JPH0630322Y2 - Support structure for spindle drive motor - Google Patents

Description

[Detailed description of the device] (a). BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle drive motor support structure suitable for application to a headstock forming a work spindle in which an output shaft of the spindle drive motor is used in a lathe or the like.

(b). 2. Description of the Related Art Conventionally, in a headstock having such a structure, a main shaft drive motor and a support base for supporting the motor are provided through a pair of support flanges provided on both side surfaces of the motor over substantially the entire axial direction of the motor. Was installed.

(c). However, in such a structure, since the support flange and the support stand are in contact with each other over a wide area, heat generated by driving the motor is transferred to the support stand side through the support flange. , A thermal gradient is formed over the entire motor casing.
Then, the thermal gradient causes thermal deformation of the casing as a whole such that the casing bends with respect to the axis of the spindle, and the spindle itself also bends accordingly, which adversely affects the machining accuracy.

In order to eliminate the above-mentioned drawbacks, the present invention provides a support structure for a spindle drive motor in which a casing of the spindle drive motor is less likely to have a thermal gradient, and therefore the deflection of the spindle due to the thermal gradient is less likely to occur. It is intended.

(d). Means for Solving the Problems That is, according to the present invention, a bearing portion (7b) sandwiching a stator portion (7a) of a casing (7) of a spindle drive motor (6).
Support means (7d) are formed on both sides of the motor, and a motor support surface (5e) is formed on the support base (5) at a position corresponding to the support means, and the spindle drive motor (6) is connected to the support means (7d). ) And the motor support surface (5e).

It should be noted that the numbers in parentheses indicate the corresponding elements in the drawings for the sake of convenience, and thus the present description is not limited to the description in the drawings. The same applies to the section "(e). Action" below.

(e). Action With the above-mentioned configuration, the present invention provides a spindle drive motor (6).
Acts so as to be supported on the support base (5) only via the support means (7d) on both sides of the stator part (7a).

(f). Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing an embodiment of a support structure for a spindle drive motor according to the present invention, and FIG. 2 is a side view of FIG.

A lathe 1 which is a machine tool has a headstock 2, and the headstock 2 is mounted on a bed 3 as shown in FIG. 1 and FIG.
It is movably supported on guide rails 3a, 3a installed in the directions of arrows A, B, which are the axial directions. The headstock 2 has a support base 5, and the support base 5 is provided on its lower surface with a plurality of bearings 5a that engage with the guide rails 3a. As shown in FIG. 2, on the upper surface of the support base 5, a groove 5b which is wide open upward in the figure is formed so as to extend in a direction perpendicular to the plane of the paper, and both ends of the groove 5b in FIG. Support portions 5c and 5c are formed in the portion. As shown in FIG. 2, each support portion 5c has a substantially semicircular relief portion 5d.
Is formed, and motor support surfaces 5e are formed on both sides of the escape portion 5d in FIG. The main shaft drive motor 6 is supported on a total of four motor support surfaces 5e of each support portion 5c, and the main shaft drive motor 6 has a casing 7 that forms the outer shape of the motor 6. The casing 7 is
In the central portion of FIG. 1, a stator portion 7 formed in a cylindrical shape is formed.
a, and a stator 7c that constitutes the spindle drive motor 6 is provided inside the stator portion 7a. Bearing portions 7b, 7b are provided on both sides of the stator portion 7a in FIG.
The bearings 10 are mounted inside the bearings 7b, 7b, respectively. Bearing 7b,
7b is a work spindle 9 as an output shaft, and a bearing 1
It is provided so as to be rotatably supported by 0, and a rotor 9a is provided at a position corresponding to the stator 7c of the work spindle 9.

By the way, the bearing portions 7b, 7b on both sides of the casing 7
At the position where the axial center CT of the work spindle 9 coincides with the vertical direction in FIG.
The work main shaft 9 is provided so as to extend from both sides in the drawing of FIG. 3B, and the motor support surface 5e of each support flange 7d and the support portion 5c is provided with a heat insulating material 11 made of ceramic or the like. It is fixedly connected via fastening means such as bolts. In addition, the spindle drive motor 6 and the support base 5 are
Only the support flange 7d and the motor support surface 5e contact each other, and in other portions, a gap 12 is formed between the stator portion 7a and the groove 5b, and the bearing portion 7b and the relief portion 5 are provided.
There is a gap 13 with respect to d. Therefore, due to the gaps 12 and 13, the main shaft drive motor 6 is moved to the support portion 5
It is in a state of being supported in the air through c and 5c.

