（翻译自The Automotive Transmission Book）
3.7 Synchronizer Units
Synchronizer units extend the positive locking of a dog clutch by adding functionalities to achieve speed synchronization prior to engage the positive locking.
3.7.1 Abstraction and Motivation
A synchronizer unit avails itself of two active principles to make engagement of a gear in the transmission easy and robust. Initially speed compensation is induced through friction locking, then the actual power transfer in the engaged gear occurs with positive locking. In principle, a modern synchronizer unit involves the parallel arrangement of a wet friction clutch (Sect. 3.6) with a dog clutch (Sect. 3.4). Figure 3.39 shows the schematic diagram of the parallel arrangement and the usual schematic presentation of a synchronizer unit.
The great challenge is to link the transmission modes or paths in the temporal sequence as well as in a common actuation system. Specifically this means that:
bull;When engaging in the temporal sequence, first the friction clutch function ensures a speed synchronization, without the positive locking beginning to act, then however the effect of the clutch is canceled when the positive locking is applied.
bull;When disengaging the clutch function is not required, rather it would act as a disturbing factor for the engagement of a different gear stage and cause unnecessary losses.
Integration in a known actuation system results in a division of the distance that must be traveled for an engagement procedure into a first part, in which the clutch is engaged, and a second part in which the positive locking is established, i.e., the dogs and pockets are brought into mesh.
The locking function of the synchronizer units ensures separation of the two parts of the travel.
3.7.2 Structure and Function of a Synchronizer Unit
Figure 3.40 shows the principle structure of a synchronizer unit. A clutch ring (2) is connected to a gear (1) that is bearing supported on the shaft. In its left position the sliding sleeve (5) engages to the clutch ring and is itself travelling on the synchronizer hub (3) to reach this position. The synchronizer ring (4) with cone friction clutch is axially connected to the sliding sleeve via a ring spring (6) or ball detents. As a rule, in the circumferential direction three synchronization struts (7) position the ring relative to the sliding sleeve with circumferential play. If the sliding sleeve is offset axially, first the presynchronization force of the detent or the ring spring presses the ring against the gear. With an appropriate design of the angle alpha;, the torque that builds up in the circumferential direction blocks further movement. At speed equivalence the torque collapses and the sliding sleeve can be moved further. It twists the gear for alignment with a taper angle beta; and permits full engagement. The distance a takes clearance and wear into account.
The friction cone can be within the synchronization gearing (Fig. 3.40a), in this case it is referred to as inner cone synchronization. However, it can also be outside with a greater friction diameter and thus higher synchronizing torque (Fig. 3.40b), in this case it is referred to as outer cone synchronization. Different radial and axial nesting possibilities occur. Either variant can be designed with multiple friction surfaces to increase the synchronization torque or lower the actuation load demands.
Figure 3.41 shows an example of a double cone synchronizer unit. The gear (1) is supported on the shaft as idler gear via a needle cage. The clutch body (2) is permanently connected with this.The clutch body carries the gearing for the positive lock connection with the sliding sleeve (5) in engaged status. Notches of the intermediate ring (3) mesh in the pockets of the clutch body, so that it rotates together with the idler gear.
The synchronizer hub (7) is permanently connected with the shaft, splined connections in combination with lock rings for axial positioning are most frequently used. The external toothing of the sliding sleeve carrier is used for torque transfer and axial slideable connection with the sliding sleeve. Three struts (6) are distributed uniformly on the circumference between sliding sleeve and sliding sleeve carrier.Positioning in the neutral position in the axial direction occurs with a spring pretensioned ball in a hole in the inner diameter of the sliding sleeve.
The blocker ring (4), also referred to as synchronizer ring carries a friction lining and the blocking toothing. Tabs engage in pockets in the sliding sleeve, so that torque can be transferred; play in the circumferential direction permits limited twist relative to the sliding sleeve.
All three synchronizer rings of the double cone synchronizer can move freely in the axial direction between the clutch body and the sliding sleeve carrier, so that the friction areas adequately vent, the lugs however remain securely positioned in the pockets of the partners. Thus the entire tolerance chain of the shaft assembly acts on each synchronizer position.
The cone friction system is the heart of every synchronization and is based on a metallic or organic friction lining, which in conjunction with an appropriately specified steel cone surface and suitable gear oil forms a tribological boundary layer. This boundary layer must provide a friction coefficient within defined limits over the entire load map, in order to ensure the required speed synchronization prior to full engagement. The torque that is
generated depending on the shift force on the friction cone, is referred to as synchronizer torque. With the cone an amplification of the synchronizer torques is achieved. The cone angles must be defined according to the number of friction surfaces, selection of friction linings, and the desi
剩余内容已隐藏，支付完成后下载完整资料
The Automotive Transmission Book
3.7 Synchronizer Units
Synchronizer units extend the positive locking of a dog clutch by adding functionalities to achieve speed synchronization prior to engage the positive locking.
