JPS63266214A - Ball joint mechanism - Google Patents

Abstract

PURPOSE:To prevent a ball from slipping and also to prevent abrasion, seizing and the like thereof in a joint mechanism for a compressor scroll fluid device in a refrigerator, by supporting the ball at three points so as set a gap above the ball. CONSTITUTION:A ball 36 is held among three contact points P1-P3 which are on the bottom surface 34a and peripheral surface 24b of a stationary side pocket hole 34 on the stationary member side and the peripheral side surface 35b of a pocket hole 35 on the rotary member side, respectively. Accordingly, the ball inhibits autorotation of the rotary member so that the rotary member revolves around the stationary member. Moreover, the contact points P1-P3 are set so as to have a predetermined relationship thereamong in reference to a rotary axis M1 and the like. Accordingly, the ball 36 rolls within both pocket holes 34, 35 without slipping, thereby it is possible to prevent abrasion and seizing of the ball due to slips.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a rotating shaft [1-
The present invention relates to a ball joint mechanism that holds a rotating member such as a ball so that it can revolve freely without rotating.

(Prior art) Generally, for example, cold? In a scroll fluid device used for one compressor, a fixed part fixed in the case,
The revolving scrolls are arranged in parallel with the scrolls with their laps meshing with each other, while a rotating shaft is connected to the back of the end plate of the revolving scrolls with its axis eccentric from the center of the revolving scrolls, and the revolving scrolls are connected to the fixed scrolls. On the other hand, the scroll is caused to revolve without rotating, and the closed chamber formed between the wraps of both scrolls is contracted to compress the refrigerant gas.

In this scroll fluid device, an Oldham joint mechanism or a ball joint mechanism is used as the rotation prevention mechanism that prevents the rotation of the revolving scroll, but since the Oldham joint moves back and forth in the Oldham joint mechanism, the balance cannot be maintained. The disadvantage is that it is difficult to remove and generates large vibrations. On the other hand, as disclosed in Japanese Patent Application Laid-Open No. 55-155916, the ball joint mechanism has, for example, a plurality of pocket holes formed in the end plate of the revolving scroll and the fixed frame provided on the back side of the end plate. Since the balls are interposed between the pocket holes, all of the elements rotate, making it easy to maintain balance and reducing vibration.

This ball joint mechanism will be explained in detail based on FIGS. 3 and 11. Annular ball holding members (a>, (b
) are provided facing each other, and both the holding parts 1t(a) and (b
) are formed with a plurality of circular pocket holes (C) and (d) facing each other, and both of these facing pocket holes (C
), (d) a steel ball <=> is interposed between
As the revolving scroll rotates, the ball (e) moves inside the pocket holes (c) and (d), thereby preventing the revolving scroll from rotating.

(Problems to be Solved by the Invention) In the above-mentioned ball joint mechanism, the pocket hole (c),
The distance between the bottom surface (g> and (h) of (d) is ball Cf3
) corresponds to the diameter R of the circumferential surface (i).

(j) is formed into a spherical surface projected onto the ball (e) as shown in FIG. 11, or a tapered surface expanding outward as shown in FIG. 12.

The ball (e) has both pocket holes (C) and (d
), but although the ball <e> has sufficient durability during rolling motion, if it slips, it will cause wear, seizure, and heat generation at the same time. Therefore, durability will be reduced. Therefore, in order to prevent this slipping phenomenon, the shapes of both pocket holes (C) and (d) that support the ball (8) at four points are made equal, and the shape of each pocket hole (i>, (j>) is , ball (
e) It is necessary to make the contact point orbital diameters equal.

However, this limits the shapes of both pocket holes (C) and (d), which poses a problem in that there are significant design constraints.

Therefore, it is conceivable to support the ball <e> at three points by having the pocket holes (0) and (d) have different shapes. However, simply making the pocket holes (C) and (d) different in shape will result in the ball (e)
As a result, a sliding phenomenon will occur, resulting in poor durability of the ball <e>.

In view of this, the present invention has been developed by placing the ball in both pocket holes three times.
The purpose is to reliably prevent the ball from slipping by providing point support and setting the three contact points at predetermined relative positions.

