JPH0138334Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a foil bearing, which is a type of dynamic pressure gas bearing.

[Prior art] A foil bearing is a device in which a rotating shaft is supported by a bearing housing via a foil. During high-speed rotation, the rotating shaft is kept in a floating state by the dynamic pressure generated between the foil and the rotating shaft. can be supported. Therefore, for example, a suitable non-contact hydrodynamic bearing can be provided for a high-speed rotating shaft such as an expansion turbine.

As shown in FIG. 6, one type of oil bearing is of the type in which a rotating shaft 1 is supported by a bearing housing 4 via a puffed oil 2 and an underfill 3. That is, in this product, first, a sheet of hot puff oil 2 that almost completely surrounds the rotating shaft 1 is placed in a housing 4, and this is elastically supported by a plurality of sheets of under-duff oil 3 that stand up from the housing 4. is supported by the housing 4.
In this type of foil bearing, the rotating shaft 1
When rotating at high speed, the rotating shaft 1 is inserted into a wedge-shaped cavity formed near the position where the underduff oil 3 is in elastic contact with the rotary shaft 1.
The gas drawn in as the surface of
It can be supported in a floating state above.

By the way, in this type of bearing, as shown in FIG. 6, each under-puff oil 3 is fixed by fitting a key 5 provided at one end into a key groove 6 provided in the axial direction on the inner surface of the housing 4, and fixing the under-puff oil 3 at one end thereof. Similarly, it has conventionally been customary for the housing 4 to be fixed by fitting a key 7 provided in a part thereof into a key groove 8 provided in the axial direction on the inner periphery of the housing 4.

[Problem that the invention aims to solve] However, with such fixing means,
The puffed oil 2 may shift in the axial direction within the housing 4, resulting in a disadvantage that the performance of the oil bearing is likely to deteriorate.

Therefore, as shown in FIG. 7, a projection 9 is further attached to a part of the longitudinal direction of the key 7 provided on the hot puff oil 2, and this is inserted into a shaft recess (not shown) provided corresponding to the key groove 8. Efforts have also been made to fit them together and prevent them from shifting in the axial direction. but,
If this is the case, one side of the hot puff oil 2, especially the opposite side (in the fixed state in Fig. 6, side A in the figure) may shift in the axial direction, causing the hot puff oil 2 to shift.
It is impossible to prevent the housing 4 from tilting in the axial direction and causing an unbalanced deformation state.
In other words, when such an imbalance occurs, the elastic force applied to the rotating shaft 1 changes depending on the position of the hot puff oil 2, resulting in an unstable support state for the rotating shaft 1, or in particular, one end of the hot puff oil 2 in the axial direction may rotate. This will cause troubles such as wrapping around the shaft 1 and interfering with it.

The present invention was developed with a focus on these circumstances, and has a simple structure that effectively prevents the axial displacement of the hot puff oil, and at the same time does not cause the unbalanced deformation described above. The purpose is to provide a foil bearing structure.

[Means for Solving the Problems] In order to achieve the above objects, the present invention employs the following configuration.

That is, the foil bearing according to the present invention is a foil bearing in which a rotating shaft is supported by a bearing housing via hot puffed oil and underdough oil that supports the hot puffed oil. The piece is cut and raised as one piece, step portions are provided at both ends in the axial direction of the bearing housing, and the edges of the cut and raised pieces are brought into contact with the end surfaces of the step portions so that the hot puff oil is latched to the housing. It is characterized by

[Function] With such a configuration, the cut and raised pieces that are in contact with the end faces of the stepped portions provided at both axial ends of the housing restrict the axial movement of the hot puff oil. , it is possible to effectively prevent the axial movement of hot puff oil. That is, when the position of the puffed oil is about to shift, the edge of the cut-and-raised piece is pressed against the step end face, and a load in the width direction of the cut-and-raised piece is applied. Therefore, even if it is a cut and raised piece cut and raised from thin hot puff oil, it exhibits relatively high rigidity, and can effectively prevent displacement and deformation of this hot puff oil.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 3.