As shown in FIG. 2, the casing 7 is vertically symmetrical with respect to the axis CT of the work spindle 9, and as shown in FIG. Has been done.

Reference numeral 15 is a rotary encoder that detects the rotation of the work spindle 9.

Since the lathe 1 has the above-described configuration, when machining by the lathe 1, the workpiece is gripped via a chuck (not shown) attached to the right end of FIG.
In this state, the spindle drive motor 6 is driven, and the spindle stock 2 is appropriately moved and driven along the guide rails 3a and 3a in the directions of arrows A and B to perform machining such as machining and milling.

While machining is performed in this manner, the spindle drive motor 6 generates heat from the stator 7c and the rotor 9a, and the temperature of the casing 7 rises accordingly. But casing 7
Even if the temperature rises, since the casing 7 and the support base 5 that supports the casing 7 are supported only through the support flanges 7d at only four places provided on both sides of the bearing portion 7b, The heat in the casing 7 is transferred to the support base 5 side only through the support flanges 7d at the four places.
However, since the contact area between the support flange 7d and the support portion 5c, that is, the heat transfer area is significantly smaller than the surface area of the casing 7 of the main shaft drive motor 6, the amount of heat transfer through that portion is small. The casing 7 as a whole is maintained at a substantially uniform temperature. Moreover, the support flange 7d
Is provided at a position substantially coincident with the axial center CT of the work spindle 9 in the vertical direction in FIG. 2, and the casing 7 is formed symmetrically with respect to the axial center CT in the vertical direction in FIG. Therefore, if there is a slight temperature gradient, the support flange 7d
Even if it occurs in the directions of arrows C and D centering on the center, the deformation occurs evenly around the support flange 7d, so that the casing 7 may bend with respect to the Z axis which is the left-right direction in FIG. However, the work spindle 9 is accurately held with its axial center CT aligned with the Z axis.

(g). As described above, according to the present invention, the supporting means such as the supporting flanges 7d are formed on both sides of the bearing portions 7b, 7b sandwiching the stator portion 7a of the casing 7 of the spindle drive motor 6. Since the motor support surface 5e is formed at a position corresponding to the support means of the support base 5 and the spindle drive motor 6 is configured to be supported only through the support means and the motor support surface 5e, the spindle drive is performed. The heat generated in the motor 6 is transferred to the support base 5 only through the support means and the motor support surface 5e, and the amount of transferred heat can be greatly reduced. Therefore, it is possible to prevent as much as possible a heat gradient that causes the work spindle 9 to be bent in the casing 7, and it is possible to maintain high machining accuracy. In addition, the spindle drive motor 6 supports the bearing portion 7 that supports the workpiece spindle 9.
Since it is directly supported by the portion b, the vibration generated in the work spindle 9 is directly transmitted to and supported by the support base 5 from the bearing portion 7b,
If the supporting means is provided in the stator portion 7a, the vibration generated in the work spindle 9 will be transferred from the bearing portion 7b to the stator portion 7a.
It is possible to prevent generation of harmful vibration of the casing 7 due to the transmission to the support base 5 via the.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a support structure for a spindle drive motor according to the present invention, and FIG. 2 is a side view of FIG. 5 ... Support base 5e ... Motor support surface 6 ... Spindle drive motor 7 ... Casing 7a ... Stator part 7b ... Bearing receiving part 7d ... Support means (support flange) 9 ... Work spindle

Claims (1)

[Scope of utility model registration request] 1. A support structure for a spindle drive motor, comprising a support base and a spindle drive motor whose output shaft constitutes a work spindle, and the spindle drive motor is supported on the support base, wherein a casing of the spindle drive motor. Support means are formed on both sides of the bearing part sandwiching the stator part of, and a motor support surface is formed at a position corresponding to the support means of the support base, and the main shaft drive motor is connected to the support means and the motor support surface. A support structure for a spindle drive motor configured to be supported only through