力士樂比溢流閥是一種液壓壓力控制閥。在液壓設(shè)備中主要起定壓溢流作用和安全保護(hù)作用。 
定壓溢流作用:在定量泵節(jié)流調(diào)節(jié)系統(tǒng)中,定量泵提供的是恒定流量先導(dǎo)式比例溢流閥帶OBE和位置反饋DBEBE6X

比例溢流閥工作原理是：比例溢流閥通過彈簧力的大小改變溢流壓力大大小變化，比例電磁鐵作用在彈簧上的力可以按比例調(diào)整，所以就輸入信號(hào)變化比例溢流閥的壓力也會(huì)變化。

定壓溢流作用：在定量泵節(jié)流調(diào)節(jié)系統(tǒng)中，定量泵提供的是恒定流量。當(dāng)系統(tǒng)壓力增大時(shí)，會(huì)使流量需求減小。此時(shí)溢流閥開啟，使多余流量溢回油箱，保證溢流閥進(jìn)口壓力，即泵出口壓力恒定（閥口常隨壓力波動(dòng)開啟）。穩(wěn)壓作用：溢流閥串聯(lián)在回油路上，溢流閥產(chǎn)生背壓，運(yùn)動(dòng)部件平穩(wěn)性增加。系統(tǒng)卸荷作用：在溢流閥的遙控口串接溢小流量的電磁閥，當(dāng)電磁鐵通電時(shí)，溢流閥的遙控口通油箱，此時(shí)液壓泵卸荷。溢流閥此時(shí)作為卸荷閥使用。

安全保護(hù)作用：系統(tǒng)正常工作時(shí)，閥門關(guān)閉。只有負(fù)載超過規(guī)定的極限（系統(tǒng)壓力超過調(diào)定壓力）時(shí)開啟溢流，進(jìn)行過載保護(hù)，使系統(tǒng)壓力不再增加（通常使溢流閥的調(diào)定壓力比系統(tǒng)工作壓力高10%～20%）。

德國Rexroth力士樂比例溢流閥部分型號(hào)：

帶位置反饋比例溢流閥DBETBX DBETBEX
0811402013 DBETBX-1X/28G24-37Z4M
0811402003 DBETBX-1X/180G24-37Z4M
0811402004 DBETBX-1X/315G24-37Z4M
帶集成放大位置反饋比例溢流閥 DBETBEX
0811402072 DBETBEX-1X/80G24K31A1M
0811402071 DBETBEX-1X/180G24K31A1M
0811402073 DBETBEX-1X/250G24K31A1M
0811402070 DBETBEX-1X/310G24K31A1M
0811402140 DBETBEX-1X/80G24K31F1M
0811402075 DBETBEX-1X/180G24K31F1M
0811402141 DBETBEX-1X/315G24K31F1M
比例溢流閥DBETX
0811402036 DBETX-10/50G24-8NZ4M
0811402018 DBETX-10/80G24-8NZ4M
0811402017 DBETX-10/180G24-8NZ4M
0811402019 DBETX-10/250G24-8NZ4M
0811402016 DBETX-10/315G24-8NZ4M
0811402034 DBETX-10/50G24-25NZ4M
0811402030 DBETX-10/80G24-25NZ4M
0811402031 DBETX-10/180G24-25NZ4M
0811402035 DBETX-10/250G24-25NZ4M
0811402032 DBETX-10/315G24-25Z4M

比例溢流閥DBEP DBET DBETE
R901000842 DBET-6X/50G24K4V
R901000845 DBET-6X/100G24K4V
R901000846 DBET-6X/200G24K4V
R901000847 DBET-6X/315G24K4V
R901000848 DBET-6X/350G24K4V
R901029966 DBETE-6X/50G24K31A1V
R901029967 DBETE-6X/100G24K31A1V
R901029968 DBETE-6X/200G24K31A1V
R901029969 DBETB-6X/315G24K31A1V
R901029970 DBETB-6X/350G24K31A1V
比例溢流閥DBETR
R900954438 DBETR-1X/30G24K4M
R900334966 DBETR-1X/80G24K4M
R900491698 DBETR-1X/180G24K4M
R900370146 DBETR-1X/230G24K4M
R900485944 DBETR-1X/315G24K4M
R900352424 DBETR-1X/350G24K4M
先導(dǎo)式比例溢流閥DBE6X型
0811402045 DBE6X-1X/80G24-8NZ4M
0811402044 DBE6X-1X/180G24-8NZ4M
0811402043 DBE6X-1X/315G24-8NZ4M
0811402040 DBE6X-1X/80G24-25NZ4M
0811402041 DBE6X-1X/180G24-25NZ4M
0811402042 DBE6X-1X/315G24-25NZ4M
0811402078 DBEBE6X-1X/80G24K31A1M
0811402077 DBEBE6X-1X/180G24K31A1M
0811402076 DBEBE6X-1X/315G24K31A1M
0811402084 DBEBE6X-1X/80G24K31F1M
0811402079 DBEBE6X-1X/180G24K31F1M