JP3095428B2 - Oil supply device for hermetic compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a scroll type compression mechanism,
The present invention relates to an oil supply device for a hermetic compressor incorporating a rotary type compression mechanism and the like.

[0002]

2. Description of the Related Art FIG. 5 shows an example of a conventional hermetic compressor. As shown in FIG. 5, inside the sealed housing 8, a scroll-type compression mechanism C is provided at an upper portion thereof, and an electric motor M is provided at a lower portion thereof. Scroll type compression mechanism C
Is a fixed scroll 1, a revolving scroll 2, and a revolving orbiting motion of the revolving scroll 2, but a rotation preventing mechanism 3 such as an Oldham link for preventing the revolving motion, and a fixed scroll 1
And a frame 6 to which the electric motor M is fastened, an upper bearing 71 and a lower bearing 72 for supporting the rotary shaft 5, a turning bearing 73 and a thrust bearing 74 for supporting the turning scroll 2, and the like.

The fixed scroll 1 has an end plate 11 and a spiral wrap 12 erected on its inner surface. The end plate 11 is provided with a discharge port 13 and a discharge valve 17 for opening and closing the discharge port. The orbiting scroll 2 includes an end plate 21 and a spiral wrap 22 erected on the inner surface of the end plate 21. A drive bush 25 rotates via a slewing bearing 73 in a boss 23 erected on the outer surface of the end plate 21. An eccentric pin 53, which is freely fitted and protrudes from the upper end of the rotary shaft 5 in a hole formed in the drive bush 25, is rotatably fitted. A bounce weight 84 is attached to the drive bush 25. A plurality of sealed spaces 24 are formed by mutually eccentrically rotating the fixed scroll 1 and the orbiting scroll 2 by the orbital turning radius and shifting the angle by 180 °.

By driving the electric motor M, the rotary shaft 5, the eccentric pin 53, the drive bush 25, and the boss
The orbiting scroll 2 is driven via 23, and the orbiting scroll 2 orbits in a circular orbit having an orbital orbital radius while being prevented from rotating by the anti-rotation mechanism 3.

Then, the gas enters the housing 8 through the suction pipe 82 and cools the electric motor M, and then passes through the passage 85 formed in the frame 6 from the suction passage 15 provided in the fixed scroll 1. The air is sucked into the closed space 24 via the suction chamber 16. Then, as the volume of the closed space 24 decreases due to the revolving orbiting motion of the orbiting scroll 2, the compressed space reaches the central portion while being compressed, pushes and opens the discharge valve 17 from the discharge port 13, enters the discharge cavity 14, and further discharges. The liquid is discharged to the outside via the pipe 83.

At the same time, the lubricating oil stored in the oil sump 81 at the bottom of the housing 8 is sucked up by the centrifugal pump 51 provided at the lower part of the rotary shaft 5, passes through the oil supply hole 52, and the lower bearing 72, the eccentric pin After lubricating the sliding parts such as 53, the upper bearing 71, the rotation preventing mechanism 3, the turning bearing 73, the thrust bearing 74, the oil is discharged through the chamber 61 and the oil drain hole 62 and stored in the oil sump 81.

[0007]

In the hermetic compressor, the pressure of the lubricating oil discharged from the centrifugal pump 51 is proportional to the square of the number of revolutions of the rotating shaft 5, so that the number of revolutions of the rotating shaft 5 is reduced. If the temperature decreases, lubrication to each sliding portion becomes insufficient, and poor lubrication and seizure accidents based on this may occur.

[0008]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems by using a small displacement pump which is smaller in size than a centrifugal pump and is inexpensive. The lubricating oil stored in the oil sump at the bottom of the sealed housing containing the mechanism is sucked up by an oil pump driven by the rotating shaft of the compression mechanism, and the lubrication oil of the compression mechanism slides through an oil supply hole formed in the rotating shaft. In a lubricating device for a hermetic compressor for supplying oil to a moving part, a circular recess concentric with the rotating shaft is formed in a lower surface of a bearing that supports a lower end of the rotating shaft, and the circular recess is formed on a lower surface of the bearing. Cover with a sliding plate fixed closely to
A donut-shaped rotor having a diameter smaller than this inner diameter is housed in the circular recess in a slidable manner, and is eccentrically formed at the lower end of the rotary shaft in a hole provided at the center of the rotor and has an eccentricity smaller than the inner diameter of the hole. A shaft part is inserted and one end of the vane fixed to the inner peripheral surface of the circular recess is attached to the outer peripheral surface of the rotor.
The rotor is inserted into a slot that is perforated and wider than the vane.
The vane is inserted and retracted so as not to hinder the swing of the vane, the suction chamber limited to one side of the vane communicates with the oil reservoir via a suction passage, and the discharge chamber limited to the other side is connected to the oil reservoir via a discharge passage. in fueling device for a hermetic compressor which is characterized in that in communication with the lower end of the oil supply hole Te.