(Means for Solving the Problems) In order to achieve the above object, the means taken by the present invention are as shown in FIG.
A plurality of pocket holes (3
4) A ball (36) is interposed between the rotary member (8) and the fixed member (22) so that the rotary member (8) revolves around the stationary member (22) without rotating.

And the two opposing pocket holes (34).

The distance between the bottom surfaces of the ball (35) is larger than the diameter of the ball (36). Furthermore, each pocket hole (34
), (35) circumferential side <34b).

(35b) is a tapered surface that spreads outward, and is a circumferential surface (35b) on the rotating member (8) side and the identification member (22) side.
5b) and (34b) are formed to have different taper angles. In addition, the pocket hole with the small taper angle (34
) contact point P2 between the circumferential side surface of <346) and the ball (36)
The vertical lengths taken from the axis of rotation M+ of the ball (36) and the center line M2 of the small taper angle pocket l to the center line M2 of the hole (34) are respectively Ua+ and (ja2), while the pocket hole with the large taper angle (35) Circumferential surface <35b
) and the ball (36) from the contact point P3 to the ball (36)
) and a pocket hole with a large taper angle (
The length of the perpendicular line drawn to the center mm3 of 35) is l respectively.
If lc+ and If (iz, the length of each perpendicular line fla
The configuration is such that t, 9az*UO+ and 9c2 have the following relationship: ja 2 /9a + =-9,02/cross C1.

(Function) With the above configuration, in the present invention, the pocket holes (
34) and (35), the ball (36) is inserted into, for example, the bottom surface (34a) and peripheral side surface (34b) of the pocket hole (34) on the fixed member side, and the pocket hole (35) on the rotating member side.
) with the circumferential surface (35b) P + * P z
+ P s.

The ball (36) is supported at three contact points P+ to P3 and rolls in both pocket holes (34) and (35) to prevent rotation of the rotating member (8), and the rotating portion U( 8) only revolves around the fixed member (22).

Moreover, since the contact points P1 to P3 of the ball (36) are set in a certain relationship with respect to the rotation axis M+ of the ball (36>), the ball (36) has both pocket holes (34), (35) It is possible to transfer without slipping in the interior, and wear and seizure caused by this sagging can be reliably prevented, and durability can be improved.

Also, the top of the ball (36) and the pocket hole (35)
Since there is 121ts between the bottom surface (35a) of
The rotating member (8) 1, for example, is not subjected to the thrust force of a revolving scroll in a scroll fluid device, and the load can be reduced, so that a longer life can be achieved.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

As shown in FIG. 4, (1) is a scroll fluid device;
Used in compressors in refrigerators to compress refrigerant gas to high pressure and discharge it.

The scroll fluid device (1) consists of a scroll mechanism (3) and a drive mechanism (4) housed in a dense case (2), and a suction pipe ( 5) but
A discharge pipe (6) is connected to the upper part. The scroll mechanism (3) is composed of a fixed scroll (7) and a revolving scroll (8), and the drive mechanism (4) is composed of an electric motor (9) and a crankshaft (10) which is a rotating shaft. There is.

The fixed scroll (7) and the revolving scroll (8) wrap (13) and (1) in front of the end plates (11) and (12).
4) are arranged in a spiral shape, both scrolls (7),
(8) is the mirror plate (11).

(12) are arranged vertically in parallel with their front surfaces facing each other, and both wraps (13) and (14) are engaged with each other. The fixed scroll (7) has a flange (11a) on the outer peripheral edge of the end plate (11).
) are connected in series, and the case (2
), and the inside of the case (2) is a fixed scroll (7
) It is divided into an upper high pressure chamber (2a) and a lower low pressure chamber (2b). Furthermore, a scroll shaft (12a) is provided protruding from the center of the back surface of the end plate (12) of the revolving scroll (8), while the crankshaft (10) has a concave scroll bearing at the upper end of the crank main shaft (10a). Hole (10b
) are connected to each other. Furthermore, the case (2) has an opening (15a).
A support frame (15) is fixedly installed, and the crank shaft (10a) is fitted into the center of the support frame (15) via a liner (16).
0) is supported. An electric motor (9) is attached to the crank main shaft (10a), and the scroll bearing hole (10b) has its bearing center (OI) aligned with the crank main shaft (10a).
The scroll shaft (12a) of the revolving scroll (8) is fitted into the scroll bearing hole (10b) via a liner (17).

