DE-102017003520-B4 - Waterproof structure for an electric motor

DE102017003520B4DE 102017003520 B4DE102017003520 B4DE 102017003520B4DE-102017003520-B4

Abstract

Waterproof structure for an electric motor (1) in which an embedding component (3) of a stator (2) is cast into a molding resin (4), a sealing element (5) is arranged in an end region (20) of the stator (2) which includes a connection point (23) between the embedding component (3) and the molding resin (4), and the sealing element (5) is attached to the end region (20) by means of an end flange (6), wherein the sealing element (5) comprises: a first sealing part (55) which is arranged further on one side of the embedding component (3) than the connection point (23) and seals one end of the embedding component (3); a second sealing part (56) which is arranged further on one side of the molding resin (4) than the connection point (23) and seals one end of the molding resin (4); and a connecting part (57) that is separated from the ends of both the embedding component (3) and the molding resin (4) and connects the first sealing part (55) and the second sealing part (56).

Inventors

Kouji Kobayashi
Takeshi Tamaki

Assignees

FANUC CORPORATION

Dates

Publication Date: 20260513
Application Date: 20170411
Priority Date: 20160414

Claims (2)

Waterproof structure for an electric motor (1) in which an embedding component (3) of a stator (2) is cast into a molding resin (4), a sealing element (5) is arranged in an end region (20) of the stator (2) which includes a connection point (23) between the embedding component (3) and the molding resin (4), and the sealing element (5) is attached to the end region (20) by means of an end flange (6), wherein the sealing element (5) comprises: a first sealing part (55) which is arranged further on one side of the embedding component (3) than the connection point (23) and seals one end of the embedding component (3); a second sealing part (56) which is arranged further on one side of the molding resin (4) than the connection point (23) and seals one end of the molding resin (4); and a connecting part (57) that is separated from the ends of both the embedding component (3) and the molding resin (4) and connects the first sealing part (55) and the second sealing part (56).
Waterproof structure of the electric motor (1) according to Claim 1 , wherein the sealing element (5) comprises a rigid body (50) inside.

Description

BACKGROUND OF THE INVENTION Scope of the invention The present invention relates to a waterproof structure for an electric motor in which embedding components of a stator are cast in molding resin. Related technology Traditionally, in stators of this type of electric motor, a gap forms at the interface where the encapsulation component and the molding resin meet, due to the temperature change after molding and the difference between their linear expansion coefficients. A sealing treatment can be applied to this gap. Therefore, as in 10 As shown, an attempt was made to perform a sealing treatment on a gap such as the one described above using an O-ring 105 (see also patent specification 1). However, it is difficult to position its sealing point at the interface where the embedding component 103 and the molding resin 104 meet, and the O-ring 105 cannot achieve a seal if the position between the sealing point and the interface shifts. To remedy this, as in 11 As shown, an attempt was made to perform a sealing treatment on a gap such as the one described above using a seal 205 with a plate-like (rectangular) cross-section. However, the plate-like seal 205 can improve the positional displacement between the sealing point and the interface; while, on the other hand, the surface pressure does not increase compared to the O-ring 105, and therefore the sealing capacity is low and a complete seal may be impossible. Patent specification 1: Unexamined Japanese patent application, publication no. JP 2010 - 226 907 A DE 10 2014 106 361 A1 This describes a stator of an electric motor in which a resin mold section is formed using injection molding, comprising an inner and an outer circumferential section. A separating element is provided at the axial end of the stator to separate the inner and outer circumferential sections. Resin injected from the axial end flows through a forked passage into the inner and outer circumferential sections. The separating element can be provided with a resin passage that allows resin to flow from the axial end of the stator to the outer circumferential section. JP 2001 - 245 453 A The description comprises a motor consisting of a cylindrical yoke with a base that accommodates a rotor, an end plate that closes an opening in the yoke with a fastening piece that is elastically fitted to the inner circumference of the yoke, and a sealing material arranged on the outer circumference of the end plate at the flange on the opening side of the yoke. The sealing material seals the inside of the outer device between the flange and the end face of the outer device and has an annular sealing surface on which two annular projecting parts extend along the sealing surface. WITTEL, Herbert [et al.]: Roloff/Matek - Machine Elements - Standardization, Calculation, Design, 22nd revised and expanded edition Wiesbaden: Springer 2015, pp. 698-717, ISBN 978-3-658-09081-4 describes seals in which the sealing material is protected by a metallic shell or metallic inserts provide support. SUMMARY OF THE INVENTION However, in the sealing treatment using the O-ring 105 or the plate-like seal 205, due to the insufficient sealing in both cases, the sealing was reinforced by soaking in a sealant 150, 250 to fill the gap at the interface, as described in the 10 and 11 This was shown. Accordingly, this required working time. It is an object of the present invention to provide a waterproof structure for an electric motor by which the interface where the embedding component of the stator and the molding resin meet can be sealed more reliably without requiring time for soaking in a sealant. According to a first aspect of the present invention, in a waterproof structure for an electric motor (for example, the electric motor 1 described below), in which an embedding component (for example, the embedding component 3 described below) of a stator (for example, the stator 2 described below) is cast into a molding resin (for example, the molding resin 4 described below), a sealing element is provided. (for example, the sealing element 5 described later) is arranged in an end region (for example, the end region 20 described later) of the stator, which includes a connection point (for example, the connection point 23 described later) between the embedding component and the molding resin, and the sealing element is attached to the end region by means of an end flange (for example, the end flange 6 described later), wherein the sealing element comprises: a first sealing part (for example, the first seal 55 described later), which is arranged further on one side of the embedding component than the connection point and seals one end of the embedding component; a second sealing part (for example, the second sealing part 56 described later), which is arranged further on one side of the molding resin than the connection point and seals one end of the molding resin; and a connecting part (for example, the connecting part 57 described later), whi