JP2002070764A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll compressor with aimed durability which is obtained without shortening life time of bearing by preventing excessive leakage of lubricant in a sealed bearing. SOLUTION: The scroll compressor is characterized by having a recessed maintaining part (120c) of a cylinder with a bottom which opens only to one end, the sealed bearing (137) which lubricant is not supplied from outside and a driving shaft (131) with a venthole (131d) penetrated from a shaft end face inserted into the bearing with the lubricant maintained in this recessed maintaining part communicating with the outside. Since air of the internal space is discharged from the venthole when the driving shaft is inserted, grease leakage from the bearing can be prevented by rising of the atmospheric pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor having a bearing structure.

[0002]

2. Description of the Related Art A scroll compressor, which is a kind of compressor, has high efficiency and is widely used in home air conditioners, air conditioners for automobiles, and the like. Furthermore, recently, it has been used to supply a compressed gas (hydrogen, oxygen, air, or the like) to an electrode of a fuel cell (hydrogen-oxygen type). Such a scroll-type compressor includes a fixed scroll and an orbiting scroll, and the orbiting scroll meshes with the fixed scroll to orbit to compress the working fluid. The orbiting scroll is imparted with orbital (revolving) motion by a drive shaft, and is prevented from rotating by a driven shaft evenly arranged around the drive shaft.

By the way, scroll type compressors have been used for a long time.
For stable operation, the bearing structure of the drive shaft and the driven shaft is very important. In particular, the bearings include rolling bearings such as ball bearings and roller bearings, and sliding bearings such as bushings and metal, and any of the bearings must maintain a good lubricating state. Otherwise, premature wear, seizure, etc. will occur, hindering stable rotation of the drive shaft and driven shaft, and the durability of the scroll compressor will be poor.

[0004] Under such circumstances, a plurality of proposals have been made for lubrication of bearings. For example, JP-A-8
Japanese Patent Application Laid-Open No. 61278/2000 and Japanese Patent Application Laid-Open No. 2000-45971 disclose such information. In JP-A-8-61278,
There is disclosed a bearing structure in which lubricating oil in an oil sump is pumped up and supplied to a bearing to actively lubricate the bearing. On the other hand, Japanese Patent Application Laid-Open No. 2000-45971 discloses a bearing structure in which grease is stored in a grease reservoir in advance, and the grease is gradually discharged to a bearing. According to this publication, an air introduction path is provided on the back surface of the grease reservoir to promote the outflow of grease.

[0005]

However, even if such a positive lubrication means is not specially provided, if a ball bearing or the like in which grease is sealed is appropriately used, it is sufficient.
It is also possible to ensure the durability of the scroll compressor. Further, depending on the use and environment of the scroll compressor, lubrication with a lubricating oil may not be preferable. For example, when supplying compressed air to the oxygen electrode of a fuel cell, even a small amount of lubricating oil or the like mixed into the air may cause damage to the electrodes.

However, the present inventor has found that even a bearing with a lubricant, such as a ball bearing, may not be able to sufficiently exhibit its original performance depending on the shape of the holding portion into which the bearing is fitted. . In other words, when the shaft is inserted into the bearing when the holding portion has a bottomed cylindrical shape, the gap between the bottom surface of the holding portion, the inner circumferential surface of the cylinder of the holding portion (or the inner circumferential surface of the bearing), and the shaft end surface. (Hereinafter referred to as “internal space”)
However, it becomes an enclosed space. In particular, since the bearing and its holding portion usually have high processing accuracy, the internal space is likely to be airtight. Therefore, as the shaft is inserted, the air in the internal space is compressed by the shaft end face,
Its pressure rises.

As a result, the grease cover of the bearing or the lip of the sealing member may be deformed, and the grease sealed inside the bearing may leak. When such a situation occurs, the bearing cannot exhibit its original life, and the durability of the scroll compressor is reduced. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a scroll compressor in which the life of a bearing is prevented from being shortened and durability is prevented from being shortened.

[0008]

The inventor of the present invention has intensively studied to solve this problem, and, as a result of repeated trial and error, has found that the internal space formed in the holding portion when the shaft is inserted into the bearing. The idea of providing a vent hole communicating with the scroll shaft was developed, and the scroll type compressor of the present invention was developed.

(1) That is, a scroll type compressor according to the present invention comprises a drive shaft for turning a revolving scroll that meshes with a fixed scroll, a bearing for supporting the drive shaft, and a holding portion for holding the bearing. A scroll-type compressor comprising: the holding unit is a bottomed cylindrical concave holding unit that is opened only at one end side; and the bearing is a bearing with a lubricant that is not supplied with a lubricant from the outside. The drive shaft is provided with a ventilation hole penetrating from a shaft end face fitted into the bearing with lubricant held by the concave holding portion and communicating with the outside.