Then, due to the eccentricity of the scroll bearing hole (10b), the orbiting scroll <8) revolves with respect to the fixed scroll (7), and the center (0) of this scroll bearing hole (10b)
+) (the center of the scroll shaft (12a)) is the movable fulcrum of the revolving scroll (8), and the axis (02) of the crank main shaft (10a) is the center of revolution.

Both wraps (13) and (14) of the fixed scroll (7) and the revolving scroll (8) are in multi-point contact on the sides (18)
Each wrap (13), (1
4) is in contact with the other end plate (12>, (11)), and a sealed chamber (19) is formed between the contact (18). A suction space (
20) is formed, and a discharge port (21) is formed in the center of the end plate (11) of the fixed scroll (7), and refrigerant gas is supplied from the suction space (20) to the sealed chamber (19). On the other hand, compressed refrigerant gas flows from the discharge port (21) to the high pressure chamber (
2a).

Further, on the back side of the end plate (12) of the revolving scroll (8), a donut-shaped fixed frame (22) fixed to the case (2) is formed parallel to the end plate (12). A through hole (22a) is bored in the outer peripheral part of the fixed frame (22), and the crankshaft (10>) is formed in the center part.
A journal (100) is fitted through the liner (23), and the journal (IOC) is rotatably supported. Furthermore, the above-mentioned revolving scroll (8) which is a rotating member
The mirror plate (12) and the fixed frame (2) which is the fixed member
2), there is a ball joint (31
) and a ring-shaped thrust bearing (41), the ball joint (31) prevents the revolution scroll (8) from rotating so that the revolution scroll (8)
7) is configured to revolve around the Earth without rotating.

In addition, (24) in Fig. 4 is a lubricating oil reservoir,
The lubricating oil is supplied to the liner (17) from an oil supply passage (10d) formed in the crankshaft (10a).

(23). Further, (25) is a balancer chamber formed between the support frame (15) and the fixed frame (22), in which refrigerant gas passes through the opening (15a) due to the rotation of the balancer (26) connected to the journal (10c). The mist-like lubricating oil inside is applied to the side wall, and the passage (
27) to return to the oil sump (24).

Next, the ball joint mechanism, which is a feature of the present invention, will be explained.

The ball joint (31) is a ball holding member (32), as shown enlarged in FIGS. 1 to 3.

(33) with multiple circular pocket holes (34).

(35) is formed, and a plurality of balls 36) are formed.
It is constructed by intervening. Then, the ball joint (
31) mainly receives the rotation prevention force of the revolving scroll (8), and the thrust bearing (41) mainly receives the thrust force of the revolving scroll (8). Both of the holding members (32) and <33) are formed into a substantially donut plate shape, and one of the holding members (32) is attached to the upper surface of the fixed frame (22) at the axis (0) of the crank main shaft (10a).
2), and the other holding member (33) is attached to the scroll shaft (
It is fixed concentrically with the center (01) of 12a).

Each of the above-mentioned holes]-holes (34) and (35) are connected to both holding members (
32) and (33) are arranged in an annular manner, and holding members (32) on the fixed side and the rotating side.

The pocket holes (34>, (35) in (33) face each other to form a pair. A steel ball (36) is placed between the pocket holes (34), (35) facing each other.
) is provided. Furthermore, each of the above pocket holes (34)
, (35) are formed into a circular shape in plan view with a diameter larger than the diameter R of the ball (36), and are tapered peripheral surfaces (34b) that continuously widen outward from the bottom surfaces (34a) and (35a).
), (35b) are formed.

