专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明授权

US3971971A Electric hoist control and braking system 失效
标题翻译：电动葫芦控制和制动系统
公开(公告)号：US3971971A
公开(公告)日：1976-07-27
申请号：US524081
申请日：1974-11-15
申请人： David C. Wycoff
发明人： David C. Wycoff
IPC分类号： B66D3/20 , H02P1/44 , H02P3/18 , H02P1/40
CPC分类号： H02P3/18 , B66D3/20 , H02P1/44
摘要： The invention relates to control and braking systems for apparatus driven by single and polyphase alternating current induction motors. The system prevents destructive and dangerous overspeeding where the nature of the driven load is such that it can furnish sufficient torque to overdrive the apparatus in any one of several potential failure modes. A capacitor selected according to this invention is permanently connected across the motor winding such as to cause the drive motor to automatically develop retarding torque in the absence of power supplied thereto sufficient to restrict the overdrive speed to a value not appreciably exceeding the normal operating speed. The system also incorporates drive motors specifically designed with a predetermined value of starting torque appreciably less than that conventionally applied to similar apparatus for the specific purpose of limiting the load handling capability of the apparatus, thus preventing dangerous overloading. Numerous related benefits are attained through the aforementioned features, including improved controllability, improved holding brake life, and more reliable arresting of motion at limits of safe travel.
摘要翻译：本发明涉及由单相和多相交流感应电动机驱动的装置的控制和制动系统。该系统防止破坏性和危险性超速，其中被驱动负载的性质使得其可以提供足够的扭矩以使其以几种潜在故障模式中的任何一种过载。根据本发明选择的电容器永久地连接在电动机绕组上，以使得驱动电动机在没有供电的功率的情况下自动地形成延迟转矩，足以将过驱动速度限制在不明显超过正常工作速度的值。该系统还包括特定设计的驱动电机，其具有明显小于传统应用于相似装置的起动转矩的预定值，用于限制装置的负载处理能力，从而防止危险的过载。通过上述特征可以获得许多相关的益处，包括改进的可控性，改善的保持制动器寿命，以及在安全行程极限下更可靠地停止运动。

2. 发明授权

US4965847A Method and apparatus for detecting deviation of motor speed from frequency of power supply 失效
标题翻译：用于检测电机速度与电源频率的偏差的方法和装置
公开(公告)号：US4965847A
公开(公告)日：1990-10-23
申请号：US304527
申请日：1989-01-31
申请人： Keith O. Jurkowski , David C. Wycoff
发明人： Keith O. Jurkowski , David C. Wycoff
IPC分类号： H02P23/08
CPC分类号： H02P23/08 , Y10S388/903
摘要： An adjustable frequency motor drive system for a hoist is disclosed in which the frequency of the power supply to the motor can be selectively varied and the speed of the motor will follow the varying frequency at a slip speed relative to the frequency. The slip speed of the motor may not exceed a value beyond which the motor can control the hoist load. Accordingly, a frequency value based on the frequency of the power supply to the motor is selected as the frequency which is not to be exceeded by the motor speed expressed as a frequency. Signals representative of the actual motor speed and the selected frequency value are compared and, if the signal representative of the motor speed exceeds the signal representative of the frequency value which is not to be exceeded, an output signal is produced which may be used to apply a brake which stops and holds the motor and hoist and thereby maintains the load suspended. A motor speed deviation time period may also be provided and the hoist brake not applied to the motor until the time period is exceeded.
摘要翻译：公开了一种用于提升机的可变频电动机驱动系统，其中可以选择性地改变对电动机的供电频率，并且电动机的速度将以相对于频率的滑动速度跟随变化的频率。电机的滑差速度可能不超过电机可以控制起重负荷的值。因此，选择基于向电动机供电的频率的频率值作为表示为频率的电动机速度不超过的频率。比较代表实际电动机速度和所选频率值的信号，并且如果表示电动机速度的信号超过表示不超过的频率值的信号，则产生可用于应用的输出信号制动器停止并保持电动机和起重机，从而保持负载悬挂。还可以提供电动机转速偏差时间段，并且在超过时间段之前将起重机制动器不施加到电动机。

3. 发明授权

US5077508A Method and apparatus for determining load holding torque 失效
标题翻译：确定负载保持力矩的方法和装置
公开(公告)号：US5077508A
公开(公告)日：1991-12-31
申请号：US303322
申请日：1989-01-30
申请人： David C. Wycoff , William A. Hipp
发明人： David C. Wycoff , William A. Hipp
IPC分类号： B66B1/28
CPC分类号： B66B1/308 , B66B1/32
摘要： A motor control method and apparatus for a hoist is disclosed in which a drive motor is connected to an adjustable frequency power supply in which the frequency of the power supplied to the motor can be selectively varied. At the initiation of a hoist operation, when the hoist brake is holding the motor and an object constituting a load on the motor stationary, power is supplied to the motor at a predetermined low frequency which is sufficient to provide load holding torque upon release of the brake. The actual current level of the power supplied to the motor is sensed at the initiation of the hoist operation and a signal representative of that current level is compared with a reference signal representative of a current level which is sufficient to provide the load holding torque. If the signal representative of the actual current level of the power supplied to the motor exceeds the reference signal, an output signal is provided which will result in the release of the hoist brake from its holding condition.
摘要翻译：公开了一种用于提升机的电动机控制方法和装置，其中驱动电动机连接到可以选择性地改变提供给电动机的功率的频率的可变频率电源。在起重操作开始时，当起重机制动器保持电动机并且将构成负载的物体固定在电动机上时，以预定的低频向电动机提供电力，该预定低频足以在释放时提供负载保持转矩制动。在起重操作开始时感测到电动机的电力的实际电流水平，并将表示该电流电平的信号与表示足以提供负载保持转矩的电流电平的参考信号进行比较。如果表示提供给电动机的电力的实际电流水平的信号超过参考信号，则提供输出信号，这将导致起重机制动器从其保持状态释放。

你已经成功收藏专利！

检索式保存成功!

IPRDB

热门服务

关于我们

友情链接

联系方式