JPS6390685A - Compressor - Google Patents

Abstract

PURPOSE:To enable lubricating oil to be properly supplied by mounting on a drive shaft of a motor a lubricating oil feeding pump provided with volume type pump elements having the volume varied by the drive of the drive shaft. CONSTITUTION:On an end of a drive shaft 4 of a motor is mounted a lubricating oil feeding pump 5 having volume type pump elements 6 having the volume varied with the drive of drive shaft 4. Thus, even if the motor is run in the high frequency region, oil supplied by the oil feeding pump 5 is increased only linearly so that superfluous oil supply can be securely prevented. Also, even if the motor is run in the low frequency region, a predetermined amount of oil can be securely satisfactorily supplied to lubricating spots.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a compressor capable of being driven under inverter control, more specifically, a compressor comprising a compression element and a motor, and capable of controlling capacity by varying the rotational speed of the motor by frequency conversion. This invention relates to a compressor that performs the following steps.

(Prior Art) Conventionally, this type of compressor is described in, for example, Japanese Patent Laid-Open No. 60-73083, and as shown in FIG. The motor (3) and the compression element are interlocked and connected via a drive shaft (4), and an oil supply passage (41) extending in the axial direction is formed in the drive shaft (4). A centrifugal pump (P) facing the bottom oil sump (1a) of the casing (1) is attached to the lower end of (4), and as the drive shaft (4) rotates, the centrifugal pump (P) P), the lubricating oil in the oil reservoir (1a) is transferred to the oil supply passage (41).
from the oil supply passageway (41) to the drive shaft (4).
The lubricating oil is supplied to the bearing parts of the compression element, the bearing parts of the compression element, and other lubricated parts.

(Problems to be Solved by the Invention) By the way, in the conventional compressor described above, since a centrifugal pump (P) is used to supply oil to each of the lubrication points, there are the following problems.

That is, the theoretical head (
(oil push-up value) is (H), the rotation speed of the centrifugal pump (P) is (ω), and the oil supply passage (41) in the drive shaft (4) is
Let the inner diameter of the lubricant be (r), and the gravity that acts when pumping up the lubricating oil be (
g), the theoretical head (H) is expressed as H=(rΦω)''/2g.

Furthermore, when the frequency of the motor (3) is (Hz),
The rotation speed (ω) is expressed as ω=Hz/60×2π.

Therefore, the lubricating oil is supplied by the centrifugal pump (P) ff
Since i (Q) is proportional to the theoretical head (H), it becomes Qoc(Hz)'.

As is clear from the above equation, the oil supply amount (Q) of the centrifugal pump (P) is determined by the frequency (H
z), the oil supply capacity of the centrifugal pump (P) when the compressor is driven increases as the frequency (Hz) increases, as shown by the dotted line curve shown as a reference example in FIG. Accordingly, the oil supply ffl (Q) increases in a quadratic manner.

Therefore, when the motor (3) is operated in a high frequency range during inverter-controlled operation of the compressor, the amount of oil supplied (Q) by the centrifugal pump (P) is significantly increased, causing excessive oil supply to each of the lubrication points. In addition, due to excessive oil supply, the amount of lubricating oil mixed into the refrigerant gas discharged from the compressor increases, causing a problem of oil drainage, and furthermore, as the amount of oil supply (Q) increases, A problem occurred in that the amount of lubricating oil in the oil reservoir (1a) in the casing (1) was insufficient.

In addition, the problem of increased oil supply in the high frequency range is that the centrifugal pump (P) is operated at the lowest value (30
Needless to say, if the minimum amount of oil supply is ensured at a low frequency (Hz), the - layer will be noticeable, but normally, in the centrifugal pump (P), in the low frequency range, There is a shortage of heads (H) necessary to obtain a predetermined amount of oil supply, and it becomes difficult to secure the minimum amount of oil supply (2).

Therefore, in the centrifugal pump (P), an abnormal situation occurs in which the above-mentioned lubrication points cannot be supplied at all in the low frequency range.

The present invention has been made in view of the above problems, and its purpose is to provide a positive displacement pump element to the oil supply pump that linearly increases the amount of oil supplied as the frequency increases, thereby facilitating operation in a high frequency range. To provide a compressor that does not sometimes carry out excessive oil supply and can also perform oil supply satisfactorily in a low frequency range.

(Means for Solving the Problems) As shown in the embodiments of the drawings, the compressor of the present invention includes a compression element (2) and a motor (3), and the number of revolutions of the motor (3) is set to In a compressor whose capacity can be controlled by frequency conversion, a positive displacement pump element is provided at the shaft end of a drive shaft (4) in the motor (3), and whose volume can be varied by driving the drive shaft (4). (8) is equipped with a lubricating oil supply pump (5).