3.7.1 Abstraction and Motivation
A synchronizer unit avails itself of two active principles to make engagement of a gear in the transmission easy and robust. Initially speed compensation is induced through friction locking, then the actual power transfer in the engaged gear occurs with positive locking. In principle, a modern synchronizer unit involves the parallel arrangement of a wet friction clutch (Sect. 3.6) with a dog clutch (Sect. 3.4). Figure 3.39 shows the schematic diagram of the parallel arrangement and the usual schematic presentation of a synchronizer unit.
The great challenge is to link the transmission modes or paths in the temporal sequence as well as in a common actuation system. Specifically this means that:
bull;When engaging in the temporal sequence, first the friction clutch function ensures a speed synchronization, without the positive locking beginning to act, then however the effect of the clutch is canceled when the positive locking is applied.
bull;When disengaging the clutch function is not required, rather it would act as a disturbing factor for the engagement of a different gear stage and cause unnecessary losses.
Integration in a known actuation system results in a division of the distance that must be traveled for an engagement procedure into a first part, in which the clutch is engaged, and a second part in which the positive locking is established, i.e., the dogs and pockets are brought into mesh.
The locking function of the synchronizer units ensures separation of the two parts of the travel.
3.7.2 Structure and Function of a Synchronizer Unit
Figure 3.40 shows the principle structure of a synchronizer unit. A clutch ring (2) is connected to a gear (1) that is bearing supported on the shaft. In its left position the sliding sleeve (5) engages to the clutch ring and is itself travelling on the synchronizer hub (3) to reach this position. The synchronizer ring (4) with cone friction clutch is axially connected to the sliding sleeve via a ring spring (6) or ball detents. As a rule, in the circumferential direction three synchronization struts (7) position the ring relative to the sliding sleeve with circumferential play. If the sliding sleeve is offset axially, first the presynchronization force of the detent or the ring spring presses the ring against the gear. With an appropriate design of the angle alpha;, the torque that builds up in the circumferential direction blocks further movement. At speed equivalence the torque collapses and the sliding sleeve can be moved further. It twists the gear for alignment with a taper angle beta; and permits full engagement. The distance a takes clearance and wear into account.
The friction cone can be within the synchronization gearing (Fig. 3.40a), in this case it is referred to as inner cone synchronization. However, it can also be outside with a greater friction diameter and thus higher synchronizing torque (Fig. 3.40b), in this case it is referred to as outer cone synchronization. Different radial and axial nesting possibilities occur. Either variant can be designed with multiple friction surfaces to increase the synchronization torque or lower the actuation load demands.
Figure 3.41 shows an example of a double cone synchronizer unit. The gear (1) is supported on the shaft as idler gear via a needle cage. The clutch body(2) is permanently connected with this.The clutch body carries the gearing for the positive lock connection with the sliding sleeve (5) in engaged status. Notches of the intermediate ring (3) mesh in the pockets of the clutch body, so that it rotates together with the idler gear.
The synchronizer hub (7) is permanently connected with the shaft, splined connections in combination with lock rings for axial positioning are most frequently used. The external toothing of the sliding sleeve carrier is used for torque transfer and axial slideable connection with the sliding sleeve. Three struts (6) are distributed uniformly on the circumference between sliding sleeve and sliding sleeve carrier.Positioning in the neutral position in the axial direction occurs with a spring pretensioned ball in a hole in the inner diameter of the sliding sleeve.
The blocker ring (4), also referred to as synchronizer ring carries a friction lining and the blocking toothing. Tabs engage in pockets in the sliding sleeve, so that torque can be transferred; play in the circumferential direction permits limited twist relative to the sliding sleeve.
All three synchronizer rings of the double cone synchronizer can move freely in the axial direction between the clutch body and the sliding sleeve carrier, so that the friction areas adequately vent, the lugs however remain securely positioned in the pockets of the partners. Thus the entire tolerance chain of the shaft assembly acts on each synchronizer position.
The cone friction system is the heart of every synchronization and is based on a metallic or organic friction lining, which in conjunction with an appropriately specified steel cone surface and suitable gear oil forms a tribological boundary layer. This boundary layer must provide a friction coefficient within defined limits over the entire load map, in order to ensure the required speed synchronization prior to full engagement. The torque that is generated depending on the shift force on the friction cone, is referred to as synchronizer torque. With the cone an amplification of the synchronizer torques is achieved. The cone angles must be defined according to the number of friction surfaces, selection of friction linings, and the design of the blocking geometry.lt;
剩余内容已隐藏，支付完成后下载完整资料
资料编号：[148041]，资料为PDF文档或Word文档，PDF文档可免费转换为Word
以上是毕业论文外文翻译，课题毕业论文、任务书、文献综述、开题报告、程序设计、图纸设计等资料可联系客服协助查找。