Furthermore, the bottom surface (34) of the fixed side pocket hole (34)
The distance between a) and the bottom surface (35a) of the rotation side pocket hole (35) is set to be larger than the diameter R of the ball (3G). The ball (36) has its bottom point and lower side surface in contact with the bottom surface (34a) and circumferential side surface (34b) of the stationary side pocket hole (34) (P+), (Pz), and its upper side surface in contact with the rotating side pocket hole (34). (Ps) is supported at three points in contact with the circumferential side surface (35b) of (35), and there is a small gap between the apex of the ball (36) and the bottom surface (35a) of the rotation side pocket hole (35). The ball (36) is held between the contact points P+, Pz, and Pz so that both pocket holes <3
4), (35) are provided for transfer.

On the other hand, the peripheral side surface (
The taper angle α1 of 34b) is the rotating side pocket hole (35〉
The taper angle α2 of the circumferential side surface (35b) is set smaller (α1<α2) to prevent the ball (36) from floating.

In other words, as shown in FIGS. 5 and 6, the peripheral surfaces (
34b>, (35b) taper angle α1. When α2 is made equal, both sides (34b) and (3
The restraining forces rb, , rb2 received from
35b), it will slide up and down along (
This slippage (floating phenomenon of the ball (36)) deteriorates the durability of the ball (36).

In addition, as shown in FIGS. 7 and 8, the above-mentioned both sides (
If the taper angles α1 and α2 of the balls (34b) and (35b) were simply made different, the rotational movement of the ball (,3'6) accompanying the revolution of the revolving scroll (8) would
), so if this centrifugal force fc is larger than the restraining force fb+, rb2 of the ball (36), the ball (36) will float due to this centrifugal force fc,
Taper angle α1. As in the case where α2 is equal, durability deteriorates due to slippage.

Therefore, in the present invention, the fixed side pocket hole (34)
and the peripheral side surface (34b) of the rotating side pocket hole (35).
) and (35b), the taper angles α1°α2 are set so as to satisfy the following equation.

fr(tan αz −tan a+ )−1llb−
rb-ω'-tan C! l>O...■f
r: Restrictive force of the ball (36) ft)+, fbz Amazing radial force mb: Mass of the ball (36) rb: Radius of revolution of the ball (36) ω: Angular velocity of the ball (36) This formula 0 is satisfied This allows the ball (36) to move within both pocket holes (34) and (35) without floating. In other words, the force fb+ that the ball (36) receives from the circumferential side (34b >, (35b),
The downward pressing force ft of fbz is set to be larger than the force lifting the ball (36) due to the centrifugal force fc.

Furthermore, the circumferential surfaces (34b) and (35b) of the stationary side pocket hole (34>) and the rotating side pocket hole (35) are set so as to satisfy the following equation, as shown in FIG.

Cross aZ/cross a + -11C2/Rc I... ■This cross a1. Cross a2. jc++ QC2 is Pz: The peripheral side surface (34) of the ball (36) and the fixed side pocket hole (34).
b) Contact point P3 = Contact point Ml between the ball (36) and the circumferential surface (35b) of the rotating side pocket hole (35): Rotation axis M2 of the ball (36): Center of the stationary side pocket hole (34) If the line M3 is the center line of the two-turn side pocket hole (35), then the length of the perpendicular line drawn from Ial:Pz to Ml is Qa2:P
Length of perpendicular line drawn from z to M2 NO+: from Pz to Ml
g grated! This is the quality of the perpendicular line drawn from the line length 9C22P3 to M3.

Therefore, the above-mentioned both side surfaces (34b) and (35b) are the above-mentioned 0
The reason for setting the formula to satisfy will be explained.

First, as shown in Fig. 9, the fixed side socket 1-hole (34
) In the rolling motion of the ball (36) as seen from
If the intersection of the straight line M4 passing through + and the center line M2 of the pocket hole (34) is Qa, then this intersection Oa and the ball (36)
A straight line M1 passing through the center Ob becomes the rotation axis of the ball (36).

When the ball (36) is transferred, this rotating shaft 11Q M + draws a conical trajectory centered on the intersection Qa, as shown in FIG. On the other hand, in the rolling motion of the ball (36) seen from the rotation side pocket hole (35), the ball ('36) only moves on the circumferential side (35b).
) are in contact with each other (see P3), so the rotation axis MI of the ball (36) coincides with the stationary side pocket hole (34).

