Film capacitor, combination type capacitor, inverter, and electric vehicle

Patent metadata

Field	Value
Publication number	US-10490357-B2
Application number	US-201615761890-A
Country	US
Kind code	B2
Filing date	Sep 21, 2016
Priority date	Sep 28, 2015
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

A film capacitor includes a body including a core body formed of an insulating material and metalized films which are wound around the core body; and first and second terminal electrodes disposed on both end surfaces in an axial direction of the body, respectively, a cross section perpendicular to an axial direction, i.e., z direction, of the core body having an oval outer periphery having a major axis and a minor axis, and an inner periphery defining a slit extending along the major axis. The provision of the core body makes it possible to suppress loosening of the metalized films or occurrence of a gap between the metalized films, thus making the film capacitor having a high insulation property.

First claim

The invention claimed is:

1. A film capacitor, comprising:
a body including a core body formed of an insulating material and a metalized film which is wound around the core body, wherein a cross section perpendicular to an axial direction of the core body has an oval outer periphery with a major axis and a minor axis; and
first and second terminal electrodes disposed on both end surfaces in an axial direction of the body, respectively;
a slit extending along the major axis, wherein the slit is a gap formed along the minor axis between adjoining parts of an inner periphery of the core body; and
bulging portions formed at two ends of the slit, respectively, in a direction of the major axis, wherein a thickness of the gap formed along the minor axis is greatest in the bulging portions.

2. The film capacitor according to claim 1 , wherein the core body is configured so that a thickness t 1 in a direction of the major axis is smaller than a thickness t 2 in a direction of the minor axis.

3. The film capacitor according to claim 1 , wherein the respective bulging portions each have a teardrop shape which ends with an arc in the direction of the major axis, on the cross section.

4. The film capacitor according to claim 1 , comprising an insulating member disposed in at least part of each of the bulging portions in the axial direction of the core body.

5. The film capacitor according to claim 1 , wherein parts of the inner periphery opposing each other in a direction of the minor axis at least partially abut on each other in the axial direction.

6. The film capacitor according to claim 1 , both end portions of the core body in the axial direction are provided with openings defined by the slit.

7. The film capacitor according to claim 1 , wherein a ratio d 2 /d 1 of d 2 to d 1 is 0.05 to 0.5, in which d 1 denotes a length of the major axis and d 2 denotes a length of the minor axis.

8. The film capacitor according to claim 1 , wherein the oval outer periphery has a pair of straight portions extending along the major axis and a pair of arc portions connecting the pair of straight portions.

9. The film capacitor according to claim 8 ,
wherein on the cross section, a value P expressed as P=(L 2 /L 1 )×(L 0 /(π· 2 )−1) is in a range of 0.8 to 1.2, in which L 0 denotes a length of the oval outer periphery, L 1 denotes a length of the straight portions, L 2 denotes a length of the arc portions, and d 2 denotes a length of the minor axis.

10. A combination type capacitor, comprising:
a plurality of the film capacitors according to claim 1 ; and
at least one bus bar connecting all of the plurality of film capacitors.

11. An inverter, comprising:
a bridge circuit including switching elements; and
a capacitance member connected to the bridge circuit,
the capacitance member including the combination type capacitor according to claim 10 .

12. An electric vehicle, comprising:
a power source;
the inverter according to claim 11 , the inverter being connected to the power source;
a motor connected to the inverter; and
a wheel driven by the motor.

13. An inverter, comprising:
a bridge circuit including switching elements; and
a capacitance member connected to the bridge circuit,
the capacitance member including the film capacitor according to claim 1 .

14. An electric vehicle, comprising:
a power source;
the inverter according to claim 13 , the inverter being connected to the power source;
a motor connected to the inverter; and
a wheel driven by the motor.

15. A film capacitor, comprising:
a body including a core body formed of an insulating material and a metalized film which is wound around the core body; and
first and second terminal electrodes disposed on both end surfaces in an axial direction of the body, respectively,
a cross section perpendicular to an axial direction of the core body having an oval outer periphery having a major axis and a minor axis, and an inner periphery defining a slit extending along the major axis,
wherein the oval outer periphery has a pair of straight portions extending along the major axis and a pair of arc portions connecting the pair of straight portions, and
on the cross section, a ratio t 2 /d 2 of a thickness t 2 at the arc portions of the core body to a length d 2 of the minor axis is in a range of 0.2 to 0.3.

Assignees

• Kyocera Corp

Inventors

• Yamazaki Youichi
• Nakao Yoshihiro

Classifications

• H01G4/38

  Multiple capacitors, i.e. structural combinations of fixed capacitors · CPC title

• B60L50/51

  characterised by AC-motors · CPC title

• H01G4/40

  Structural combinations of fixed capacitors with other electric elements, the structure mainly consisting of a capacitor, e.g. RC combinations · CPC title

• H01G13/02

  Machines for winding capacitors · CPC title

• H01G9/048

  characterised by their structure (H01G11/22 takes precedence) · CPC title