When the drive shaft is fitted into the bearing with lubricant held by the concave holding portion, the bottom surface of the concave holding portion and the cylindrical inner peripheral surface of the bearing with lubricant (or the cylindrical inner circumference of the concave holding portion). Surface) and the shaft end surface form a cylindrical internal space. But,
In the present invention, since the drive shaft is provided through the shaft end face and has a ventilation hole communicating with the outside, this internal space does not become a closed space, and air is discharged from the ventilation hole according to the insertion of the drive shaft. To prevent the pressure in the internal space from rising. As a result, the lubricant sealed inside the bearing with the lubricant does not leak to the outside, the original life of the bearing can be exhibited, and a decrease in the durability of the scroll compressor can be prevented.

(2) In the scroll compressor described above,
Although the ventilation hole is provided in the drive shaft, it may be provided in a driven shaft for preventing the orbiting scroll from rotating. That is, a scroll type compressor according to the present invention includes a driven shaft for preventing rotation of an orbiting scroll meshing with a fixed scroll, a bearing for supporting the driven shaft, and a holding portion for holding the bearing. Wherein the holding portion is a bottomed cylindrical concave holding portion opened only at one end side, the bearing is a bearing with a lubricant that is not supplied with a lubricant from the outside, and the driven shaft May be provided with a ventilation hole penetrating from a shaft end face fitted into the bearing with lubricant held by the concave holding portion and communicating with the outside.

[0012] It should be noted that the pressure increase in the internal space is not limited to the case where the drive shaft or the driven shaft is fitted into the concave holding portion, but may occur during the operation of the scroll compressor. Even in this case, by providing a vent hole that allows the internal space to communicate with the outside, even if the drive shaft or the driven shaft moves slightly back and forth in the axial direction during operation, the pressure in the internal space is substantially large. It is maintained at the atmospheric pressure, and grease or the like in the bearing can be prevented from leaking. The “lubricant” is generally a semi-solid lubricant such as grease, but is not limited thereto, and may be a solid lubricant such as graphite or molybdenum disulfide, or a liquid lubricant such as a lubricating oil.

(3) Further, it is preferable that the drive shaft or the driven shaft has a hollow portion opened on the shaft end face side to be fitted into the bearing with lubricant.

By having a hollow portion opened on the shaft end face side, the degree of freedom in designing the ventilation hole is increased, and in many cases, the ventilation hole can be easily processed. In addition, since the hollow portion increases the volume of the above-mentioned internal space, even if the shaft is suddenly fitted, an increase in the internal pressure is alleviated. Needless to say, the provision of the hollow portion can reduce the weight of the shaft.

(4) Further, a seal member is provided on the open end side of the concave holding portion to prevent the lubricant in the concave holding portion from leaking to the outside. It is preferable that the drive shaft or the driven shaft be located inside the seal member after being fitted into the bearing with lubricant. By providing the seal member on the opening end side of the concave holding portion, it is possible to prevent the lubricant from leaking from the inside to the outside. As a result, the inside of the scroll compressor can be kept clean and the lubricant can be prevented from being mixed into each part. Of course, the life of the bearing can be extended. And
When the drive shaft or the like is assembled to the bearing, the opening outside the ventilation hole is located inside the sealing member, so that the lubricant does not leak outside through the ventilation hole.

(5) There are no particular restrictions on the location or position where such a bearing structure is provided, but it is particularly effective when it is difficult to provide a ventilation hole on the holding portion side. For example, it is preferable that the concave holding portion is provided on the back surface of the orbiting scroll.

(6) Such a bearing structure is effective when used when lubrication with lubricating oil is difficult.
For example, it is preferable that the scroll compressor of the present invention supplies compressed gas to the electrodes of the fuel cell. For example, as a gas to be compressed, there are hydrogen, oxygen, air, and the like, as electrodes, there are a hydrogen electrode and an oxygen electrode, and as a fuel cell, an alkaline aqueous solution type, a solid polymer type, a phosphoric acid type,
There are a molten carbonate type, a solid electrolyte type and the like.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically with reference to embodiments. (Overall Structure of Scroll Compressor) FIG. 1 shows a scroll air compressor 10 for a fuel cell according to an embodiment of the present invention.
0 (hereinafter simply referred to as “compressor 100”). The compressor 100 roughly includes a compression mechanism, a crank mechanism, and a drive motor. Hereinafter, each will be described specifically.

