JPH0720072U - Spindle motor cooling device - Google Patents

Abstract

(57) [Summary] [Structure] A stator 2 provided inside a hollow cylindrical frame 1, a spindle 3 provided inside the stator 2, and a rotor 4 provided at an intermediate portion of the spindle 3. The thrust receiving disk 13 provided on the tip end side of the spindle, the thrust bearings 5 and 5 ′ provided on the inner side of the frame so as to sandwich the thrust receiving disk from the axial direction with a gap, and both sides of the stator 2. , And two radial bearings 6 and 6'provided inside the frame 1, a feed pipe 72 extending in the axial direction inside the frame 1, and a radial pipe of one communicating with the feed pipe 72. An annular first relay groove 76 provided on the outer periphery of 6,
A plurality of cooling grooves 73 provided around the thrust bearing 5 and a plurality of cooling pipes 7 communicating with the cooling grooves 73 and the first relay groove 76.
8, an annular second relay groove 77 provided on the outer periphery of the radial bearing 6 ′, a plurality of cooling pipes 79 communicating with the second relay groove 77 and the cooling groove 73, and the second relay groove 77. And a delivery pipe 74 communicating with each other. [Effect] The cooling effect of the spindle motor is significantly enhanced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cooling device for a spindle motor having radial and thrust static pressure bearings.

[0002]

[Prior art]

 Conventionally, spindle motors that perform tooling at the tip of the spindle to perform small-diameter hole drilling, dicing, and slicing require high-speed rotation. It is equipped with bearings. In order to maintain the processing accuracy, for example, as shown in FIGS. 3 and 4 (a) and (b), the stator 2 is provided inside the hollow cylindrical frame 1, and the inside of the stator 2 is empty. A spindle 3 is provided so as to be rotatable through a gap, and a rotor 4 is fixed to an intermediate portion of the spindle 3 facing the stator 2. A thrust receiving disk 31 is provided on the tip side of the spindle 3 for fixing the tool T, and both sides of the thrust receiving disk 31 are sandwiched from the axial direction with a gap, and a hydrostatic bearing is provided inside the frame 1. It is provided with thrust bearings 5 and 5 ', which receive axial thrust applied to the spindle 3. Further, on both sides of the stator 2 and on the inside of the frame 1, radial bearings 6 and 6 ′, which are static pressure bearings, are provided to support the spindle 3. Since the thrust bearings 5 and 5 ', the radial bearings 6 and 6', and the stator 2 generate heat during rotation, a cooling device 7 is provided to cool them. The cooling device 7 includes a supply port 71 that opens to the outer periphery of the bracket 11 on the anti-load side to supply a cooling liquid, an inlet pipe 72 that extends axially into the frame 1 and communicates with the supply port 71, and a frame. 1. A cooling groove 73 which is formed in a substantially annular shape so as to surround the thrust bearings 5 and 5'provided at the load side front end portion of 1 and communicates with the inlet pipe 72, and an inlet pipe 72 which communicates with the cooling groove 73. And a delivery pipe 74 that is provided in parallel with the cooling liquid and discharges the cooling liquid to the outside through a discharge port 75 provided in the bracket 11. Therefore, the cooling device 7 passes the cooling liquid from the supply port 71 through the inlet pipe 72, the cooling groove 73, and the outlet pipe 72 to generate heat from the stator 2, the thrust bearings 5 and 5 ', and the radial bearings 6 and 6'. It is adapted to be absorbed by the cooling liquid and discharged to the outside through the discharge port 75.

[0003]

[Problems to be solved by the device]

 However, in the conventional technology, the stator, the thrust bearing, and the radial bearing, which are the heat generating portions, are in contact with only one cooling groove and two cooling liquid pipelines of the inlet pipe and the outlet pipe, so that the cooling is performed. There was a drawback that the effect was low, and therefore the temperature rise became large, the spindle thermally expanded, and the processing accuracy deteriorated. It is an object of the present invention to increase the contact area between the cooling liquid pipe of the cooling device and the heat generating portion to enhance the cooling effect of the spindle motor.

[0004]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention provides a stator provided inside a hollow cylindrical frame, a spindle provided inside the stator, a rotor provided at an intermediate portion of the spindle, and the spindle. A thrust receiving disk provided on the tip side of the frame, a thrust bearing provided on the inner side of the frame so as to sandwich the thrust receiving disk from the axial direction with a gap, and on both sides of the stator and on the frame. In a cooling device for a spindle motor, which comprises two radial bearings provided on the inside of a frame, a feed pipe extending in the axial direction inside the frame, and a radial bearing communicating with the feed pipe and the one radial bearing. An annular first relay groove provided on the outer periphery of the bearing, a plurality of cooling grooves provided around the thrust bearing, a plurality of cooling pipes communicating with the cooling groove and the first relay groove, Radius An annular second relay groove provided on the outer periphery of the bearing, a plurality of cooling pipes communicating with the second relay groove and the cooling groove, and a delivery pipe communicating with the second relay groove are provided. It is a thing.

[0005]

[Action]

 When the cooling liquid is sent from the supply port to the relay groove via the inlet pipe by the above means, the outer periphery of the radial bearing is cooled, and then the cooling liquid is passed from the relay groove to the plurality of cooling pipes passing through the frame. Coolant passes through each cooling groove to cool the periphery of the thrust bearing. Further, the outer circumferences of the thrust bearing, the stator and the radial bearing are cooled from the other end of each cooling groove via a cooling pipe, and are fed into the relay groove, and the radial bearing is cooled and discharged through the feeding pipe. Exhausted from the mouth.

