JPH0541367U - Double shaft type electric motor - Google Patents

Abstract

(57) [Abstract] [Purpose] To achieve the sealing between the rotating shaft protruding from the detector and the detector within an extremely small temperature rise range. [Constitution] In place of the conventional oil seal, a contact rubber seal type ball bearing 6 is mounted between the case 4 of the detector part 3 and the hollow rotary shaft 1 by means of a clearance fit between the inner and outer rings, and a case 4 and a hollow are provided. The O-rings 7 and 8 are attached to the bearing fitting portion of the rotary shaft 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a double shaft electric motor.

[0002]

[Prior Art]

 In recent years, electric motors equipped with position or speed detectors for precise positioning have been widely used in various fields.

This type of electric motor will be described with reference to FIG. 2 by taking a double shaft type electric motor with a detector used in a loom as an example. In FIG. 2, the double shaft electric motor with detector is composed of an electric motor unit 2 having a hollow rotary shaft 1 through which a thread is inserted, and a detector unit 3 arranged in contact with the lower end thereof. The detector unit 3 seals the case 4 and the hollow rotary shaft 1 penetrating the case 4 with an oil seal 5 to prevent dust, oil, water, etc., which may cause detection failure, from entering from the outside. It has a closed structure.

[0004]

[Problems to be solved by the device]

 However, the above configuration has a problem that the temperature of the detector unit 3 rises due to the friction heat between the oil seal 5 and the hollow rotating shaft 1 when the electric motor rotates at high speed.

Further, there is a problem that the rotation speed and output of the double-shaft electric motor are limited due to the temperature rise.

The present invention solves the above-mentioned conventional problems, and provides a double-shaft electric motor that does not increase in temperature at high speed and does not require output limitation.

[0007]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention uses a contact rubber seal type ball bearing instead of an oil seal, and uses a loose fit for fitting the bearing between the case 4 and the hollow rotary shaft 1. An O-ring is attached to the fit seat.

[0008]

[Action]

 With the above structure, the contact rubber seal type ball bearing prevents foreign matter from entering from the outside by the rubber seal plate and the enclosed grease, and supports it by the clearance fit gap and the O-ring fitted to it. This prevents excessive load due to misalignment of the detector unit. Therefore, it is possible to prevent the temperature of the detector part from rising and to realize a closed structure.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, the present embodiment is different from the conventional example shown in FIG. 2 in that a contact rubber seal type ball bearing 6 is mounted between the case 4 at the lower end of the detector part 3 and the hollow rotating shaft 1 with a clearance fit for both the inner and outer rings. And the points where the O-rings 7 and 8 are attached to the bearing fitting surfaces of the case 4 and the hollow rotary shaft 1, respectively. Since the other parts are the same as the conventional example, the same components are designated by the same reference numerals and the description thereof will be omitted.

In the present embodiment configured as described above, a sufficient sealing effect can be obtained by the contact rubber seal type ball bearing and the O-rings arranged on both sides thereof, and heat generation due to friction is small.

[0011]

[Effect of the device]

 As described above, according to the present invention, it is possible to obtain a double-shaft electric motor in which the temperature rise is extremely small and the detector section is sealed.

[Brief description of drawings]

FIG. 1 is a sectional view of a double shaft type electric motor according to an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional example.

[Explanation of symbols]

1 ... Hollow rotating shaft, 2 ... Electric motor part, 3 ... Detector part,
4 ... Case, 6 ... Contact rubber seal type ball bearing, 7, 8
… O-ring.

Claims (2)

[Scope of utility model registration request] 1. A dual-shaft electric motor equipped with a speed or position detector, and a rotary shaft protruding from both sides of the electric motor and the detector, wherein a contact rubber seal type ball bearing is provided at the rear end of the detector. A double shaft type electric motor, which is mounted as a bearing of the. 2. The inner ring and the outer ring of the third bearing are loosely fitted to fit between the rotary shaft and the housing, and O-rings are mounted in the respective gaps. Axial electric motor.