(Function) Therefore, the oil supply pump (5) has a positive displacement pump element (
8), even when the motor (3) is operated in a high frequency range, the oil supply pump (5)
The amount of lubricating oil increases only linearly, so there is no need to over-lubricate the lubricating points, and the required amount of lubricating oil is supplied to the lubricating points. Even in the frequency range, the positive displacement pump element (
8) It is possible to secure the amount of oil supply commensurate with the volume.

(Example) A compressor according to the present invention will be described below with reference to an example shown in the drawings.

Figure 10 shows the overall structure of a scroll compressor, with lower bridges (
11) and a lower frame (12), the lower bridge (11) supports a compression element (2) consisting of a fixed scroll (21) and a revolving scroll (22), and the upper frame (11) and the lower bridge (12),
While supporting a motor (3) whose rotational speed is variable by frequency conversion, the motor (3) and compression element (2) are connected to a drive shaft (4) supported by bearings on each of the bridges (11) and (12). ), and the rotation of the drive shaft (4) accompanying the drive of the motor (3) causes the compression element (2
)'s revolving scroll (22) is fixed scroll (21)
Both scrolls (21) (
22) The refrigerant gas is compressed between the two.

Further, an oil supply pump (5) facing the bottom oil sump (1a) of the casing (1) is installed at the lower end of the drive $111 (4).
) is installed, and the oil sump (1) is supplied via the oil supply pump (5).
The lubricating oil of a) is pumped up into the oil supply passage (41) formed through the axial center of the drive shaft (4), and the oil supply passage (41) is pumped up.
from the drive shaft (4) and the six racks t, I (11) (12
), the bearings of the drive shaft (4) and the revolving scroll (22), and other lubricating locations are supplied with the lubricating oil.

Therefore, in the above compressor, the oil supply pump (5) is equipped with a positive displacement pump element (8) whose volume can be varied by the rotation of the drive shaft (4).

As shown in detail in FIGS. 1 and 2, the refueling pump (5) is fixedly supported on the lower end surface of the lower bridge (12) via a pump housing (B).
51), a cylinder (52) having an oval pump chamber (52a) and freely supported by the housing (51) in a reciprocating manner only in the short diameter direction; It is fixed via a connecting cylinder (53), and the cylinder (
The rotor (52) is eccentrically rotated in the pump chamber (52a).
54), and a pump spacer (B) fixed to the lower surface of the rotor (54) and the cylinder (52).
55).

Further, as is clear from FIG. 3, the housing (51) is integrally provided with a mounting piece (5l b) extending radially outward at the upper end of the cylindrical body (51a).
b) is fixed to the lower frame (12) via the fixing bolt (B), and the cylindrical body (51a)
An extension piece (51c) that extends downward (51c)
are formed to face each other, and a guide groove (51d) is provided at the lower end of each of the six extension pieces (51c).

Furthermore, as is clear from FIG. 4, the cylinder (52) has semicircular portions inside thereof on both sides in the lateral direction,
A horizontally elongated pump chamber (52a) is formed by connecting the semicircular portions with a straight line portion, and a short diameter of the pump chamber (52a) is formed at the outer peripheral portion of the cylinder (52). In other words, in the vertical direction in the same figure, the supporting pieces (52b) (5
2b) are formed integrally, and each support piece (52b) is inserted into a guide groove (51d) provided in each extension piece (5lb) of the housing (Sl), and each guide The groove (51d) allows the cylinder (52) to
is guided back and forth only in the minor axis direction of the pump chamber (52a).

Further, as is clear from FIGS. 5 and 6, the rotor (54) is integrally formed with an eccentric portion (54a) eccentric to the axial center of the drive shaft (4) at its lower end, and Part (5
4a) is interposed in the pump chamber (52a) of the cylinder (52), and the eccentric portion (52a) is disposed within the pump chamber (52a).
By eccentrically rotating the cylinder (54a), the cylinder (
52) in the minor axis direction of the pump chamber (52a), while moving the eccentric portion (54a) into the pump chamber (52a).
) is reciprocated in the long diameter direction to suction and compress lubricating oil, and a suction port (54b) is provided at a location eccentric to the axis on the lower end surface of the eccentric portion (54a), and the suction port (54b) is discharged to the outer peripheral surface. While opening each port (54c),
The suction port (54) is provided inside the rotor (54).
b), which communicates with the suction passage (54d) and extends radially outward from below; and a suction passage (54d) which communicates with the discharge port (54C) and extends from the bottom upward, and which extends from the drive shaft (4).
A discharge passageway (54e) that opens into the oil supply passageway (41) is formed.