[0006]

【Example】

 The present invention will be described with reference to the embodiments shown in the drawings. 1 is a side sectional view showing an embodiment of the present invention, FIG. 2 (a) is a front sectional view taken along the line AA, and FIG. 2 (b) is a front sectional view taken along the line BB. FIG. 2C is a front sectional view taken along the line CC, and FIG. 2D is a front sectional view taken along the line DD. In the figure, a stator 2 provided inside a hollow cylindrical frame 1, a spindle 3 provided inside the stator 2, a rotor 4 provided at an intermediate portion of the spindle 3, and a spindle 3 fixed to the spindle 3. Thrust receiving disk 31 provided on the tool T side, thrust bearings 5 and 5'provided inside the frame 1, and radial bearings 6 and 6'provided on both sides of the stator 2 and inside the frame 1. The cooling liquid is sent to the cooling groove 73 surrounding the thrust bearings 5 and 5'through the inlet pipe 72 extending in the axial direction from the supply port 71 to the inside of the frame 1 and cooled via the delivery pipe 74. The structure provided with the cooling device 7 for discharging the liquid from the discharge port 75 is almost the same as the structure described in the conventional example. The difference from the conventional one is that the cooling device 7 is configured as follows. That is, an annular first relay groove 76 and a second relay groove 77 are provided on the surfaces of the radial bearings 6 and 6 ′ that contact the frame 1, and the feed pipe 72 is connected to the first relay groove 76. The delivery pipe 74 is communicated with the second relay groove 77. The cooling groove 73 surrounding the thrust bearing 5, 5 ′ is divided into four in the circumferential direction, one end of each cooling groove 73 is radially extended, and the cooling groove 73 is extended through a cooling pipe 78 extending in the axial direction. One of the relay grooves 76 is communicated with the other end of each cooling groove 73, and the other end of the cooling groove 73 is radially extended in the same manner, and is communicated with the second relay groove 77 through the extension building cooling pipe 79 in the axial direction. When the cooling liquid is fed from the supply port 71 into the first relay groove 76 through the feed pipe 72, first, the outer periphery of the radial bearing 6 is cooled, as shown in FIG. 2B. Next, the cooling liquid passes from the first relay groove 76 to each cooling groove 73 through the four cooling pipes 78 that pass through the frame 1 facing the outer circumference of the thrust receiving disk 31, and the cooling liquid flows to the cooling groove 73 as shown in FIG. As shown, the surroundings of the thrust bearings 5, 5'are cooled. The cooling liquid further cools the outer circumferences of the thrust bearings 5 and 5 ′, the stator 2 and the radial bearing 6 via the cooling pipe 79 from the other end of each cooling groove 73, and is fed into the second relay groove 77. , The radial bearing 6 ′ is cooled and discharged from the discharge port 75 via the delivery pipe 72. . In the above embodiment, the cooling groove 4 is divided into four in the circumferential direction, but the number of divisions is not limited to this.

[0007]

[Effect of device]

 As described above, according to the present invention, since a plurality of cooling pipes are brought into contact with the thrust bearing, the stator, and the radial bearing to cool them, one cooling groove and two cooling pipe lines are provided as in the conventional case. The cooling area of the cooling device is several times larger than that of the cooling by, and the cooling effect of the spindle motor is significantly enhanced.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention.

2A is a front sectional view taken along the line AA in FIG.
1B is a front sectional view taken along the line BB of FIG. 1, FIG. 7C is a front sectional view taken along the line CC of FIG. 1, and FIG.
FIG.

FIG. 3 is a side sectional view showing a conventional example.

4A is a front sectional view taken along the line A′-A ′ of FIG. 3, and FIG. 4B is a front sectional view taken along the line B′-B ′ of FIG.

[Explanation of symbols]

1 frame, 2 stators, 3 spindles, 31 thrust receiving disks, 4 rotors, 5 and 5'thrust bearings,
6,6 'radial bearing, 7 cooling device, 71 supply port, 7
2 inlet pipe, 73 cooling groove, 74 outlet pipe, 75 discharge port, 76 first relay groove, 77 second relay groove, 78, 7
9 Cooling pipe

Claims (1)

[Scope of utility model registration request] 1. A stator provided inside a hollow cylindrical frame, a spindle provided inside the stator, a rotor provided at an intermediate portion of the spindle, and a tip end side of the spindle. A thrust receiving disk, a thrust bearing provided inside the frame so as to sandwich the thrust receiving disk from the axial direction through a gap, and two bearings provided on both sides of the stator and inside the frame. In a cooling device for a spindle motor including a radial bearing of the above, a feed pipe extending in the axial direction inside the frame, and an annular first pipe communicating with the feed pipe and provided on the outer circumference of the one radial bearing. One relay groove, a plurality of cooling grooves provided around the thrust bearing, a plurality of cooling pipes communicating with the cooling groove and the first relay groove, and an annular shape provided on the outer circumference of the other radial bearing. The first 2. A cooling of a spindle motor, comprising: two relay grooves; a plurality of cooling pipes that communicate with the second relay groove and the cooling groove; and a delivery pipe that communicates with the second relay groove. apparatus.