Therefore, the contact point P2 of the ball (36) between the stationary side pocket hole (34) and the rotating side pocket hole (35) J3. P3
If the ratio of the length of one revolution and the speed of the ball is equal, then the ball (36)
are each pocket hole (34).

(35) will be transferred without slipping.

Therefore, ja2 and 1lcz are selected as parameters related to the length of each contact point P2 and P3, and 1a+ and ff1C+ are selected as parameters related to speed, so that the above equation 0 is satisfied.

On the other hand, the above-mentioned thrust bearing (41) is connected to the ball joint (31).
), and absorbs most of the thrust force of the revolving scroll (8). In other words, the restraining force fb2 that the ball (36) in the ball joint (31) receives from the circumferential surface (35b) of the rotation side pocket hole (35) is, if the centrifugal force "C" is ignored, fbz-fr/cosα2... ■
The thrust force ft of this constraint fbz is f
t -fr -tan a 2-...■. This ball joint (31) stops the thrust force of the revolving scroll (8) except for the thrust force rt.

Next, the operation of this scroll fluid device (1) will be explained.

First, refrigerant gas flows into the case (2) from the suction pipe (5), passes through the air gap of the electric motor (9) in the low pressure chamber (2b), and enters the opening (15a) of the support frame (15).
, the balancer chamber (25), and the through hole (22a) of the fixed frame (22) in order from the suction space (20) of the fixed scroll (7) to the closed chamber (19).

On the other hand, the revolving scroll (8) rotates eccentrically due to the rotation of the crankshaft (10), and the ball joint (31)
As a result, the closed chamber (19) revolves around the fixed scroll (7) without rotating, and the closed chamber (19) is surrounded by both wraps (13) and (14).
) are sequentially formed and contract. And a closed room (19
) The refrigerant gas introduced into the fixed scroll (
7) is discharged from the discharge port (21) into the pressure chamber (2a') and led out of the case (2) via the discharge pipe (6).

During this compression operation, the balls (36) in the ball joint (31) are inserted into pocket holes (3) on both the stationary side and the rotating side.
4) and (35) to prevent the revolution scroll (8) from rotating. And the above-mentioned revolving scroll (8)
is subjected to a downward thrust force by the high-pressure refrigerant gas in the closed chamber (19), and this thrust force is mainly stopped by the thrust bearing (41). That is, the balls (36) in the ball joint (31) have pocket holes (34) on the fixed side and the rotating side.

Since the distance between the bottom surfaces (34a > and (35a) of (35)) is larger than the diameter R of the ball (36), it will be supported at the bottom point and three contact points P1 to P3 on the lower side and upper side. Circumferential side (35b) of rotating side pocket hole (35)
Of the restraining force fb2 received from the vertical thrust force [
As shown in equation 0, t is small, and most of the forces received by the ball (36) and the holding members (32) and (33) serve as rotation-preventing force. The thrust force of the revolving scroll (8), excluding the thrust force rt received by the ball joint (31), is stopped by a thrust bearing (41).

Furthermore, pocket holes (34) on the stationary side and the rotating side (
Since the circumferential side (34b >, (35b) of 35) satisfies the above formula (■), the ball (36) is
>, (35b) will be transferred without slipping.

Therefore, the ball joint (31) has a revolving scroll (8).
Since the thrust force does not act as it is, the ball (36
) and the holding members (32), (33) can have a long life. In addition, the peripheral surfaces (34b) and (3
5b) taper angle α1. Since α2 satisfies the above formula 0, the ball (36) does not float, and slippage due to this floating does not occur, and deterioration of the ball (36) can be prevented.

Furthermore, since the three contact points P1 to P3 of the ball (36) satisfy the above condition (2), the slip rate S in the transfer direction can be reduced. Note that this slip rate S is expressed by the following equation.

5-1u -ν l/v...
■U: Baud/I of contact points P2 and P3, moving speed on the (36) side V: Contact point P 21 P s no pocket hole (34).

(35) Side movement speed Since this slip rate S is small, it is possible to prevent wear, seizure, heat generation, etc. due to slip, and together with the above-mentioned reduction in load, durability can be significantly improved.

