JPS63272989A - Crankshaft of rotary compressor - Google Patents

Abstract

PURPOSE:To provide a crankshaft excellent in rigidity and workability by making a core portion of a bar-like body such as steel material having high rigidity and forming the outer peripheral surface of said core portion and an eccentric portion by internal chill or die cast with Al material or the like. CONSTITUTION:A crankshaft 1 is constituted from a steel pipe 2 of a core portion, the outer peripheral surface portion 3 and an eccentric portion 4 made of Al material by internal chill or die casting. Then to prevent the outer peripheral surface portion 3 and eccentric portion 4 from the relative rotation to the steel pipe 2 along with the rotation of crankshaft 1, the steel pipe 2 is formed with a hole or slit 6 for example. Also, the outer peripheral surface portion 3, outer surface of eccentric portion 4 and particularly slide surface is subjected to the surface treatment giving solid lubricating property. Thus, the rigidity of core portion 2 is improved while the workability of said portions 3, 4 is improved. Also, the antiwear property of said portions 3, 4 is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a crankshaft 1 shift for a rotary compressor used in refrigeration machines, air conditioners, etc.

(Prior Art) Conventionally, cast materials have been most widely used for crankshafts of rotary compressors. In addition, some m
Some use tubes.

(Problem to be Solved by the Invention) When the crankshaft is made of cast material, the center hole and oil grooves on the outer circumferential surface of the crankshaft are finished by machining or grinding using a drilling machine, lathe, etc. However, it takes a long time to process, and there is also a lot of processing costs and a lot of meat to throw away.

Furthermore, in the case of the TLF& crankshaft, there is currently no definitive method for forming the eccentric portion (crank portion), and the overall cost increases. Furthermore, since there is no surface treatment method at low temperatures, and one has no choice but to resort to hot water surface treatment, deformation after treatment becomes a problem.

Note that if the crankshaft is made of β material in one piece, the workability will be improved, but the problem will be a decrease in rigidity.

The present invention has been made in consideration of the above circumstances, and one object thereof is to provide a crankshaft for a rotary compressor that has excellent workability and high rigidity.

[Structure of the Invention] (Means for Solving the Problems) The present invention has a highly rigid rod-shaped body made of steel or ceramic material as a core, and its outer circumferential surface and eccentric portion meet AN44 standards.
Also, it is made of Get AN alloy material by casting or die casting.

<For M') Cranksy 1? The core part of the throat is made of JJ444, so it has high rigidity, and the outer peripheral part and eccentric part are made of Al material, etc., so it has good workability.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 6 does not show the overall configuration of a vertical rotary compressor, and the compressor main body is housed in a sealed case 10. The upper end of the crankshaft 1 is the rotor 1
2 is press-fitted. The stator 11 is attached directly to the inner peripheral surface of the case 10. A lower end portion of the crankshaft 1 is rotatably supported by a main bearing 15 and a sub-bearing 16. The cylinder block '14 is sandwiched between a main bearing 15 and a sub-bearing 16 to form a cylinder chamber. A roller 13 fitted into the eccentric portion 4 of the crankshaft 1 rotates eccentrically in this cylinder chamber. A blade 19 urged by a spring 20 is in contact with the roller 13 . A mounting frame 18 is integrally formed on the outer periphery of the cylinder tab 14 by an aluminum die-casting method, as will be described later. Then, the cylinder block 14 is mounted via the mounting frame 18.
Compression elements such as the following are fixed to the case 10.

Is Figure 1 Cranksi 1? This shows an example of a shaft 1, in which a steel pipe 2 serving as a core has an outer circumferential surface portion 3 and an eccentric portion 4 formed by die-casting or casting.A crankshaft is manufactured using a die-casting method. In this case, the steel pipe 2 is first set in a mold, then a die-casting mold is fitted, and the crankshaft 17 is formed as shown in Fig. 1. Since the part 4 is made of Δρ material, it can be easily machined on a precision lathe for high-speed operation and finished with an accuracy on the order of μm.

In the case of β material, a forming precision of 1:1 is quite good, so the finishing allowance may be at most 0.2 to 0.3 n+m. Furthermore, the above accuracy can be achieved at a speed approximately 10 times faster than in the case of casting. In other words, efficiency is significantly increased and equipment costs are also reduced.

If the eccentricity f of the eccentric part 4 is large, the minimum wall thickness of the eccentric part 4 becomes thin, and modeling becomes difficult. In such a case, as shown in FIG. 2, the problem can be solved by reducing the diameter of the portion 5 of the steel pipe 2 facing the eccentric portion 4.

In addition, in order to prevent the outer circumferential surface portion 3 and eccentric portion 4 of /11FJ from rotating relative to the steel pipe 2 due to the rotation of the crankshaft 1, the steps shown in FIGS. 3 and 4 are taken. Good. In FIG. 3, a hole or slit 6 is provided in the steel pipe 2. In addition, Fig. 4 (Fig. 4 (a '') is a longitudinal cross-sectional view,
In the figure (b) is a cross-sectional view, a concave portion 7 is formed in the steel pipe 2 along its longitudinal direction. Others include steel! 2
A convex portion may be formed on the surface, or a knurl I process may be performed.

