circumference of the rotor shaft 2 which is rotatably arranged in the housing 1 via the bearing 3, the mechanical seal 4 is fitted onto the outer periphery of the rotor 3 while the sliding contact surface 4a is in sliding contact with the inside of the bearing 3. A space S is formed between the bearing 3 and the mechanical seal 4.

A timing gear 6 is fixed to the shaft end of the rotor shaft 2. The timing gear 6 is covered by a cover 7 attached to the housing 1 from the outside. An oil chamber 8 is formed between the cover 7 at the lower part of 6 and the housing 1, and oil is stored in the oil chamber 8. When the timing shaft 6 is rotated by the rotation of the rotor shaft 2, the oil chamber 8 is rotated. The oil in 8 is configured to be raked upward, and an oil receiving member 9 is provided inside the upper portion of the timing gear 6, and the oil receiving member 9 collects the raked oil. In the housing 1 inside the oil receiving member 9, an inclined supply hole 10 is formed. The lower end of 0 is opened in the space S, and oil is supplied into the space S through the supply hole 10 and can lubricate the bearing 3 and the mechanical seal 4.

In this example, as shown in the longitudinal sectional view of the main part in FIG. 2, an air vent hole 11 is formed in the housing 1 at an angle α with respect to the supply hole 10 formed in the housing 1. The air vent hole 11 has a lower end opening at the space S and an upper end opening at an upper portion of the oil chamber. The air vent hole 11 is for releasing the internal pressure generated in the space S to the oil chamber 8 side, and the sliding contact surface 4a of the mechanical seal 4 generates heat as the rotor shaft 2 rotates, which causes the space Although the pressure of S increases, the increased internal pressure is satisfactorily released through the air vent hole 11 so that the blowback due to the internal pressure to the supply hole 10 side is eliminated, and as a result, it is supplied to the mechanical seal 4 through the supply hole 10. The amount of oil that enters the space S increases and the amount of oil that enters the space S increases, so that a sufficient amount of oil can be supplied to the bearing 3 and the mechanical seal 4 side, and good lubricating performance can be secured.

As a result of an experiment on the angle α of the air vent hole 11 with respect to the supply hole 10, the result as shown in FIG. 3 is obtained, and when the angle α is in the range of 20 ° to 45 °, the most space is obtained. The result is that the oil supply amount to S increases, and when the angle α is set to 20 degrees or less, the internal pressure escapes better, but the air vent hole 11 and the lower end opening of the supply hole 10 on the space S side are improved. Is extremely close to each other, the amount of the internal pressure blown back into the oil supply hole 10 increases, and as a result, the amount of oil dropped into the space S decreases. Further, when the angle α is set to 45 degrees or more, the escape of the internal pressure from the air vent hole 11 is reduced, and the blowback of the internal pressure into the oil supply hole 10 is increased, whereby the amount of oil dropped into the space S is increased. Decrease. Therefore, setting the angle α in the range of 20 degrees to 45 degrees is most effective for increasing the amount of oil supplied to the space S.

In FIG. 2, a discharge hole 12 for returning the oil from the space S to the oil chamber 8 side is formed in the housing 1. The discharge hole 12 is formed in the mechanical seal 4 in this example. It is formed by opening to the space S side at a height position below the axis of the sliding contact surface 4a. If the discharge hole 12 is formed at such a position, the space S It is possible to prevent excessive accumulation of oil in the sliding contact surface 4a, so that new oil is constantly supplied to the sliding contact surface 4a to improve the cooling efficiency of the sliding contact surface 4a. Since the amount of oil to be reduced also decreases, it is possible to suppress the increase in the internal pressure in the space S.

[0010]

[Effect of device]

 According to the present invention, a timing gear is fixed to the shaft end of a rotor shaft rotatably disposed in a housing through a bearing, and the rotation of the timing gear causes the oil in the oil chamber to be lifted up and lifted up. In a mechanical supercharger configured to supply the supplied oil through a supply hole formed in the housing to the space between the bearing and the mechanical seal disposed inside the bearing, the pressure in the space By forming an air vent hole for letting air into the housing at an angle position of 20 to 45 degrees with respect to the supply hole, the internal pressure generated in the space can be satisfactorily escaped through the air vent hole. The blowback to the supply hole is reduced, and it is possible to secure a sufficient amount of oil that passes through the supply hole and is dripped into the space, and the oil is sufficiently supplied to the mechanical seal. Having well maintained can effectively sealability Lucille. In addition, the discharge hole for returning the oil in the space portion to the oil chamber is formed at a position below the axial center of the sliding surface of the mechanical seal with respect to the rotor shaft, so that the oil in the space portion is prevented. There is no accumulation of oil, and new oil is constantly supplied to the sliding contact surface of the mechanical seal to cool the sliding contact surface sufficiently, and the amount of oil agitated in the space decreases and the oil It has an effect that the rise of internal pressure in the space due to stirring can be suppressed well.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram of a main part on a shaft end side of a rotor shaft of a mechanical supercharger.

FIG. 2 is a vertical cross-sectional configuration diagram of a space portion in FIG.

FIG. 3 is a diagram showing an oil supply amount with respect to a space portion.

FIG. 4 is a cross-sectional configuration diagram of essential parts corresponding to FIG. 1 showing a conventional lubricating structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Rotor shaft 3 Bearing 4 Mechanical seal 4a Sliding surface 6 Timing gear 7 Cover 8 Oil chamber 9 Oil receiving member 10 Supply hole 11 Air vent hole 12 Exhaust hole S Space section

Claims (2)

[Scope of utility model registration request] 1. A timing gear 6 is fixed to the shaft end of a rotor shaft 2 rotatably disposed in a housing 1 through a bearing 3, and the rotation of the timing gear 6 causes the oil in an oil chamber 8 to be removed. A machine configured to be lifted up and supplied to the space S between the bearing 3 and the mechanical seal 4 arranged inside the bearing 3 through the supply hole 10 formed in the housing 1. 1 in a turbocharger for releasing the pressure in the space S
1 is formed in the housing 1 at an angle position of 20 degrees to 45 degrees with respect to the supply hole 10, and a lubricating structure for a mechanical supercharger. 2. The mechanical seal 4 is provided with a discharge hole 12 for returning the oil in the space S to the oil chamber 8.
2. The lubrication structure for the mechanical supercharger according to claim 1, wherein an opening is formed at a height position below the axis of the sliding contact surface 4 a with respect to the rotor shaft 2.