Although the ball joint (31) in this embodiment was provided between the revolving scroll (8) and the fixed frame (22), it may also be provided between the revolving scroll (8) and the fixed scroll (7). It goes without saying that the ball joint mechanism of the present invention is not limited to scroll fluid devices, but can be applied to various types of compressors.

(Effect of R Light) As described above, according to the ball joint mechanism of the present invention, the ball is supported at three points, a gap is created above the ball, and the three support points are kept in a predetermined relationship. Because of this setting, it is possible to reliably prevent the above-mentioned ball slipping phenomenon and allow the ball to perform only its original rolling motion, thereby preventing wear and seizure caused by such slipping and improving durability. be able to. Furthermore, since the shapes of the opposing pocket holes can be made different, the degree of freedom in design is expanded. In addition, since it is possible to reduce the load such as thrust force, it is possible to prevent the above-mentioned slipping phenomenon and further improve durability and extend the lifespan, so it is suitable for compressors with large thrust force. can also be fully applied.

[Brief explanation of the drawing]

Figures 1 to 10 show an embodiment of the present invention, with Figure 1 being an enlarged sectional view showing the main parts of a ball joint, and Figure 2 being an enlarged sectional view of the same showing the taper angle of the circumferential side of a pocket hole. figure,
FIG. 3 is a front view of the ball joint. FIG. 4 is a longitudinal sectional view of a scroll fluid device using a ball joint. Fifth
6 and 6 are enlarged cross-sectional views of the main parts of a ball joint showing the floating phenomenon of balls when the taper angle of the circumferential side of the pocket hole is the same, and FIGS. It is the same enlarged sectional view showing a floating phenomenon. FIG. 9 is an enlarged cross-sectional view of the main part of the ball joint showing the axis of rotation of the ball, and FIG. 10 is a diagram illustrating the locus of rotation of the axis of rotation. FIG. 11 and FIG. 12 show a conventional example, and are sectional views showing essential parts of a ball joint, respectively. (1)...Scroll fluid device, (7)...Fixed scroll, (8)...Revolving scroll, (10)...
・Crankshaft, (19)...Tight r#1 chamber, (22)・
... Fixed frame, (31) ... Ball joint, (32
). (33) Ball holding member, (34), (35)
...Pocket hole, (34a), (35a>...bottom, (34b), (35b)...peripheral side, (36
)...Ball, (41)...Thrust bearing, (P+
), (P2), (P3)...Contact points. Patent applicant Daikin Industries, Ltd. ]-1!
Oki, -1- Agent 1)
Hiroshi, 1-Figure 2 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] (1) The rotating member (8) is provided close to and facing the fixed member (22), and the rotating member (8) and the fixed member (22)
2) have multiple circular pocket holes (
34) and (35) are formed facing each other, and a ball (36) is formed between the pocket holes (34) and (35) facing each other.
is interposed between the rotating member (8) and the fixed member (2).
2) In a ball joint mechanism configured to revolve around the ball without rotating, the distance between the bottom surfaces of the opposing pocket holes (34) and (35) is formed to be larger than the diameter of the ball (36); The peripheral side surface (34) of each pocket hole (34), (35) above
b) and (35b) are tapered surfaces that widen outward, and the circumferential surfaces (35b) and (34b) are formed to have different taper angles on the rotating member (8) side and the fixed member (22) side. On the other hand, the pocket hole (34) with a small taper angle
Contact point P_2 between the circumferential side surface (34b) and the ball (36)
The lengths of perpendicular lines drawn from the axis of rotation M_1 of the ball (36) to the center line M_2 of the pocket hole (34) with a small taper angle are respectively la_1 and la_2, and the circumference of the pocket hole (35) with a large taper angle is defined as la_1 and la_2, respectively. Side (35b)
and the ball (36) from the contact point P_3 to the rotation axis M_1 of the ball (36) and the pocket hole (3) with a large taper angle.
The length of the perpendicular line drawn to the center line M_3 of 5) is l.
When c_1 and lc_2, the length of each perpendicular line la_1
, la_2, lc_1 and lc_2 are set to have the following relationship: la_2/la_1=lc_2/lc_1,
Ball joint mechanism.