In this oil bearing, as described above, the rotating shaft 1 is supported by the bearing housing 4 via the hot puff oil 2 and the underdough oil 3, and the hot puff oil 2 is directly connected to the housing 4 by the following engagement groove structure. I'm trying to make it hang. First, as shown in FIG. 2, the hot puff oil 2 is provided with a plurality of outwardly projecting protrusions 13 at equal intervals on both axial ends thereof. That is, the cut and raised pieces 13 are tongue-like pieces formed by intermittently cutting and raising both axial ends of the hot puff oil 2 radially. On the other hand, as shown in FIG. 3, the housing 4 is provided at both ends thereof with stepped portions 11 having a larger diameter on the open end surface side over the entire circumference. Thus, the hot puff oil 2 is moved in the circumferential direction of the bearing housing 4 by fitting the key 7 provided at one end of the bearing housing 4 into the key groove 8 provided in the axial direction on the inner surface of the housing 4, as in the previous case. In addition, the edge 13a of each of the cut and raised pieces 13 is brought into contact with the end surface 11a of the stepped portion 11 in a substantially orthogonal state, so that the puffed oil 2 can be held immovably in the axial direction. It is hung like this.

If the structure is like this, the housing 4
The cut-and-raised pieces 13 in contact with the end surfaces 11a of the stepped portions 11 provided at both ends of the piston 13 uniformly restrict the axial movement of the hot puff oil 2 over its entire circumferential position. Directional movement can be almost completely prevented.

Next, another embodiment will be described with reference to FIGS. 4 and 5.

In this embodiment, cut and raised pieces 14 shaped into a coil shaft shape are provided at both axial ends of the upper foil 2. This cut and raised piece 14 is obtained by cutting and raising a member into a long length and winding it. Steps 11 are provided at both ends of the housing 2, and the edges 14a of the cut and raised pieces 14 are brought into contact with the end surfaces 11a of the steps 11, so that the hot puff oil 2 is latched onto the housing 4. . Furthermore, a recess 15 is provided on the inner circumferential surface of the stepped portion 11 so that each of the cut and raised pieces 14 can be brought into close contact with the spring back force.

With this configuration, the same effects as in the embodiment described above can be obtained, but in addition, this configuration allows the movement of hot puff oil 2 in the circumferential direction by the engagement of each cut and raised piece 14 with each recess 15. Since the key 7 can be restrained well, it becomes possible to easily replace the key 7 with this convex portion.

Note that the number and shape of the cut and raised pieces provided on the hot puff oil can be variously modified without departing from the spirit of the present invention.

[Effects of the invention] Since the present invention has the above-described configuration, it is possible to provide a oil bearing that can effectively prevent axial displacement of hot puffed oil and unbalanced deformation from occurring. It is something. In addition, in the present invention, misalignment and undue deformation of the hot puff oil are avoided by using cut pieces cut and raised from the hot puff oil, so the manufacturing process is much easier than when special protrusions are fixed to the hot puff oil. It will be easy. Moreover, since the hot puff oil is positioned by bringing the end edge of the raised piece into contact with the end face of the stepped portion of the housing, if the position of the hot puff oil tries to shift, the cut piece has a thickness. The load acts not in the direction but in the width direction. Therefore, even if the piece is cut and raised from thin hot puff oil, it exhibits relatively high rigidity, and can effectively prevent displacement and deformation of the hot puff oil.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a foil bearing showing an embodiment of the present invention, FIG. 2 is a perspective view showing the puffed oil, and FIG. 3 is a perspective view showing the end structure of the housing. 4 and 5 show other embodiments of the present invention, FIG. 4 being a perspective view of puff oil, and FIG. 5 being a perspective view showing the end structure of the housing. FIG. 6 is a cross-sectional view showing the internal structure of a foil bearing to which the present invention is applied.
FIG. 7 is a perspective view of hot puff oil for explaining a conventional example. 1... Rotating shaft, 2... Hot puff oil, 3...
Under-duff oil, 4...Bearing housing, 11...
...Stepped portion, 11a... End face, 13... Cut and raised piece, 13
a...edge, 14...cut and raised piece, 14a...edge.

Claims (1)

[Scope of utility model registration request] In a oil bearing in which a rotating shaft is supported by a bearing housing via hot puff oil and underdough oil that supports it, cut-and-raise pieces projecting outward are integrally cut and raised at both axial ends of the hot puff oil, and the bearing What is claimed is: 1. A foil bearing, characterized in that a stepped portion is provided at both axial ends of the housing, and the end edges of the cut and raised pieces are brought into contact with the end faces of the stepped portions, so that the puffed oil is latched to the housing.