The compression mechanism comprises a fixed scroll 110 and an orbiting scroll 120. Fixed scroll 110
Is a disk-shaped fixed base 110a and the fixed base 110
The fixed spiral part 110b is provided standing upright from a and a peripheral wall 110c that covers the fixed spiral part 110b. The fixed housing 110a and the outer peripheral wall 110c form a front housing. Note that a discharge port 111 connected to the oxygen electrode of the fuel cell is provided at the center of the fixed base 110a. The orbiting scroll 120 is also a disc-shaped orbiting base 120.
a and a swirling swirling part 120b standing upright from the turning base 120a, and a bottomed cylindrical concave holding part 120c is provided at the rear center of the turning base 120a.
On its outer peripheral side, there are provided bottomed cylindrical concave holding portions 120d which are evenly arranged at three places.

The orbiting scroll 120 has a crank mechanism.
Drive crank mechanism 1 that causes the robot to make a turning motion (orbiting motion)
40 and a driven crank mechanism 150 for preventing the orbiting scroll 120 from rotating. Drive crank mechanism 140
Is composed of the concave holding portion 120c, the crankpin 131a of the motor main shaft 131, and two rows of roller bearings 137 that support the crankpin 131a. Here, the motor main shaft 131 and its crank pin 131a correspond to the drive shaft according to the present invention, and the roller bearing 137 corresponds to the bearing with lubricant according to the present invention, and a predetermined amount of grease is surrounded around the roller. Is attached.

The driven crank mechanism 150 has the concave holding portion 120d, the crankpin 151a of the driven crankshaft 151, and the two supporting the crankpin 151a.
It consists of a row of radial ball bearings 153. Also in this case, the driven crankshaft 151 and the crankpin 151
a corresponds to a driven shaft according to the present invention, and the radial ball bearing 153 corresponds to a bearing with a lubricant according to the present invention.
Grease is sealed inside. The front side of the motor main shaft 131 is supported by a ball bearing 138. The rear side of the driven crankshaft 151 is supported by double-row ball bearings 152. In order to cancel the moment of inertia generated when the orbiting scroll 120 orbits, a balance weight 131b is attached to the motor main shaft 131, and the driven crank shaft 151
Is provided with a balance weight 151b to reduce vibration. The details of the crankpin 131a of the motor main shaft 131 and the crankpin 151a of the driven crankshaft 151 will be described later.

The crank mechanism is housed in the center housing 170 together with the drive motor. The crank mechanism and the drive motor are connected to the center housing 17.
0 is partitioned by a support frame 171 integrally formed at substantially the center of the center. The above-described ball bearing 138 is used.
And the ball bearing 152 are connected to the support frame 17.
1.

The drive motor section includes a center housing 17
0, a rear housing 190, and a drive motor 130 housed between them. First, the drive motor 130 includes a motor main shaft 131 that penetrates the center of the shaft,
The induction motor is an induction motor including a rotor 133 fitted into the motor main shaft 131 and a stator 134 further provided on an outer peripheral side thereof and around which a coil 135 is wound. Therefore, the rotation speed and the like of the drive motor 130 can be controlled by an inverter (not shown). Further, a water jacket 171 is provided substantially at the center of the center housing 170 that covers the drive motor 130 in accordance with the position of the stator 134, so that the drive motor 130 is cooled by cooling water.

At the rear end of the drive motor 130, a rear housing 190 is fixed to the center housing 170 by bolts, and a motor chamber for housing the drive motor 130 is formed therebetween. In the center of the rear housing 190, a motor main shaft 131 is supported by a ball bearing 139 and is sealed by a seal member 136.

When power is supplied to the drive motor 130, the motor main shaft 131 rotates, and the orbiting scroll 120 orbits while engaging with the fixed scroll 110 via the drive crank mechanism 150. Then, the fixed scroll 110 and the orbiting scroll 1
Air is sucked into a compression chamber formed between the fuel cell 20 and the orbiting scroll 120, and the suctioned intake air is compressed and discharged from the discharge port 111 to supply compressed air to the oxygen electrode of the fuel cell.

(Bearing Structure) An embodiment of the bearing structure, which is a feature of the present invention, will be described in detail with reference to FIG. 2, which is a partially enlarged view of FIG. A hollow portion 131c is coaxially formed in the crankpin 131a of the motor main shaft 131 to a length substantially equal to that of the crankpin 131a. And the hollow part 131c
On the rear side, an air vent 131d is laid out perpendicular to the axis of the hollow portion 131c, and communicates with the hollow portion 131c. And the ventilation hole referred to in the present invention is the hollow portion 13.
1c and a hole 131d.

