TURBOCHARGER

• US 20140321990A1
• Filed: 11/13/2012
• Published: 10/30/2014
• Est. Priority Date: 11/16/2011
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toyota Jidoshokki, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Kabushiki Kaisha Toyota Jidoshokki, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ikegami, Hiroaki, Uesugi, Tsuyoshi
• Granted Patent: US 10,161,305 B2
• Time in Patent Office: Days
• US Class Current: 415/148
• CPC Class Codes: F01D 17/165 for radial flow, i.e. the vanes turning around axes which are essentially parallel to the rotor centre line F01D17/167 takes precedence
• CPC Class Codes: F02B 43/02 Engines characterised by means for increasing operating efficiency
• CPC Class Codes: F02C 6/12 Turbochargers, i.e. plants for augmenting mechanical power output of internal-combustion piston engines by increase of charge pressure
• CPC Class Codes: F05D 2220/40 in turbochargers

Abstract

A circular ring-shaped shroud plate is arranged between a scroll passage and a turbine chamber. The shroud plate has a through-hole that penetrates therethrough in a direction along an axis of a turbine shaft. A variable nozzle is supported in an openable/closable manner on the shroud plate by a shaft inserted through the through-hole. A gap between the shroud plate and a turbine housing in the direction along the axis is partitioned into a first space that communicates with an outlet of exhaust gas that faces the through-hole and is provided upstream of a turbine wheel with respect to the flow of exhaust gas, and a second space that communicates with the scroll passage, by a disc spring that is so arranged as to surround the turbine wheel.

Claims

1. A turbocharger comprising:

a turbine housing that has a convolute scroll passage around a turbine chamber;

a turbine wheel that is provided on a turbine shaft, rotates in the turbine chamber, and is rotationally driven when exhaust gas that has flowed along the scroll passage after being discharged from an engine is blown thereonto;

an annular support member that is arranged between the scroll passage and the turbine chamber, and has through-holes, which penetrate in a direction along an axis of the turbine shaft, at a plurality of spots around the turbine wheel;

a plurality of variable nozzles that are supported in an openable/closable manner on the support member by shafts inserted through the respective through-holes, and make variable a flow velocity of exhaust gas blown onto the turbine wheel through changes in opening degrees thereof; and

an annular sealing member that is so arranged as to surround the turbine wheel, and partitions a gap between the support member and the turbine housing in the direction along the axis into a first space that communicates with an outlet of exhaust gas, which faces the through-holes and is provided upstream of the turbine wheel with respect to flow of exhaust gas, wherein exhaust gas passing through the outlet being blown onto the turbine wheel to rotationally drive the turbine wheel, and a second space that communicates with the scroll passage.

2. The turbocharger according to claim 1, wherein a passage that establishes communication between the first space and operation ranges of the variable nozzles where each of the variable nozzles turns together with a corresponding one of the shafts, namely, those regions of the variable nozzles which are located downstream of the shafts respectively with respect to the flow of exhaust gas is provided, and the outlet is constituted by an opening region of the passage in the operation ranges.

3. The turbocharger according to claim 2, wherein the turbine housing is provided with a bulge portion that extends toward a side of a bearing housing that rotatably supports the turbine shaft and is located between the support member and the turbine wheel in a state of being spaced apart from the support member, and the passage is constituted by a space between the support member and the bulge portion.

4. The turbocharger according to claim 1, further comprising:

an annular plate that is arranged opposite the support member across the variable nozzle and is integrally coupled to the support member, wherein

the sealing member is constituted by a disc spring that is so arranged as to surround the turbine wheel in the gap, and the disc spring is in contact, at one of an outer peripheral edge portion thereof and an inner peripheral edge portion thereof, with the support member and in contact, at the other of the outer peripheral edge portion thereof and the inner peripheral edge portion thereof, with the turbine housing, in a state of being elastically deformed such that a dimension of the disc spring in the direction along the axis decreases, thereby urges the support member toward a side of a bearing housing that supports the turbine shaft, presses the plate against the bearing housing, and partitions the gap into the first space and the second space as the sealing member.