Resin molded stators

• US 4,352,897 A
• Filed: 12/14/1979
• Issued: 10/05/1982
• Est. Priority Date: 12/20/1978
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nemoto, Masanori, Ogata, Masatsugu, Takasaki, Hirokazu, Narahara, Toshikazu, Hironaka, Kenichi, Ishikawa, Tetuo
• Primary Examiner(s): Jacobs, Lewis T.
• Application Number:
  US06/103,506
• Time in Patent Office: 1,026 Days
• Field of Search: 260/40 R, 310/43
• US Class Current: 523/220
• CPC Class Codes: C08K 13/04 Ingredients characterised by their shape and organic or inorganic ingredients
• CPC Class Codes: C08K 3/00 Use of inorganic substances as compounding ingredients
• CPC Class Codes: C08L 1/00 Compositions of cellulose, modified cellulose or cellulose derivatives
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 29/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C08L 67/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence
• CPC Class Codes: C08L 67/06 Unsaturated polyesters
• CPC Class Codes: C08L 77/00 Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain of polyhydrazides C08L79/06; of polyamideimides or polyamide acids C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: H01B 3/425 Non-saturated polyesters derived from polycarboxylic acids and polyhydroxy compounds, in which at least one of the two components contains aliphatic unsaturation
• CPC Class Codes: H02K 3/32 Windings characterised by the shape, form or construction of the insulation
• CPC Class Codes: H02K 5/08 Insulating casings

Abstract

A resin molded stator comprising a stator core and coils as major constituents at least parts of which are molded into one piece by a molding material, said molding material comprising (a) a low-shrink unsaturated polyester resin, (b) a filler having a particle size of 44 μ or less, and (c) a fibrous material having a length of 3 mm or less, in proportions of 15 to 40% by weight of the component (a) and 60 to 85% by weight of a total of the components (b) and (c), and a weight ratio of the component (b) to the component (c) being 3/1 to 30/1, is excellent in crack resistance, moisture resistance and insulating properties.

Claims

1. A resin molded stator comprising a stator core and coils as major constituents at least parts of which are molded into one piece by a molding material, said molding material comprising

(a) a low-shrink unsaturated polyester resin,

(b) a filler material consisting of particulate filler having a particle size of 44μ

or less, and

(c) a fibrous material consisting of fibers having a length of 3 mm or less,

in proportions of 15 to 40% by weight of the component (a) and 60 to 85% by weight of a total of the components (b) and (c), and a weight ratio of the component (b) to the component (c) being 3 to 30/1;

all of any filler material contained in the molding material consisting of component (b).

2. A resin molded stator according to claim 1, wherein the molding material has molding shrinkage of 0.5% or less at the time of molding.

3. A resin molded stator according to claim 1, wherein the low-shrink unsaturated polyester resin comprises

(i) a terephthalic acid series unsaturated polyester,

(ii) styrene, and

(iii) a saturated polyester,

in which the proportion of a total of (i) and (ii) is 90 to 70% by weight and the proportion of (iii) is 10 to 30% by weight and a weight ratio of (i) to (ii) is 80/20 to 40/60.

4. A resin molded stator according to claim 3, wherein the saturated polyester is an isophthalic acid series saturated polyester.

5. A resin molded stator according to claim 1, wherein the molding material contains 20% by weight or more of aluminum hydroxide as said filler material based on the total weight of the molding material.

6. A resin molded stator according to claim 1, wherein the fibrous material is glass fiber.

7. A resin molded stator according to claim 1, 2 or 3, wherein coil end portions, slot portions, terminal portions in addition to a stator core and coils of a stator assembly are molded into one piece by using the molding material.

8. A resin molded stator according to claim 1, 2 or 3, wherein the outer circumference of a stator core is partially exposed when a stator assembly is molded into one piece.

9. A resin molded stator according to claim 1, wherein the molding material contains fibrous material consisting of fibers having a length of from 0.5 to 3 mm.

10. A resin molded stator according to claim 1, wherein the particulate filler contained within said molding material consists of inorganic mineral filler or an admixture of inorganic mineral filler and organic non-fibrous filler.

11. A resin molded stator according to claim 10, wherein said inorganic mineral filler is selected from the group consisting of calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, alumina, clay, kaoline, talc, diatomaceous earth, mica powder, glass fiber powder, aluminum hydroxide, magnesium hydroxide, hydrated gypsum, zinc borate, borax, silica sand, and mixtures thereof and said organic non-fibrous filler is selected from the group consisting of wood meal, rice hull powder, waste wood powder treated with a resin and cellulose powder.

12. A resin molded stator according to claim 11, wherein said fibrous material contained within said molding material is selected from the group consisting of glass fibers, carbon fibers, polyvinyl alcohol fibers, nylon fibers, cellulose fibers and mixtures thereof.