The opening of the hole 131d is located inside the lip of the seal member 123 when assembled, and the roller (rolling element) of the roller bearing 137 and the seal member 12
It is squeezed out so as not to be involved in the third lip. This is to prevent the lubricant such as grease from leaking out of the seal member 123 through the hole 131d and to prevent the rollers and the lip from being damaged. Further, until the insertion of the crank pin 131a into the inner peripheral portion of the roller bearing 137 is completely completed,
It is not necessary that the hole 131d be in communication with the outside.
This is because there is no problem even if a slight increase in air pressure occurs in the hollow portion 131c. If the pressure rises slightly, the pressure in the hollow portion 131c becomes substantially atmospheric within a short time. However, it is preferable to provide the hole 131d as far as possible from the end face of the crankpin 131a within the above-described range. This is because an increase in the air pressure in the hollow portion 131c can be further suppressed.

Crank pin 1 of driven crankshaft 151
51a is the same as the crankpin 131a, and the hollow portion 151c is coaxially stretched to the same length as the crankpin 151a. And, on the rear side of the hollow portion 151c, an air vent hole 151d is provided.
The hollow portion 151 is laid out orthogonal to the axis of 51c.
It communicates with c. The ventilation hole according to the present invention is formed by the hollow portion 151c and the hole 151d. In addition, the opening of the hole 151d is made by the sealing member 1 when assembled.
23, and the opening thereof is squeezed so as not to engage with the ball (rolling element) of the radial ball bearing 153 or the lip of the seal member 125. Also in this case, it is preferable to provide the hole 151d as far as possible from the end face of the crank pin 151a.

In the above-described embodiment, the ventilation hole according to the present invention is formed by the hollow portion and the hole, but may be a single through hole extending obliquely from the shaft end face. Further, in the above-described embodiment, an example in which all the concave holding portions are provided in the orbiting scroll has been described.
When the center of the shaft 90 is a concave holding portion, the bearing structure of the present invention can be used. The same applies to the rear side of the driven crankshaft, which is the driven shaft.

[0030]

According to the scroll compressor of the present invention,
Excessive leakage of the lubricant sealed in the bearing is eliminated, so that the life of the bearing is not shortened and the durability of the scroll compressor can be prevented from lowering.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a scroll compressor according to an embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view of the embodiment.

[Explanation of symbols]

Reference Signs List 110 fixed scroll 120 orbiting scroll 120c, 120d concave holding portion 131 motor main shaft (drive shaft) 151 driven crankshaft (driven shaft) 131c, 151c hollow portion (vent) 131d, 151d extraction hole (vent) 137 roller bearing (lubricant) Bearing) 153 Radial ball bearing (bearing with lubricant)

Continued on the front page (72) Inventor Ryuta Kawaguchi 2-1-1, Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Koji Kawamura 2-1-1, Toyota-cho, Kariya-shi, Aichi Prefecture Toyota Corporation Inside the Automatic Loom Works (72) Inventor Mari Mari Sawa 2-1-1, Toyota-cho, Kariya-shi, Aichi Pref. F term in the Toyota Industries Corporation (reference) 3H029 AA02 AA15 AB02 AB05 BB04 CC17 3H039 AA02 AA12 BB11 CC13 CC19

Claims (6)

[Claims] 1. A scroll type compressor comprising: a drive shaft for rotating a revolving scroll meshing with a fixed scroll; a bearing for supporting the drive shaft; and a holding portion for holding the bearing. Is a bottomed cylindrical concave holding portion opened only at one end side, the bearing is a lubricant bearing to which lubricant is not supplied from the outside, and the drive shaft is held by the concave holding portion. A scroll type compressor provided with a ventilation hole penetrating from a shaft end face fitted into the lubricated bearing and communicating with the outside. A driven shaft for preventing rotation of the orbiting scroll meshing with the fixed scroll, a bearing for supporting the driven shaft,
A holding portion for holding the bearing, wherein the holding portion is a bottomed cylindrical concave holding portion opened only at one end side, and the bearing is provided with a lubricant from the outside. A lubricant bearing that is not supplied, wherein the driven shaft has a ventilation hole that penetrates from a shaft end face fitted into the lubricant bearing held by the concave holding portion and communicates with the outside. A scroll type compressor. 3. The scroll-type compressor according to claim 1, wherein the drive shaft or the driven shaft has a hollow portion that is opened on a shaft end face side that is fitted into the bearing with lubricant. 4. A sealing member for preventing the lubricant in the concave holding portion from leaking to the outside at an opening end side of the concave holding portion. 3. The scroll compressor according to claim 1, wherein the compressor is located inside the seal member after the drive shaft or the driven shaft is fitted into the lubricant bearing. 4. 5. The scroll compressor according to claim 1, wherein said concave holding portion is provided on a back surface of said orbiting scroll. 6. The scroll compressor according to claim 1, wherein a compressed gas is supplied to an electrode of the fuel cell.