The cylinder (52) supported by the housing (51) and the pump chamber (52) of the cylinder (52)
The above-mentioned positive displacement pump element (8) is formed by the eccentric portion (54a) of the rotor (54) which is reciprocated in the longitudinal direction within a), and its operation will be described in detail later.

Further, as shown in FIG. 7, the pump spacer (55) is formed in a circular shape so that its outer diameter is larger than the pump chamber (52a) of the cylinder (52), and A lubricating oil suction hole (55a) is provided at a position opposite to the suction port (54b) of (54), and mounting holes (55b) are provided at two intermediate locations of the spacer (55).
is formed through the spacer (55), and the fixing bolt (B) is screwed from each mounting hole (55b) into each mounting hole (54g> formed in the rotor (54)), thereby fixing the spacer (55) to the spacer (55). The spacer (55) is installed integrally with the rotor (54).
The cylinder (52) is supported by the housing (51).

Next, the operation of the oil supply pump (5) constructed as above will be explained based on FIG. 8.

First, as shown in (A) of the same figure, the rotor (54)
is rotated in the direction of the arrow so that the cylinder (52) is located at the lowest position, the eccentric portion (54a) of the rotor (54) is rotated in the direction of the arrow, and the eccentric portion (54a) of the rotor (54) is located at the intermediate portion of the pump chamber (52a) in the cylinder (52). , and the eccentric part (5
A right chamber (a) and a left chamber (b) of a predetermined size are formed on both sides of the pump chamber (52a) in the lateral direction centering on the pump chamber (52a).
) is supplied with lubricating oil through the suction passage (54d), and the left chamber (b) is supplied with lubricating oil from the discharge port (54c).
The lubricating oil is communicated with the oil supply passage (41) of the drive shaft (4) through the discharge passage (54e), and the lubricating oil is discharged from the left chamber (B) to the oil supply passage (41). In the case of Figure (A), the right ventricle (A) is in the process of sucking in lubricating oil, and the left ventricle (B) is in the middle of discharging lubricating oil.

As shown in this rear surface CB), when the cylinder (52) is moved upward from the lowest position by the rotation of the rotor (54), the eccentric portion (
54a), the left ventricle (b) of the pump chamber (52a)
is occluded, and the right ventricle (a) becomes enlarged, so that the left ventricle (b) completes the discharge of lubricating oil, and the right ventricle (a) becomes larger.
In b), suction of lubricating oil is completed.

Further, as shown in FIGS. (B) to (C), when the cylinder (52) is positioned at the uppermost position due to the rotation of the rotor (54), the eccentric portion (54a) of the rotor (54) is located in the middle part of the pump chamber (52a) in the cylinder (52), and the left ventricle (b)
The suction port (54b) is communicated with the right ventricle (A), and the right ventricle (A) is communicated with the discharge port (54c). Therefore, in the case of FIG. )
is in the process of sucking in lubricating oil, and the right ventricle (A) is in the process of discharging lubricating oil.

Further, as shown in FIGS. (C) to (D), when the cylinder (52) is moved downward from the uppermost position due to the rotation of the rotor (54), the rotor (S
4), the eccentric portion (54a) of the pump chamber (52a)
), the right ventricle (a) is occluded, and the left ventricle (b) becomes enlarged. Therefore, the right ventricle (a) completes the discharge of lubricating oil, and the left ventricle (b) starts sucking in lubricating oil. This means that you have completed.

As described above, the pump chamber (52a) of the cylinder (52)
), the eccentric portion (54a) of the rotor (54)
By eccentrically rotating the lubricating oil, suction and discharge of lubricating oil are repeated in the left and right chambers (a) and (b), and constant volume operation is performed by the volume pump element (8).

That is, the radius of the eccentric part (54a) in the rotor (54) is (R), the pump chamber (52) of the cylinder (52) is
The amount of eccentricity of the eccentric part (54a) with respect to a) is (r),
If the thickness of the cylinder (52) is (L), then the pump chamber (52a)
Since two compressions take place within the volumetric pump element (
The oil supply amount (Q) according to 8) is expressed as Q=4R@r*Le2*80Hz, and becomes Q(X:H2).

As is clear from the above equation, the oil supply ffi (Q) by the pump element (8) is directly proportional to the frequency (Hz) of the motor (3). Even if the frequency (Hz) of ) is increased, the oil supply fl (Q) will only be increased in a -shape curve.

