JPH0294903U

JPH0294903U -

Info

Publication number: JPH0294903U
Application number: JP367789U
Authority: JP
Priority date: 1989-01-17
Filing date: 1989-01-17
Publication date: 1990-07-27
Anticipated expiration: 2004-01-17
Also published as: JPH0724642Y2

Description

[Brief explanation of drawings]

第１図ないし第３図は本考案の第１の実施例を
示し、第１図は本実施例によるモータの容量制御
装置を示す縦断面図、第２図はパイロツト圧とモ
ータ容量の関係を示す線図、第３図は容量制御装
置を組込んだ油圧モータの縦断面図、第４図は第
２の実施例を示す第１図と同様の縦断面図、第５
図および第６図は従来技術を示し、第５図は油圧
モータの容量制御装置を示す回路構成図、第６図
は駆動圧力とモータ容量の関係を示す線図である
。１……油圧モータ、１Ａ……容量可変部、２Ａ
，２Ｂ……油圧配管、３……高圧選択弁、１１…
…ケーシング、１２……ケーシング本体、１３…
…蓋体、１４……シリンダ、１６……制御ピスト
ン、１７……スプール用シリンダ、１９，４１…
…スプール、２０，４３……圧縮ばね、２１……
圧力導入ポート、２２，２６，２９，４４……連
通ポート、２３……切換ポート、２７……連通路
、２５，２８……周溝、２７，３０，３４……連
絡ポート、３１……切換弁、３２……外部油圧源
、Ａ……大油室、Ｂ……小油室、Ｃ……スプール
端部室、Ｄ……スプール環状室、Ｅ……ばね室。 1 to 3 show a first embodiment of the present invention, FIG. 1 is a longitudinal sectional view showing a motor capacity control device according to this embodiment, and FIG. 2 shows the relationship between pilot pressure and motor capacity. FIG. 3 is a longitudinal sectional view of a hydraulic motor incorporating a displacement control device, FIG. 4 is a longitudinal sectional view similar to FIG. 1 showing the second embodiment, and FIG.
6 and 6 show the prior art, FIG. 5 is a circuit configuration diagram showing a displacement control device for a hydraulic motor, and FIG. 6 is a diagram showing the relationship between driving pressure and motor displacement. 1...Hydraulic motor, 1A...Variable capacity section, 2A
, 2B...Hydraulic piping, 3...High pressure selection valve, 11...
...Casing, 12...Casing body, 13...
... Lid body, 14 ... Cylinder, 16 ... Control piston, 17 ... Spool cylinder, 19, 41 ...
...Spool, 20, 43...Compression spring, 21...
Pressure introduction port, 22, 26, 29, 44... Communication port, 23... Switching port, 27... Communication path, 25, 28... Circumferential groove, 27, 30, 34... Communication port, 31... Switching Valve, 32...External hydraulic power source, A...Large oil chamber, B...Small oil chamber, C...Spool end chamber, D...Spool annular chamber, E...Spring chamber.

Claims

[Scope of utility model registration request]

A casing whose inside is a cylinder, one end of which is slidably attached to the cylinder of the casing, defines the inside of the casing into a large oil chamber and a small oil chamber, and the other end of which protrudes outside the casing. a control piston connected to a variable displacement portion of a hydraulic motor; a spool slidably provided within a spool cylinder formed on the control piston; defined within the spool cylinder by the spool; a spool annular chamber formed in the axial middle of the spool and always communicating with the small oil chamber; a spool end chamber formed at one end; a spring chamber formed at the other end; a spring that constantly biases the spool toward the spool end chamber;
a pressure introduction port for introducing the driving pressure of the hydraulic motor into the small oil chamber; and a pressure introduction port formed in the control piston, which is configured to convert the large oil chamber into either a spring chamber or a spool annular chamber by sliding the spool. a switching port for selective communication; a communication port for communicating the spool end chamber with the casing or the outside of the control piston; a switching valve for switchingly connecting the communication port to a hydraulic power source and a drain; and the spring chamber. A displacement control device for a hydraulic motor, comprising another communication port that communicates with the outside of the casing or control piston, and a drain that is constantly connected to the other communication port.