Another feature is that the discharge passage is formed in a cover fixed to the lower surface of the sliding plate, and when the pressure of the lubricating oil passing through the discharge passage becomes higher than a set pressure, the discharge passage is formed. A relief valve for allowing oil to escape to the oil reservoir is attached to the lower surface of the cover.

[0010]

In the present invention, when the rotating shaft rotates, the rotor is driven by the eccentric shaft portion, and the vane is moved.
When sliding into and out of the slot while sliding against the inner surface of the slot
In both cases, the rotor swings around the point of contact with the vane while its rotation is blocked by the vane.
As a result , the contact point between the outer peripheral surface of the rotor and the inner peripheral surface of the circular recess moves. As a result, the lubricating oil stored in the oil reservoir is sucked into the suction chamber through the suction passage, and the lubricating oil urged in the discharge chamber is supplied to the sliding portion of the compression mechanism through the discharge passage and the oil supply hole. Is done. When the pressure of the lubricating oil passing through the discharge passage becomes equal to or higher than the set pressure, the oil pushes open the relief valve and escapes to the oil sump.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIGS. The lower end of the rotating shaft 5 is supported by a bearing 30, which is fixed to the housing 8 via a stay 31. The stay 31 has a plurality of holes 32 through which the lubricating oil 81 flows. And
The rotary shaft 5 is provided with an oil supply hole 52 that penetrates the axis thereof. A circular recess 33 having a predetermined depth is formed in the lower surface of the central portion of the bearing 30. The recess 33 is coaxial with a hole 34 through which the rotary shaft 5 passes and has a larger diameter. A sliding plate 35 is closely attached to the lower surface of the bearing 30, and the sliding plate 35
The sliding plate 35 and the cover 36 are fastened by screwing the ends of a pair of bolts 38 penetrating through bolt holes 37 formed in the bearing 30 into the bearing 30. .

At the lower end of the rotary shaft 5, an eccentric shaft portion 39 having a smaller diameter and eccentric with respect to this shaft center by a predetermined amount is formed, and a donut-shaped rotor 40 is fitted to the eccentric shaft portion 39. The inner diameter of the rotor 40 is slightly larger than the diameter of the eccentric shaft 39, the outer diameter is slightly smaller than the inner diameter of the recess 33, and the upper end surface is hermetically sealed on the bottom of the recess 33 and the shoulder of the eccentric shaft 39. Sliding,
The lower end surface is set so as to sealingly contact the upper surface of the sliding surface 35. One slot is provided on the outer peripheral surface of the rotor 40.
The other end of the vane 42 which is formed so as to be able to protrude and retract into the slot 42 is fitted and fixed in a slot 43 formed on the inner peripheral surface of the recess 33. Slot 41 is for rotor 40
It is wider than Vane 42 so as not to hinder swing.
You.

A chamber 44 limited to one side of the vane 42 is a suction port.
The oil reservoir 81 communicates with the oil reservoir 81 through a suction passage 45 formed in the bearing 55, the bearing 30, the sliding plate 35, and the cover 36. The chamber 46 which is limited to the other side of the vane 42 has a discharge port 56, a bearing 30, and a sliding plate 35.
And an oil supply hole 52 through a discharge passage 54 formed in the cover 36.
Communicates with the lower end of the A relief port 47 communicating with the oil sump 81 is provided in the middle of the discharge passage 54, and this relief port 47 is opened and closed by a relief valve 50 fastened by a bolt 49 together with a retainer 48 on the lower surface of the cover 36. It has become.

When the rotary shaft 5 is driven by the motor M, the eccentric shaft 39 rotates around the axis of the rotary shaft 5. Then, the outer peripheral surface of the eccentric shaft portion 39 comes into sliding contact with the inner peripheral surface of the rotor 40, so that the rotor 40
Is driven, and the rotor 40 is prevented from rotating by the vane 42.
Swing around the point of contact with the vane 42 in the recess 33
You. Accordingly, the vane 52 slides into and out of the slot 41 while sliding on the inner surface of the slot 41, and the contact point between the outer peripheral surface of the rotor 40 and the inner peripheral surface of the recess 33 moves, so that the chambers 44 and 46 are moved. Volume increases or decreases. During the process of increasing the volume of the chamber 44, the lubricating oil in the oil sump 81 enters the suction passage 45 and the suction port in the chamber 44.
The oil flows into the chamber 46 through the outlet 55 and is discharged to the oil supply hole 52 through the discharge port 56 and the discharge passage 54 while the volume of the chamber 46 is reduced. The slot 41 is wider than the vane 42
However, one side of the vane 42 is always in sliding contact with the side of the slot 41.
The lubricating oil in the chamber 46
It does not leak into the chamber 44 through the gap.