Next, the oil supply characteristic graph shown in FIG. 9 will be explained.

In this figure, the horizontal axis shows frequency (Hz), and the vertical axis shows 30
2 shows a refueling characteristic graph in which the refueling amount ratio is taken with the refueling amount set to 1 during operation at (Hz). The compressor is normally operated under inverter control in the range of 30 to 120 (Hz), so even when operating at 30 (Hz), the minimum required lubrication at the lubrication points is In order to supply the oil amount, the oil supply amount is set based on the above-mentioned 30 (Hz).

As is clear from Figure 9 above, in the conventional system, the amount of oil supplied increases quadratically from the low frequency range to the high frequency range, as shown by the dotted line graph in the same figure, and excessive oil supply occurs when operating in the high frequency range. However, in the present invention, as shown by the solid line graph in the same figure, the amount of oil supplied increases linearly from the low frequency range to the high frequency range. Even when the engine is in operation, the necessary predetermined amount of oil is refilled without overfilling.

Furthermore, even in the low frequency range, it is possible to ensure the amount of oil supplied commensurate with the volume of the pump chamber (52a) constituting the positive displacement pump element (8).

In the embodiment of the drawings, a tapered opening surface in the upper interior of the discharge passageway (54e) of the rotor (54) has an inverted conical cross-sectional shape and expands in diameter toward the oil supply passageway (41) of the drive shaft (4). (54f) is provided, and the opening surface (54f)
This allows the centrifugal pump action to be exerted.

Further, an oil supply passage (41) for the drive shaft (4) is formed in the center of the drive shaft (4) along the axial direction thereof, and a discharge passage (54e) for the rotor (54) is formed in the center of the drive shaft (4). This discharge passage (
54e) through the opening surface (541) to the oil supply passage (
41).

By doing so, the discharge port (
54c) through the discharge passage (54e) to the rotor (
The lubricating oil that has reached the lower end position of the opening surface (54f) in 54) is lifted upward along the opening surface (54f) by the centrifugal force accompanying the rotation of the rotor (54). An oil supply passage (41) is formed inside the shaft center of the shaft (4) and extends vertically concentrically with the opening surface (54f).
The lubricating oil lifted up by 41 is transferred to the oil supply passage (41).
It is lifted upward along the wall surface of the cylinder, and each lubricating point is supplied with oil.

Further, in the illustrated embodiment, a notch is formed in the upper outer circumferential wall of the rotor (54), and a circumferential groove (54h) is formed between the notch and the connecting cylinder (53) that fixedly supports the rotor (54). Lubricant is supplied from the opening surface (54f) of the rotor (54) to the oil supply passage (41) of the drive shaft (4) via the connecting cylinder (53) through the circumferential groove (54h). It is designed to collect dust and other substances that get mixed into the oil.

(Effects of the Invention) As explained above, in the compressor according to the present invention, the shaft end of the drive shaft (4) of the motor (3) is connected to the drive shaft (
4) Displacement pump element (8) whose volume can be varied by driving
Since the lubricating oil supply pump (5) is installed, even when the motor (3) is operated in a high frequency range,
The amount of oil supplied by the oil supply pump (5) is increased only linearly, and therefore only the predetermined amount of lubricant required for the lubricated area can be supplied, and it is not possible to over-lubricate this lubricated area. It has now been possible to reliably prevent this.

Furthermore, even when operating in a low frequency range, a predetermined amount of oil can be ensured, and the lubricated parts can be well supplied with oil.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main parts of the compressor according to the present invention, FIG. 2 is a bottom view of the compressor, and FIG. 3 is a sectional view of the pump housing.
Figure 4 is a plan view of the cylinder, Figure 5 is a sectional view of the rotor,
Figure 6 is a bottom view of the same, Figure 7 is a plan view of the pump spacer, Figure 8
9 is a graph showing the oil supply characteristics, FIG. 10 is a vertical sectional view showing the overall structure of the compressor, and FIG. 11 is a drawing showing a conventional example. (2)...Compression element (3) 1...Motor (4), 11I...Drive shaft (5)...Refueling pump (8), 11111+, Displacement pump element Fig. 1 Figure 2 1d Figure 5 Figure 8 Figure 9/a p

Claims (1)

[Claims] (1) A compressor comprising a compression element (2) and a motor (3), in which the rotation speed of the motor (3) can be adjusted by frequency conversion to perform capacity control.
) is equipped with a lubricating oil supply pump (5) equipped with a positive displacement pump element (8) whose volume can be varied by driving the drive shaft (4). compressor.