When manufacturing crankshafts using the die-casting method, sprues are made at several locations on the external surface of the crankshaft in order to allow the lagoon to flow uniformly and quickly. It is best to avoid the sliding surface of the shaft. Furthermore, as shown in FIG. 5, if a seam 8 is formed in the center of the concave portion, the problem of the protrusion on the 4th will be eliminated.

In addition, in the above embodiment, the steel pipe 2 was used as the core, but
A solid steel bar or a hollow or solid bar of ceramic material may be used as the core. Also, the outer peripheral surface portion 3
In addition to the Al material, the material of the eccentric portion 4 may be a hard wear-resistant AJ2 alloy material containing 3i or the like.

In addition, the outer surface of the outer circumferential surface portion 3 and the eccentric portion 4, especially 11111
Applying a surface treatment that improves lubricity to the surface is extremely effective in terms of wear resistance. Examples of surface treatments include alumite treatment, alumite treatment, and Tef treatment.
There are other types of processing, such as + Me 82 processing.

The cylinder portion in the embodiment shown in FIG. 6 is also a composite of Δβ material and steel, and this will be explained next with reference to FIGS. 7 and 8.

A mounting frame 18 made of a steel plate and a cylinder block 14 made of 8 (or Δβ alloy material) are integrally joined by an aluminum die-casting method.As shown by the broken line, the blade groove 2-1 and the inner circumference of the cylinder 22 is covered with a second material on the cylinder block 14 portion so that the mounting frame 18 made of a steel plate is not exposed.

This is to avoid cutting a steel plate whose hardness is higher than that of Al during Al cutting process 1&i. Further, a hole 23 is previously formed in the mounting frame 18 so that the mounting bolt hole 22 of the bolt 17 also serves as a through hole. Usually, a tap is made in this mounting bolt hole 22 and the bolt 17 is fixed there. However, if the strength of the aluminum tap is insufficient, it is also possible to tap the mounting room 18 made of a steel plate in advance and tighten the bolt 17 thereto.

The weak point that the cylinder block 14 is made of aluminum and has low rigidity can be overcome by reinforcing the mounting frame 18 made of a steel plate. For example, blade groove 21
During operation, the blade groove 21 receives lateral pressure from the blade, but the width of the blade groove 21 does not increase due to the reinforcement of the steel plate.

In addition, since all the processed parts (A, B, 0 faces, etc.) are Δ(, the processing time can be shortened and the processing cost can be reduced.

Further, the blade groove 21 has conventionally relied on broaching for all cast materials or sintered alloys, but since the cutting properties are good due to the β-forming, machining using a so-called rotary blade such as milling becomes possible. This not only reduces machining costs, but also allows the blade groove 21 to be machined with the same groove width at all times. In broaching, the width of the broaching blade becomes the width of the blade groove, but when the blade wears out, it is re-ground and the blade size decreases, which causes the blade groove 21 to have a larger width. Therefore, in order to maintain a constant clearance with the blade 19, a fitting operation is always required.

If the wear resistance of the blade groove 21 is inferior to that of a cast material using /l type material, the blade groove 21 may be coated with alumite or Ma.
This can be dealt with by applying R2 treatment, and it is also effective to use carbon-based or Plus Deck-based materials as the blade material.

FIG. 9 shows a steel plate 25 as a reinforcing plate on the cylinder block 14.
In this case, a mounting hole 26 is formed in the steel plate 25 for connecting other parts.

In this example, the steel plate 25 is not attached directly to the inner circumference of the case.

[Effects of the Invention] As described above, the present invention uses rigidity in the core part of the crankshaft, and also makes the outer circumferential surface part and the eccentric part of the crankshaft made of Δβ material or Δβ material.
Since β-based alloy material is used, the crankshaft has both rigidity and workability. That is, a high quality crankshaft can be obtained at low cost.

[Brief explanation of the drawing]

1 to 5 are side views showing embodiments of the crankshaft according to the present invention, FIG. 6 is a vertical sectional view showing an example of a rotary compressor, and FIG. 7 is a cylinder section of the rotary compressor. The plan view of Figure 8 is the ■ of Figure 7.
9 is a plan view showing another example of the cylinder portion. In the figure, 1 is a crankshaft, 2 is a steel pipe (core part), 3 is an outer peripheral surface part, 4 is an eccentric part, 6 is a hole, 7 is a recessed part, 8 is a sprue,
10 is a case, 13 is a coater, 14 is a cylinder block, 15 is a main bearing, 16 is a sub-bearing, 18 is a mounting room, 19 is a blade, 20 is a spring, 21 is a blade groove, 22 is a mounting bolt hole, 23 is a hole, 24 is an inner peripheral portion of the cylinder, 25 is a steel plate, and 26 is a mounting hole. C1 to h! Figure 5 Figure 6 Figure 9

Claims (3)

[Claims] (1) Crankshaft of a rotary compressor, which has a core made of a highly rigid rod-shaped body made of steel or ceramic material, and whose outer peripheral surface and eccentric portion are made of Al material or Al-based alloy material by casting or die casting. . (2) The crankshaft according to claim 1, wherein the core portion has a concave portion or a convex portion formed on its outer circumferential surface in order to increase mechanical bonding strength with the outer circumferential surface portion and the eccentric portion. (3) The crankshaft according to claim 1 or 2, wherein the outer circumferential surface portion or the outer circumferential surface of the eccentric portion is surface-treated to have solid lubricating properties.