Method for manufacturing bearing cage

Patent metadata

Field	Value
Publication number	US-10377070-B2
Application number	US-201616077884-A
Country	US
Kind code	B2
Filing date	Feb 26, 2016
Priority date	Feb 26, 2016
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

A resin reservoir capable of storing the melted resin is provided in the pillar radially facing the pillar provided with the resin injection gate having a cross-sectional area larger than those of the other resin injection gates among a plurality of the pillars not provided with the resin injection gate or the pillar in the vicinity of the pillar facing the pillar provided with the resin injection gate having a cross-sectional area larger than those of the other resin injection gates among the plurality of the pillars not provided with the resin injection gate. A cross-sectional area of a communicating portion of the resin reservoir which communicates with the pillar is smaller than the smallest of cross-sectional areas of a plurality of the resin injection gates.

First claim

The invention claimed is:

1. A method for manufacturing a bearing cage molded by injecting a melted resin into a cavity from a plurality of resin injection gates provided at a peripheral portion of a substantially annular cavity formed in a mold, wherein,
the bearing cage includes
a substantially annular base portion,
a plurality and an even number of pillars projecting in an axial direction from an axial lateral surface of the base portion at a predetermined interval in a circumferential direction, and
pockets whose number is equal to a number of the pillars formed by mutually facing surfaces of a pair of adjacent pillars and the axial lateral surface of the base portion,

the resin injection gates are provided in half of a plurality of the pillars respectively,
the pillar provided with the resin injection gate and the pillar not provided with the resin injection gate are arranged alternately in the circumferential direction,
a cross-sectional area of one resin injection gate is larger than cross-sectional areas of the other resin injection gates among a plurality of the resin injection gates,
a resin reservoir capable of storing the melted resin is provided in:
(a) the pillar radially facing the pillar provided with the resin injection gate having a cross-sectional area larger than those of the other resin injection gates among a plurality of the pillars not provided with the resin injection gate; or
(b) the pillar in the vicinity of the pillar facing the pillar provided with the resin injection gate having a cross-sectional area larger than those of the other resin injection gates among the plurality of the pillars not provided with the resin injection gate, and

a cross-sectional area of a communicating portion of the resin reservoir which communicates with the pillar is smaller than the smallest of cross-sectional areas of a plurality of the resin injection gates.

2. The method for manufacturing a bearing cage according to claim 1 , wherein,
the other resin injection gates is configured such that a gate whose cross-sectional area is larger and a gate whose cross-sectional area is smaller are arranged alternately in the circumferential direction.

3. A bearing cage manufactured by the method for manufacturing the bearing cage according to claim 1 .

Assignees

• Nsk Ltd

Inventors

• Kuramoto Yoshikazu
• Aihara Nariaki
• Hiramoto Takayuki

Classifications

• F16C33/416

  made from plastic, e.g. injection moulded comb cages · CPC title

• B29C45/2616

  having annular mould cavities · CPC title

• B29C45/0046

  Details relating to the filling pattern or flow paths or flow characteristics of moulding material in the mould cavity · CPC title

• B29C2045/0044

  expelling moulding material outside the mould cavity at the weld line location · CPC title

• B29C45/0025

  Preventing defects on the moulded article, e.g. weld lines, shrinkage marks (preventing defects on the preformed parts or layers B29C45/14836) · CPC title