JPH0514631U - Dynamic pressure air bearing - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the air suction of the dynamic pressure air bearing from being impaired due to variations in machining accuracy, etc., and to prevent the reduction in bearing rigidity. [Structure] A plurality of herringbone grooves d, e, f, on the outer circumference
In a dynamic pressure air bearing configured by loosely fitting a sleeve 2 on a dynamic pressure shaft 1 provided with g, each of the groove ends j and k of the herringbone grooves d and g on the air suction port h and i side is a sleeve. The two end surfaces 2a and 2b are arranged outside.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dynamic pressure air bearing which constitutes a dynamic pressure air bearing type optical deflector used in information equipment, image equipment and measuring equipment.

[0002]

[Prior Art]

 The structure and operation of an example of a conventional dynamic pressure air bearing will be described with reference to FIG. Herringbone grooves da, ea, fa, ga for generating dynamic pressure having suction angles opposite to each other are provided on the outer peripheral surface of the dynamic pressure shaft 3. When the sleeve 2 rotates, dynamic pressure is generated in the gap P between the dynamic pressure shaft 3 and the sleeve 2, and this dynamic pressure causes bearing rigidity.

In this structure, the lengths of the herringbone grooves da, ea, fa and ga are all equal, and the end faces 2a and 2b of the sleeve 2 and the groove ends of the herringbone grooves da and ga on the air suction ports h and i sides are designed. It was a match.

[0004]

[Problems to be solved by the device]

 In the conventional dynamic pressure air bearing, the groove ends of the herringbone grooves da and ga on the side of the air suction ports h and i are located inside the end surface 2a or the end surface 2b of the sleeve 2 due to variations in processing accuracy. In some cases, the air intake was impaired and the required bearing rigidity could not be obtained.

[0005]

[Means for Solving the Problems]

 The present invention has been made to solve the above-mentioned problems, and will be described with reference to FIGS. 1 and 2 corresponding to the embodiments. A dynamic air bearing according to the present invention has a plurality of herringbone grooves d, e, In a dynamic pressure air bearing configured by loosely fitting a sleeve 2 on a dynamic pressure shaft 1 provided with f and g, groove ends j 1 and k of herringbone grooves d and g on the air suction port h and i sides are respectively sleeves. It is arranged so as to be outside the end faces 1 and m of No. 2.

[0006]

[Action]

 In the present invention, in the dynamic pressure air bearing, the herringbone grooves d, g on the side of the air suction ports h, i are arranged so that the groove ends j, k are located outside the end surface of the sleeve 2 in advance. Even if there is a variation in accuracy as in the past, it is possible to prevent reduction in bearing rigidity without impairing air suction.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a sectional view of a dynamic air bearing type optical deflector constructed by a dynamic pressure air bearing according to the present invention. The dynamic pressure shaft 1 is firmly fixed to the motor case 14 by shrink fitting or the like. Further, the dynamic pressure shaft 1 and the cover 4 are firmly fixed to each other via the O-ring 11, and the cover 4 and the motor case 14 are also tightly fixed to each other via the O-ring 12. When the motor portion composed of the yoke 9, coil 8, ..., Hall element 10, and magnet 13 is driven, the hollow cylindrical sleeve 2 fixed to the magnet 13 rotates and is further fixed to the sleeve 2. The rotary polygon mirror 5 fixed to the hub 6 with screws 7 rotates. At this time, a dynamic pressure is generated in a gap P between the dynamic pressure shaft 1 and the sleeve 2 which form the dynamic pressure air bearing, and the dynamic pressure causes bearing rigidity.

The structure of the dynamic pressure air bearing at this time will be described with reference to FIG. FIG. 1 is a structural diagram of an embodiment of a dynamic pressure air bearing according to the present invention, in which the dynamic pressure shaft 1 is provided with herringbone grooves d, e, f, g, of which the herringbone on the air intake side. The groove ends j and k of the grooves d and g are located 1 mm outside the end surfaces 2a and 2b of the sleeve 2, respectively. Therefore, even if an error occurs in the dimensions of the herringbone grooves d and g or the sleeve 2 due to variations in processing accuracy, air suction into the gap P due to the rotation of the sleeve 2 is not impaired, and the required bearing rigidity can be obtained. ..

[0009]

As described in detail above, according to the present invention, by making the end of the herringbone groove on the air intake port side of the dynamic pressure air bearing outside the sleeve end surface, the air intake is not impaired and the bearing rigidity is improved. Reduction can be prevented. In addition, since there is a margin in the dimension of the herringbone groove of the dynamic pressure shaft, sleeves with different dimensions should be combined within the allowable range to form dynamic pressure air bearings with different performance using the same dynamic pressure shaft. I can do it.

[Brief description of drawings]

FIG. 1 is a structural diagram of an embodiment of a dynamic pressure air bearing according to the present invention.

FIG. 2 is a sectional view of an embodiment of a dynamic pressure air bearing type optical deflector according to the present invention.

FIG. 3 is an external view of a conventional dynamic pressure air bearing.

[Explanation of symbols]

1,3 Dynamic pressure shaft 2 Sleeves 2a, 2b Sleeve 4 Cover 5 Rotating polygon mirror 6 Hub 7 Screw 8 Coil 9 Yoke 10 Hall element 11, 12 O-ring 13 Magnet 14 Motor case d, e, f, g, da, ea , Fa, ga Herringbone groove h, i Air suction port j, k Groove end P Gap

Front page continuation (72) Inventor Takeyuki Miura 110-1 Shinkushitaita, Iruma-shi, Saitama Copal Electronics Co., Ltd. Iruma Office (72) Author Hiroshi Nakayoshi 110, Shinkushita, Iruma-shi, Saitama 1 Inside the Copal Electronics Co., Ltd. Iruma Office

Claims (1)

[Scope of utility model registration request] 1. A plurality of herringbone grooves (d) on the outer circumference,
In a dynamic pressure air bearing configured by loosely fitting a sleeve (2) on a dynamic pressure shaft (1) provided with (e), (f) and (g),
Each of the herringbone grooves (d) on the side of the air suction port (h), (i), and the groove ends (j) and (k) of the (g) are outside the end faces (2a) and (2b) of the sleeve 2. A dynamic pressure air bearing characterized in that it is arranged as described above.