Thus, since the positive displacement type oil supply pump P is provided at the lower end of the rotary shaft 5, this pump discharges an amount of lubricating oil proportional to the number of rotations of the rotary shaft 5, so that the number of rotations of the motor M is reduced. Even in the case of a decrease, the lubricating oil can be supplied to each sliding portion of the compression mechanism C. When the discharge oil pressure of the pump becomes equal to or higher than the set pressure, the discharge oil pushes open the relief valve 50 from the relief port 47 and escapes to the oil sump 81. Other configurations and operations are the same as those of the conventional one shown in FIG. 5, and corresponding members are denoted by the same reference numerals and description thereof is omitted.

[0016]

According to the present invention, a circular recess concentric with the rotating shaft is formed in the lower surface of the bearing which bears the lower end of the rotating shaft, and this circular recess is fixed closely to the lower surface of the bearing. A donut-shaped rotor having a diameter smaller than this inner diameter is housed slidably and hermetically in a circular recess, and is eccentrically formed at the lower end of the rotating shaft in a hole provided at the center of the rotor. A smaller-diameter eccentric shaft portion is inserted, and one end of a vane fixed to the inner peripheral surface of the circular recess is bored in the outer peripheral surface of the rotor and a slot wider than the vane
The vane is inserted so as not to disturb the swinging of the rotor so as to be freely retractable, the suction chamber limited to one side of the vane communicates with the oil reservoir via the suction passage, and the discharge chamber limited to the other end is discharged. because it communicates with the lower end of the oil supply hole through a passage, the oil supply
The device has a simple structure and a small number of parts, and therefore can be easily miniaturized and manufactured at low cost. Then, the contact point between the outer peripheral surface of the rotor and the inner peripheral surface of the circular recess moves in accordance with the rotation of the rotating shaft. Therefore, accidents such as poor lubrication of the compression mechanism and seizure based on the lubrication can be prevented.

A discharge valve is formed in a cover fixed to the lower surface of the sliding plate, and a relief valve for releasing the oil to an oil reservoir when the pressure of the lubricating oil passing through the discharge passage becomes higher than a set pressure. Is attached to the lower surface of the cover, power can be prevented from being wasted, and so-called oil rising, in which the lubricating oil is discharged together with the discharge gas, can be suppressed.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view taken along the line II-II of FIG.

FIG. 3 is an end view along the line III-III in FIG. 1;

FIG. 4 is an end view taken along the line IV-IV in FIG. 1;

FIG. 5 is a longitudinal sectional view of a conventional hermetic compressor.

[Explanation of symbols]

 8 Sealed housing 5 Rotary shaft 81 Oil reservoir 52 Oil supply hole 39 Eccentric shaft 54 Discharge passage 50 Relief valve P Positive displacement oil pump

Continuation of the front page (72) Inventor Kimitake Takeda 3-chome, Asahimachi, Nishibiwajima-cho, Nishi-Kasugai-gun, Aichi Prefecture Mitsubishi Heavy Industries, Ltd. Aircon Works (56) References JP-A-63-90685 (JP, A) JP-A-63-272992 (JP, A) JP-A-2-5787 (JP, A) JP-A-2-114786 (JP, U)

Claims (2)

(57) [Claims] 1. A lubricating oil stored in an oil reservoir at a bottom of a sealed housing containing a compression mechanism is sucked up by an oil supply pump driven by a rotation shaft of the compression mechanism, and is supplied through an oil supply hole formed in the rotation shaft. In the lubricating device for a hermetic compressor for supplying oil to a sliding portion of the compression mechanism, a circular recess concentric with the rotary shaft is formed in a lower surface of a bearing that bears a lower end of the rotary shaft. A donut-shaped rotor smaller in diameter than the inner diameter is housed in the circular recess in a slidable manner, and is provided at the center of the rotor. An eccentric shaft portion formed eccentrically at the lower end of the rotary shaft and having a diameter smaller than the inner diameter of the hole is inserted into the hole, and one end of the vane fixed to the inner peripheral surface of the circular recess is connected to the rotor.
Perforated on the outer surface and above the slot wider than the vane
Insert and retract freely so as not to hinder the swing of the rotor ,
And characterized in that the suction chamber which is limited in one side of the vane through the suction passage communicates with the oil reservoir and the discharge chamber which is limited in the other side through the discharge passage communicated with the lower end of the oil supply hole Refueling system for hermetic compressor. 2. The discharge passage is formed in a cover fixed to the lower surface of the sliding plate, and when the pressure of the lubricating oil passing through the discharge passage reaches a set pressure, the oil is released to the oil sump. The oil supply device for a hermetic compressor according to claim 1, wherein a relief valve is attached to a lower surface of the cover.